allison AD for explosion rings

[lamanated]

83 thousand touch it seems...

[Aesir]

I assume you are reffering to this A.D. (http://www.airweb.faa.gov/Regulatory_and_Guidance_Library/rgAD.nsf/0/92E802EF2CAA44EF862570050057FB7A?OpenDocument)

We´ll aint that just great :rolleyes: And I have only about 150 cycles left ´till overhaul.

[Lama Bear]

$87,325,000 is the estimated cost to US operators alone. I wonder what the world wide cost will be for a modification that does not address the failures, just a bandaid to contain the damage.

Read the whole thing, especially the comments and the FAA replies. Somebody is sleeping with Rolls-Royce!

http://www.airweb.faa.gov/Regulatory_and_Guidance_Library/rgad.nsf/0/92E802EF2CAA44EF862570050057FB7A?OpenDocument

[cpt]

This engine explosion happened to me on a AS 355 F some years ago, just on take off to go long lining.
Allison twin sisters where torn off like old tin cans....on top of this they had set everething on fire because of auto relight.

Very lucky !

[fling-wing_1]

So what's going on here? Has there been a rash of failures I haven't heard of? As far as I'm aware the 250 is a bloody reliable engine. We've had nary a peep of trouble with the ones we've run aside from occasional minor issues (e.g. fuel control / governor leaks, etc.) Somebody fill us in...

[SASless]

Times two for twins, right?

[The Nr Fairy]

Any idea if / when the UK will follow suit ?

[Lama Bear]

My understanding, and I'm not a mechanic, is that this has been a SB for over a year.

I would think you will get to pay too.

[Aesir]

I with my very limited mathematical capability figured a much lower cost of $18.880.-

Am I missing something somewhere or what!

If you read the "Cost of Compliance" part then they say:

16 hrs to install blast ring
35 hrs for support assy
20 hrs for 1st & 2nd stage nozzle

71 M/hrs x $65 pr/hr
= $ 4.615.-

$10.765.- energy absorbing ring
$2.500.- for gas support assy
$1.000.- for nozzles.

$18.880.- Total

It´s still a crime but lot less damage than nearly $90.000.-

One commenter requested that RRC should supply parts at no cost, but that was not accepted. Go figure..

Does anyone know what a "Gas producer support assembly" is? Out of 5000 engines on the US registry about 4000 will require this mod. I must assume it applies to the single engine B206B series then, since there are probably not that many 355F series in the US!

Is there any one out there that wants to buy a cheap JetRanger or sell me a recently overhauled 250 C20 that I can use until yr 2011 :)

----------------------

Ohhh...:ouch: I just woke up now! It seems that the total cost is $87 million total for ALL US operators. Just teaches you to read the stuff more thoroughly. Somebody even mentiones it above, just to many 0.. in one number :p

edited to add thinking after coffee.

[sprocket]

Does anyone know what a "Gas producer support assembly" is?

Aesir, the GP support is the first turbine casing attached to the rear side of the exhaust duct.

Dont overlook the compliance time for this AD ...

Compliance

(e) You are responsible for having the actions required by this AD performed at the next time the gas producer turbine rotor is disassembled for any reason, or within 1,750 hours time-since-last- overhaul, time-since-new, time-since-last-heavy-maintenance, or time-since-last-hot section inspection after the effective date of this AD, whichever occurs first, but no later than October 31, 2011, unless already done.

.. I would think most operators will end up having to comply at next overhaul.

[Aesir]

Thanks Sprocket

Do you know if the Gas producer support assy is required for the B206 installation?

Yes thanks I was aware of the compliance time limits but since my 206 only flies about 200 hrs a year a newly overhauled engine would last me until 31st Oct. 2011 without having to do this AD. I assume that the AD does not apply when removing and installing engines, only when work is performed on the gas producer is dissasembled and/or repaired for any reason.

However since I now figured out that the AD only costs about $20.000.- then I guess I might as well have it done when my turbine is due in 150 cycles.

Might be good to have it done. I would simply hate to have that stage one wheel decide to leave the turbine and cut through the tail rotor driveshaft or worse yet decide to go up and pass through the main rotor blade on the way.

Best to have it done :ugh:

[diethelm]

Most C20B's already have an energy containment ring. Check your last overhaul paperwork to see if it has one. You can get the paperwork from the overhaul shop using the Work Order listed in your engine log books.

In the event you do not, In addition to the usual costs associated with a hot section overhaul, you will need to have your GP support modified in order for the Containment Ring to be inserted. If you are purchasing a used aircraft, it is definitely something to check.

AESIR, if you can have your number 1 and 2 nozzle overhualed for $1,000 I need the name of your component repair shop. If you have 1750 hours on a number 1 nozzle in a Jet Ranger, it probably does not flow very well. The number 1 nozzle is right next to the flame so it takes a lot of abuse. There are some PMA nozzles which are pretty good and a lot cheaper than RR nozzles. All Model 250 engines have a GP support. The GP support contains the number 1 and 2 wheels. Technically, if you are only doing a hot section, you can remove the hot section and send it in for overhaul or exchange without sending in the entire turbine, however the safe but more expensive route is to send the entire turbine section in.

[Aesir]

Thanks diethelm

I didnt realise that the containment ring might already be installed but of course it could be.. I´ll check first thing monday :ok:

Ok now I'm starting to understand this deal abour the gas producer support the AD refers to.. so it´s not actually a new support but rather a modification to an existing one. got it now : )


I have all the overhaul/parts costs from the Airworthiness Directive, I have not been quoted yet, by a repair shop.