Bad News for the Lemon Sqeeze

[MartinPred]

ALCON:

I'm afraid we just had a bit of an incident with My RV-4, the Lemon Squeeze. Good news: no injuries. Both me and my passenger walked away.

Bad news: prop strike resulting in shattered prop and engine stoppage, bent tailwheel fork as a result of coming back down pretty hard, and a fair amount of cracked fiber glass.

Secondary good news: insurance is paid up and I have no reason to expect we won't be covered in full. So here's a few questions for you.

- We'll have the engine taken apart and fully inspected. What sort of damage should we make sure to look for?

- If we end up getting a new engine, should we go with the same O-360-A1D or something else?

- Can fiber glass be repaired or does it need to be replaced? We have damage to upper and lower cowls, and both wheel pants. What's the best way to get those parts back up to speed?

- Anything else we should be working on?

Thanks,

-Matt
402BD

[Flyguytki]

Sorry to hear, If you don't mind, when everything gets settled down, could you share what happened?

david

[Brantel]

Matt,

Sorry to hear this!

[szicree]

I assume the cowl got creamed when the prop hit the ground. If the engine moved enough to wreck the cowl, I'd take a good look at the engine mount. I'd also take a close look at the tailgear weldment and the weldments on the back of the firewall. Fiberglass can be fixed quite easily, and would probably be easier than fitting a new cowl and pants.

Glad everybody is ok.

[glenn654]

Matt,
First of all, I think I can write for all of us that the best possible result is that you nor your passenger were hurt.

The great thing about a wood or fiberglass prop is that it sacrifices itself and saves your engine.....its a good idea to have the engine inspected but there will not likely be any damage.

The fiberglass parts can all be repaired if not totally destroyed.

You should very carefully inspect every part of the fuse, empennage and wings looking for buckled skin and bulkheads, popped rivets etc so needed repairs can be made.

Good Luck....Hope everything checks out OK.

Glenn Wilkinson

[the_other_dougreeves]

Sorry to hear about your mishap, glad everyone is Ok and the airplane sounds fixable.

Originally Posted by MartinPred

- We'll have the engine taken apart and fully inspected. What sort of damage should we make sure to look for?

There's a Lycoming Service Bulletin on this. Basically, engine teardown, visual inspection of all moving and magnaflux most moving parts as well.

How do I know? .....

TODR

[rgbewley]

Matt:

Sorry to hear about your incident, but glad that no one was injured.

Here's what our engine shop does at teardown inspection for sudden stoppage. Cold compression check prior to teardown. If they are good, we do not access the cylinders. Complete teardown, check the run out on the crankshaft, mag particle of components, 500 hour magneto inspection, replacement of all mandatory replacement parts at access (bearings, gear attaching bolts, all gaskets and locking devices, pin plugs, mag cushions, rod bolts and nuts, thrust buttons, ct'wt washers, drain hoses), crankshaft balance, paint, assemble and one hour dyno test.

Specifically, we are looking for damage to the crankshaft and gear attaching bolts at inspection, but the majority of the time it is a precautionary measure. More commonly, we find scoring on the bearing journals of the crank and frequently corrosion on the cam/lifters (if it is a flat tappet engine.) When we find that, we must have the crank polished and/or reground if it is still within serviceable limits. The same goes for the cam. We always use new lifters rather than repaired. If you have a Lycoming roller tappet engine, there are some other considerations with the tappets. We also make sure that all ADs and SBs are in compliance at return to service.

Hope this is helpful to you. Good luck.

[Geico266]

Glad to hear you are making lemon aid........

[SteinAir]

Couple things to look at on the -4's after a "firm" arrival (if I'm interpreting correctly). Look specifically at the engine mount where it connects to the footwell on the firewall and look very carefully for any wrinkles/crinkles on that area of the firewall. Look very carefully at the lower engine mount weldments and the side skins for any wavy/wrinkly at all. If you see a wrinkle/wave/crinkle in any of those areas, then it's time to start taking 'er apart.

Also, look very cloesly (with a bright lights/magnifying glass) at the HS stab attach points. I've seen a number of cracked ones after incidents similar to yours - specifially the outer sides of the bolt holes towards the flanges of the spar.

As far as the cowl goes, it can be repaire, but if the damage is significant and the cowl is the old gel coat type, sometimes it can be easier to start from new.

Anyway, those are the main things I'd look at. The firewally is a weak point in the -4's, and with a 360 hanging on the front the mount/firewall or main longerons up there usually suffer some damage, even if you don't see it. We've done a lot of work on -4's over the years, and have almost re-built some from the ground up after damage, so I can say that almost everything can be repaired. Just depends on time/money, etc..

If the prop was glass or wood, then that's a bit of a different story when it comes to the engine.

My 2 cents as usual.

Cheers,
Stein

[Mike S]

Originally Posted by MartinPred

Bad news: prop strike resulting in shattered prop

Originally Posted by SteinAir

If the prop was glass or wood, then that's a bit of a different story when it comes to the engine.

My 2 cents as usual.

Cheers,
Stein

Stein ---good points on the tail attach fittings------------sounds like he may have dodged a bullet with the prop strike.