Today's Message Index:
----------------------
1. 08:29 AM - Re: Re: ELT Antenna (Robert L. Nuckolls, III)
2. 04:30 PM - Re: Lancair 235 Accident (Robert L. Nuckolls, III)
3. 06:10 PM - Re: Lancair 235 Accident (Richard Girard)
4. 09:36 PM - Strobe switches (Charles Brame)
5. 11:20 PM - Re: Strobe switches (B Tomm)
Message 1
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At 03:03 PM 1/19/2014, you wrote:
>
>I had the same problem with a client's composite aircraft, it was
>the Ameri-King AK-450 ELT unit that was susceptible to com RF
>triggering. It could have also been the un-shielded RJ-11 style
>phone cable used for the remote display.
>
>-James
Interesting! . . . and no AD's against these
products? Defending a device from the ravages
of external radio frequency energy sources
is virtual child's play in engineering circles.
If I were directing the activities of a engineering
design and development group, EVERBODY . . . but
particularly the rookies . . . would spend some
time in the qual-test facilities followed by
a stint in the packaging design group. Shielding
the i/o wires is not acceptable practice for
the purpose of passing qual-tests.
No matter what you're going to design or program,
it first has to perform and survive in the
intended environment and be packaged in a way
that fits into the end-use while not driving
up cost and MTBF risk.
Too many of our contemporaries have evolved
their careers with little appreciation for where
and how their work-product has to perform only
to find out that 'little problems' surface after
a few thousand units are in the field.
The folks-who-know-more-about-airplanes-than-we-do
have assured us that this isn't supposed to happen . . .
Bob . . .
Message 2
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Subject: | Re: Lancair 235 Accident |
At 09:48 AM 1/19/2014, you wrote:
>
>In the January 2014 issue of Sport Aviation is an article, "What
>Went Wrong", about an accident involving N235MW, a Lancair 235.
>http://tinyurl.com/myzgxkv
>The NTSB probable cause is , "The pilot's decision to operate the
>airplane with known electrical system problems . . ."
This is the same incident on which I published
these documents some months ago
http://tinyurl.com/mwo3f4x
Unfortunately, the SA article is typical of many
that I have dubbed "dark-n-stormy night' stories . . .
narratives long story-value, short on understanding.
If one suffers loss of oil because the drain
plug fell out, it's not an "engine problem".
If the elevator becomes disconnected from
the stick, it's not a "controls problem".
The fact that this guy diddled around on numerous
flights to craft a work-around for operating
the landing gear did not make it a "landing gear
problem" . . . or even an "electrical problem."
The issues with the 235 had foundation
in a lack of demonstrated understanding for the
physics of how things work and appreciation for the
performance limits of the components involved.
The guy was flown to another location to get
a couple of freshly charged batteries . . . say
what? The FAA probable cause narrative speaks
to the pilot willingness to initiate flight under battery-
only conditions . . . and do what? Swap
'em out in flight if the first one didn't
get him home? I'd bet he had not a clue as
to the capacity of either "freshly charged
battery."
The same conditions were evident in
the Lancair IV-P accident I cited; I.e.
not one single component of the accident
airframe was defective. Every component
performed in a manner predicted by study
of limits in design and maintenance.
Both of these incidents were "due diligence
problems" waiting to masquerade as an "accident".
You can't do an FMEA without understanding
limits to performance. Rudimentary skills
go a long way toward keeping useful components
attached to each other and performing as
intended. Preventative maintenance
rotates worn-out or abused parts before they
fail. These are but two of many examples of why
we strive for low-risk FMEA combined with
good craftsmanship and responsible operation/
ownership.
Bob . . .
Message 3
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Subject: | Re: Lancair 235 Accident |
Bob, Back in the standard Rogallo days of hang gliding Chris Price of Wills
Wing told me about a phone call the factory received from a fellow who was
having trouble getting his new glider to take off.
"I get started running and the second the scoops get filled the glider
tries to swap ends.", was what he told Chris.
The fellow with the two battery solution was just filling the scoops.
Rick Girard
do not archive
On Mon, Jan 20, 2014 at 6:26 PM, Robert L. Nuckolls, III <
nuckolls.bob@aeroelectric.com> wrote:
> nuckolls.bob@aeroelectric.com>
>
> At 09:48 AM 1/19/2014, you wrote:
>
>>
>> In the January 2014 issue of Sport Aviation is an article, "What Went
>> Wrong", about an accident involving N235MW, a Lancair 235.
>> http://tinyurl.com/myzgxkv
>> The NTSB probable cause is , "The pilot's decision to operate the
>> airplane with known electrical system problems . . ."
>>
>
> This is the same incident on which I published
> these documents some months ago
>
> http://tinyurl.com/mwo3f4x
>
> Unfortunately, the SA article is typical of many
> that I have dubbed "dark-n-stormy night' stories . . .
> narratives long story-value, short on understanding.
>
> If one suffers loss of oil because the drain
> plug fell out, it's not an "engine problem".
> If the elevator becomes disconnected from
> the stick, it's not a "controls problem".
> The fact that this guy diddled around on numerous
> flights to craft a work-around for operating
> the landing gear did not make it a "landing gear
> problem" . . . or even an "electrical problem."
>
> The issues with the 235 had foundation
> in a lack of demonstrated understanding for the
> physics of how things work and appreciation for the
> performance limits of the components involved.
>
> The guy was flown to another location to get
> a couple of freshly charged batteries . . . say
> what? The FAA probable cause narrative speaks
> to the pilot willingness to initiate flight under battery-
> only conditions . . . and do what? Swap
> 'em out in flight if the first one didn't
> get him home? I'd bet he had not a clue as
> to the capacity of either "freshly charged
> battery."
>
> The same conditions were evident in
> the Lancair IV-P accident I cited; I.e.
> not one single component of the accident
> airframe was defective. Every component
> performed in a manner predicted by study
> of limits in design and maintenance.
>
> Both of these incidents were "due diligence
> problems" waiting to masquerade as an "accident".
>
> You can't do an FMEA without understanding
> limits to performance. Rudimentary skills
> go a long way toward keeping useful components
> attached to each other and performing as
> intended. Preventative maintenance
> rotates worn-out or abused parts before they
> fail. These are but two of many examples of why
> we strive for low-risk FMEA combined with
> good craftsmanship and responsible operation/
> ownership.
>
>
> Bob . . .
>
>
--
Zulu Delta
Mk IIIC
Thanks, Homer GBYM
It isn't necessary to have relatives in Kansas City in order to be unhappy.
- Groucho Marx
Message 4
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Bob, et.al.,
I just replaced my fourth S700-1(or equivalent) strobe switch in about 200 hours
of flying time. Both fast on terminals were badly burned as was about an inch
of the 18ga. wire attached to the fast on. My first two switches were Carlings
from B&C. Based on AeroElectric recommendations made some years back, I ordered
a S700-1 equivalent switch from Honeywell - same result. Then I tried a switch
from DigiKey, same result. I'm back to a Carling, at least for the short
term. I have Carlings for the Nav lights, Landing and Wig Wag lights and instrument
lights, and I have had no problem with any of them. The strobe switch is
backed up by a 7 amp fuse which is recommended for the strobe system (Whelen)
and it has never popped. The run of 18 ga. wire is about ten feet. Of all the
switches, only the strobe switch gets real hot after only a few minutes of use.
I was searching B&C for a relay I could use to reroute the strobe heavy current
wire, and discovered that B&C now advertises a MilSpec single pole switch (MS35058-22)
that is the equivalent of the S700-1. The dimensions appear the same,
with screw type connections rather than fast ons. It ain't cheap, but it would
be worth it to avoid having to frequently replace a burnt out standard switch.
Would this MilSpec switch be a viable solution to the strobe switch problem?
Charlie Brame
RV-6A, N11CB
San Antonio
Message 5
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What about using a relay to switch the strobe current? Use the carling
switch to control the relay.
Bevan
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Charles
Brame
Sent: Monday, January 20, 2014 9:33 PM
Subject: AeroElectric-List: Strobe switches
--> <chasb@satx.rr.com>
Bob, et.al.,
I just replaced my fourth S700-1(or equivalent) strobe switch in about 200
hours of flying time. Both fast on terminals were badly burned as was about
an inch of the 18ga. wire attached to the fast on. My first two switches
were Carlings from B&C. Based on AeroElectric recommendations made some
years back, I ordered a S700-1 equivalent switch from Honeywell - same
result. Then I tried a switch from DigiKey, same result. I'm back to a
Carling, at least for the short term. I have Carlings for the Nav lights,
Landing and Wig Wag lights and instrument lights, and I have had no problem
with any of them. The strobe switch is backed up by a 7 amp fuse which is
recommended for the strobe system (Whelen) and it has never popped. The run
of 18 ga. wire is about ten feet. Of all the switches, only the strobe
switch gets real hot after only a few minutes of use.
I was searching B&C for a relay I could use to reroute the strobe heavy
current wire, and discovered that B&C now advertises a MilSpec single pole
switch (MS35058-22) that is the equivalent of the S700-1. The dimensions
appear the same, with screw type connections rather than fast ons. It ain't
cheap, but it would be worth it to avoid having to frequently replace a
burnt out standard switch. Would this MilSpec switch be a viable solution to
the strobe switch problem?
Charlie Brame
RV-6A, N11CB
San Antonio
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