Today's Message Index:
----------------------
1. 12:47 AM - Re: Static Events On Composite Airplanes (Peter Pengilly)
2. 01:16 AM - Re: Static Events On Composite Airplanes (Peter Pengilly)
3. 06:16 AM - Re: Static Events On Composite Airplanes (donjohnston)
4. 07:55 AM - Re: Re: Static Events On Composite Airplanes (Charlie England)
5. 07:59 AM - Re: Static Events On Composite Airplanes (William Hunter)
6. 08:52 AM - Re: Static Events On Composite Airplanes (donjohnston)
7. 09:48 AM - Re: Re: Static Events On Composite Airplanes (Charlie England)
8. 02:16 PM - Re: AeroElectric-List Digest: 2 Msgs - 03/04/22 (Ron Cox)
9. 05:32 PM - Re: Static Events On Composite Airplanes (Sebastien)
10. 05:38 PM - Re: Static Events On Composite Airplanes (Sebastien)
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| Subject: | Static Events On Composite Airplanes |
Dear Bill & Sebastien,
* flying IMC with a composite amateur built aircraft is risky
I really disagree with this statement. I also really disagree that the
certification rules are particularly relevant as they are designed to
mainly address lightning strike. It is worth looking at the data that is
available.
Some years ago I undertook an investigation for the UK homebuilt
association into IMC & night flying for homebuilts as UK homebuilts were
limited to day VFR. The conclusion was the risk of lightning strike on
single engined aircraft in IMC is so small it is not worth worrying
about. The risk of lightning strike in VMC was already accepted (and is
also very small). From the accident data for 40 years of flying in the
UK and 10 years in the US there was only one instance of a single
engined aircraft flying in IMC being hit by lightning, a 210 in the
eastern US, and that ended with a diversion and safe landing. For
whatever reason single engined aircraft are not hit by lightning. I do
completely agree that the thunderstorm is much more likely to kill you
than being hit by lightning! In the period we looked at around 60
aircraft, flying in IMC, came to grief because of flying into a
thunderstorm.
I have no experience of the effects of static discharge. We found no
similar instances to yours when we searched the accident/incident
reports, but that was 10 years ago and the number of EFIS equipped
aircraft has increased considerably in the intervening years. However,
EFIS (or solid state instruments) are between 2 and 5 times more
reliable than vacuum or electric gyros. It doesn=99t matter if the
instruments are certified or experimental, apart from the first 50 or so
hours.
Flying in IMC in any single engined aircraft is inherently more risky
than in VMC, but the level of increased risk is not easy to determine.
The impact of electrical phenomenon on single engined aircraft in IMC
are very difficult to measure from accident/incident data as there are
very few reported incidents.
I work at a Part 145 repair company, we maintain and repair several
types of composite light aircraft. In general the outer layer of carbon
has aluminium woven into it to improve conductivity =93 carbon
laminates are conductive. There is usually 20mm wide 1mm thick aluminium
bonding straps throughout the aircraft. They all use static discharge
wicks on the te of the wing tips and empennage. We have a fleet of
around 20 aircraft on our books for maintenance, most involved in
commercial training, and have not had a similar incident to yours
reported. Including such =9Cprotection=9D in a homebuilt
would not be something to be undertaken lightly, I am not convinced it
would buy very much except a longer build time, lower useful load and
corroded wings.
In the UK certified gliders (with little bonding or protection)
regularly fly in IMC. I am not aware of any static problems. The
incident of the K-21 being blown apart by lightning was when the glider
knowingly flew (in VMC) close but not into a CB, it wasn=99t a
embedded in stratus. The strike was so severe that the moisture within
the structure was heated so rapidly that it vapourised and blew the
structure apart, the control rods were melted and fused together.
Fortunately the pilots wore parachutes and escaped. The amount of energy
absorbed by the aircraft meant that it was unlikely to have been
survivable no matter how much bonding was used.
Most recreational pilots don=99t fly in hard IMC for very long
=93 even in the UK where we seem to have more low stratus than
many other countries. The usual operational profile is to climb through
the clag to VMC on top. Clearly commercial flight training spends much
more time in the soup, but certainly here homebuilts cannot be used for
commercial training. The conclusion we came to was that no additional
requirements from the bonding perspective were required for homebuilt
aircraft to fly in IMC, except to impose a limitation not to fly near
areas of forecast or actual thunderstorms =93 although that is not
policeable but it keeps the certification authorities happy!
Peter
From: owner-aeroelectric-list-server@matronics.com
<owner-aeroelectric-list-server@matronics.com> On Behalf Of Sebastien
Sent: 03 March 2022 23:24
Subject: Re: AeroElectric-List: Static Events On Composite Airplanes
Hello Bill,
I don't have any data, just anecdotal evidence that flying IMC with a
composite amateur built aircraft is risky. You could look up the bonding
section in the certification requirements for composite aircraft, that
would probably give you a good idea of how thorough you have to be to
make a composite aircraft safe for IMC flights.
I have flown several different models of certified fiberglass aircraft
IFR. These aircraft are designed and built with conductive mesh
throughout the airframe to dissipate any static electricity build up.
Despite this, on two different occasions I have had severe problems with
static while IMC requiring a diversion. In one case it was so bad that
the student was getting electric shocks through the yoke. The other
incident took out half the avionics and magnetized the compass.
As for lightning, I think usually the aircraft gets destroyed by
turbulence induced loss of control before getting close enough to be hit
by lightning but I know of one incident with a glider in the UK which
was flying near what they thought was stratus cloud but had an embedded
CB in it. The composite glider (factory built but with no bonding
material embedded) basically exploded when it was hit. Very high
resistance = very high temperature during a lightning strike and the
entire airframe disintegrated. They found themselves falling in free air
but both successfully deployed their parachutes and survived. The
passenger was on his first small aircraft flight.
I think anyone flying IMC regularly in a composite amateur built
aircraft is going to run into a problem sooner or later. I know of no
solution, everyone just seems to roll the dice and hope they keep
getting 7s.
On Thu, Mar 3, 2022 at 8:28 AM William Hunter
<billhuntersemail@gmail.com <mailto:billhuntersemail@gmail.com> > wrote:
Greetings,
I fly a composite airplane that is built using a foam core with regular
fiberglass BID material bonded to the core for most of the construction
and flight control surfaces and then in some small sections there is
some carbon fiber bonded in to certain places of the structure where
needed for extra support so essentially the airplane is mostly core foam
and regular fiberglass.
There has been one static event in the community where the pilot of this
type of airplane who had a full EFIS system was climbing through dry
snow and his Garmin EFIS screen blacked out and then a few minutes later
the screen returned however the autopilot was still operating as usual
so it seems that it was only the EFIS screen that was affected during
the event and not the rest of the system. The data was downloaded and
sent to Garmin and they determined that it was a static discharge. I
have not heard what their remedy was for this concern.
So the questions that popped up are the following...
-How does the builder/ pilot mitigate the risk of this type of issue
from happening in a composite airplane?
-Is this a common concern in airplanes designed like this?
-There are commercially available static wicks that could be attached to
the structure however if the structure does not have any kind of
conductive material/ mesh embedded in the fiberglass I would not think
that the static buildup would get to the static wicks.
-The plans do not call for any type if bonding cable be installed to
electrically connect the flight controls to the fuselage so the question
is...should there be bonding straps in this type of airplane?
-What risks does an airplane like this have when flying near lightning?
-If the fuselage was not conductive and there is no practical way to get
it to discharge the static through static wicks then what other
technique is there to mitigate the risk of static buildup damaging/
disabling the electrical components of the airplane?
-And other questions that we are not smart enough to know to ask?
THANKS all and as always I am very grateful for your advice and
expertise.
Bill
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| Subject: | Static Events On Composite Airplanes |
Perhaps I should add that we looked at some kind of =9CIMC
lite=9D clearance and quickly came to the conclusion that it was
not possible. The aircraft is either clear for IMC or it is not. That
doesn=99t mean the pilot should press on regardless. Known icing
capability in homebuilts is very unusual. With regard to the aircraft
climbing through snow, I would question the pilot=99s sanity!
Flying in visible moisture in an aircraft with no icing protection does
not seem sensible to me
I guess the question is how much are you prepared to spend to be able to
penetrate all conceivable weather conditions. Sounds like the pilot
concerned found the edge of his system=99s envelope and was lucky
to be able to report his findings Not my idea of fun!
Peter
From: owner-aeroelectric-list-server@matronics.com
<owner-aeroelectric-list-server@matronics.com> On Behalf Of William
Hunter
Sent: 04 March 2022 16:08
Subject: Re: AeroElectric-List: Static Events On Composite Airplanes
Thanks Sebastien for the information. Greatly appreciated.
Does anyone else have any information that they can share?
On 3/3/2022 4:24 PM, Sebastien wrote:
Hello Bill,
I don't have any data, just anecdotal evidence that flying IMC with a
composite amateur built aircraft is risky. You could look up the bonding
section in the certification requirements for composite aircraft, that
would probably give you a good idea of how thorough you have to be to
make a composite aircraft safe for IMC flights.
I have flown several different models of certified fiberglass aircraft
IFR. These aircraft are designed and built with conductive mesh
throughout the airframe to dissipate any static electricity build up.
Despite this, on two different occasions I have had severe problems with
static while IMC requiring a diversion. In one case it was so bad that
the student was getting electric shocks through the yoke. The other
incident took out half the avionics and magnetized the compass.
As for lightning, I think usually the aircraft gets destroyed by
turbulence induced loss of control before getting close enough to be hit
by lightning but I know of one incident with a glider in the UK which
was flying near what they thought was stratus cloud but had an embedded
CB in it. The composite glider (factory built but with no bonding
material embedded) basically exploded when it was hit. Very high
resistance = very high temperature during a lightning strike and the
entire airframe disintegrated. They found themselves falling in free air
but both successfully deployed their parachutes and survived. The
passenger was on his first small aircraft flight.
I think anyone flying IMC regularly in a composite amateur built
aircraft is going to run into a problem sooner or later. I know of no
solution, everyone just seems to roll the dice and hope they keep
getting 7s.
On Thu, Mar 3, 2022 at 8:28 AM William Hunter
<billhuntersemail@gmail.com <mailto:billhuntersemail@gmail.com> > wrote:
Greetings,
I fly a composite airplane that is built using a foam core with regular
fiberglass BID material bonded to the core for most of the construction
and flight control surfaces and then in some small sections there is
some carbon fiber bonded in to certain places of the structure where
needed for extra support so essentially the airplane is mostly core foam
and regular fiberglass.
There has been one static event in the community where the pilot of this
type of airplane who had a full EFIS system was climbing through dry
snow and his Garmin EFIS screen blacked out and then a few minutes later
the screen returned however the autopilot was still operating as usual
so it seems that it was only the EFIS screen that was affected during
the event and not the rest of the system. The data was downloaded and
sent to Garmin and they determined that it was a static discharge. I
have not heard what their remedy was for this concern.
So the questions that popped up are the following...
-How does the builder/ pilot mitigate the risk of this type of issue
from happening in a composite airplane?
-Is this a common concern in airplanes designed like this?
-There are commercially available static wicks that could be attached to
the structure however if the structure does not have any kind of
conductive material/ mesh embedded in the fiberglass I would not think
that the static buildup would get to the static wicks.
-The plans do not call for any type if bonding cable be installed to
electrically connect the flight controls to the fuselage so the question
is...should there be bonding straps in this type of airplane?
-What risks does an airplane like this have when flying near lightning?
-If the fuselage was not conductive and there is no practical way to get
it to discharge the static through static wicks then what other
technique is there to mitigate the risk of static buildup damaging/
disabling the electrical components of the airplane?
-And other questions that we are not smart enough to know to ask?
THANKS all and as always I am very grateful for your advice and
expertise.
Bill
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| Subject: | Re: Static Events On Composite Airplanes |
My pilot side Grand Rapids HXr attitude and magnetic heading went wonky while flying
through light rain in between layers. Showed a continuous steep descending
left turn. That got my attention!
A/P automatically switched to the co-pilot side EFIS/AHRS. Once on the ground I
rebooted it and performed fine.
GRT said it was probably a static discharge on the magnetometer that caused the
problem. When I asked why a confused magnetometer would cause an indicated attitude
change, I got some very weird reasoning. But I didn't design and build
the box so okay. As to what I should do to prevent the issue, they suggested
static wicks. Even though it's a composite airplane with now underlying conductive
mesh? "Absolutely." My response was "What else ya got?"
They offered to sell me their Adaptive AHRS to replace my older Dual AHRS for almost
nothing.
I think they discovered a flaw in their Dual AHRS and this was a way of fixing
it without losing face.
I never did get around to installing the Adaptive AHRS and never had another event.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=506226#506226
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| Subject: | Re: Static Events On Composite Airplanes |
On 3/5/2022 8:16 AM, donjohnston wrote:
>
> My pilot side Grand Rapids HXr attitude and magnetic heading went wonky while
flying through light rain in between layers. Showed a continuous steep descending
left turn. That got my attention!
>
> A/P automatically switched to the co-pilot side EFIS/AHRS. Once on the ground
I rebooted it and performed fine.
>
> GRT said it was probably a static discharge on the magnetometer that caused the
problem. When I asked why a confused magnetometer would cause an indicated
attitude change, I got some very weird reasoning. But I didn't design and build
the box so okay. As to what I should do to prevent the issue, they suggested
static wicks. Even though it's a composite airplane with now underlying conductive
mesh? "Absolutely." My response was "What else ya got?"
>
> They offered to sell me their Adaptive AHRS to replace my older Dual AHRS for
almost nothing.
>
> I think they discovered a flaw in their Dual AHRS and this was a way of fixing
it without losing face.
>
> I never did get around to installing the Adaptive AHRS and never had another
event.
>
>
/Even though it's a composite airplane with now underlying conductive
mesh? "Absolutely." My response was "What else ya got?" /Well, aluminum airframes
use static wicks; why not composite with conductive mesh? The wicks are there
to bleed off the built-up charge.
Charlie
//
--
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| Subject: | Re: Static Events On Composite Airplanes |
Good information...THANKS All for your relies!!!
On 3/4/2022 11:18 AM, Robert L. Nuckolls, III wrote:
> At 10:23 AM 3/3/2022, you wrote:
>> Greetings,
>>
>> I fly a composite airplane that is built using a foam core with
>> regular fiberglass BID material bonded to the core for most of the
>> construction and flight control surfaces and then in some small
>> sections there is some carbon fiber bonded in to certain places of
>> the structure where needed for extra support so essentially the
>> airplane is mostly core foam and regular fiberglass.
>>
>> There has been one static event in the community where the pilot of
>> this type of airplane who had a full EFIS system was climbing through
>> dry snow and his Garmin EFIS screen blacked out and then a few
>> minutes later the screen returned however the autopilot was still
>> operating as usual so it seems that it was only the EFIS screen that
>> was affected during the event and not the rest of the system. The
>> data was downloaded and sent to Garmin and they determined that it
>> was a static discharge. I have not heard what their remedy was for
>> this concern.
>>
>> So the questions that popped up are the following...
>>
>> -How does the builder/ pilot mitigate the risk of this type of issue
>> from happening in a composite airplane?
>
> Control of p-static in aircraft is a blend of
> science and practice derived from over a century
> of observation and attempts at mitigation. Bottom
> line is that you can attenuate the effects of
> p-static on most aircraft but it's ranges
> exceedingly difficult up to impossible to
> reduce effects to negligible.
>
> There are file cabinets full of test reports
> and studies on p-static management in
> type certificated aircraft . . . all metal
> ones at that. There are companies that
> specialize in identification of optimal
> placement of static wicks.
>
> They set the airplane up on insulators and
> charge the airframe with tens of thousands
> of volts. Then they walk around the airplane
> with a hand held probe (a very long one!)
> and search out locations on the airframe
> most conducive to forming a corona discharge.
> Those locations are deemed best locations
> for static wicks.
>
> I asked a p-static guy at Piper that given
> the high-velocity nature of p-static generation,
> how do they know that those explorations at zero
> airspeed correspond to the same locations
> that exist in flight? "We don't", sez he,
> "just a best guess". A guess that costs a
> few $thousand$ to make.
>
> Now, ask one of those guys to survey your plastic
> airplane and all bets are off. Static-charge
> mitigation is absolutely dependent on conductivity
> between the generation surface and the ideal
> discharge locations.
>
>
>> -Is this a common concern in airplanes designed like this?
>
> Yup
>
>
>> -There are commercially available static wicks that could be attached
>> to the structure however if the structure does not have any kind
>> of conductive material/ mesh embedded in the fiberglass I would
>> not think that the static buildup would get to the static wicks.
>
> Exactly right.
>
>> -The plans do not call for any type if bonding cable be installed
>> to electrically connect the flight controls to the fuselage so
>> the question is...should there be bonding straps in this type of
>> airplane?
>
> There is no foundation in physics that supports
> an oft cited value in 'bonding' all the metal
> stuff together in a plastic airplane.
>
>> -What risks does an airplane like this have when flying near lightning?
>
> See https://tinyurl.com/hre2hkz
>
> I am aware of no incident where in-flight strike
> brought down an OBAM airplane or caused injury to
> crew. If anyone runs across such a case, I'd
> like to hear about it. I recall a case where
> an airplane was struck on the ramp and burned
> (a GlasAir I think).
>
>> -If the fuselage was not conductive and there is no practical way to
>> get it to discharge the static through static wicks then what other
>> technique is there to mitigate the risk of static buildup
>> damaging/disabling the electrical components of the airplane?
>
> There was a lot of head-scratching and long
> discussions over beers at Lancair 20+ years ago
> as they explored ways to make their products
> more resistant to the effects of lightning
> and p-static. The activity seemed to die off
> with no significant advances/changes to the
> airplane's design. I may be out of date on
> that . . . again, if anyone has more current
> info on p-static/lightning issues on OBAM
> aircraft, please let me know.
>
> The heavy iron birds EXPECT to receive in-flight
> strikes . . . with some regularity. See
>
> https://tinyurl.com/ydh37e4s
>
> Type certification for (1) flight in to known
> ice and (2) standing off lightning strike is
> an arduous and expensive task and is still only
> 90% sure. There have been some unhappy outcomes
> due to strike on large aircraft.
>
> https://tinyurl.com/bdf47pzk
>
>
> https://tinyurl.com/245d3wzz
>
>
> My instructors always advised that a weather
> briefing was the best prophylactic for such
> risks . . . from wheels up to plop down,
> flying should be fun.
>
> Bob . . .
>
> Un impeachable logic: George Carlin asked, "If black boxes
> survive crashes, why don't they make the whole airplane
> out of that stuff?"
>
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| Subject: | Re: Static Events On Composite Airplanes |
Ceengland wrote:
> Even though it's a composite airplane with now underlying conductive mesh? "Absolutely."
My response was "What else ya got?"
>
> [/i]Well, aluminum airframes use static wicks; why not composite with conductive
mesh? The wicks are there to bleed off the built-up charge.
>
> Charlie
>
Should have been: no underlying conductive mesh.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=506229#506229
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| Subject: | Re: Static Events On Composite Airplanes |
On Sat, Mar 5, 2022 at 10:55 AM donjohnston <don@velocity-xl.com> wrote:
> don@velocity-xl.com>
>
>
> Ceengland wrote:
> > Even though it's a composite airplane with now underlying conductive
> mesh? "Absolutely." My response was "What else ya got?"
> >
> > [/i]Well, aluminum airframes use static wicks; why not composite with
> conductive mesh? The wicks are there to bleed off the built-up charge.
> >
> > Charlie
> >
>
>
> Should have been: no underlying conductive mesh.
>
>
> Still might well help, though you might need more of them. For instance,
remember the old silk rag/glass rod science demo? Neither are conductive,
but both can build up (opposite) charges. Anything you can do to bleed off
the charge would be a good thing, don't you think?
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| Subject: | Re: AeroElectric-List Digest: 2 Msgs - 03/04/22 |
These links are about the Glasair LP that was built and tested under a
NASA grant for lightning resistance. It was then offered as a (Very
expensive) option back then for the Glasair III, but as I understand it, no
one ever purchased the option.
https://thumbs-media.smithsonianmag.com/filer/JJ11-Lightning-Protection-6-G
ALL.jpg__600x0_q85_upscale.jpg
The only Glasair I have seen documentation on that had significant damage
from a lightning strike was hit on a ramp, and it burned to the ground.
https://www.expressnews.com/entertainment/article/NASA-funded-San-Antonio-p
ilot-s-one-of-a-kind-14455830.php
https://www.youtube.com/watch?v=YDpkrBE3yrQ
I think the key is Ted's quote in the article: =9CI try to stay away
from
situations where there=99s lightning around when I fly,=9D Bain
said.
Here's a link to the SAE paper about this project from 1993.
https://www.sae.org/publications/technical-papers/content/931241/
Ron
>
> Time: 08:08:21 AM PST US
> From: William Hunter <billhuntersemail@gmail.com>
> Subject: Re: AeroElectric-List: Static Events On Composite Airplanes
>
> Thanks Sebastien for the information. Greatly appreciated.
>
> Does anyone else have any information that they can share?
>
>
>
>
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| Subject: | Re: Static Events On Composite Airplanes |
Hello Peter,
Like I said, I have no data. I included the anecdotes specifically because
I'm not sure that "We found no similar instances to yours when we searched
the accident/incident reports" is data either. An incident which takes out
half of the aircraft avionics and requires a diversion to a nearby VMC
airport would not show up in any accident database that I am aware of. No
one was injured and the aircraft did not suffer any damage after the
initial event. Both my incidents were in uncontrolled airspace so
definitely no report there. A friend of mine lost all avionics except for a
radio and the turn co-ordinator in an IMC static event over the rocky
mountains and required a great deal of help from controllers to safely get
the aircraft on the ground. Again, no database that I know of contains this
incident and it only happened 15 years ago.
Instrument failures happen for many reasons and when training IFR I go to
great lengths to make sure my students are as prepared as possible for them
but we rarely simulate losing most of the instrument panel. The closest we
get to that scenario is an alternator failure that eventually leaves us on
backup battery power for the approach.
These days I regularly see newly built amateur built that are IFR capable.
Many of these are built by pilots who have no IMC experience. Sometimes the
builder has given some thought to fault tolerance, other times not. I have
yet to see one where the builder gave any thought to static problems, so I
share my anecdotes and my caution to encourage builders to think about the
possibilities. All flying is risky to some degree so I suppose my statement
isn't very useful. I'm just trying to point out the increase in risk.
On Sat, Mar 5, 2022 at 1:01 AM Peter Pengilly <Peter@sportingaero.com>
wrote:
> Dear Bill & Sebastien,
>
>
> - flying IMC with a composite amateur built aircraft is risky
>
>
> I really disagree with this statement. I also really disagree that the
> certification rules are particularly relevant as they are designed to
> mainly address lightning strike. It is worth looking at the data that is
> available.
>
>
> Some years ago I undertook an investigation for the UK homebuilt
> association into IMC & night flying for homebuilts as UK homebuilts were
> limited to day VFR. The conclusion was the risk of lightning strike on
> single engined aircraft in IMC is so small it is not worth worrying about
.
> The risk of lightning strike in VMC was already accepted (and is also ver
y
> small). From the accident data for 40 years of flying in the UK and 10
> years in the US there was only one instance of a single engined aircraft
> flying in IMC being hit by lightning, a 210 in the eastern US, and that
> ended with a diversion and safe landing. For whatever reason single engin
ed
> aircraft are not hit by lightning. I do completely agree that the
> thunderstorm is much more likely to kill you than being hit by lightning!
> In the period we looked at around 60 aircraft, flying in IMC, came to gri
ef
> because of flying into a thunderstorm.
>
>
> I have no experience of the effects of static discharge. We found no
> similar instances to yours when we searched the accident/incident reports
,
> but that was 10 years ago and the number of EFIS equipped aircraft has
> increased considerably in the intervening years. However, EFIS (or solid
> state instruments) are between 2 and 5 times more reliable than vacuum or
> electric gyros. It doesn=99t matter if the instruments are certifie
d or
> experimental, apart from the first 50 or so hours.
>
>
> Flying in IMC in any single engined aircraft is inherently more risky tha
n
> in VMC, but the level of increased risk is not easy to determine. The
> impact of electrical phenomenon on single engined aircraft in IMC are ver
y
> difficult to measure from accident/incident data as there are very few
> reported incidents.
>
>
> I work at a Part 145 repair company, we maintain and repair several types
> of composite light aircraft. In general the outer layer of carbon has
> aluminium woven into it to improve conductivity =93 carbon laminate
s are
> conductive. There is usually 20mm wide 1mm thick aluminium bonding straps
> throughout the aircraft. They all use static discharge wicks on the te of
> the wing tips and empennage. We have a fleet of around 20 aircraft on our
> books for maintenance, most involved in commercial training, and have not
> had a similar incident to yours reported. Including such =9Cprotect
ion=9D in a
> homebuilt would not be something to be undertaken lightly, I am not
> convinced it would buy very much except a longer build time, lower useful
> load and corroded wings.
>
>
> In the UK certified gliders (with little bonding or protection) regularly
> fly in IMC. I am not aware of any static problems. The incident of the K-
21
> being blown apart by lightning was when the glider knowingly flew (in VMC
)
> close but not into a CB, it wasn=99t a embedded in stratus. The str
ike was so
> severe that the moisture within the structure was heated so rapidly that
it
> vapourised and blew the structure apart, the control rods were melted and
> fused together. Fortunately the pilots wore parachutes and escaped. The
> amount of energy absorbed by the aircraft meant that it was unlikely to
> have been survivable no matter how much bonding was used.
>
>
> Most recreational pilots don=99t fly in hard IMC for very long
=93 even in the
> UK where we seem to have more low stratus than many other countries. The
> usual operational profile is to climb through the clag to VMC on top.
> Clearly commercial flight training spends much more time in the soup, but
> certainly here homebuilts cannot be used for commercial training. The
> conclusion we came to was that no additional requirements from the bondin
g
> perspective were required for homebuilt aircraft to fly in IMC, except to
> impose a limitation not to fly near areas of forecast or actual
> thunderstorms =93 although that is not policeable but it keeps the
> certification authorities happy!
>
>
> Peter
>
>
> *From:* owner-aeroelectric-list-server@matronics.com <
> owner-aeroelectric-list-server@matronics.com> *On Behalf Of *Sebastien
> *Sent:* 03 March 2022 23:24
> *To:* aeroelectric-l. <aeroelectric-list@matronics.com>
> *Subject:* Re: AeroElectric-List: Static Events On Composite Airplanes
>
>
> Hello Bill,
>
>
> I don't have any data, just anecdotal evidence that flying IMC with a
> composite amateur built aircraft is risky. You could look up the bonding
> section in the certification requirements for composite aircraft, that
> would probably give you a good idea of how thorough you have to be to mak
e
> a composite aircraft safe for IMC flights.
>
>
> I have flown several different models of certified fiberglass aircraft
> IFR. These aircraft are designed and built with conductive mesh throughou
t
> the airframe to dissipate any static electricity build up. Despite this,
on
> two different occasions I have had severe problems with static while IMC
> requiring a diversion. In one case it was so bad that the student was
> getting electric shocks through the yoke. The other incident took out hal
f
> the avionics and magnetized the compass.
>
>
> As for lightning, I think usually the aircraft gets destroyed by
> turbulence induced loss of control before getting close enough to be hit
by
> lightning but I know of one incident with a glider in the UK which was
> flying near what they thought was stratus cloud but had an embedded CB in
> it. The composite glider (factory built but with no bonding material
> embedded) basically exploded when it was hit. Very high resistance = ve
ry
> high temperature during a lightning strike and the entire airframe
> disintegrated. They found themselves falling in free air but both
> successfully deployed their parachutes and survived. The passenger was on
> his first small aircraft flight.
>
>
> I think anyone flying IMC regularly in a composite amateur built aircraft
> is going to run into a problem sooner or later. I know of no solution,
> everyone just seems to roll the dice and hope they keep getting 7s.
>
>
> On Thu, Mar 3, 2022 at 8:28 AM William Hunter <billhuntersemail@gmail.com
>
> wrote:
>
> Greetings,
>
> I fly a composite airplane that is built using a foam core with regular
> fiberglass BID material bonded to the core for most of the construction a
nd
> flight control surfaces and then in some small sections there is some
> carbon fiber bonded in to certain places of the structure where needed fo
r
> extra support so essentially the airplane is mostly core foam and regular
> fiberglass.
>
> There has been one static event in the community where the pilot of this
> type of airplane who had a full EFIS system was climbing through dry snow
> and his Garmin EFIS screen blacked out and then a few minutes later the
> screen returned however the autopilot was still operating as usual so it
> seems that it was only the EFIS screen that was affected during the event
> and not the rest of the system. The data was downloaded and sent to Garm
in
> and they determined that it was a static discharge. I have not heard wha
t
> their remedy was for this concern.
>
> So the questions that popped up are the following...
>
> -How does the builder/ pilot mitigate the risk of this type of issue from
> happening in a composite airplane?
>
> -Is this a common concern in airplanes designed like this?
>
> -There are commercially available static wicks that could be attached to
> the structure however if the structure does not have any kind of conducti
ve
> material/ mesh embedded in the fiberglass I would not think that the stat
ic
> buildup would get to the static wicks.
>
> -The plans do not call for any type if bonding cable be installed to
> electrically connect the flight controls to the fuselage so the question
> is...should there be bonding straps in this type of airplane?
>
> -What risks does an airplane like this have when flying near lightning?
>
> -If the fuselage was not conductive and there is no practical way to get
> it to discharge the static through static wicks then what other technique
> is there to mitigate the risk of static buildup damaging/ disabling the
> electrical components of the airplane?
>
> -And other questions that we are not smart enough to know to ask?
>
> THANKS all and as always I am very grateful for your advice and expertise
.
>
> Bill
>
>
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| Subject: | Re: Static Events On Composite Airplanes |
I have a student right now who is very much only interested in "IMC lite".
He just wants to get his instrument rating so that he can punch through a
layer on departure and be on his sunny way to a VMC destination. He's quite
bitter about having to learn how to operate down to 200' and 1/2 mile
visibility just to be able to do what he wants to do. But an instrument
rating is an instrument rating and it's the same rating to punch through a
cloud as it is to fly in a rainy cloud in the dark. Throw in some
instrument failures and it's not so much fun anymore. Best for pilots to
know the risks.
On Sat, Mar 5, 2022 at 1:19 AM Peter Pengilly <Peter@sportingaero.com>
wrote:
> Perhaps I should add that we looked at some kind of =9CIMC lite
=9D clearance
> and quickly came to the conclusion that it was not possible. The aircraft
> is either clear for IMC or it is not. That doesn=99t mean the pilot
should
> press on regardless. Known icing capability in homebuilts is very unusual
.
> With regard to the aircraft climbing through snow, I would question the
> pilot=99s sanity! Flying in visible moisture in an aircraft with no
icing
> protection does not seem sensible to me
>
>
> I guess the question is how much are you prepared to spend to be able to
> penetrate all conceivable weather conditions. Sounds like the pilot
> concerned found the edge of his system=99s envelope and was lucky
to be able
> to report his findings Not my idea of fun!
>
>
> Peter
>
>
> *From:* owner-aeroelectric-list-server@matronics.com <
> owner-aeroelectric-list-server@matronics.com> *On Behalf Of *William
> Hunter
> *Sent:* 04 March 2022 16:08
> *To:* aeroelectric-list@matronics.com
> *Subject:* Re: AeroElectric-List: Static Events On Composite Airplanes
>
>
> Thanks Sebastien for the information. Greatly appreciated.
>
> Does anyone else have any information that they can share?
>
> On 3/3/2022 4:24 PM, Sebastien wrote:
>
> Hello Bill,
>
>
> I don't have any data, just anecdotal evidence that flying IMC with a
> composite amateur built aircraft is risky. You could look up the bonding
> section in the certification requirements for composite aircraft, that
> would probably give you a good idea of how thorough you have to be to mak
e
> a composite aircraft safe for IMC flights.
>
>
> I have flown several different models of certified fiberglass aircraft
> IFR. These aircraft are designed and built with conductive mesh throughou
t
> the airframe to dissipate any static electricity build up. Despite this,
on
> two different occasions I have had severe problems with static while IMC
> requiring a diversion. In one case it was so bad that the student was
> getting electric shocks through the yoke. The other incident took out hal
f
> the avionics and magnetized the compass.
>
>
> As for lightning, I think usually the aircraft gets destroyed by
> turbulence induced loss of control before getting close enough to be hit
by
> lightning but I know of one incident with a glider in the UK which was
> flying near what they thought was stratus cloud but had an embedded CB in
> it. The composite glider (factory built but with no bonding material
> embedded) basically exploded when it was hit. Very high resistance = ve
ry
> high temperature during a lightning strike and the entire airframe
> disintegrated. They found themselves falling in free air but both
> successfully deployed their parachutes and survived. The passenger was on
> his first small aircraft flight.
>
>
> I think anyone flying IMC regularly in a composite amateur built aircraft
> is going to run into a problem sooner or later. I know of no solution,
> everyone just seems to roll the dice and hope they keep getting 7s.
>
>
> On Thu, Mar 3, 2022 at 8:28 AM William Hunter <billhuntersemail@gmail.com
>
> wrote:
>
> Greetings,
>
> I fly a composite airplane that is built using a foam core with regular
> fiberglass BID material bonded to the core for most of the construction a
nd
> flight control surfaces and then in some small sections there is some
> carbon fiber bonded in to certain places of the structure where needed fo
r
> extra support so essentially the airplane is mostly core foam and regular
> fiberglass.
>
> There has been one static event in the community where the pilot of this
> type of airplane who had a full EFIS system was climbing through dry snow
> and his Garmin EFIS screen blacked out and then a few minutes later the
> screen returned however the autopilot was still operating as usual so it
> seems that it was only the EFIS screen that was affected during the event
> and not the rest of the system. The data was downloaded and sent to Garm
in
> and they determined that it was a static discharge. I have not heard wha
t
> their remedy was for this concern.
>
> So the questions that popped up are the following...
>
> -How does the builder/ pilot mitigate the risk of this type of issue from
> happening in a composite airplane?
>
> -Is this a common concern in airplanes designed like this?
>
> -There are commercially available static wicks that could be attached to
> the structure however if the structure does not have any kind of conducti
ve
> material/ mesh embedded in the fiberglass I would not think that the stat
ic
> buildup would get to the static wicks.
>
> -The plans do not call for any type if bonding cable be installed to
> electrically connect the flight controls to the fuselage so the question
> is...should there be bonding straps in this type of airplane?
>
> -What risks does an airplane like this have when flying near lightning?
>
> -If the fuselage was not conductive and there is no practical way to get
> it to discharge the static through static wicks then what other technique
> is there to mitigate the risk of static buildup damaging/ disabling the
> electrical components of the airplane?
>
> -And other questions that we are not smart enough to know to ask?
>
> THANKS all and as always I am very grateful for your advice and expertise
.
>
> Bill
>
>
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