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Tale of Woe! (a mystery prop strike) G-NONI

Yes several people are pointing towards a towbar strike. Problem is going to be getting the ground handlers to own up to it.

Sorry to hear that your first powered ’plane purchase started off this way. Not sure why the ground handlers might be at fault – you would need to have the engine running to achieve that damage?

Hope it works out and you are flying soon.

Oxford (EGTK), United Kingdom

It takes a lot of force to do that damage. The engine must have been running.

At present you can prove pretty conclusively that this happened prior to delivery. The logs (signed by the pilot) shows the finishing hobbs time, which is the same as it is now. So (unless the hobbs doesn’t start until over a certain RPM) you can show that the engine hasn’t been run since delivery. If the damage only occurred with the engine running, then clearly it happened before the aircraft was handed over.

Is the broker in the same country as you? If so, threatening to repot them to the local CAA might help resolve the situation. Clearly the pilot flew an unairworthy aircraft. That aircraft should not have been flown, and there could be serious repercussions for he pilot. If it’s shown that the pilot was also responsible for the damage, then they should have also reported the incident, which they didn’t, and they’ve falsified the tech long (not recording the damage). One way or another, the pilot should not have flown that aircraft. It’s not a conversation I’d like to have with the local CAA!

Don’t be bothered by the 20 day thing. That’s their own guarantee, but what you’re looking at is not a warranty claim, but rather a misrepresentation on the condition of the aircraft.

EIWT Weston, Ireland

You are unlikely to want to blame your own ground crew as why would they have run the engine with a tow bar attached. Presumably if that is the problem it was the previous owner or whoever delivered it.

To be honest when buying you will have accepted the aircraft at some point, paid and then risk transferred to you. If you never actually checked it at acceptance you will struggle to get your own insurance company to pay. And why would the sellers’ or brokers’? Most brokerage agreements give no warranty as to condition, you need to make your own enquiries.

I would suggest absent an admission from the seller that they did it, you bite the bullet, replace or repair the prop as required and move on.

EGTK Oxford

At present you can prove pretty conclusively that this happened prior to delivery. The logs (signed by the pilot) shows the finishing hobbs time, which is the same as it is now. So (unless the hobbs doesn’t start until over a certain RPM) you can show that the engine hasn’t been run since delivery. If the damage only occurred with the engine running, then clearly it happened before the aircraft was handed over.

I think the most likely scenario, certainly in the hitting-the-towbar case, is that the engine was started and immediately the towbar was hit, probably before the engine fired up. No further attempt is then made to do anything and the person walks away quietly.

The less likely one is that it happened before the delivery flight, and the delivery flight was made with the damage. This would assume the delivery pilot is either extremely dishonest (and has balls made of solid brass because he “knows” the customer won’t spot it) or is a complete muppet to not have noticed this on a preflight.

However, you can get bad damage like this and not be aware of it – by hitting a big stone. But to me the damage here doesn’t look like a stone. And almost nobody does a post-flight inspection… So in tht case the delivery pilot would not have been aware. Loads of people have got bad prop strikes (all blades bent at the tips) during taxi and then flown the plane and discovered it only before the next flight… there is a report here somewhere of somebody doing that in a twin. My prop strike (on concrete) was not noticed and would have gone on to a flight if somebody had not heard the “ding” and made a radio call.

It’s going to cost somebody of the order of 10k plus 6-8 weeks of downtime.

Administrator
Shoreham EGKA, United Kingdom

The damage is pretty far from the tip. I don’t see how that could have happened unless the engine was tried fired up and immediately hit it on the first turn over. The imprint looks like some “structure” hit it, not a stone. There is a big oval dent in the middle, and two smaller, but sharper on each side. Does a tow bar look like that? Maybe, but the ones I have seen have been just a round steel tube, without the two sharper dents. This could therefore be caused by any sort of “structure” placed just in front of the airplane when it was tried started up.

The other cause could be it picket up some rather huge piece of metal while running. But how likely is that?

It is IMO extremely unlikely that the maintenance organisation would let the airplane go with that damage (not impossible of course). It is also unlikely that it was hit by some debris. To me it looks that someone in the hangar wanted to see if it started, and didn’t remove the tool case/tow bar/whatever before cranking the prop.

The elephant is the circulation
ENVA ENOP ENMO, Norway

Ian,

first of all, while it is not a time to celebrate or anything, still congratulations to you for your plane. It looks like a lovely aircraft, I personally like the AA5 a lot and was several times very close to picking one up before I got my airplane. It is a plane with an economical engine and fix pitch prop and while the Traveller has a bit shorter range than the Cheetah, it is still a very capable and reasonably fast plane. I am sure that you will enjoy it a lot once your inital problems are over.

As for the prop, it may look like a towbar strike but I agree with LeSving it is rather weird. What does indeed puzzle me is that it’s only one blade which is damaged and also the way it looks. I’ve seen other prop strikes and almost always it was both blades and the damage looked very different, even from towbars. The only way I could explain this is that someone tried to start the engine but it never fired, instead the prop hit the towbar on the first turn over and stopped there or even someone turned the prop over by hand. If only one blade is involved, that is what it does look like.

Now: If the engine never started up or did not even turn over fully or indeed turned by hand, the question is whether a teardown will be neccessary indeed or not. Only a real expert can assess this, once the damage of the prop has been definitly identified and assessed. I suggest that this is the way to go now, get someone who really knows propellers and their damage to look at this and go on from there. I would think that if it comes out that it was something like that with a low energy impact, you might avoid a teardown altogether, but it will be the maintenance organisation who have to determine that.

On the other hand, I strongly doubt that this prop is repairable or a repair should be attempted even, so in order to save you some time, you might want to look around for sourcing a replacement. Normally, this is a McCauley 73 inch prop, which is quite common also with other planes. You might want to talk to Mühlbauer at Straubing or a good prop shop in the UK for both looking at your current one but also for possibly sourcing a replacement, they did a really god job on my variable prop and for a very competitive price. Getting a replacement prop should not be a big deal, neither is mounting it, and it will save time if it turns out that a teardown is not necessary. If one blade is damaged only, then I would say the chances for that are not bad at all.

Likewise, you might want to ask around for a exchange engine too, the O320-E2G is not a very uncommon engine, to get you flying again. While I doubt that this prop strike has fatally damaged your engine, a tear down will take about a month to complete if it can be delivered to a reputable shop quick. Unfortunately I am not familiar with the engine shop scene in the UK, but there are several shops who can do a teardown. Also, depending on the total hours and time since the last overhaul, it may be a variant to look into an overhaul rather than a teardown if it is significantly over TBO or so. As a sidenote: IF you need to do a teardown/overhaul and the engine does NOT have the 160hp mod, this might be your change of getting it. The AA5 can profit from the 10 extra horsepower quite well and if it becomes clear that you should need new cylinders for some reason, I would absolutely try to get the 160 hp STC done at the same time, the extra cost will most probably be minimal.

Finally, depending on how you are insured, your insurance should cover this damage if you have a hull insurance. You should definitly talk to them right now, nonwithstanding who was finally responsible, so action can be taken quickly. If it turns out that someone else is responsible the insurance will see that they get their money back from them, but first and foremost you need to get your plane back flying now.

From a technical point of view, I do strongly suspect that this plane did not fly like this, the vibration would have been quite pronounced, so it must have happened on the ground where you are now. As to the who, well, it may pay out to play a good cop / bad cop strategy, with you telling the operator and anyone else who might know that you are forced to let the insurance and it’s lawyers look at this and they will not be so forthcoming as you are…. so with regret you’d have to refer the story to the legal folks or even the police to do forensics if an unauthorized movement of the plane is suspected. It might scare the culprit sufficiently to owe up… or not, but at least you tried.

So you need urgently to get the insurance assessor onto this as well as maintenance who know what they are talking about, as well as possibly involving law enforcement and their forensic teams to find out what happened if 3rd party involvement is suspected.

Not a good way to start ownership but prop damages are definitly not uncommon and, on the up side, you will start your flying with most probably a new prop and an engine which has been given a clean bill of health either through a teardown or an overhaul (if it is over TBO it might be more economical).

Last Edited by Mooney_Driver at 20 Apr 12:27
LSZH(work) LSZF (GA base), Switzerland

Actually one more thing which bothers me:

The ground handlers who moved the plane after arrival would have been very likely to see a damage like this if it had been there at the time and if I was them, I would not touch the plane with a barge pole (even though the prop looks like someone did exactly that…) but call the owner right there and then to see it!

Something smells here. It does look to me from that conclusion and others that it may indeed have happened after the arrival and then that some unknown third party did something he was not supposed to do with this plane. Maybe it is really time to involve the law here.

LSZH(work) LSZF (GA base), Switzerland

I reckon the plane could have been flown like that. People have flown planes with bad prop strikes and didn’t notice anything. The amount of metal actually missing is very small. If a tip came off that would be very obvious…

The only UK engine shop with anything like a good reputation is Nicolson McLaren.

The prop shop I have just used for mine is General Aero Services at Thurrock. Really nice people, very straight, and did a great job. Right price too; less than I paid in 2008.

Administrator
Shoreham EGKA, United Kingdom

Could a starting motor really give enough power to cause that damage? I’d have thought it required engine power for that much damage.

EIWT Weston, Ireland

dublinpilot wrote:

Could a starting motor really give enough power to cause that damage? I’d have thought it required engine power for that much damage.

I doubt it could do that much damage without the engine itself running.

EGTK Oxford
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