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ACRO E-mail Archive Thread: [IAC-L:1819] Re: MT3 Prop AD

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ACRO E-mail Archive Thread: [IAC-L:1819] Re: MT3 Prop AD


Thread: [IAC-L:1819] Re: MT3 Prop AD

Message: [IAC-L:1819] Re: MT3 Prop AD

Follow-Up To: ACRO Email list (for List Members only)

From: pilots at

Date: Tue, 11 Nov 1997 21:21:34 UTC



On Mon, 10 Nov 1997, "drew hurley" <attydhurley at> wrote:

>As was posted here recently, the FAA has issued an AD on the MT3 props 
>calling for repetitive inspection/replacement of the hub depending on which 
>model hub you have. 

Just a 'fine' point: Experimental aircraft fixtures (props) are NOT
subject to AD's. An experimental aircraft is never technically
'airworthy' which legally means that it is in compliance with its
type certificate. No type certificate = no "airworthiness" per se. 
No Airworthiness = no airworthiness directive compliance required. 
it might be 'smart' to listen to them, but not required. 

This is why an A&P can inspect an experimental every year. An
IA (Inspection Authorization) is only needed to inspect an aircraft
to be in compliance with a type certificate. Also an experimental
aircraft is never signed off as 'airworthy' by an A&P, only
'in a condition for safe flight'.

The AD is effective ONLY to certified aircraft with this propeller.

>I have a Yak 55M with an MT3 prop less than a year old.

Put back the 3 bladed V-520TA and you'll never notice the
difference. Works good, lasts a long time. You will still
have more thrust than you can use. 

>For some reason I feel somewhat chagrined at having to pay for something that 
>should have been right in the first place.  For some reason it somehow seems 
>fair and equitable that the manufacturer bear the cost.  I haven't heard of 
>any ADs where the users (us) got together and forced the manufacturer who put 
>the bad part on the street to pay for the the AD compliance.  Has anyone?

Nope, and you can forget it. Lots of luck litigating against
(German) MT, as well. Hartzells have repeated AD's as well,
but it is just part of aviation. 

>Am I thinking too much like a lawyer (hard to stop)?  

You bet! Sorry to say, yer shit out of luck ;-).
If this is the least expensive screwing you
take in aviation, you're doing better than me.  
Spend your time sourcing a Russian prop and
enjoy your (nice) Yak-55 without further ado...

See you at Sky Manor? Just got a Yak-55 for myself, at last.

Dave Sutton
Yak-50, Yak-52, Yak-55, Fouga Magister, 
DeHavilland Vampire, MiG-17F (whew..)


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