canard down by fire

[argoldman]

At lunch Saturday, a group of Geezers were discussing engine compartment fire and the incursion of, to quote George Carlin, "Sh#t" getting into the cockpit through the firewall.

 

Colin Koebel, one of the guest Geezers said, " you know, the Longs and the Veris have an unsealed tube from the firewall to the instrument pannel as part of the design. To make matters worse, he stated that the Cozy's and other side by side versions have TWO of these unsealed conduits."

:yikes:

 

After hearing this, I felt it necessary to tell the crowd as I think this could be major, and the fix is relatively minor.

 

DRUM ROLL PLEASE------

 

Our aileron control torque tubes are open in just such a way.

the MKCS124 or equivalent in the other birds of the flock are open as is/are the torque tube/s to the control stick/s.

 

The fix---- Weld a cap on the 124 to make this a non-issue....

 

Chrissie and Randi-- What do you think???

[bferrell]

Yea, my Velocity has two big-a$s NACA holes on top, and two large conduits on the bottom. I added fire block foam to seal the conduit this weekend, not sure what could be done with the NACAs, to be honest.

 

http://www.velocityxl.com/plenum_split_2.JPG

http://www.velocityxl.com/Oil_Tube_Bracket.JPG |Conduit with oil lines and engine cables

 

Brett

[TMann]

Does it get any closer than this?

The pictures are in the reverse order. The last shows Jack about 50 ft from the plane and if you zoom in ......... well, you tell me how he got out alive?

The first picture show the nice shiney new fire station (the large building in the background.) Jack said the response time was about 10 minutes.

[Cozy Girrrl]

The fix---- Weld a cap on the 124 to make this a non-issue....

 

Chrissie and Randi-- What do you think???

No problem $$$ Seriously, welding a cap on the end would be a worse jobe than welding the bellcrank on. Just avoid doing it to existing ones, the cadmium is nasty stuff.

The solution is pretty simple, pack some micro or flox in the forward end of the CS-124 and you shold be fine, plug the other end with dry micro to prevent rain water from sitting in the tube, its surprizing how much water migrates into a canard sitting outside in rain. Plugging up the electrical conduits is another matter as well, RTV? Foam? Silly strings? combination?

What do people do to plug these up effectively?

...Chrissi

[argoldman]

yahbut yahbut yahbut, Chrissi and Randi,

 

With the heat generated by an engine fire, and the pressure differntial between AFT FW and cabin, and the transmission of that heat through the weldment, how long would it take before the epoxy in the flox/micro liquidifies and the plug(s) is/are are blown/burned out, not to mention the acrid fumes/smoke that this combustion would provide into the cabin?

 

Might the welding of this cap be done before the plating and grinding??. What would be the approximate additional cost on a new part? Is this a consideration for future?

 

for retrofits what about a machined plug secured by a pin???

 

Cough Cough, inspiring and expiring lungs want to know!!

[TMann]

I'm sure I'll have some scraps of fiberfrax left over, couldn't I just carm a bunch into one end of the tube and call it a day?

[argoldman]

I'm sure I'll have some scraps of fiberfrax left over, couldn't I just carm a bunch into one end of the tube and call it a day?

Inelegant, but it may work. My concern with that is that with the vibration, moisture (as suggested by the girllls), what would keep that material in the tubes over the long or semi-long term. If it does exit and exits between the whirring prop blades, that's good. If it wedges in a throttle or mixture linkage, plasters itself over an oil cooler, has it served much of it's purpose for safety?

 

It also would be a small barrier to gasses transiting from the engine compartment to the lower pressure cabin through the tubing.

 

Carbon monoxide is odorless. Is it possible that all ez pilots are breathing small quantities when they fly but are not clinically suffering the resultant hypoxia ?

 

Just some questions that come to mind

[TMann]

Inelegant, but it may work. My concern with that is that with the vibration, moisture (as suggested by the girllls), what would keep that material in the tubes over the long or semi-long term.

Pin it! A piece of safety wire should do it or use some of the adhesive the you used to attach it to the firewall (or both.)

 

.............. and by the way, I believe it is pronounced 'Girrrls'.

[TMann]

Just to clarify, the firehouse was accross from the airport. You can see the roof in the area I circled.

For a fully staffed, full time fire department, you would think that they could make it accross the street in less than 10 minutes.

[satch]

Jack, just lookin' at that last picture ... whew ... May I say I am very glad you're still with us?

[argoldman]

Pin it! A piece of safety wire should do it or use some of the adhesive the you used to attach it to the firewall (or both.)

 

 

.............. and by the way, I believe it is pronounced 'Girrrls'.

 

I guess that's what happens when you put a dyslexic in fornt of a kyebroad!

 

 

T.,

 

The wire is possibly a good Idea, but hardly gas tite, however. perhaps if you then covered it with high temp RTV it would satisfy the requirements---unitl the material, probably not rated in the 1000s of degrees, chars, burns and leaves and you are left with the possibly loosely packed (over time) ceramic wadding to protect your lungs and assorted appendages.

[WileEZ]

Use "fire stop" caulk. They come in different rating for how long they stop the fire, from 20 minutes up to four hours.

 

They work primarily by "burning", yes you read that right!

 

When they burn, they expand and form a high carbon or silicon seal that resist further burning for a period of time. (Exact process not clear to me, need to spend more time researching to understand the process.)

 

Well, they don't really burn so much, as the heat makes the product expand and sometime they will smoke in the process.

 

The technology apparently has changed since the last time I used such caulk. Now there are caulks that gives off little smoke and what smoke they do emit is supposedly low toxic.

 

Ask the local building department and/or the fire code inspector what they suggest. Many construction supply houses also carry them. Tell them it's the stuff that's used in commercial kitchens steel walls.

 

Since the price difference isn't that much, I would tend to choose the four hours stuff over the shorter rating stuff, but even two hours rating ought to be enough.

 

I just googled and surprise! Prices seems to have come down quite a bit, the stuff I bought many years ago was like $30 a tube, now they're in the $8 to $15 range!

 

One 10oz tube should be enough (need caulking gun) to seal the edge of a homebuilt firewall as well as any small openings (wires, cables, fuel lines, etc..)

 

Larger openings of course will need something different.

[argoldman]

Sounds like a winner.

 

Tapping into the collective unconscious (conscious) of this group is really something to behold.

 

This wold be a terrific material to fill in the end of the control tubes as well as the fw ends of the conduits. It would probably be a good material to substitute for the rubber grommets in the through the FW fittings around control cables etc.

 

Thanks.

[Jerry Schneider]

Colin Koebel, one of the guest Geezers said, " you know, the Longs and the Veris have an unsealed tube from the firewall to the instrument pannel as part of the design. To make matters worse, he stated that the Cozy's and other side by side versions have TWO of these unsealed conduits."Our aileron control torque tubes are open in just such a way.

the MKCS124 or equivalent in the other birds of the flock are open as is/are the torque tube/s to the control stick/s.

I'm not sure this is right. The torque tube universal joints at the seatback are not thru-n-thru. So it wouldn't go all the way to the IP.

Seal the tubing joints (high temp RTV?) at the seatback and just forward of the landing gear bulkhead, and you're good to go.

[Cozy Girrrl]

Jerry is so totally right on the universals thingy, maybe some RTV at the joint and its all sealed up?

...Chrissi

[ZUCZZ]

On my Cozy they are sealed with some foam & RTV.

The electrical duct is sealed in a similar manner.

 

yet, I can still smell if there is some oil leak ...

 

Especially when you slow down and the belly brake is out, then the airflow in the Cozy engine compartment is actually negative in the Naca duct. (seen by oil leak streaking)

[Hennie Engelbrecht]

Hilti has a very good range of intumescent foams, calking and fittings for use in sealing penetrations. I used it in electrical switchrooms

 

Hennie

[Beastus_Maximus]

Jack, first of all, let me say that is some damned outstanding flying on your part getting a flaming aircraft down onto the runway and getting out safe. It is something we can all throw in the face of the nay sayers who bring up John Denver and the fact that "you cant just pull an airplane over to the side of the road"

 

I think that your case goes a long ways to show that experimental aircraft, with a properly trained pilot at the controls are safer than many would like to speculate. Granted it was an awful close shave, but you made it through.

 

As a future Long EZ builder, I would really like to thank you for being so honest and upfront with people here about what happened, it has provided me miles of insight on things I need to think about in my own build. I am sure that there are many of us here who are going to benefit from the lessons learned here.