Today's Message Index:
----------------------
1. 01:00 AM - Re: Electric Hydraulic Pump Ideas (Robert Feldtman)
2. 05:06 AM - Re: Electric Hydraulic Pump Ideas (Richard & Jacqui Thompson)
3. 05:55 AM - Re: Electric Hydraulic Pump Ideas (Steve at Col-East)
4. 06:35 AM - "stering" (Dan Farmer)
5. 06:56 AM - Re: Electric Hydraulic Pump Ideas (Tom Fisher)
6. 06:56 AM - Re: "stering" (BobsV35B@aol.com)
7. 09:44 AM - Re: Electric Hydraulic Pump Ideas (nico css)
8. 04:18 PM - Re: Electric Hydraulic Pump Ideas (Nancy Gilliam)
9. 06:09 PM - Re: Electric Hydraulic Pump Ideas (BobsV35B@aol.com)
Message 1
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| Subject: | Re: Electric Hydraulic Pump Ideas |
Let me think outloud hear. I have cleveland brakes on the 500B, and I
"think" it is a separate hydraulic system from the "hydraulics" of the flap
s
and nose wheel steering. Correct me if I am wrong, but it should be no
different than the "hydraulics" on my experimental, a piper, etc. So, if
that is true. all of the comments about ailerons steering is interesting,
educational, and irrelevant for directional control if the brakes are
working.
I'm 99% sure cause once had an issue with line boy dragging the commander,
and the pilot flying had "locked" the brakes days before. I don't have a
hydraulic accumulator - and the brakes were locked when he tried to drag -
of course nothing was "on"
That should stimulate some discussion.
bobf
500B
On 4/7/08, John Vormbaum <john@vormbaum.com> wrote:
>
>
> Don,
>
> After reading your results and comparing them to mine, I wonder now if
> this is something the designers HAD thought of. Between you & me, we've h
ad
> 4 complete hydraulic failures. In all cases the result was a non-event,
> essentially. In all cases we had brakes....the argument would then seem t
o
> be, "do we need hydraulics for flaps & gear?" We know the gear will come
> down too....so then we're just down to flaps. A no-flap landing isn't a b
ig
> deal, if you're not flying in the bush, or into a 900-ft. strip.
>
> So suddenly, should I really be pulling the breaker? I might still argue
> that having an additional available system ready to come on-line might be
> cheap insurance....but now we're up to what, 4, 5, maybe 6 cases of hyd.
> failure on this list, all with safe outcomes. Not reversing myself, just
> pointing out what I'm seeing.
>
> /John
>
> dfalik@sbcglobal.net wrote:
>
> >
> > All,
> >
> > As I related previously, I have had 2 major hydraulic failures due to
> > the rupture of a line (abrasion/wear) and failure of a flared fitting a
long
> > a hydraulic line in a wing root. Each time I had sufficient pressure fo
r the
> > brakes upon landing. The gear extension was due to the bungies and spri
ngs
> > for the nose gear.
> >
> > I don't know where the information came from that relates to ALL the
> > hydraulic fluid being pumped overboard in the event of a line breaking.
It
> > didn't happen on my 500S.
> >
> > I'm not pulling the breaker, I have enough to remember prior to landing
.
> >
> > Don
> >
> > -----Original Message-----
> > *From:* owner-commander-list-server@matronics.com [mailto:
> > owner-commander-list-server@matronics.com] *On Behalf Of *Robert S.
> > Randazzo
> > *Sent:* Monday, April 07, 2008 10:59 PM
> > *To:* commander-list@matronics.com
> > *Subject:* RE: Commander-List: Electric Hydraulic Pump Ideas
> >
> > Donnie, et al-
> >
> > I'm not so sure I agree with "the wise ones" who are pulling the
> > breaker.
> >
> > Back in my chief piloting days we used to see "in cockpit solutions" to
> > these types of things roll around the pilot ranks on occasion. This has
led
> > me to believe that if we do a comparative risk analysis on the per-flig
ht
> > chances of landing with the breaker pulled and suffering adverse
> > consequences- versus the chance of suffering the hydraulic failure
> > mentioned- we are very likely putting the airplane at a greater overall
risk
> > exposure by using a system in a manner for which it wasn't designed.
> >
> > Based on my knowledge of the system, it does seem to me that the system
> > was designed to provide positive pressure in all failure modes EXCEPT a
leak
> > condition- but knowing how well my commander is built- I'm betting the
> > engineers who dreamed these airplanes up were probably very comfortable
with
> > the risk level for such a failure and the ability of the pilot to handl
e it
> > effectively.
> >
> > Other achillies heals on our commanders? Pulling all fuel from a centra
l
> > tank- AND pulling all fuel from a central sump=85 But again- I'm sure t
he
> > designers weighed carefully the actual risk factors versus alternative
> > design theories=85
> >
> > I'm leaving the breaker in.
> >
> > Robert S. Randazzo
> >
> > *From:* owner-commander-list-server@matronics.com [mailto:
> > owner-commander-list-server@matronics.com] *On Behalf Of *Donnie Rose
> > *Sent:* Monday, April 07, 2008 7:14 PM
> > *To:* commander-list@matronics.com
> > *Subject:* Re: Commander-List: Electric Hydraulic Pump Ideas
> >
> > Hey there John, yes per my POH and experience the pump will Paul you
> > down to the sump giving you only minimal braking. That is why the wise
ones
> > are pulling the breaker (everyone included).
> >
> >
> > **Donnie Rose ***
> > **205/492-8444***
> >
> > ----- Original Message ----
> > From: John Vormbaum <john@vormbaum.com>
> > To: commander-list@matronics.com
> > Sent: Sunday, April 6, 2008 7:10:57 PM
> > Subject: Re: Commander-List: Electric Hydraulic Pump Ideas
> >
mailto:
> > john@vormbaum.com>>
> >
> > Donnie, do you mean it would pump everything above the standpipe in the
> > hydraulic fluid reservoir out? The standpipe is for the engine-driven
> > pumps IIRC....the aux pump runs from a drain at the bottom of the
> > reservoir. That's so you always have a little fluid in reserve for the
> > aux pump to use for steering & brakes in a hydraulic failure event....s
o
> > in a properly functioning hydraulic system (in a 500B anyway), the aux
> > pump would pump EVERY DROP overboard if you had a hose rupture.
> > Again....ask me how I know :-).
> >
> > With my total hydraulic failure, I went to an airport with an 8,000 foo
t
> > runway (OK, it was Morris' home base :-), landed normally & held the
> > nose off until the last taxiway, when I reduced power until I lost
> > elevator authority. The nose settled slowly, I rolled a few feet, and
> > the nose gear gently folded. I broke a bellcrank and damaged one gear
> > door. No fuselage skin damage at all. Could have been worse. At least I
> > didn't block the runway!
> >
> > After that I pulled the tail down, we locked the nose gear down, and
> > towed it to Morris' hangar where he fixed it with a minimum of
> > difficulty.
> >
> > I would be very reluctant to feather both engines on short final or
> > after landing, after a hydraulic failure; I would rather retain some
> > directional control. In a truly life-threatening situation I think I
> > would still be able to use asymmetrical power & rudder to intentionally
> > ground-loop the airplane. I've also found that windmilling props are
> > quite a set of brakes on their own. The airplane feels much more slick
> > with one feathered...and I think Bob Hoover's routine shows how slick
> > the airframe is with two feathered!
> >
> > /J
> >
> > Donnie Rose wrote:
> > > WCG, that's absolutely right since a Hyd. rupture would cause the aux
> > > pump to pump everything above the sump overboard.
> > >
> > >
> > > *Donnie Rose
> > > 205/492-8444*
> > >
> > >
> > >
> > > ----- Original Message ----
> > > From: Keith S. Gordon <cloudcraft@aol.com <mailto:cloudcraft@aol.com>
>
> > > To: commander-list@matronics.com <mailto:commander-list@matronics.com
>
> > > Sent: Sunday, April 6, 2008 5:15:09 PM
> > > Subject: Commander-List: Electric Hydraulic Pump Ideas
> > >
> > > *As the French say, "Each to his own fish." At least I've been told
> > > they say that.
> > >
> > > I always taught a flow pattern that linked the gear handle movement
> > > with the aux hydraulic c/b.
> > >
> > > Gear up, pull the c/b.
> > >
> > > Gear down (after verifying stable hydraulic pressure) aux hydraulic
> > > c/b set.
> > >
> > > I know there is a school of thought that says c/b's are not switches.
> > > There is a school of thought that says a c/b can take thousands of
> > resets.
> > >
> > > My suggestion has always been to replace the aux hydraulic c/b with a
> > > breaker switch. I really like that idea because you can install the
> > > switch so that up is off. (If this were not such a public place, I'd
> > > suggest moving this switch next to the gear handle.)
> > >
> > > In normal ops, gear handle and switch position are the same: Gear up
/
> > > switch up = aux hydraulic pump disabled.
> > >
> > > Gear handle down / switch down (on) = aux pump enabled.
> > >
> > > With a hydraulic abnormal, the pump stays disabled until just prior t
o
> > > touchdown, possibly restoring brakes, the most important appliance at
> > > that moment.
> > >
> > > This may be a bit much for some Commander owners to wrap their minds
> > > around but with a bit of time in type and a practiced flow pattern,
> > > I'm convinced it's the way to go.
> > >
> > > I've been through 3 catastrophic hydraulic failures a n d the fact
> > > that I disable the aux pump gave me brakes and nose wheel steering 2
> > > out of the 3 times.
> > >
> > > But then, I prefer salmon to flounder.
> > >
> > > Wing Commander Gordon
> > > *
> > >
> > >
> > >
> > > -----Original Message-----
> > > From: dfalik@sbcglobal.net <mailto:dfalik@sbcglobal.net>
> > > To: commander-list@matronics.com <mailto:commander-list@matronics.com
>
> > > Sent: Sun, 6 Apr 2008 12:04 pm
> > > Subject: RE: Commander-List: Electric fuel pump cycling
> > >
> > dfalik@sbcglobal.net> <mailto:dfalik@sbcglobal.net <mailto:
> > dfalik@sbcglobal.net>>>
> > >
> > >
> > >
> > > All,
> > >
> > >
> > >
> > > Just to share:
> > >
> > >
> > >
> > > In the last year, I have had two occasions of loss of all hyd.
> > >
> > > Pressure/fluid due to holes in the hydraulic lines. Each time I was
> > >
> > > airborne and the landing and roll out was no issue due to the
> > remaining
> > >
> > > fluid in
> >
> > * *
> > * *
> > * *
> > *http://www.matronics.com/Navigator?Commander-List*
> > * *
> > *http://forums.matronics.com*
> > * *
> > *http://www.matronics.com/contribution*
> > * *
> > * *
> >
> >
> >
> > __________ NOD32 3008 (20080408) Information __________
> >
> > * *
> > * *
> > **
> > * - The Commander-List Email Forum -*
> > **
> > **
> > **
> > **
> > * --> http://www.matronics.com/Navigator?Commander-List*
> > **
> > * - MATRONICS WEB FORUMS -*
> > **
> > * --> http://forums.matronics.com*
> > **
> > * - List Contribution Web Site -*
> > * Thank you for your generous support!*
> > * -Matt Dralle, List Admin.*
> > * --> http://www.matronics.com/contribution*
> > **
> > * *
> > *
> >
> >
> > *
> >
>
===========
===========
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===========
>
>
Message 2
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| Subject: | Electric Hydraulic Pump Ideas |
OOOPS. Very different from you Piper ( not knocking Pipers, I have 5 of
them)
The braking system and steering system work off the same brake valves. Hence
the first bit does the steering and then the brakes. Both systems therefore
rely on the hydraulic pressure from the pumps. The parking brake valve shuts
the system off between the calipers and the brake/steering valves thus
locking the pressure on the brakes. The accumulator has nothing to do with
it. Its only function really is to stop the pressure relief valve from
chattering by essentially adding a little 'give' in the system. Not trusting
the good old park brake is the reason we pressurize the system either by
hand pump or electric before we start the engines. Nothing is more
entertaining than a commander starting to move before the hydraulics
pressurize. Particularly good in those older models that only have one pump
and its not on the engine you decided to start.
Just a thought from Down Under.( where everything works backwards etc)
Cheers
Richard
-----Original Message-----
From: owner-commander-list-server@matronics.com
[mailto:owner-commander-list-server@matronics.com] On Behalf Of Robert
Feldtman
Sent: Tuesday, 8 April 2008 5:57 PM
Subject: Re: Commander-List: Electric Hydraulic Pump Ideas
Let me think outloud hear. I have cleveland brakes on the 500B, and I
"think" it is a separate hydraulic system from the "hydraulics" of the flaps
and nose wheel steering. Correct me if I am wrong, but it should be no
different than the "hydraulics" on my experimental, a piper, etc. So, if
that is true. all of the comments about ailerons steering is interesting,
educational, and irrelevant for directional control if the brakes are
working.
I'm 99% sure cause once had an issue with line boy dragging the commander,
and the pilot flying had "locked" the brakes days before. I don't have a
hydraulic accumulator - and the brakes were locked when he tried to drag -
of course nothing was "on"
That should stimulate some discussion.
bobf
500B
On 4/7/08, John Vormbaum <john@vormbaum.com> wrote:
Don,
After reading your results and comparing them to mine, I wonder now if this
is something the designers HAD thought of. Between you & me, we've had 4
complete hydraulic failures. In all cases the result was a non-event,
essentially. In all cases we had brakes....the argument would then seem to
be, "do we need hydraulics for flaps & gear?" We know the gear will come
down too....so then we're just down to flaps. A no-flap landing isn't a big
deal, if you're not flying in the bush, or into a 900-ft. strip.
So suddenly, should I really be pulling the breaker? I might still argue
that having an additional available system ready to come on-line might be
cheap insurance....but now we're up to what, 4, 5, maybe 6 cases of hyd.
failure on this list, all with safe outcomes. Not reversing myself, just
pointing out what I'm seeing.
/John
dfalik@sbcglobal.net wrote:
All,
As I related previously, I have had 2 major hydraulic failures due to the
rupture of a line (abrasion/wear) and failure of a flared fitting along a
hydraulic line in a wing root. Each time I had sufficient pressure for the
brakes upon landing. The gear extension was due to the bungies and springs
for the nose gear.
I don't know where the information came from that relates to ALL the
hydraulic fluid being pumped overboard in the event of a line breaking. It
didn't happen on my 500S.
I'm not pulling the breaker, I have enough to remember prior to landing.
Don
-----Original Message-----
*From:* owner-commander-list-server@matronics.com
[mailto:owner-commander-list-server@matronics.com] *On Behalf Of *Robert S.
Randazzo
*Sent:* Monday, April 07, 2008 10:59 PM
*To:* commander-list@matronics.com
*Subject:* RE: Commander-List: Electric Hydraulic Pump Ideas
Donnie, et al-
I'm not so sure I agree with "the wise ones" who are pulling the breaker.
Back in my chief piloting days we used to see "in cockpit solutions" to
these types of things roll around the pilot ranks on occasion. This has led
me to believe that if we do a comparative risk analysis on the per-flight
chances of landing with the breaker pulled and suffering adverse
consequences- versus the chance of suffering the hydraulic failure
mentioned- we are very likely putting the airplane at a greater overall risk
exposure by using a system in a manner for which it wasn't designed.
Based on my knowledge of the system, it does seem to me that the system was
designed to provide positive pressure in all failure modes EXCEPT a leak
condition- but knowing how well my commander is built- I'm betting the
engineers who dreamed these airplanes up were probably very comfortable with
the risk level for such a failure and the ability of the pilot to handle it
effectively.
Other achillies heals on our commanders? Pulling all fuel from a central
tank- AND pulling all fuel from a central sump. But again- I'm sure the
designers weighed carefully the actual risk factors versus alternative
design theories.
I'm leaving the breaker in.
Robert S. Randazzo
*From:* owner-commander-list-server@matronics.com
[mailto:owner-commander-list-server@matronics.com] *On Behalf Of *Donnie
Rose
*Sent:* Monday, April 07, 2008 7:14 PM
*To:* commander-list@matronics.com
*Subject:* Re: Commander-List: Electric Hydraulic Pump Ideas
Hey there John, yes per my POH and experience the pump will Paul you down to
the sump giving you only minimal braking. That is why the wise ones are
pulling the breaker (everyone included).
**Donnie Rose ***
**205/492-8444***
----- Original Message ----
From: John Vormbaum <john@vormbaum.com>
Sent: Sunday, April 6, 2008 7:10:57 PM
Subject: Re: Commander-List: Electric Hydraulic Pump Ideas
<mailto:john@vormbaum.com>>
Donnie, do you mean it would pump everything above the standpipe in the
hydraulic fluid reservoir out? The standpipe is for the engine-driven
pumps IIRC....the aux pump runs from a drain at the bottom of the
reservoir. That's so you always have a little fluid in reserve for the
aux pump to use for steering & brakes in a hydraulic failure event....so
in a properly functioning hydraulic system (in a 500B anyway), the aux
pump would pump EVERY DROP overboard if you had a hose rupture.
Again....ask me how I know :-).
With my total hydraulic failure, I went to an airport with an 8,000 foot
runway (OK, it was Morris' home base :-), landed normally & held the
nose off until the last taxiway, when I reduced power until I lost
elevator authority. The nose settled slowly, I rolled a few feet, and
the nose gear gently folded. I broke a bellcrank and damaged one gear
door. No fuselage skin damage at all. Could have been worse. At least I
didn't block the runway!
After that I pulled the tail down, we locked the nose gear down, and
towed it to Morris' hangar where he fixed it with a minimum of difficulty.
I would be very reluctant to feather both engines on short final or
after landing, after a hydraulic failure; I would rather retain some
directional control. In a truly life-threatening situation I think I
would still be able to use asymmetrical power & rudder to intentionally
ground-loop the airplane. I've also found that windmilling props are
quite a set of brakes on their own. The airplane feels much more slick
with one feathered...and I think Bob Hoover's routine shows how slick
the airframe is with two feathered!
/J
Donnie Rose wrote:
> WCG, that's absolutely right since a Hyd. rupture would cause the aux
> pump to pump everything above the sump overboard.
>
>
> *Donnie Rose
> 205/492-8444*
>
>
> ----- Original Message ----
> From: Keith S. Gordon <cloudcraft@aol.com <mailto:cloudcraft@aol.com>>
> To: commander-list@matronics.com <mailto:commander-list@matronics.com>
> Sent: Sunday, April 6, 2008 5:15:09 PM
> Subject: Commander-List: Electric Hydraulic Pump Ideas
>
> *As the French say, "Each to his own fish." At least I've been told
> they say that.
>
> I always taught a flow pattern that linked the gear handle movement
> with the aux hydraulic c/b.
>
> Gear up, pull the c/b.
>
> Gear down (after verifying stable hydraulic pressure) aux hydraulic
> c/b set.
>
> I know there is a school of thought that says c/b's are not switches.
> There is a school of thought that says a c/b can take thousands of resets.
>
> My suggestion has always been to replace the aux hydraulic c/b with a
> breaker switch. I really like that idea because you can install the
> switch so that up is off. (If this were not such a public place, I'd
> suggest moving this switch next to the gear handle.)
>
> In normal ops, gear handle and switch position are the same: Gear up /
> switch up = aux hydraulic pump disabled.
>
> Gear handle down / switch down (on) = aux pump enabled.
>
> With a hydraulic abnormal, the pump stays disabled until just prior to
> touchdown, possibly restoring brakes, the most important appliance at
> that moment.
>
> This may be a bit much for some Commander owners to wrap their minds
> around but with a bit of time in type and a practiced flow pattern,
> I'm convinced it's the way to go.
>
> I've been through 3 catastrophic hydraulic failures a n d the fact
> that I disable the aux pump gave me brakes and nose wheel steering 2
> out of the 3 times.
>
> But then, I prefer salmon to flounder.
>
> Wing Commander Gordon
> *
>
>
> -----Original Message-----
> From: dfalik@sbcglobal.net <mailto:dfalik@sbcglobal.net>
> To: commander-list@matronics.com <mailto:commander-list@matronics.com>
> Sent: Sun, 6 Apr 2008 12:04 pm
> Subject: RE: Commander-List: Electric fuel pump cycling
>
<mailto:dfalik@sbcglobal.net> <mailto:dfalik@sbcglobal.net
<mailto:dfalik@sbcglobal.net>>>
>
>
> All,
>
>
> Just to share:
>
>
> In the last year, I have had two occasions of loss of all hyd.
>
> Pressure/fluid due to holes in the hydraulic lines. Each time I was
>
> airborne and the landing and roll out was no issue due to the remaining
>
> fluid in
* *
* *
* *
*http://www.matronics.com/Navigator?Commander-List*
* *
*http://forums.matronics.com*
* *
*http://www.matronics.com/contribution*
* *
* *
__________ NOD32 3008 (20080408) Information __________
* *
* *
**
* - The Commander-List Email Forum -*
**
**
**
**
* --> http://www.matronics.com/Navigator?Commander-List*
**
* - MATRONICS WEB FORUMS -*
**
* --> http://forums.matronics.com*
**
* - List Contribution Web Site -*
* Thank you for your generous support!*
* -Matt Dralle, List Admin.*
* --> http://www.matronics.com/contribution*
**
* *
*
*
owse
ink(window,event,this)"
href="http://www.matronics.com/Navigator?Commander-List"
target="_blank">http://www.matronics.com/Navigator?Commander-List
op.js.OpenExtLink(window,event,this)" href="http://forums.matronics.com/"
target="_blank">http://forums.matronics.com
-Matt Dralle, List Admin.
is)" href="http://www.matronics.com/contribution"
target="_blank">http:=================
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Message 3
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| Subject: | Re: Electric Hydraulic Pump Ideas |
My Dad relates a very funny story years ago of having the hydraulic
pressure gauge fail internally as the pumps on a 680E happily pumped the
remainder of the fluid out. I'll check with him to make sure I've got
this right...... After losing rudder authority and going very slowly I
believe he shut both engines down as he entered a giant snow bank and
gently buried the thing up to the wing roots.... I had wondered when you
would use the emergency cut-off's in anger in the 500B, and I guess this
would have been one of those times.......
I too was very, very reluctant to incorporate some "clever idea" in the
cockpit.
Before the electric pump was added to the airframes, the handpump used
the same arrangment of the lower standpipe?
I think I've been comfortable with the idea then that the electric pump
takes the place of the hand pump, 'when I want it to', rather than it
just sitting there and pumping the remaining fluid overboard.
As to consequences of accidentally leaving the pump off, the only dire
one I can think of is a momentary loss of braking and steering at
startup. I've tried this on the ground several times, and haven't been
able to make the ship do anything scary. Am I missing anything? An
inflight failure without the pump I believe would have been noticed by
odd behavior in the gear and flaps........
Steve
----- Original Message -----
From: Robert Feldtman
To: commander-list@matronics.com
Sent: Tuesday, April 08, 2008 3:57 AM
Subject: Re: Commander-List: Electric Hydraulic Pump Ideas
Let me think outloud hear. I have cleveland brakes on the 500B, and I
"think" it is a separate hydraulic system from the "hydraulics" of the
flaps and nose wheel steering. Correct me if I am wrong, but it should
be no different than the "hydraulics" on my experimental, a piper, etc.
So, if that is true. all of the comments about ailerons steering is
interesting, educational, and irrelevant for directional control if the
brakes are working.
I'm 99% sure cause once had an issue with line boy dragging the
commander, and the pilot flying had "locked" the brakes days before. I
don't have a hydraulic accumulator - and the brakes were locked when he
tried to drag - of course nothing was "on"
That should stimulate some discussion.
bobf
500B
On 4/7/08, John Vormbaum <john@vormbaum.com> wrote:
<john@vormbaum.com>
Don,
After reading your results and comparing them to mine, I wonder now
if this is something the designers HAD thought of. Between you & me,
we've had 4 complete hydraulic failures. In all cases the result was a
non-event, essentially. In all cases we had brakes....the argument would
then seem to be, "do we need hydraulics for flaps & gear?" We know the
gear will come down too....so then we're just down to flaps. A no-flap
landing isn't a big deal, if you're not flying in the bush, or into a
900-ft. strip.
So suddenly, should I really be pulling the breaker? I might still
argue that having an additional available system ready to come on-line
might be cheap insurance....but now we're up to what, 4, 5, maybe 6
cases of hyd. failure on this list, all with safe outcomes. Not
reversing myself, just pointing out what I'm seeing.
/John
dfalik@sbcglobal.net wrote:
All,
As I related previously, I have had 2 major hydraulic failures due
to the rupture of a line (abrasion/wear) and failure of a flared fitting
along a hydraulic line in a wing root. Each time I had sufficient
pressure for the brakes upon landing. The gear extension was due to the
bungies and springs for the nose gear.
I don't know where the information came from that relates to ALL
the hydraulic fluid being pumped overboard in the event of a line
breaking. It didn't happen on my 500S.
I'm not pulling the breaker, I have enough to remember prior to
landing.
Don
-----Original Message-----
*From:* owner-commander-list-server@matronics.com
[mailto:owner-commander-list-server@matronics.com] *On Behalf Of *Robert
S. Randazzo
*Sent:* Monday, April 07, 2008 10:59 PM
*To:* commander-list@matronics.com
*Subject:* RE: Commander-List: Electric Hydraulic Pump Ideas
Donnie, et al-
I'm not so sure I agree with "the wise ones" who are pulling the
breaker.
Back in my chief piloting days we used to see "in cockpit
solutions" to these types of things roll around the pilot ranks on
occasion. This has led me to believe that if we do a comparative risk
analysis on the per-flight chances of landing with the breaker pulled
and suffering adverse consequences- versus the chance of suffering the
hydraulic failure mentioned- we are very likely putting the airplane at
a greater overall risk exposure by using a system in a manner for which
it wasn't designed.
Based on my knowledge of the system, it does seem to me that the
system was designed to provide positive pressure in all failure modes
EXCEPT a leak condition- but knowing how well my commander is built- I'm
betting the engineers who dreamed these airplanes up were probably very
comfortable with the risk level for such a failure and the ability of
the pilot to handle it effectively.
Other achillies heals on our commanders? Pulling all fuel from a
central tank- AND pulling all fuel from a central sump=85 But again- I'm
sure the designers weighed carefully the actual risk factors versus
alternative design theories=85
I'm leaving the breaker in.
Robert S. Randazzo
*From:* owner-commander-list-server@matronics.com
[mailto:owner-commander-list-server@matronics.com] *On Behalf Of *Donnie
Rose
*Sent:* Monday, April 07, 2008 7:14 PM
*To:* commander-list@matronics.com
*Subject:* Re: Commander-List: Electric Hydraulic Pump Ideas
Hey there John, yes per my POH and experience the pump will Paul
you down to the sump giving you only minimal braking. That is why the
wise ones are pulling the breaker (everyone included).
**Donnie Rose ***
**205/492-8444***
----- Original Message ----
From: John Vormbaum <john@vormbaum.com>
To: commander-list@matronics.com
Sent: Sunday, April 6, 2008 7:10:57 PM
Subject: Re: Commander-List: Electric Hydraulic Pump Ideas
<john@vormbaum.com <mailto:john@vormbaum.com>>
Donnie, do you mean it would pump everything above the standpipe
in the
hydraulic fluid reservoir out? The standpipe is for the
engine-driven
pumps IIRC....the aux pump runs from a drain at the bottom of the
reservoir. That's so you always have a little fluid in reserve for
the
aux pump to use for steering & brakes in a hydraulic failure
event....so
in a properly functioning hydraulic system (in a 500B anyway), the
aux
pump would pump EVERY DROP overboard if you had a hose rupture.
Again....ask me how I know :-).
With my total hydraulic failure, I went to an airport with an
8,000 foot
runway (OK, it was Morris' home base :-), landed normally & held
the
nose off until the last taxiway, when I reduced power until I lost
elevator authority. The nose settled slowly, I rolled a few feet,
and
the nose gear gently folded. I broke a bellcrank and damaged one
gear
door. No fuselage skin damage at all. Could have been worse. At
least I
didn't block the runway!
After that I pulled the tail down, we locked the nose gear down,
and
towed it to Morris' hangar where he fixed it with a minimum of
difficulty.
I would be very reluctant to feather both engines on short final
or
after landing, after a hydraulic failure; I would rather retain
some
directional control. In a truly life-threatening situation I think
I
would still be able to use asymmetrical power & rudder to
intentionally
ground-loop the airplane. I've also found that windmilling props
are
quite a set of brakes on their own. The airplane feels much more
slick
with one feathered...and I think Bob Hoover's routine shows how
slick
the airframe is with two feathered!
/J
Donnie Rose wrote:
> WCG, that's absolutely right since a Hyd. rupture would cause
the aux
> pump to pump everything above the sump overboard.
>
>
> *Donnie Rose
> 205/492-8444*
>
>
>
> ----- Original Message ----
> From: Keith S. Gordon <cloudcraft@aol.com
<mailto:cloudcraft@aol.com>>
> To: commander-list@matronics.com
<mailto:commander-list@matronics.com>
> Sent: Sunday, April 6, 2008 5:15:09 PM
> Subject: Commander-List: Electric Hydraulic Pump Ideas
>
> *As the French say, "Each to his own fish." At least I've been
told
> they say that.
>
> I always taught a flow pattern that linked the gear handle
movement
> with the aux hydraulic c/b.
>
> Gear up, pull the c/b.
>
> Gear down (after verifying stable hydraulic pressure) aux
hydraulic
> c/b set.
>
> I know there is a school of thought that says c/b's are not
switches.
> There is a school of thought that says a c/b can take thousands
of resets.
>
> My suggestion has always been to replace the aux hydraulic c/b
with a
> breaker switch. I really like that idea because you can install
the
> switch so that up is off. (If this were not such a public place,
I'd
> suggest moving this switch next to the gear handle.)
>
> In normal ops, gear handle and switch position are the same:
Gear up /
> switch up = aux hydraulic pump disabled.
>
> Gear handle down / switch down (on) = aux pump enabled.
>
> With a hydraulic abnormal, the pump stays disabled until just
prior to
> touchdown, possibly restoring brakes, the most important
appliance at
> that moment.
>
> This may be a bit much for some Commander owners to wrap their
minds
> around but with a bit of time in type and a practiced flow
pattern,
> I'm convinced it's the way to go.
>
> I've been through 3 catastrophic hydraulic failures a n d the
fact
> that I disable the aux pump gave me brakes and nose wheel
steering 2
> out of the 3 times.
>
> But then, I prefer salmon to flounder.
>
> Wing Commander Gordon
> *
>
>
>
> -----Original Message-----
> From: dfalik@sbcglobal.net <mailto:dfalik@sbcglobal.net>
> To: commander-list@matronics.com
<mailto:commander-list@matronics.com>
> Sent: Sun, 6 Apr 2008 12:04 pm
> Subject: RE: Commander-List: Electric fuel pump cycling
>
<mailto:dfalik@sbcglobal.net> <mailto:dfalik@sbcglobal.net
<mailto:dfalik@sbcglobal.net>>>
>
>
>
> All,
>
>
>
> Just to share:
>
>
>
> In the last year, I have had two occasions of loss of all hyd.
>
> Pressure/fluid due to holes in the hydraulic lines. Each time I
was
>
> airborne and the landing and roll out was no issue due to the
remaining
>
> fluid in
* *
* *
* *
*http://www.matronics.com/Navigator?Commander-List*
* *
*http://forums.matronics.com*
* *
*http://www.matronics.com/contribution*
* *
* *
__________ NOD32 3008 (20080408) Information __________
* *
* *
**
* - The Commander-List Email Forum -*
**
**
**
**
* --> http://www.matronics.com/Navigator?Commander-List*
**
* - MATRONICS WEB FORUMS -*
**
* --> http://forums.matronics.com*
**
* - List Contribution Web Site -*
* Thank you for your generous support!*
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* --> http://www.matronics.com/contribution*
**
* *
*
*
owse
ink(window,event,this)"
href="http://www.matronics.com/Navigator?Commander-List"
target="_blank">http://www.matronics.com/Navigator?Commander-List
op.js.OpenExtLink(window,event,this)"
href="http://forums.matronics.com/"
target="_blank">http://forums.matronics.com
-Matt Dralle, List Admin.
is)" href="http://www.matronics.com/contribution"
target="_blank">http:=================
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Old Bob Ancient Aviator,
I was wondering because you did not touch on it; did you first discover this
with wing warping on the Wright flyer? Actually I am just envious of your experience,
dan f
---------------------------------
You rock. That's why Blockbuster's offering you one month of Blockbuster Total
Access, No Cost.
Message 5
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| Subject: | Re: Electric Hydraulic Pump Ideas |
"An inflight failure without the pump I believe would have been noticed
by odd behavior in the gear and flaps........"
Or by looking at the hydraulic pressure gauge.
I put a enunciator light on my electric hydraulic pump.
Tom...
----- Original Message -----
From: Steve at Col-East
To: commander-list@matronics.com
Sent: Tuesday, April 08, 2008 4:51 AM
Subject: Re: Commander-List: Electric Hydraulic Pump Ideas
My Dad relates a very funny story years ago of having the hydraulic
pressure gauge fail internally as the pumps on a 680E happily pumped the
remainder of the fluid out. I'll check with him to make sure I've got
this right...... After losing rudder authority and going very slowly I
believe he shut both engines down as he entered a giant snow bank and
gently buried the thing up to the wing roots.... I had wondered when you
would use the emergency cut-off's in anger in the 500B, and I guess this
would have been one of those times.......
I too was very, very reluctant to incorporate some "clever idea" in
the cockpit.
Before the electric pump was added to the airframes, the handpump used
the same arrangment of the lower standpipe?
I think I've been comfortable with the idea then that the electric
pump takes the place of the hand pump, 'when I want it to', rather than
it just sitting there and pumping the remaining fluid overboard.
As to consequences of accidentally leaving the pump off, the only dire
one I can think of is a momentary loss of braking and steering at
startup. I've tried this on the ground several times, and haven't been
able to make the ship do anything scary. Am I missing anything? An
inflight failure without the pump I believe would have been noticed by
odd behavior in the gear and flaps........
Steve
----- Original Message -----
From: Robert Feldtman
To: commander-list@matronics.com
Sent: Tuesday, April 08, 2008 3:57 AM
Subject: Re: Commander-List: Electric Hydraulic Pump Ideas
Let me think outloud hear. I have cleveland brakes on the 500B, and
I "think" it is a separate hydraulic system from the "hydraulics" of the
flaps and nose wheel steering. Correct me if I am wrong, but it should
be no different than the "hydraulics" on my experimental, a piper, etc.
So, if that is true. all of the comments about ailerons steering is
interesting, educational, and irrelevant for directional control if the
brakes are working.
I'm 99% sure cause once had an issue with line boy dragging the
commander, and the pilot flying had "locked" the brakes days before. I
don't have a hydraulic accumulator - and the brakes were locked when he
tried to drag - of course nothing was "on"
That should stimulate some discussion.
bobf
500B
On 4/7/08, John Vormbaum <john@vormbaum.com> wrote:
<john@vormbaum.com>
Don,
After reading your results and comparing them to mine, I wonder
now if this is something the designers HAD thought of. Between you & me,
we've had 4 complete hydraulic failures. In all cases the result was a
non-event, essentially. In all cases we had brakes....the argument would
then seem to be, "do we need hydraulics for flaps & gear?" We know the
gear will come down too....so then we're just down to flaps. A no-flap
landing isn't a big deal, if you're not flying in the bush, or into a
900-ft. strip.
So suddenly, should I really be pulling the breaker? I might still
argue that having an additional available system ready to come on-line
might be cheap insurance....but now we're up to what, 4, 5, maybe 6
cases of hyd. failure on this list, all with safe outcomes. Not
reversing myself, just pointing out what I'm seeing.
/John
dfalik@sbcglobal.net wrote:
All,
As I related previously, I have had 2 major hydraulic failures
due to the rupture of a line (abrasion/wear) and failure of a flared
fitting along a hydraulic line in a wing root. Each time I had
sufficient pressure for the brakes upon landing. The gear extension was
due to the bungies and springs for the nose gear.
I don't know where the information came from that relates to ALL
the hydraulic fluid being pumped overboard in the event of a line
breaking. It didn't happen on my 500S.
I'm not pulling the breaker, I have enough to remember prior to
landing.
Don
-----Original Message-----
*From:* owner-commander-list-server@matronics.com
[mailto:owner-commander-list-server@matronics.com] *On Behalf Of *Robert
S. Randazzo
*Sent:* Monday, April 07, 2008 10:59 PM
*To:* commander-list@matronics.com
*Subject:* RE: Commander-List: Electric Hydraulic Pump Ideas
Donnie, et al-
I'm not so sure I agree with "the wise ones" who are pulling the
breaker.
Back in my chief piloting days we used to see "in cockpit
solutions" to these types of things roll around the pilot ranks on
occasion. This has led me to believe that if we do a comparative risk
analysis on the per-flight chances of landing with the breaker pulled
and suffering adverse consequences- versus the chance of suffering the
hydraulic failure mentioned- we are very likely putting the airplane at
a greater overall risk exposure by using a system in a manner for which
it wasn't designed.
Based on my knowledge of the system, it does seem to me that the
system was designed to provide positive pressure in all failure modes
EXCEPT a leak condition- but knowing how well my commander is built- I'm
betting the engineers who dreamed these airplanes up were probably very
comfortable with the risk level for such a failure and the ability of
the pilot to handle it effectively.
Other achillies heals on our commanders? Pulling all fuel from a
central tank- AND pulling all fuel from a central sump=85 But again- I'm
sure the designers weighed carefully the actual risk factors versus
alternative design theories=85
I'm leaving the breaker in.
Robert S. Randazzo
*From:* owner-commander-list-server@matronics.com
[mailto:owner-commander-list-server@matronics.com] *On Behalf Of *Donnie
Rose
*Sent:* Monday, April 07, 2008 7:14 PM
*To:* commander-list@matronics.com
*Subject:* Re: Commander-List: Electric Hydraulic Pump Ideas
Hey there John, yes per my POH and experience the pump will Paul
you down to the sump giving you only minimal braking. That is why the
wise ones are pulling the breaker (everyone included).
**Donnie Rose ***
**205/492-8444***
----- Original Message ----
From: John Vormbaum <john@vormbaum.com>
To: commander-list@matronics.com
Sent: Sunday, April 6, 2008 7:10:57 PM
Subject: Re: Commander-List: Electric Hydraulic Pump Ideas
<john@vormbaum.com <mailto:john@vormbaum.com>>
Donnie, do you mean it would pump everything above the standpipe
in the
hydraulic fluid reservoir out? The standpipe is for the
engine-driven
pumps IIRC....the aux pump runs from a drain at the bottom of
the
reservoir. That's so you always have a little fluid in reserve
for the
aux pump to use for steering & brakes in a hydraulic failure
event....so
in a properly functioning hydraulic system (in a 500B anyway),
the aux
pump would pump EVERY DROP overboard if you had a hose rupture.
Again....ask me how I know :-).
With my total hydraulic failure, I went to an airport with an
8,000 foot
runway (OK, it was Morris' home base :-), landed normally & held
the
nose off until the last taxiway, when I reduced power until I
lost
elevator authority. The nose settled slowly, I rolled a few
feet, and
the nose gear gently folded. I broke a bellcrank and damaged one
gear
door. No fuselage skin damage at all. Could have been worse. At
least I
didn't block the runway!
After that I pulled the tail down, we locked the nose gear down,
and
towed it to Morris' hangar where he fixed it with a minimum of
difficulty.
I would be very reluctant to feather both engines on short final
or
after landing, after a hydraulic failure; I would rather retain
some
directional control. In a truly life-threatening situation I
think I
would still be able to use asymmetrical power & rudder to
intentionally
ground-loop the airplane. I've also found that windmilling props
are
quite a set of brakes on their own. The airplane feels much more
slick
with one feathered...and I think Bob Hoover's routine shows how
slick
the airframe is with two feathered!
/J
Donnie Rose wrote:
> WCG, that's absolutely right since a Hyd. rupture would cause
the aux
> pump to pump everything above the sump overboard.
>
>
> *Donnie Rose
> 205/492-8444*
>
>
>
> ----- Original Message ----
> From: Keith S. Gordon <cloudcraft@aol.com
<mailto:cloudcraft@aol.com>>
> To: commander-list@matronics.com
<mailto:commander-list@matronics.com>
> Sent: Sunday, April 6, 2008 5:15:09 PM
> Subject: Commander-List: Electric Hydraulic Pump Ideas
>
> *As the French say, "Each to his own fish." At least I've been
told
> they say that.
>
> I always taught a flow pattern that linked the gear handle
movement
> with the aux hydraulic c/b.
>
> Gear up, pull the c/b.
>
> Gear down (after verifying stable hydraulic pressure) aux
hydraulic
> c/b set.
>
> I know there is a school of thought that says c/b's are not
switches.
> There is a school of thought that says a c/b can take
thousands of resets.
>
> My suggestion has always been to replace the aux hydraulic c/b
with a
> breaker switch. I really like that idea because you can
install the
> switch so that up is off. (If this were not such a public
place, I'd
> suggest moving this switch next to the gear handle.)
>
> In normal ops, gear handle and switch position are the same:
Gear up /
> switch up = aux hydraulic pump disabled.
>
> Gear handle down / switch down (on) = aux pump enabled.
>
> With a hydraulic abnormal, the pump stays disabled until just
prior to
> touchdown, possibly restoring brakes, the most important
appliance at
> that moment.
>
> This may be a bit much for some Commander owners to wrap their
minds
> around but with a bit of time in type and a practiced flow
pattern,
> I'm convinced it's the way to go.
>
> I've been through 3 catastrophic hydraulic failures a n d the
fact
> that I disable the aux pump gave me brakes and nose wheel
steering 2
> out of the 3 times.
>
> But then, I prefer salmon to flounder.
>
> Wing Commander Gordon
> *
>
>
>
> -----Original Message-----
> From: dfalik@sbcglobal.net <mailto:dfalik@sbcglobal.net>
> To: commander-list@matronics.com
<mailto:commander-list@matronics.com>
> Sent: Sun, 6 Apr 2008 12:04 pm
> Subject: RE: Commander-List: Electric fuel pump cycling
>
<mailto:dfalik@sbcglobal.net> <mailto:dfalik@sbcglobal.net
<mailto:dfalik@sbcglobal.net>>>
>
>
>
> All,
>
>
>
> Just to share:
>
>
>
> In the last year, I have had two occasions of loss of all hyd.
>
> Pressure/fluid due to holes in the hydraulic lines. Each time
I was
>
> airborne and the landing and roll out was no issue due to the
remaining
>
> fluid in
* *
* *
* *
*http://www.matronics.com/Navigator?Commander-List*
* *
*http://forums.matronics.com*
* *
*http://www.matronics.com/contribution*
* *
* *
__________ NOD32 3008 (20080408) Information __________
* *
* *
**
* - The Commander-List Email Forum -*
**
**
**
**
* --> http://www.matronics.com/Navigator?Commander-List*
**
* - MATRONICS WEB FORUMS -*
**
* --> http://forums.matronics.com*
**
* - List Contribution Web Site -*
* Thank you for your generous support!*
* -Matt Dralle, List Admin.*
* --> http://www.matronics.com/contribution*
**
* *
*
*
owse
ink(window,event,this)"
href="http://www.matronics.com/Navigator?Commander-List"
target="_blank">http://www.matronics.com/Navigator?Commander-List
op.js.OpenExtLink(window,event,this)"
href="http://forums.matronics.com/"
target="_blank">http://forums.matronics.com
-Matt Dralle, List Admin.
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target="_blank">http:=================
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href="http://www.matronics.com/Navigator?Commander-List">http://www.mat
ronics.com/Navigator?Commander-List
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Message 6
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Good Morning Dan,
Experience is nice, but it doesn't hold a candle to youth and vigor!
Happy Skies,
Old Bob
In a message dated 4/8/2008 8:36:09 A.M. Central Daylight Time,
daniellfarmer@yahoo.com writes:
Actually I am just envious of your experience,
(http://travel.aol.com/travel-guide/united-states?ncid=aoltrv00030000000016)
Message 7
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| Subject: | Electric Hydraulic Pump Ideas |
That jogged my memory, Richard.
My straight 500 a strictly left-engine-starter.
Once I had a young hot-shot fly a charter in her and I went out to make sure
everything was taken care of, when I briefed him on the plane's
peculiarities, such as, starting the left engine first at all times. He, of
course, fired up the right engine because it was the furthest from the door
in case they had to evacuate. Those Lyc's had no need for a second opinion
when it came to starting; they fired up right away. So, there I was pushing
back on the nose while he tried to get the left engine going. It wasn't
hilarious at the time, but we laughed about it afterwards. He had to deal
with his pax for the duration of the flight. Served him right.
_____
From: owner-commander-list-server@matronics.com
[mailto:owner-commander-list-server@matronics.com] On Behalf Of Richard &
Jacqui Thompson
Sent: Tuesday, April 08, 2008 5:04 AM
Subject: RE: Commander-List: Electric Hydraulic Pump Ideas
OOOPS. Very different from you Piper ( not knocking Pipers, I have 5 of
them)
The braking system and steering system work off the same brake valves. Hence
the first bit does the steering and then the brakes. Both systems therefore
rely on the hydraulic pressure from the pumps. The parking brake valve shuts
the system off between the calipers and the brake/steering valves thus
locking the pressure on the brakes. The accumulator has nothing to do with
it. Its only function really is to stop the pressure relief valve from
chattering by essentially adding a little 'give' in the system. Not trusting
the good old park brake is the reason we pressurize the system either by
hand pump or electric before we start the engines. Nothing is more
entertaining than a commander starting to move before the hydraulics
pressurize. Particularly good in those older models that only have one pump
and its not on the engine you decided to start.
Just a thought from Down Under.( where everything works backwards etc)
Cheers
Richard
-----Original Message-----
From: owner-commander-list-server@matronics.com
[mailto:owner-commander-list-server@matronics.com] On Behalf Of Robert
Feldtman
Sent: Tuesday, 8 April 2008 5:57 PM
Subject: Re: Commander-List: Electric Hydraulic Pump Ideas
Let me think outloud hear. I have cleveland brakes on the 500B, and I
"think" it is a separate hydraulic system from the "hydraulics" of the flaps
and nose wheel steering. Correct me if I am wrong, but it should be no
different than the "hydraulics" on my experimental, a piper, etc. So, if
that is true. all of the comments about ailerons steering is interesting,
educational, and irrelevant for directional control if the brakes are
working.
I'm 99% sure cause once had an issue with line boy dragging the commander,
and the pilot flying had "locked" the brakes days before. I don't have a
hydraulic accumulator - and the brakes were locked when he tried to drag -
of course nothing was "on"
That should stimulate some discussion.
bobf
500B
On 4/7/08, John Vormbaum <john@vormbaum.com> wrote:
Don,
After reading your results and comparing them to mine, I wonder now if this
is something the designers HAD thought of. Between you & me, we've had 4
complete hydraulic failures. In all cases the result was a non-event,
essentially. In all cases we had brakes....the argument would then seem to
be, "do we need hydraulics for flaps & gear?" We know the gear will come
down too....so then we're just down to flaps. A no-flap landing isn't a big
deal, if you're not flying in the bush, or into a 900-ft. strip.
So suddenly, should I really be pulling the breaker? I might still argue
that having an additional available system ready to come on-line might be
cheap insurance....but now we're up to what, 4, 5, maybe 6 cases of hyd.
failure on this list, all with safe outcomes. Not reversing myself, just
pointing out what I'm seeing.
/John
dfalik@sbcglobal.net wrote:
All,
As I related previously, I have had 2 major hydraulic failures due to the
rupture of a line (abrasion/wear) and failure of a flared fitting along a
hydraulic line in a wing root. Each time I had sufficient pressure for the
brakes upon landing. The gear extension was due to the bungies and springs
for the nose gear.
I don't know where the information came from that relates to ALL the
hydraulic fluid being pumped overboard in the event of a line breaking. It
didn't happen on my 500S.
I'm not pulling the breaker, I have enough to remember prior to landing.
Don
-----Original Message-----
*From:* owner-commander-list-server@matronics.com
[mailto:owner-commander-list-server@matronics.com] *On Behalf Of *Robert S.
Randazzo
*Sent:* Monday, April 07, 2008 10:59 PM
*To:* commander-list@matronics.com
*Subject:* RE: Commander-List: Electric Hydraulic Pump Ideas
Donnie, et al-
I'm not so sure I agree with "the wise ones" who are pulling the breaker.
Back in my chief piloting days we used to see "in cockpit solutions" to
these types of things roll around the pilot ranks on occasion. This has led
me to believe that if we do a comparative risk analysis on the per-flight
chances of landing with the breaker pulled and suffering adverse
consequences- versus the chance of suffering the hydraulic failure
mentioned- we are very likely putting the airplane at a greater overall risk
exposure by using a system in a manner for which it wasn't designed.
Based on my knowledge of the system, it does seem to me that the system was
designed to provide positive pressure in all failure modes EXCEPT a leak
condition- but knowing how well my commander is built- I'm betting the
engineers who dreamed these airplanes up were probably very comfortable with
the risk level for such a failure and the ability of the pilot to handle it
effectively.
Other achillies heals on our commanders? Pulling all fuel from a central
tank- AND pulling all fuel from a central sump. But again- I'm sure the
designers weighed carefully the actual risk factors versus alternative
design theories.
I'm leaving the breaker in.
Robert S. Randazzo
*From:* owner-commander-list-server@matronics.com
[mailto:owner-commander-list-server@matronics.com] *On Behalf Of *Donnie
Rose
*Sent:* Monday, April 07, 2008 7:14 PM
*To:* commander-list@matronics.com
*Subject:* Re: Commander-List: Electric Hydraulic Pump Ideas
Hey there John, yes per my POH and experience the pump will Paul you down to
the sump giving you only minimal braking. That is why the wise ones are
pulling the breaker (everyone included).
**Donnie Rose ***
**205/492-8444***
----- Original Message ----
From: John Vormbaum <john@vormbaum.com>
Sent: Sunday, April 6, 2008 7:10:57 PM
Subject: Re: Commander-List: Electric Hydraulic Pump Ideas
<mailto:john@vormbaum.com>>
Donnie, do you mean it would pump everything above the standpipe in the
hydraulic fluid reservoir out? The standpipe is for the engine-driven
pumps IIRC....the aux pump runs from a drain at the bottom of the
reservoir. That's so you always have a little fluid in reserve for the
aux pump to use for steering & brakes in a hydraulic failure event....so
in a properly functioning hydraulic system (in a 500B anyway), the aux
pump would pump EVERY DROP overboard if you had a hose rupture.
Again....ask me how I know :-).
With my total hydraulic failure, I went to an airport with an 8,000 foot
runway (OK, it was Morris' home base :-), landed normally & held the
nose off until the last taxiway, when I reduced power until I lost
elevator authority. The nose settled slowly, I rolled a few feet, and
the nose gear gently folded. I broke a bellcrank and damaged one gear
door. No fuselage skin damage at all. Could have been worse. At least I
didn't block the runway!
After that I pulled the tail down, we locked the nose gear down, and
towed it to Morris' hangar where he fixed it with a minimum of difficulty.
I would be very reluctant to feather both engines on short final or
after landing, after a hydraulic failure; I would rather retain some
directional control. In a truly life-threatening situation I think I
would still be able to use asymmetrical power & rudder to intentionally
ground-loop the airplane. I've also found that windmilling props are
quite a set of brakes on their own. The airplane feels much more slick
with one feathered...and I think Bob Hoover's routine shows how slick
the airframe is with two feathered!
/J
Donnie Rose wrote:
> WCG, that's absolutely right since a Hyd. rupture would cause the aux
> pump to pump everything above the sump overboard.
>
>
> *Donnie Rose
> 205/492-8444*
>
>
> ----- Original Message ----
> From: Keith S. Gordon <cloudcraft@aol.com <mailto:cloudcraft@aol.com>>
> To: commander-list@matronics.com <mailto:commander-list@matronics.com>
> Sent: Sunday, April 6, 2008 5:15:09 PM
> Subject: Commander-List: Electric Hydraulic Pump Ideas
>
> *As the French say, "Each to his own fish." At least I've been told
> they say that.
>
> I always taught a flow pattern that linked the gear handle movement
> with the aux hydraulic c/b.
>
> Gear up, pull the c/b.
>
> Gear down (after verifying stable hydraulic pressure) aux hydraulic
> c/b set.
>
> I know there is a school of thought that says c/b's are not switches.
> There is a school of thought that says a c/b can take thousands of resets.
>
> My suggestion has always been to replace the aux hydraulic c/b with a
> breaker switch. I really like that idea because you can install the
> switch so that up is off. (If this were not such a public place, I'd
> suggest moving this switch next to the gear handle.)
>
> In normal ops, gear handle and switch position are the same: Gear up /
> switch up = aux hydraulic pump disabled.
>
> Gear handle down / switch down (on) = aux pump enabled.
>
> With a hydraulic abnormal, the pump stays disabled until just prior to
> touchdown, possibly restoring brakes, the most important appliance at
> that moment.
>
> This may be a bit much for some Commander owners to wrap their minds
> around but with a bit of time in type and a practiced flow pattern,
> I'm convinced it's the way to go.
>
> I've been through 3 catastrophic hydraulic failures a n d the fact
> that I disable the aux pump gave me brakes and nose wheel steering 2
> out of the 3 times.
>
> But then, I prefer salmon to flounder.
>
> Wing Commander Gordon
> *
>
>
> -----Original Message-----
> From: dfalik@sbcglobal.net <mailto:dfalik@sbcglobal.net>
> To: commander-list@matronics.com <mailto:commander-list@matronics.com>
> Sent: Sun, 6 Apr 2008 12:04 pm
> Subject: RE: Commander-List: Electric fuel pump cycling
>
<mailto:dfalik@sbcglobal.net> <mailto:dfalik@sbcglobal.net
<mailto:dfalik@sbcglobal.net>>>
>
>
> All,
>
>
> Just to share:
>
>
> In the last year, I have had two occasions of loss of all hyd.
>
> Pressure/fluid due to holes in the hydraulic lines. Each time I was
>
> airborne and the landing and roll out was no issue due to the remaining
>
> fluid in
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| Subject: | Electric Hydraulic Pump Ideas |
Since this thread is called "pump ideas", it looks like it would have been
a good idea to put the intake for the electric pump at the same place as t
he engine pump. Then saved the hand pump for the emergency. I understand my
straight 500 is plumbed where the electric pump on the later models are. I
n case both pumps ,and the electric pump went out, you could still hand pu
mp for brakes and flaps. Correct me if I am wrong. I fly a straight 500, a
nd love the simplicity .
Question for old Bob ( or anyone) . If my plane has a hose rupture, can I p
ump
for brakes and flaps without pumping overboard, as long as the problem is n
ot in
brake or flap plumbing??
Thanks,
Roland Gilliam AC 500 N6291b
> Date: Mon, 7 Apr 2008 20:46:05 -0700> From: john@vormbaum.com> To: comman
der-list@matronics.com> Subject: Re: Commander-List: Electric Hydraulic Pum
um.com>> > Don,> > After reading your results and comparing them to mine, I
wonder now if > this is something the designers HAD thought of. Between yo
u & me, we've > had 4 complete hydraulic failures. In all cases the result
was a > non-event, essentially. In all cases we had brakes....the argument
would > then seem to be, "do we need hydraulics for flaps & gear?" We know
the > gear will come down too....so then we're just down to flaps. A no-fla
p > landing isn't a big deal, if you're not flying in the bush, or into a >
900-ft. strip.> > So suddenly, should I really be pulling the breaker? I m
ight still argue > that having an additional available system ready to come
on-line might > be cheap insurance....but now we're up to what, 4, 5, mayb
e 6 cases of > hyd. failure on this list, all with safe outcomes. Not rever
sing myself, > just pointing out what I'm seeing.> > /John> > dfalik@sbcglo
bal.net wrote:> >> > All,> >> > As I related previously, I have had 2 major
hydraulic failures due to > > the rupture of a line (abrasion/wear) and fa
ilure of a flared fitting > > along a hydraulic line in a wing root. Each t
ime I had sufficient > > pressure for the brakes upon landing. The gear ext
ension was due to > > the bungies and springs for the nose gear.> >> > I do
n=92t know where the information came from that relates to ALL the > > hydr
aulic fluid being pumped overboard in the event of a line > > breaking. It
didn=92t happen on my 500S.> >> > I=92m not pulling the breaker, I have eno
ugh to remember prior to landing.> >> > Don> >> > -----Original Message----
-> > *From:* owner-commander-list-server@matronics.com > > [mailto:owner-co
mmander-list-server@matronics.com] *On Behalf Of > > *Robert S. Randazzo> >
*Sent:* Monday, April 07, 2008 10:59 PM> > *To:* commander-list@matronics.
com> > *Subject:* RE: Commander-List: Electric Hydraulic Pump Ideas> >> > D
onnie, et al-> >> > I=92m not so sure I agree with =93the wise ones=94 who
are pulling the breaker.> >> > Back in my chief piloting days we used to se
e =93in cockpit solutions=94 > > to these types of things roll around the p
ilot ranks on occasion. This > > has led me to believe that if we do a comp
arative risk analysis on the > > per-flight chances of landing with the bre
aker pulled and suffering > > adverse consequences- versus the chance of su
ffering the hydraulic > > failure mentioned- we are very likely putting the
airplane at a > > greater overall risk exposure by using a system in a man
ner for which > > it wasn=92t designed.> >> > Based on my knowledge of the
system, it does seem to me that the > > system was designed to provide posi
tive pressure in all failure modes > > EXCEPT a leak condition- but knowing
how well my commander is built- > > I=92m betting the engineers who dreame
d these airplanes up were probably > > very comfortable with the risk level
for such a failure and the > > ability of the pilot to handle it effective
ly.> >> > Other achillies heals on our commanders? Pulling all fuel from a
> > central tank- AND pulling all fuel from a central sump=85 But again- I
=92m > > sure the designers weighed carefully the actual risk factors versu
s > > alternative design theories=85> >> > I=92m leaving the breaker in.> >
> > Robert S. Randazzo> >> > *From:* owner-commander-list-server@matronics.
com > > [mailto:owner-commander-list-server@matronics.com] *On Behalf Of >
> *Donnie Rose> > *Sent:* Monday, April 07, 2008 7:14 PM> > *To:* commander
-list@matronics.com> > *Subject:* Re: Commander-List: Electric Hydraulic Pu
mp Ideas> >> > Hey there John, yes per my POH and experience the pump will
Paul you > > down to the sump giving you only minimal braking. That is why
the wise > > ones are pulling the breaker (everyone included).> >> >> > **D
onnie Rose ***> > **205/492-8444***> >> > ----- Original Message ----> > Fr
om: John Vormbaum <john@vormbaum.com>> > To: commander-list@matronics.com>
> Sent: Sunday, April 6, 2008 7:10:57 PM> > Subject: Re: Commander-List: El
n Vormbaum <john@vormbaum.com > > <mailto:john@vormbaum.com>>> >> > Donnie,
do you mean it would pump everything above the standpipe in the> > hydraul
ic fluid reservoir out? The standpipe is for the engine-driven> > pumps IIR
C....the aux pump runs from a drain at the bottom of the> > reservoir. That
's so you always have a little fluid in reserve for the> > aux pump to use
for steering & brakes in a hydraulic failure event....so> > in a properly f
unctioning hydraulic system (in a 500B anyway), the aux> > pump would pump
EVERY DROP overboard if you had a hose rupture.> > Again....ask me how I kn
ow :-).> >> > With my total hydraulic failure, I went to an airport with an
8,000 foot> > runway (OK, it was Morris' home base :-), landed normally &
held the> > nose off until the last taxiway, when I reduced power until I l
ost> > elevator authority. The nose settled slowly, I rolled a few feet, an
d> > the nose gear gently folded. I broke a bellcrank and damaged one gear>
> door. No fuselage skin damage at all. Could have been worse. At least I>
> didn't block the runway!> >> > After that I pulled the tail down, we loc
ked the nose gear down, and> > towed it to Morris' hangar where he fixed it
with a minimum of difficulty.> >> > I would be very reluctant to feather b
oth engines on short final or> > after landing, after a hydraulic failure;
I would rather retain some> > directional control. In a truly life-threaten
ing situation I think I> > would still be able to use asymmetrical power &
rudder to intentionally> > ground-loop the airplane. I've also found that w
indmilling props are> > quite a set of brakes on their own. The airplane fe
els much more slick> > with one feathered...and I think Bob Hoover's routin
e shows how slick> > the airframe is with two feathered!> >> > /J> >> > Don
nie Rose wrote:> > > WCG, that's absolutely right since a Hyd. rupture woul
d cause the aux> > > pump to pump everything above the sump overboard.> > >
> > >> > > *Donnie Rose> > > 205/492-8444*> > >> > >> > >> > > ----- Origin
al Message ----> > > From: Keith S. Gordon <cloudcraft@aol.com <mailto:clou
dcraft@aol.com>>> > > To: commander-list@matronics.com <mailto:commander-li
st@matronics.com>> > > Sent: Sunday, April 6, 2008 5:15:09 PM> > > Subject:
Commander-List: Electric Hydraulic Pump Ideas> > >> > > *As the French say
, "Each to his own fish." At least I've been told> > > they say that.> > >>
> > I always taught a flow pattern that linked the gear handle movement> >
> with the aux hydraulic c/b.> > >> > > Gear up, pull the c/b.> > >> > > G
ear down (after verifying stable hydraulic pressure) aux hydraulic> > > c/b
set.> > >> > > I know there is a school of thought that says c/b's are not
switches.> > > There is a school of thought that says a c/b can take thous
ands of > > resets.> > >> > > My suggestion has always been to replace the
aux hydraulic c/b with a> > > breaker switch. I really like that idea becau
se you can install the> > > switch so that up is off. (If this were not suc
h a public place, I'd> > > suggest moving this switch next to the gear hand
le.)> > >> > > In normal ops, gear handle and switch position are the same:
Gear up /> > > switch up = aux hydraulic pump disabled.> > >> > > Gear h
andle down / switch down (on) = aux pump enabled.> > >> > > With a hydrau
lic abnormal, the pump stays disabled until just prior to> > > touchdown, p
ossibly restoring brakes, the most important appliance at> > > that moment.
> > >> > > This may be a bit much for some Commander owners to wrap their m
inds> > > around but with a bit of time in type and a practiced flow patter
n,> > > I'm convinced it's the way to go.> > >> > > I've been through 3 cat
astrophic hydraulic failures a n d the fact> > > that I disable the aux pum
p gave me brakes and nose wheel steering 2> > > out of the 3 times.> > >> >
> But then, I prefer salmon to flounder.> > >> > > Wing Commander Gordon>
> > *> > >> > >> > >> > > -----Original Message-----> > > From: dfalik@sbcg
lobal.net <mailto:dfalik@sbcglobal.net>> > > To: commander-list@matronics.c
om <mailto:commander-list@matronics.com>> > > Sent: Sun, 6 Apr 2008 12:04 p
m> > > Subject: RE: Commander-List: Electric fuel pump cycling> > >> > > --
k@sbcglobal.net> <mailto:dfalik@sbcglobal.net > > <mailto:dfalik@sbcglobal.
net>>>> > >> > >> > >> > > All,> > >> > >> > >> > > Just to share:> > >> >
>> > >> > > In the last year, I have had two occasions of loss of all hyd.>
> >> > > Pressure/fluid due to holes in the hydraulic lines. Each time I w
as> > >> > > airborne and the landing and roll out was no issue due to the
remaining> > >> > > fluid in> >> > * *> > * *> > * *> > *http://www.matroni
cs.com/Navigator?Commander-List*> > * *> > *http://forums.matronics.com*> >
* *> > *http://www.matronics.com/contribution*> > * *> > * *> >> >> >> > _
_________ NOD32 3008 (20080408) Information __________> >> > * *> > * *> >
**> > * - The Commander-List Email Forum -*> > **> > **> > **> > **> > * --
> http://www.matronics.com/Navigator?Commander-List*> > **> > * - MATRONICS
WEB FORUMS -*> > **> > * --> http://forums.matronics.com*> > **> > * - Lis
t Contribution Web Site -*> > * Thank you for your generous support!*> > *
-Matt Dralle, List Admin.*> > * --> http://www.matronics.com/contribution*>
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Message 9
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| Subject: | Re: Electric Hydraulic Pump Ideas |
Good Evening Roland,
Since it has been at least forty years since I flew an Aero Commander, I am
not qualified to make a broad and or authoritative statement concerning the
hydraulic variations of the aircraft.
However, such a lack of knowledge very rarely keeps me quiet!
In general, It All Depends!
Depends on where the leak is located. If you can isolate the leaking system
by setting a valve in neutral, you may be able to retain the standby fluid
long enough to operate whatever is the most important at the time. Any time a
hydraulic fluid loss becomes apparent, it is good practice to isolate any
suspect system and to depressurize the entire system if that is practical.
I do have one old Commander war story.
I was out one dark and stormy night when I lost the left engine. It was Aero
Commander serial number twenty-four and was still equipped with the T-handle
one shot feathering device. The one and only engine driven hydraulic pump
was on the left engine. Fortunately for me, the landing gear free fell as
designed. I did have a copilot available who could wobble the hand pump, but hard
as he was pumping, the pressure was very slow to build. I elected to forgo
the use of flap and save what pressure was being built up to use for the
brakes.
We later found out that the hand pump seals were quite badly worn. I should
have picked that up when I built up hydraulic pressure before engine start,
but that was the first and, at that time, the only Aero Commander I had ever
flown. I thought the number of strokes needed to build up adequate prestart
pressure was normal. Later Commanders that I flew could get adequate prestart
pressure by using only three or four strokes on the hand pump.
So I guess the only thing I could add would be that it is important that
the hand pump be working well and that the pilot understand how to isolate
various systems.
My dumb luck held out and I was able to retain braking action by my friend's
furious pumping of the handle!
Happy Skies,
Old Bob
AKA
Bob Siegfried
Ancient Aviator
628 West 86th Street
Downers Grove, IL 60516
630 985-8502
Stearman N3977A
Brookeridge Air Park LL22
In a message dated 4/8/2008 6:19:29 P.M. Central Daylight Time, a
mg3636@hotmail.com writes:
Question for old Bob ( or anyone) . If my plane has a hose rupture, can I
pump
for brakes and flaps without pumping overboard, as long as the problem is
not in
brake or flap plumbing??
Thanks,
Roland Gilliam AC 500 N6291b
(http://travel.aol.com/travel-guide/united-states?ncid=aoltrv00030000000016)
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