What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Smoke/Fumes and smell in cockpit

Blakegambsky

I'm New Here
Hey guys,

So I've been dealing with this issue for quite a while. I finally got my RV-10 flying a couple months ago with a fun set of issues that I have to deal with on a daily basis. I've finally been narrowing things down but theres one that no matter what I do the problem persists.

A few flights ago after I landed, there was smoke in the cockpit. It was most definitely (at least at the time) determined to be electrical smoke. No fire came of it. I shut off the batteries and taxied to the hangar. The smoke went away and I started to look for anything that would be causing the issue.

Long story short, I've pulled apart the center tunnel (A pain in the *** in my plane), the side panels, under the seats, and even the baggage bulkhead to find the source of the smoke. Just today I left my high suspect access panels off as well as my autopilot panel (GNC 307 sits right above my circuit breakers/bus bar and can see where I was originally suspect of the bus bar coming into contact with the carbon fiber).

I went and flew, and nothing. The smell was still there, but the smoke wasn't very apparent. Its driving me crazy. So I called Aerotronics, my avionics dealer, and asked them for some troubleshooting tips. Obviously my airplane is my airplane and I'm the only one who knows exactly where every wire run is but I needed some other opinions. After an hour or so troubleshooting and this flight, my avionics guy suggested the possibility it wasn't electrical. He suggested the possibility that the electric fuel boost pump was getting hot enough if I left it on too long that it could be burning off the preservative oil that it came in the bag with.

I couldn't see anyone else in a search having smoke or smells due to this issue. The thing that baffles me is I ONLY ever see smoke when I land the plane (fuel pump on). And in flight the smoke would escape through any holes in the plane it can fly due to low pressure outside.

Anyway, I think thats most of the essential information I can give.

Anyone else have this (the fuel pump burning preservative oil off) issue?

I hate that I cant definitively find the issue and know what it is.

Thanks in advance

Blake
 
Smoke & fumes is one condition that would keep me on the ground till I definitely resolved it first.

Did you test it on the ground with same equipment activated as during your landing phase?

Did you ground run it and switch off a circuit one at a time to try to identify the problem?

Are you sure its electrical? Have someone in the plane during a ground run to help identify it?

Sorry, my suggestions are pretty generic as there isn't much here to go on.
 
Blake-----I wouldnt fly again until this is solved. You may not see anything now, and I hope you dont at 5000 feet. Lots of things in your plane dont react well to flames.

Tom
 
Smells can be misleading...

I once had an influx of smoke shortly after startup. I could have sworn it was electrical and I have smelt a few. After a hurried shutdown and checking everywhere to no avail, I realised that on the last cowl removal I had shot some mouse milk on the exhaust joints and it was burning off... Electrical fires leave a lot of evidence. Don't rule it out but stay open to other causes.

Cheers, Sean
 
Do you have a CO detector in your cockpit? I sure hope so, and I would not fly it until you really know what's up.

Have you pulled the cowl and done a finely-detailed inspection forward of the firewall?
 
I couldn't see anyone else in a search having smoke or smells due to this issue. The thing that baffles me is I ONLY ever see smoke when I land the plane (fuel pump on). And in flight the smoke would escape through any holes in the plane it can fly due to low pressure outside.

Yes exactly! When you’re landing pitch and airspeed changes will cause changes in airflow in the cockpit that allow the smoke to be seen while in flight it’s sucked out the back.

I had an in-flight electrical short that was only evident during landing where I’d planned a few circuits with touch and goes. On the first landing I smelled the smoke, which disappeared when I pushed the power in to take off again. I dismissed the smoke smell as having come from outside the aircraft. On the second landing I saw smoke coming out from under the seat in the flare. It was one of the shortest landings I’ve done followed by a very quick exit off the runway while I killed the master, fuel and mags, and tried to get my passenger grab the fire extinguisher from the cockpit floor, although he was a pilot he hadn’t seen the smoke and with no power we had no intercom, so he was still wondering what was going on by the time I was out the aircraft grabbing the extinguisher and pulling the seat forward to isolate the battery terminals

In my case there was a shorted wire underneath the seat going to the master, It wasn’t an RV and the battery under the seat was only for radio and intercom, (a non-electric Aeronca Chief), and so it was easy to disconnect the SLA gel-cell battery by disconnecting the spade terminals. The battery terminals were hot enough to raise blisters on my fingers!

We were very lucky as I’d been flying for at least 35-40 minutes beforehand. It could have been shorted and started a fire in the aircraft well before I smelled the smoke. I still have the burnt wired hanging on the wall of the hangar as a reminder.

Don H
 
simple stuff

This might be the very simplest thing but when the exhaust come new they have stickers on them and sometimes the stickers end up under the connection sleeves. And they would smoke.
The second thing is make sure the boots that seal the firewall penetrations are there.
Thanks, Larry
 
Try checking the high amperage circuits first. A friend of mine had smoke in the cockpit from an incompatible wig-wag box for the landing lights. Check any stand alone relays or dimmers also.
 
Smell from tires

Good day, I have 900hrs on my RV10; sometimes I will get fumes/smell from the tires after I land coming up thru the leg fairings but never any visible smoke. This happens usually in a cross wind with a little higher approach speed and 1/2 flaps. Just one point to think about
 
As others have already stated, please diagnose this problem on the ground and correct it before any further flights.
 
Another thing to check...

Pull off the bottom cowl and see if the alternator pulley is rubbing/has rubbed against it.

Heated/Burning fiberglass will smell "electrical" in nature...
 
Easier on the ground

PERHAPS an IR POINT AND READ THERMOMETER

Perhaps with 3 or 4 friends all with thermometers and a plan for the various team members as in who is going to measure what for short power on intervals.

Or as previously mentioned, an amp meter and turn one item on at a time and know about how many amps each item is supposed to draw vs what the actual draw indicates.
 
Last edited:
Back
Top