RV-3 Flight Number Two?.There is a Reason We Prepare!

[rocketbob]

Fuel selector.

[Chino Tom]

Glad you are OK. Great job on planning and preperation. Geez if it can
happen to you the rest of us should stand up and take notice. Thanks for
telling the story.

Now lets hear the rest of the story.

[fatherson]

Wow! I always learn so much from every one of your posts, Paul, but this one takes the cake. I'm thankful I get to "steal" so much NASA training from you. Great work!

--
Stephen

[Walt]

Great job under pressure Paul!!!

The only single screw I can think of that would cause something like this would be the throttle arm retainer nut, you probably loosened it to adjust the postion of the arm and then forgot to tighten it all the way, when it came loose the engine went to idle power.

[Kyle Boatright]

Originally Posted by Walt

Great job under pressure Paul!!!

The only single screw I can think of that would cause something like this would be the throttle arm clamp screw, you probably loosened it to adjust the postion of the arm and then forgot to tighten it all the way, when it came loose the engine went to idle power.

Yep. Has to be something in the throttle linkage. And reading Paul's story, the engine didn't stop, it just lost power - went to idle, presumably.

The fuel selector valve is keyed to the shaft. If the screw comes out (at least on mine) the selector still works fine unless the handle falls into the floorboards. Even if that happened, it wouldn't result in lost power.

[comfortcat]

Hey, we can figure this out!

1. Only three things are required to keep engine running:

compression
fuel
spark

2. plane flew out w/o major work, so maybe we can eliminate Compression

3. Loose mag hold down CAN stop an engine, but with one mag still working, there would be a HECK of a noise to let you know you are in grief. Backfire, poping, etc. Also, after an incident like that, I'm not sure you would fly the plane out before a more careful inspection

4. Single point of failure for mags is at the ignition switch. If they field fixed the problem, this is probably out.

4. Two mags makes other electrical grief cause by one screw rare. Mag grounding? nah. I believe your plane does have two mags, right?

5. No mention of cockpit FILLING with gas smell (and they did fly the plane out) means no fuel failure behind the firewall.

So, fuel between firewall and cylinders is probable location.

BUT Louise said linkage was NOT the problem. (did I read that right?)

I can't wait to see the final episode!

Dkb

[highflight42x]

awright, yer killin' me! What was it???

(hmmm ... sudden power loss, no oil on belly and no fuel leak. It's not an engine control cable coming loose - even a mixture control would have to back-off two turns or so to come off. Throttle control would never 'come off'. Those are held on with nuts/bolts anyway, not a 'screw'. The problem had to be somewhere in the fuel injection system. Mine's carburated so I can't guess any further)

- Steven
700 hour RV3

[DakotaHawk]

I have to cast my vote with Walt. If the throttle arm screw backs out, the arm can swing free and cause a loss of throttle control. Because of the critical nature of the throttle and mixture linkages, those screws should be safety wired to prevent such an event.

It's Christmas time! Quit being such a "screw-ge" and tell us what happened!

[Kahuna]

Any chance his IO 320 has an AFP purge valve? Often during installation the safety wire is cut on a couple of screws to mount the purge valve. There have been multiple failures of this where a set screws back out, causing the purve valve to go into by-pass, starving the engine of fuel. Ask me how I know.

[JoeBlank]

I'm thinking Kahuna's on the right track. I'm going to venture that 'if' it has a purge valve, the purge control cable attach somehow became loose. Valve went to 'purge' position and things got quiet. To any AFP fans out there, I recommend installing a spring that forces the valve into the 'run' position if this happens.

Glad you had a great team to provide backup, and that your contigency plans were well thought out.