Today's Message Index:
----------------------
1. 04:04 AM - Re: Audio system design (Radioflyer)
2. 11:05 AM - Re: Re: Audio system design (Daniel Hooper)
3. 11:36 AM - Re: Re: Push Button "Speed Brakes"? (Valin & Allyson Thorn)
4. 11:38 AM - Re: Re: Push Button "Speed Brakes"? (Robert L. Nuckolls, III)
5. 02:32 PM - Re: Re: Push Button "Speed Brakes"? (Robert Sultzbach)
6. 02:34 PM - Re: Re: Push Button "Speed Brakes"? (Bob McCallum)
7. 03:34 PM - Toggle Relay (Gordon Smith)
8. 03:34 PM - LV Warn Light vs. Alternator Light (Gordon Smith)
9. 04:26 PM - Re: LV Warn Light vs. Alternator Light (Robert L. Nuckolls, III)
10. 04:26 PM - Re: Re: Push Button "Speed Brakes"? (Valin & Allyson Thorn)
11. 04:26 PM - Re: Re: Push Button "Speed Brakes"? (Valin & Allyson Thorn)
12. 06:28 PM - Starter light (Loman)
13. 07:11 PM - Re: Re: Push Button "Speed Brakes"? (Bob McCallum)
14. 07:18 PM - Re: Starter light (Robert L. Nuckolls, III)
15. 07:39 PM - Re: Toggle Relay (Bob McCallum)
Message 1
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Subject: | Re: Audio system design |
Someone asked where to get the unit I suggested. The CS-408 unit is from Precision
Instrument & Control, Inc. (Ft Worth, TX). The company sells these directly.
They are an electronics OEM for several aircraft manufacturers. I'm away from
my files so can't provide the phone number, but they are probably listed in
the phonebooks. Harvey is the main contact there for this product. Between the
CS-408, the VX unit, and the Aerolectric unit, there is no longer any excuse
for not having an almost invisible "audio panel".
--Jose
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=302661#302661
Message 2
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Subject: | Re: Audio system design |
Is this it?
http://maps.google.com/places/us/tx/haslet/aviator-dr/512/-precision-instrument-&-control?hl=en&gl=us
--Daniel
On Jun 27, 2010, at 6:03 AM, Radioflyer wrote:
>
> Someone asked where to get the unit I suggested. The CS-408 unit is from Precision
Instrument & Control, Inc. (Ft Worth, TX). The company sells these directly.
They are an electronics OEM for several aircraft manufacturers. I'm away
from my files so can't provide the phone number, but they are probably listed
in the phonebooks. Harvey is the main contact there for this product. Between
the CS-408, the VX unit, and the Aerolectric unit, there is no longer any excuse
for not having an almost invisible "audio panel".
> --Jose
>
>
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=302661#302661
>
>
>
>
>
>
>
>
>
>
Message 3
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Subject: | Re: Push Button "Speed Brakes"? |
Hi Bob and everyone,
Thanks for the history of the Precise Flight Speedbrakes/Spoilers. Since
they brand them "speed brakes" I've been using that term even though I know
they are really spoilers. The accident scenario you described really brings
to light how someone without a clear understanding of what they actually do
could call for them at a bad time.
I think they can be easily misunderstood since even spoilers can perform as
speed brakes. I like to think of them as lift/drag ratio reducers. As you
point out, an aircraft designer can go after bumping up the drag side or
lowering the lift side to give the pilot more aircraft control when high on
energy and wanting less altitude and/or airspeed. Even as spoilers they can
act like speed brakes since when deployed, lowering lift, one can increase
the wing angle of attack to keep the same lift (hold same altitude rate)
while getting higher drag at the new higher AOA, slowing the airplane down.
Anyway, your accident example has convinced me to label them as spoilers and
not speed brakes.
The discussion has me reconsidering my decision to add the spoiler control
to the joystick grips. But, let me summarize my rules for picking what's on
the stick.
1. Actions required frequently
2. Functions needed while it's very inconvenient to remove hand from
throttle
3. No functions that if accidentally activated would create a safety
of flight issue
So these are my basic criteria for selecting what's switches are on the
joystick. Based on this, I've tentatively made these assignments:
THORN Legacy Joystick Button Assignments.jpg
For those who can't see the graphic, I have:
Hat Switch: Pitch & Yaw Trim
Trigger: Radio Transmit
Lower Button: Alarm Mute
Upper Right Button: Autopilot On/Off Toggle
Upper Left Button: Spoilers Up/Down Toggle
I did not put flaps or gear on the stick since one usually only activates
them twice during a typical cross country flight and if they were to be
accidentally deployed when flying too fast it would damage the aircraft -
violating strategy rule 3 above.
I'm thinking having the spoilers on the stick is a good option because the
Lancair Legacy is a very low drag airframe making them very useful for
descents, the Legacy can be easily landed with them deployed, and there is
no speed limit on their deployment. With this discussion ongoing I have
heard from a Legacy flyer with a spoiler switch on his throttle control and
that he wishes he had a guard on it because it has been accidentally
activated a few times. The good news from his experiences is that he'd even
landed without realizing they were deployed and it was not an issue. I'm
also checking with another Legacy flyer who has the control on his joystick
to see if it's been a problem for him or if he'd do it again. From earlier
discussion with him he said he did it because the Mooney he used to fly had
it that way and it was very convenient to toggle them when needed on
descents.
Anyway, I appreciate and encourage the discussion about the best way to
design all this with aircraft operations and human factors in mind.
Even if I don't do it this way, I'd still like to know the best way to
design a circuit to toggle back and forth between two poles with a push
button switch. J Anyone have any advice on that question?
Thanks,
Valin
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Robert L.
Nuckolls, III
Sent: Saturday, June 26, 2010 11:45 PM
Subject: AeroElectric-List: Re: Push Button "Speed Brakes"?
<nuckolls.bob@aeroelectric.com>
At 08:24 PM 6/26/2010, you wrote:
>I think it has to have a voltage applied at pin 7 continuously to
>keep the speed brakes up. It's designed so that if the unit loses
>power they fail to the retracted position.
This is an excellent topic for discussions of failure
mode effects analysis =AND= understand the simple-ideas
behind the system design goals.
A really important side note concerning the Precise Flight
product is that it's not a "speed brake" in the aerodynamic
sense of the phrase . . .
A speed brake is a means by which aerodynamic DRAG is
added to the mix of thrust-lift-mass-drag combination
that dictates airframe behavior/performance. Drag can
be and most often is added to the performance mix by
throwing large surface areas out into the slipstream.
I've participated in programs that crafted special
actuators to extend large panels out of aft
locations on the airplane where design goals called for
an increase in the airframe's total drag component
while having little or no effect on lift.
Large air transport aircraft will lift rather large
areas of aluminum from the top surface of the wing.
In cruising flight, only the outboard panels will
occasionally lift during roll control maneuvers. In
this mode, the panels are SPOILERS that reduce lift
on one wing at a time. Loss of lift augments rolling
moment offered by the ailerons.
However, during landing roll-out, one often sees
every square foot of aluminum through out into
the breeze with the obvious intent of making the
whole machine a very draggy aerodynamic shape where
flying efficiency is not important while slowing
down is most important.
The space shuttle has a bifurcated rudder that can
be simultaneously extend both to the right and left
of the vertical fin for the purpose of throwing out
some aerodynamic drag.
The Precise Flight product is the brainchild of on
Bill Thompson who was chief of flight test at Cessna
single engine division while I was a tech writer.
Bill was directly responsible for introducing me to
Ken Razak, former dean of engineering at Wichita
State who became my second most revered mentor,
business partner and friend with more than 40 years
of collaboration on interesting things. But that's
another story.
Bill's product first evolved on the Cessna 210
and was later approved for installation on a host
of TC aircraft. I was introduced to the device
in Kerrville, TX by a Mooney test pilot and later
on another Mooney by George Masey.
It was then that I was given to understand that
the Precise flight product is NOT A SPEED BRAKE.
It's a SPOILER. Design goals for this device call
for reducing lift on the wing while having very
little effect on total drag. The artfully installed
blades can be extended during a stabilized approach
to offer a profound effect on rate of descent
while having little effect on pitch angle or
indicated airspeed.
There are similar devices on the top of the wing
in a Beechjet that offer augmentation of tiny
ailerons for roll control in fight -OR- an increased
rate of descent when fully extended on both sides.
These also are NOT SPEED BRAKES. They might be extended
during a roll out for the purpose of killing lift
to increase weight on wheels and improve braking
by the tires . . . but their effect as aerodynamic
speed brakes is nil.
The reason why this distinction is important has
to do with proper and useful deployment of SPOILERS.
I'm working an accident case where a pilot reports
having extended his Precise Flight "speed brakes"
a few seconds before an off-airport landing. He
was under the mistaken understanding that they
would help slow things down before an un-planned
contact with the ground. In fact, the impact forces
were probably GREATER than if he had not extended
the SPOILERS at all. The net effect of extending the
Precise Flight paddles on top of the wing was to
INCREASE rate of descent to the ground.
So after understanding what these things are designed
to do for you, I'll suggest that its a really good
thing to make sure that under no circumstances
can they can extend when you don't want them to
and that they can always be retracted when they're
not needed . . . or their extension would increase
risks of bent airplanes or broken people.
When considering departures from the manufacture's
instructions, make sure that you're not crafting
a situation that increases risk of unintended
extension or loss of pilot control for that
extension. The system should probably include an
easily accessed power switch. Removal of power
from the system insures positive retraction
irrespective of what other switch becomes
stuck.
Itty-bitty switches on stick-grips are not renowned
for their robustness. Take care that your quest
for convenience does not increase risks for
un-intended consequences.
Bob . . .
Message 4
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Subject: | Re: Push Button "Speed Brakes"? |
At 11:44 PM 6/26/2010, you wrote:
><nuckolls.bob@aeroelectric.com>
My late-night contribution to this thread was hammered out
too quickly and after the 3rd straight, 14-hour day working
one of Dr. Dee's "mother of all garage sales". The organization,
syntax and typos in the posting left much to be desired.
Here's an updated version of the posting which is in much
better shape.
http://www.aeroelectric.com/articles/Speed_Brakes_vs_Spoilers.pdf
As always, comments and corrections welcome.
Bob . . .
Message 5
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Subject: | Re: Push Button "Speed Brakes"? |
Hi Valin,=0A=0A I would suggest putting them on the throttle. That is whe
re they were on military aircraft I flew. The beauty of having them there
is it is extremely easy to develop a habit pattern of activating the spoile
rs to retract WHENEVER you ask for full power. There are thumb switches th
at have existed for these production aircraft so I would think they would b
e available. See if you can find pictures of military aircraft like the A-
4 whose throttle had that setup. As the throttle is advanced the thumb pus
hes the thumb switch forward to retract the spoilers and vice versa when lo
w thrust high drag is needed. Good luck.=0A=0A=0A =0A=0ASent from my iPhon
e=0A=0AOn Jun 28, 2010, at 2:34, "Valin & Allyson Thorn" <thorn@starflight.
aero> wrote:=0A=0AHi Bob and everyone,=0A=0A =0A=0AThanks for the history o
f the Precise Flight Speedbrakes/Spoilers. Since they brand them =9C
speed brakes=9D I=99ve been using that term even though I know
they are really spoilers. The accident scenario you described really bring
s to light how someone without a clear understanding of what they actually
do could call for them at a bad time. =0A=0A =0A=0AI think they can be easi
ly misunderstood since even spoilers can perform as speed brakes. I like t
o think of them as lift/drag ratio reducers. As you point out, an aircraft
designer can go after bumping up the drag side or lowering the lift side t
o give the pilot more aircraft control when high on energy and wanting less
altitude and/or airspeed. Even as spoilers they can act like speed brakes
since when deployed, lowering lift, one can increase the wing angle of att
ack to keep the same lift (hold same altitude rate) while getting higher dr
ag at the new higher AOA, slowing the airplane down=0A=0A =0A=0AAn
yway, your accident example has convinced me to label them as spoilers and
not speed brakes.=0A=0A =0A=0AThe discussion has me reconsidering my decisi
on to add the spoiler control to the joystick grips. But, let me summarize
my rules for picking what=99s on the stick.=0A=0A =0A=0A1. Ac
tions required frequently=0A=0A2. Functions needed while it=99s
very inconvenient to remove hand from throttle=0A=0A3. No functions
that if accidentally activated would create a safety of flight issue=0A=0A
=0A=0ASo these are my basic criteria for selecting what=99s switches
are on the joystick. Based on this, I=99ve tentatively made these as
signments:=0A=0A =0A=0A<image001.jpg>=0A=0AFor those who can=99t see
the graphic, I have:=0A=0A =0A=0AHat Switch: Pitch & Yaw Trim=0A=0ATrigger
: Radio Transmit=0A=0ALower Button: Alarm Mute=0A=0AUpper Right Button: Au
topilot On/Off Toggle=0A=0AUpper Left Button: Spoilers Up/Down Toggle=0A=0A
=0A=0AI did not put flaps or gear on the stick since one usually only acti
vates them twice during a typical cross country flight and if they were to
be accidentally deployed when flying too fast it would damage the aircraft
=93 violating strategy rule 3 above.=0A=0A =0A=0AI=99m thinking
having the spoilers on the stick is a good option because the Lancair Lega
cy is a very low drag airframe making them very useful for descents, the Le
gacy can be easily landed with them deployed, and there is no speed limit o
n their deployment. With this discussion ongoing I have heard from a Legac
y flyer with a spoiler switch on his throttle control and that he wishes he
had a guard on it because it has been accidentally activated a few times.
The good news from his experiences is that he=99d even landed withou
t realizing they were deployed and it was not an issue. I=99m also c
hecking with another Legacy flyer who has the control on his joystick to se
e if it=99s been a problem for him or if he=99d do it again. F
rom earlier discussion with him he said he did it because the Mooney he use
d to fly had it that way and it was very convenient to toggle them when nee
ded on descents.=0A=0A =0A=0AAnyway, I appreciate and encourage the discuss
ion about the best way to design all this with aircraft operations and huma
n factors in mind. =0A=0A =0A=0AEven if I don=99t do it this way, I
=99d still like to know the best way to design a circuit to toggle ba
ck and forth between two poles with a push button switch J Anyone
have any advice on that question?=0A=0A =0A=0AThanks,=0A=0A =0A=0AValin=0A
=0A =0A=0A =0A=0A =0A=0A =0A=0A-----Original Message-----=0AFrom: owner-aer
oelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@
matronics.com] On Behalf Of Robert L. Nuckolls, III=0ASent: Saturday, June
26, 2010 11:45 PM=0ATo: aeroelectric-list@matronics.com=0ASubject: AeroElec
tric-List: Re: Push Button "Speed Brakes"?=0A=0A =0A=0A--> AeroElectric-Lis
t message posted by: "Robert L. Nuckolls, III" <nuckolls.bob@aeroelectric.c
om>=0A=0A =0A=0AAt 08:24 PM 6/26/2010, you wrote:=0A=0A>I think it has to h
ave a voltage applied at pin 7 continuously to=0A=0A>keep the speed brakes
up. It's designed so that if the unit loses=0A=0A>power they fail to the r
etracted position.=0A=0A =0A=0A =0A=0A This is an excellent topic for dis
cussions of failure=0A=0A mode effects analysis =AND= understand the
simple-ideas=0A=0A behind the system design goals.=0A=0A =0A=0A A reall
y important side note concerning the Precise Flight=0A=0A product is that
it's not a "speed brake" in the aerodynamic=0A=0A sense of the phrase .
. .=0A=0A =0A=0A A speed brake is a means by which aerodynamic DRAG is=0A
=0A added to the mix of thrust-lift-mass-drag combination=0A=0A that di
ctates airframe behavior/performance. Drag can=0A=0A be and most often is
added to the performance mix by=0A=0A throwing large surface areas out i
nto the slipstream.=0A=0A =0A=0A I've participated in programs that craft
ed special=0A=0A actuators to extend large panels out of aft=0A=0A loca
tions on the airplane where design goals called for=0A=0A an increase in
the airframe's total drag component=0A=0A while having little or no effe
ct on lift.=0A=0A =0A=0A Large air transport aircraft will lift rather la
rge=0A=0A areas of aluminum from the top surface of the wing.=0A=0A In
cruising flight, only the outboard panels will=0A=0A occasionally lift du
ring roll control maneuvers. In=0A=0A this mode, the panels are SPOILERS
that reduce lift=0A=0A on one wing at a time. Loss of lift augments rolli
ng=0A=0A moment offered by the ailerons.=0A=0A =0A=0A However, during l
anding roll-out, one often sees=0A=0A every square foot of aluminum throu
gh out into=0A=0A the breeze with the obvious intent of making the=0A=0A
whole machine a very draggy aerodynamic shape where=0A=0A flying effici
ency is not important while slowing=0A=0A down is most important.=0A=0A
=0A=0A The space shuttle has a bifurcated rudder that can=0A=0A be simu
ltaneously extend both to the right and left=0A=0A of the vertical fin fo
r the purpose of throwing out=0A=0A some aerodynamic drag.=0A=0A =0A=0A
The Precise Flight product is the brainchild of on=0A=0A Bill Thompson w
ho was chief of flight test at Cessna=0A=0A single engine division while
I was a tech writer.=0A=0A Bill was directly responsible for introducing
me to=0A=0A Ken Razak, former dean of engineering at Wichita=0A=0A Stat
e who became my second most revered mentor,=0A=0A business partner and fr
iend with more than 40 years=0A=0A of collaboration on interesting things
. But that's=0A=0A another story.=0A=0A =0A=0A Bill's product first evo
lved on the Cessna 210=0A=0A and was later approved for installation on a
host=0A=0A of TC aircraft. I was introduced to the device=0A=0A in Ker
rville, TX by a Mooney test pilot and later=0A=0A on another Mooney by Ge
orge Masey.=0A=0A =0A=0A It was then that I was given to understand that
=0A=0A the Precise flight product is NOT A SPEED BRAKE.=0A=0A It's a SP
OILER. Design goals for this device call=0A=0A for reducing lift on the w
ing while having very=0A=0A little effect on total drag. The artfully ins
talled=0A=0A blades can be extended during a stabilized approach=0A=0A
to offer a profound effect on rate of descent=0A=0A while having little e
ffect on pitch angle or=0A=0A indicated airspeed.=0A=0A =0A=0A There ar
e similar devices on the top of the wing=0A=0A in a Beechjet that offer a
ugmentation of tiny=0A=0A ailerons for roll control in fight -OR- an incr
eased=0A=0A rate of descent when fully extended on both sides.=0A=0A Th
ese also are NOT SPEED BRAKES. They might be extended=0A=0A during a roll
out for the purpose of killing lift=0A=0A to increase weight on wheels a
nd improve braking=0A=0A by the tires . . . but their effect as aerodynam
ic=0A=0A speed brakes is nil.=0A=0A =0A=0A The reason why this distinct
ion is important has=0A=0A to do with proper and useful deployment of SPO
ILERS.=0A=0A I'm working an accident case where a pilot reports=0A=0A h
aving extended his Precise Flight "speed brakes"=0A=0A a few seconds befo
re an off-airport landing. He=0A=0A was under the mistaken understanding
that they=0A=0A would help slow things down before an un-planned=0A=0A
contact with the ground. In fact, the impact forces=0A=0A were probably G
REATER than if he had not extended=0A=0A the SPOILERS at all. The net eff
ect of extending the=0A=0A Precise Flight paddles on top of the wing was
to=0A=0A INCREASE rate of descent to the ground.=0A=0A =0A=0A So after
understanding what these things are designed=0A=0A to do for you, I'll su
ggest that its a really good=0A=0A thing to make sure that under no circu
mstances=0A=0A can they can extend when you don't want them to=0A=0A an
d that they can always be retracted when they're=0A=0A not needed . . . o
r their extension would increase=0A=0A risks of bent airplanes or broken
people.=0A=0A =0A=0A When considering departures from the manufacture's
=0A=0A instructions, make sure that you're not crafting=0A=0A a situati
on that increases risk of unintended=0A=0A extension or loss of pilot con
trol for that=0A=0A extension. The system should probably include an=0A
=0A easily accessed power switch. Removal of power=0A=0A from the syste
m insures positive retraction=0A=0A irrespective of what other switch bec
omes=0A=0A stuck.=0A=0A =0A=0A Itty-bitty switches on stick-grips are n
ot renowned=0A=0A for their robustness. Take care that your quest=0A=0A
for convenience does not increase risks for=0A=0A un-intended consequenc
es.=0A=0A =0A=0A Bob . . .=0A=0A =0A=0A =0A=0A=0Ato browse=0AUn/Subscript
ion,=0ABrowse, Chat, FAQ,=0Amore:=0Ahttp://www.matronics.com/Navigator?Aero
Electric-List=0A=0AWeb Forums!=0Ahttp://forums.matronics.com=0A=0Asupport!
=0A=0Ahttp://www.matronics.com/contribution=0A =0A=0A =0A=0A =0A=0A=0A=0A
Message 6
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Subject: | Re: Push Button "Speed Brakes"? |
Valin;
The simplest circuit to accomplish your request would be to use your SPST
push button to switch coil power to a bi-stable relay and use the relay
contacts to switch the power to whatever load you wish. Each push of the
button will toggle the relay. The second item on this page (part number
RLY7742) is an example of a 12VDC 15 amp DPDT bi-stable relay.
http://tinyurl.com/2ffvkur
Bob McC
_____
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Valin &
Allyson Thorn
Sent: Sunday, June 27, 2010 2:35 PM
Subject: RE: AeroElectric-List: Re: Push Button "Speed Brakes"?
Hi Bob and everyone,
Thanks for the history of the Precise Flight Speedbrakes/Spoilers. Since
they brand them "speed brakes" I've been using that term even though I know
they are really spoilers. The accident scenario you described really brings
to light how someone without a clear understanding of what they actually do
could call for them at a bad time.
****** Big Clip**********
Anyway, I appreciate and encourage the discussion about the best way to
design all this with aircraft operations and human factors in mind.
Even if I don't do it this way, I'd still like to know the best way to
design a circuit to toggle back and forth between two poles with a push
button switch. :-) Anyone have any advice on that question?
Thanks,
Valin
Message 7
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Is there a 12V. Relay device (SPST or SPDT) that can be toggled OFF/ON from
a remote momentary SPST mini switch?- It should remain in the off or on
position until toggled again. -I am looking for something in the class of
a S704-1 regarding robustness and capacity.
-
Gordon Smith
Message 8
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Subject: | LV Warn Light vs. Alternator Light |
Given =93 You have installed a device for active notification of low
voltage that moniters Main Bus voltage and lights an indicator lamp/Led if
voltage drops below a programmed level.
=C2-
The first thought if this light comes on is that the alternator is off line
and not outputting to the battery or aircraft bus systems. =C2-However t
his is not necessarily true.
=C2-
Can not there be a condition where the alternator is puitting out it
=99s maximum capacity but you are trying to use a total load greater than t
hat capacity. =C2-I think this would eventually pull the battery and main
bus voltage down to a point where the LV warning light would turn on.
=C2-
My thought was that maybe it would be advantageous to have an additional in
dicator of alternator function.=C2- Many regulators for both field wound
and/or permanent magnet alternators have a =9Clight=9D. =C2-B
ut what does that light actually tell you?
=C2-
On a schematic supplied by Jabiru for the J3300 the stock supplied regulato
r for the permanent magnet regulator system has a =9Clight=9D c
onnection. =C2-It is identified as =9CTo Low Voltage Warning Light
=9D.=C2- Is this just redundant LV warning or does it actually tell
=C2- if the there is alternator output?
=C2-
Gordon Smith
Message 9
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Subject: | Re: LV Warn Light vs. Alternator Light |
>
>The first thought if this light comes on is that
>the alternator is off line and not outputting to
>the battery or aircraft bus systems. However this is not necessarily true.
>
>Can not there be a condition where the
>alternator is puitting out its maximum
>capacity but you are trying to use a total load
>greater than that capacity. I think this would
>eventually pull the battery and main bus voltage
>down to a point where the LV warning light would turn on.
Not if one has accomplished the customary load
analysis. The legacy approach to sizing alternators
to loads makes it impossible to overload the alternator.
Now, if one PLANS to have more potential load than
the alternator can carry, then an alternator loadmeter
is indicated to assist the pilot in turning things
on/off as needed to stay within the alternator's
capabilities.
>My thought was that maybe it would be
>advantageous to have an additional indicator of
>alternator function. Many regulators for both
>field wound and/or permanent magnet alternators
>have a light. But what does that light actually tell you?
Those are in the same class as the alternator warning
light on vehicles for 50+ years. They accurately indicate
a broken wire, broken belt and some system failures but
not all. An they're not a LV warning light.
The stand-alone, active notification of LV is still
the single most useful electrical system flight instrument.
>On a schematic supplied by Jabiru for the J3300
>the stock supplied regulator for the permanent
>magnet regulator system has a light
>connection. It is identified as To Low
>Voltage Warning Light. Is this just
>redundant LV warning or does it actually
>tell if the there is alternator output?
Same as cited above. Not a 'real' lv warning
system.
Bob . . .
Message 10
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Subject: | Re: Push Button "Speed Brakes"? |
Thanks Robert -- that would be nice if I didn=99t already have a
throttle quadrant that isn=99t very conducive to adding a switch
to it See photo below.
Valin
throttle quadrant 2009.jpg
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
Robert Sultzbach
Sent: Sunday, June 27, 2010 4:31 PM
Subject: Re: AeroElectric-List: Re: Push Button "Speed Brakes"?
Hi Valin,
I would suggest putting them on the throttle. That is where they were
on military aircraft I flew. The beauty of having them there is it is
extremely easy to develop a habit pattern of activating the spoilers to
retract WHENEVER you ask for full power. There are thumb switches that
have existed for these production aircraft so I would think they would
be available. See if you can find pictures of military aircraft like
the A-4 whose throttle had that setup. As the throttle is advanced the
thumb pushes the thumb switch forward to retract the spoilers and vice
versa when low thrust high drag is needed. Good luck.
Sent from my iPhone
On Jun 28, 2010, at 2:34, "Valin & Allyson Thorn"
<thorn@starflight.aero> wrote:
Hi Bob and everyone,
Thanks for the history of the Precise Flight Speedbrakes/Spoilers.
Since they brand them =9Cspeed brakes=9D I=99ve been
using that term even though I know they are really spoilers. The
accident scenario you described really brings to light how someone
without a clear understanding of what they actually do could call for
them at a bad time.
I think they can be easily misunderstood since even spoilers can perform
as speed brakes. I like to think of them as lift/drag ratio reducers.
As you point out, an aircraft designer can go after bumping up the drag
side or lowering the lift side to give the pilot more aircraft control
when high on energy and wanting less altitude and/or airspeed. Even as
spoilers they can act like speed brakes since when deployed, lowering
lift, one can increase the wing angle of attack to keep the same lift
(hold same altitude rate) while getting higher drag at the new higher
AOA, slowing the airplane down
Anyway, your accident example has convinced me to label them as spoilers
and not speed brakes.
The discussion has me reconsidering my decision to add the spoiler
control to the joystick grips. But, let me summarize my rules for
picking what=99s on the stick.
1. Actions required frequently
2. Functions needed while it=99s very inconvenient to remove
hand from throttle
3. No functions that if accidentally activated would create a
safety of flight issue
So these are my basic criteria for selecting what=99s switches are
on the joystick. Based on this, I=99ve tentatively made these
assignments:
<image001.jpg>
For those who can=99t see the graphic, I have:
Hat Switch: Pitch & Yaw Trim
Trigger: Radio Transmit
Lower Button: Alarm Mute
Upper Right Button: Autopilot On/Off Toggle
Upper Left Button: Spoilers Up/Down Toggle
I did not put flaps or gear on the stick since one usually only
activates them twice during a typical cross country flight and if they
were to be accidentally deployed when flying too fast it would damage
the aircraft =93 violating strategy rule 3 above.
I=99m thinking having the spoilers on the stick is a good option
because the Lancair Legacy is a very low drag airframe making them very
useful for descents, the Legacy can be easily landed with them deployed,
and there is no speed limit on their deployment. With this discussion
ongoing I have heard from a Legacy flyer with a spoiler switch on his
throttle control and that he wishes he had a guard on it because it has
been accidentally activated a few times. The good news from his
experiences is that he=99d even landed without realizing they were
deployed and it was not an issue. I=99m also checking with
another Legacy flyer who has the control on his joystick to see if
it=99s been a problem for him or if he=99d do it again.
>From earlier discussion with him he said he did it because the Mooney he
used to fly had it that way and it was very convenient to toggle them
when needed on descents.
Anyway, I appreciate and encourage the discussion about the best way to
design all this with aircraft operations and human factors in mind.
Even if I don=99t do it this way, I=99d still like to know
the best way to design a circuit to toggle back and forth between two
poles with a push button switch J Anyone have any advice on
that question?
Thanks,
Valin
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
Robert L. Nuckolls, III
Sent: Saturday, June 26, 2010 11:45 PM
Subject: AeroElectric-List: Re: Push Button "Speed Brakes"?
<nuckolls.bob@aeroelectric.com>
At 08:24 PM 6/26/2010, you wrote:
>I think it has to have a voltage applied at pin 7 continuously to
>keep the speed brakes up. It's designed so that if the unit loses
>power they fail to the retracted position.
This is an excellent topic for discussions of failure
mode effects analysis =AND= understand the simple-ideas
behind the system design goals.
A really important side note concerning the Precise Flight
product is that it's not a "speed brake" in the aerodynamic
sense of the phrase . . .
A speed brake is a means by which aerodynamic DRAG is
added to the mix of thrust-lift-mass-drag combination
that dictates airframe behavior/performance. Drag can
be and most often is added to the performance mix by
throwing large surface areas out into the slipstream.
I've participated in programs that crafted special
actuators to extend large panels out of aft
locations on the airplane where design goals called for
an increase in the airframe's total drag component
while having little or no effect on lift.
Large air transport aircraft will lift rather large
areas of aluminum from the top surface of the wing.
In cruising flight, only the outboard panels will
occasionally lift during roll control maneuvers. In
this mode, the panels are SPOILERS that reduce lift
on one wing at a time. Loss of lift augments rolling
moment offered by the ailerons.
However, during landing roll-out, one often sees
every square foot of aluminum through out into
the breeze with the obvious intent of making the
whole machine a very draggy aerodynamic shape where
flying efficiency is not important while slowing
down is most important.
The space shuttle has a bifurcated rudder that can
be simultaneously extend both to the right and left
of the vertical fin for the purpose of throwing out
some aerodynamic drag.
The Precise Flight product is the brainchild of on
Bill Thompson who was chief of flight test at Cessna
single engine division while I was a tech writer.
Bill was directly responsible for introducing me to
Ken Razak, former dean of engineering at Wichita
State who became my second most revered mentor,
business partner and friend with more than 40 years
of collaboration on interesting things. But that's
another story.
Bill's product first evolved on the Cessna 210
and was later approved for installation on a host
of TC aircraft. I was introduced to the device
in Kerrville, TX by a Mooney test pilot and later
on another Mooney by George Masey.
It was then that I was given to understand that
the Precise flight product is NOT A SPEED BRAKE.
It's a SPOILER. Design goals for this device call
for reducing lift on the wing while having very
little effect on total drag. The artfully installed
blades can be extended during a stabilized approach
to offer a profound effect on rate of descent
while having little effect on pitch angle or
indicated airspeed.
There are similar devices on the top of the wing
in a Beechjet that offer augmentation of tiny
ailerons for roll control in fight -OR- an increased
rate of descent when fully extended on both sides.
These also are NOT SPEED BRAKES. They might be extended
during a roll out for the purpose of killing lift
to increase weight on wheels and improve braking
by the tires . . . but their effect as aerodynamic
speed brakes is nil.
The reason why this distinction is important has
to do with proper and useful deployment of SPOILERS.
I'm working an accident case where a pilot reports
having extended his Precise Flight "speed brakes"
a few seconds before an off-airport landing. He
was under the mistaken understanding that they
would help slow things down before an un-planned
contact with the ground. In fact, the impact forces
were probably GREATER than if he had not extended
the SPOILERS at all. The net effect of extending the
Precise Flight paddles on top of the wing was to
INCREASE rate of descent to the ground.
So after understanding what these things are designed
to do for you, I'll suggest that its a really good
thing to make sure that under no circumstances
can they can extend when you don't want them to
and that they can always be retracted when they're
not needed . . . or their extension would increase
risks of bent airplanes or broken people.
When considering departures from the manufacture's
instructions, make sure that you're not crafting
a situation that increases risk of unintended
extension or loss of pilot control for that
extension. The system should probably include an
easily accessed power switch. Removal of power
from the system insures positive retraction
irrespective of what other switch becomes
stuck.
Itty-bitty switches on stick-grips are not renowned
for their robustness. Take care that your quest
for convenience does not increase risks for
un-intended consequences.
Bob . . .
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Message 11
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Subject: | Re: Push Button "Speed Brakes"? |
Thanks Bob - looks like something along those lines would do the trick.
These examples switch AC current with the DC control. I'm not sure if that
matters or not. But, I figured relays that behave like this must be out
there somewhere. Guess I need DPST bi-stable 24V DC relay.
Valin
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Bob
McCallum
Sent: Sunday, June 27, 2010 4:34 PM
Subject: RE: AeroElectric-List: Re: Push Button "Speed Brakes"?
Valin;
The simplest circuit to accomplish your request would be to use your SPST
push button to switch coil power to a bi-stable relay and use the relay
contacts to switch the power to whatever load you wish. Each push of the
button will toggle the relay. The second item on this page (part number
RLY7742) is an example of a 12VDC 15 amp DPDT bi-stable relay.
http://tinyurl.com/2ffvkur
Bob McC
_____
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Valin &
Allyson Thorn
Sent: Sunday, June 27, 2010 2:35 PM
Subject: RE: AeroElectric-List: Re: Push Button "Speed Brakes"?
Hi Bob and everyone,
Thanks for the history of the Precise Flight Speedbrakes/Spoilers. Since
they brand them "speed brakes" I've been using that term even though I know
they are really spoilers. The accident scenario you described really brings
to light how someone without a clear understanding of what they actually do
could call for them at a bad time.
****** Big Clip**********
Anyway, I appreciate and encourage the discussion about the best way to
design all this with aircraft operations and human factors in mind.
Even if I don't do it this way, I'd still like to know the best way to
design a circuit to toggle back and forth between two poles with a push
button switch. J Anyone have any advice on that question?
Thanks,
Valin
Message 12
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Other builders tell me they wired in a light to indicate that the starter motor
is 'doin its thang'. They value this because you can't hear a Lycoming starter
working and if it continues running, due to welded contacts or some other problem
in the circuit, something needs to be done about it.
What I would really like is a light to indicate A) that the starter is available
to be engaged OR B) is actually energized and working. It would switch off
when the engine was running and the starter was no longer working. Such a light
would come back on when the engine was cut off as long as the master is still
on. This is pretty much how my car status lights work.
I am still learning about electrics but would somebody more knowledgeable know;
can a starter light be wired to this effect and how would it be done?
I will be using the z13/8 architecture for my RV-9.
--------
Loman O'Byrne
RV-9 builder: Emp Done, Wings Done, Fuse underway
Dublin, Ireland
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=302755#302755
Message 13
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Subject: | Re: Push Button "Speed Brakes"? |
Valin;
You're welcome. The 24V version would be part #RLY7443 4th item down on the
link I sent previously. Also although they state these relays switch AC they
work equally well on DC as the switching elements are mechanical micro
switches. You can see this detail clearly if you view the photos on the
linked page.
Bob McC
_____
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Valin &
Allyson Thorn
Sent: Sunday, June 27, 2010 7:21 PM
Subject: RE: AeroElectric-List: Re: Push Button "Speed Brakes"?
Thanks Bob - looks like something along those lines would do the trick.
These examples switch AC current with the DC control. I'm not sure if that
matters or not. But, I figured relays that behave like this must be out
there somewhere. Guess I need DPST bi-stable 24V DC relay.
Valin
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Bob
McCallum
Sent: Sunday, June 27, 2010 4:34 PM
Subject: RE: AeroElectric-List: Re: Push Button "Speed Brakes"?
Valin;
The simplest circuit to accomplish your request would be to use your SPST
push button to switch coil power to a bi-stable relay and use the relay
contacts to switch the power to whatever load you wish. Each push of the
button will toggle the relay. The second item on this page (part number
RLY7742) is an example of a 12VDC 15 amp DPDT bi-stable relay.
http://tinyurl.com/2ffvkur
Bob McC
_____
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Valin &
Allyson Thorn
Sent: Sunday, June 27, 2010 2:35 PM
Subject: RE: AeroElectric-List: Re: Push Button "Speed Brakes"?
Hi Bob and everyone,
Thanks for the history of the Precise Flight Speedbrakes/Spoilers. Since
they brand them "speed brakes" I've been using that term even though I know
they are really spoilers. The accident scenario you described really brings
to light how someone without a clear understanding of what they actually do
could call for them at a bad time.
****** Big Clip**********
Anyway, I appreciate and encourage the discussion about the best way to
design all this with aircraft operations and human factors in mind.
Even if I don't do it this way, I'd still like to know the best way to
design a circuit to toggle back and forth between two poles with a push
button switch. :-) Anyone have any advice on that question?
Thanks,
Valin
Message 14
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Subject: | Re: Starter light |
At 08:26 PM 6/27/2010, you wrote:
Other builders tell me they wired in a light to indicate that the
starter motor is 'doin its thang'. They value this because you can't
hear a Lycoming starter working and if it continues running, due to
welded contacts or some other problem in the circuit, something
needs to be done about it.
What I would really like is a light to indicate A) that the starter
is available to be engaged OR B) is actually energized and
working. It would switch off when the engine was running and the
starter was no longer working. Such a light would come back on when
the engine was cut off as long as the master is still on. This is
pretty much how my car status lights work.
I am still learning about electrics but would somebody more
knowledgeable know; can a starter light be wired to this effect and
how would it be done?
I will be using the Z13/8 architecture for my RV-9.
A simple "starter energized" light is powered from
the downstream side of the starter contactor. It's
illuminated all times the contactor is closed either
because your finger is on the button . . . or because
it's stuck. See:
http://www.aeroelectric.com/Pictures/Schematics/Starter_Engaged_Warning_Lt.pdf
Do an archives search on "starter engaged" for a constellation
of the problem and variables associated with the various
starter technologies.
Bob . . .
Message 15
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Gordon;
See my reply to Valin re: the speed brakes thread, a couple of posts up the
list. This bi-stable relay does what you are describing. The one I cited is
a DPDT device rated 15 amps per contact. You could parallel the two contacts
to approximate the 704's rating. The contacts won't precisely share the load
but unless you are running at absolutely max rating they'll work well. If
the switch ratings are a real concern, the supplied switches on this relay
could be replaced with Omron V-15-1C5 switches which are rated at 15Amps
250VDC.
Bob McC
_____
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Gordon
Smith
Sent: Sunday, June 27, 2010 6:33 PM
Subject: AeroElectric-List: Toggle Relay
Is there a 12V. Relay device (SPST or SPDT) that can be toggled OFF/ON from
a remote momentary SPST mini switch? It should remain in the off or on
position until toggled again. I am looking for something in the class of a
S704-1 regarding robustness and capacity.
Gordon Smith
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