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Tale of Woe! (a mystery prop strike)

Thanks Urs.

Now …. I have been reading that you can go all the way to 180 hp on an 0-320!

I guess that would need at least a coarser pitch prop …………….

Waiting for a call from the adjuster and I’ll take it from there. One step at a time.

It's not rocket science!

Nimbusgb wrote:

Would anyone be dumb enough to crank an aircraft in the hangar?

Perhaps not to start it, but to move the prop into a horizontal position so the a/c is easier to maneuver with a towbar. Now, if you do this with the towbar already attached…..

I found a shop in the UK who claims they can do shock load inspections in 15 working days.

http://www.norvic.com/shock-load/

does anyone know them here?

regarding the 160 hp upgrade, check it out but I just read that you loose the capability of going MOGAS with that. If so, stay away but get the MOGAS STC, which will save you a lot of money if you fly in Germany particularly.

Cruise prop vs Climb Prop: Quite a lot of people put cruise props on their AA5’s to cruise faster. This comes at the price of mediocre climb performance however. I’d go for a standard prop instead, respectively have the prop toned to the normal pitch.

As to avionics, if you want to do something while the airplane is on the ground, check out Trigg. They have all you need. My recommendation would be to replace the Mode C transponder you have with a TT31 and, if you want to go 8.33 already, stick a TY91 in the place of the inoperative Narco NAV. You still have the KX155 as a full nav com and broken avoinic should go out. For VFR that is more than enough, GPS e.t.c. I’d go for a handheld with yoke mount or a tablett or Ipad solution.

Last Edited by Mooney_Driver at 20 Apr 22:08

Mooney_Driver wrote:

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.

Mooney_Driver wrote:

regarding the 160 hp upgrade, check it out but I just read that you loose the capability of going MOGAS with that. If so, stay away but get the MOGAS STC, which will save you a lot of money if you fly in Germany particularly.

Yes, the 160 HP versions require 100LL Avgas due to higher compression ratio, while the 150 HP versions were originally certified for 80/87 Avgas and are covered under STCs for alternate fuels.

Also check for issues potentially resulting from crankshaft AD 98-02-08 that applies only to 160 HP versions of the O-320, for no particularly logical reason. Leave the same engine at 150 HP and its not applicable. The AD may not be a major concern if the engine is being overhauled anyway.

Last Edited by Silvaire at 20 Apr 22:35

Mooney_Driver wrote:

http://www.norvic.com/shock-load/
does anyone know them here?

Norvic overhauled my engine – although it was the previous owner that had the work done. The OH was done three years ago, which seems to have gone smoothly, at least according to the paperwork. Under my ownership, I’m very happy with the engine. It runs very smoothly.

As to avionics, if you want to do something while the airplane is on the ground, check out Trigg. They have all you need. My recommendation would be to replace the Mode C transponder you have with a TT31 and, if you want to go 8.33 already, stick a TY91 in the place of the inoperative Narco NAV.

At this point in time I think you have far more chance of getting your engine and prop sorted out long before you will get your hands on a new Trig 8.33 radio. There is a long waiting list.

Last Edited by Finners at 21 Apr 05:29
EGTT, The London FIR

Thanks folks.

Lots to consider here. The lass at the maintenance hangar really knows her stuff and has already looked at the status on the crank AD ( Currently N/a as the engine is 150 hp not 160 ). She has also mentioned that a re manufactured unit would probably be a later spec and could benefit from roller lifters with engine lifetime benefits in the future.

Looking at the Trig TT31, that looks like a no brainer. The matching 8.33 radio looks good too.

Will look into fitting proper yoke mounted push button PTT switches.

Will fit an STC’d USB power socket as these days you can drive anything from one of those.

Did I see a panel mount for an ipad that had an STC? Seems like a good way to go.

It's not rocket science!

The crank AD is a major concern because an affected crank has to be thrown away, and a new one is hugely expensive. On 99% of overhauls you re-use the old crank, which is why you can get e.g. an IO540 overhauled for $35k or so (the US price I paid). If this is the same sort of AD that I had, the Lyco discounts ended in 2009 – details here. A number of people missed out on them and a number were not even made aware of the AD by their maintenance shop… I don’t recall the cost of a crank but from vague memory it is something like 15-20k (6 cylinder; less for a 4) and as a result anybody caught with a bad crank is facing a Lyco factory remanufactured engine as the least expensive option.

The roller tappets should last longer, on infrequently run engines. However engine shop reports are that there is no extra power and any shock load inspection costs a few k more because they are a mandatory replacement item.

Administrator
Shoreham EGKA

Mooney_Driver wrote:

I found a shop in the UK who claims they can do shock load inspections in 15 working days.

http://www.norvic.com/shock-load/

does anyone know them here?

We exchanged an IO-360-L2A for a newly overhauled engine from Norvic two years ago. No complaints, except that they were slow in returning the deposit on the old engine core.

Last Edited by Airborne_Again at 21 Apr 07:50
ESKC (Uppsala/Sundbro)

Silvaire wrote:

Yes, the 160 HP versions require 100LL Avgas due to higher compression ratio, while the 150 HP versions were originally certified for 80/87 Avgas and are covered under STCs for alternate fuels.

Lycoming approved a bunch of (all of?) the 160 hp versions a few years ago to also run on 91UL (unleaded avgas) too, which is available at some GA airfields here.

Last Edited by alioth at 21 Apr 07:56
Andreas IOM

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.

The prop is aluminium… relatively soft…see how much damage a little stone chip makes…a whack on the first half rotation on the starter which sent the tow bar flying seems quite plausible to me..

EGPD / OMDW / YPJT
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