TriStars off into the sunset...?

[Kitsune]

What with the new Lockheed AD requirements (as detailed in the 'Freight Dogs' L1011 thread) it seems that the grey whale might be going (much) sooner rather than later...

AD 2011-27-02 released today

SUMMARY: We are adopting a new airworthiness directive (AD) for certain Lockheed Martin Corporation/Lockheed Martin Aeronautics Company Model L-1011-385-1, L-1011-385-1-14, L-1011-385-1-15, and L-1011-385-3 airplanes. This AD was prompted by results from a damage tolerance analysis conducted by the manufacturer indicating that fatigue cracking could occur in wing rear spar and upper surface zones. This AD requires repetitive inspections for cracking of the wing rear spar and upper surface zones, and repair if necessary. We are issuing this AD to detect and correct such fatigue cracking, which could result in cracking that grows large enough to reduce the wing strength below certificated requirements and possibly cause fracture of the rear spar, resulting in extensive damage to the wing and possible fuel leaks.

[Dengue_Dude]

If it's being monitored, what's the problem?

I was only ever concerned by UNmonitored cracking. We'll see . . .

[Courtney Mil]

But to get to this stage, the cracking must already be pretty bad?

[NutLoose]

Well the RAF don't need spars in them, they have already flight tested one just using the wing skins to hold the wings on.....:O


Also the aircraft were modified by Marshalls and not Lockheed who if I remember correctly at the time said it couldn't be done, so it may be conversion specific.

AD 's like this come out all the time and are normally not a big deal.

[Rigga]

I've always taken great interest in any AD's concerning the types I work with - purely because they are deemed so critical by National Airworthiness Authorities that they make them mandatory. As the RAF in general don't handle "ADs" I believe they don't realise the importance of them, treating them instead as STIs or the like which can be dismissed/deferred as situations/perceptions require.

So, if the RAF is receiving this information, it would be quite interesting to see the tristar PT/CAMO and Marshall's assessments of this AD's applicability to the frames and modifications made....wouldn't it?

It may be applicable....

[Dengue_Dude]

For all the criticism pointed at the RAF, post Haddon-Cave, I don't think anyone is taking ADs lightly, they haven't got cojones that big.

ADs too, really have to look at the worst-case scenario (and why wouldn't they). So it's not surprising in this age of 'duty of care' and vicarious liability, they wish it to be acted on rather than shelved.

We'll see. If it was so dangerous, the AD would say the aircraft are grounded until the AD is carried out. I was not aware that had been said (perhaps 'yet').

[NutLoose]

An AD will have a date it has to be complied with by, either as a one off or as a reoccuring inspection, Civi street wise if this isn't complied with by that date or time period the aircraft is grounded until such time as the requirements of the AD have been satisfied, though there are a few caveats to that.


The AD in question is effective from Feb 2nd, you can view it here

EASA Airworthiness Directives Publishing Tool (http://ad.easa.europa.eu/search/simple/result/)

If you read the AD, it is estimated to cover 4 aircraft on the US register and simply involves eddy current inspections folllowed by repairs if needed. though that does not preclude other aircraft on other National registers either civilian or military being in the serial number range mentioned.


Though the freight dog thread does say there are rumours of another AD in the summer and this has been posted


RAF - L1011
Well finally the word is out that the RAF fleet is going to be retired.
No more overhauls and repairs only as necessary.

Should be all done in 12 months
*

[Buster Hyman]

Lasted longer than the A380 wings! :D

[Kitsune]

Nutloose, the FAA AD is only required to estimate the impact on American registered airframes, not worldwide airframes, hence the low number of aircraft impacted in the AD. However, the AD is mandatory on airframes worldwide. Certainly this is expected to ground all the remaining civilian L10111s due the cost and downtime required for the checks, especially if, as expected, many of them need remedial action...

[NutLoose]

I know how AD's work, not all FAA AD's are adopted by EASA BTW, though in this case I would be suprised if it wasn't.


The thing here though is that unlike a Civilian airline the RAF is not known for doing the normal thing and are not constrained as such by the normal financial considerations of an Airline....... Just look at the one they re spared after it's accident..... Though with it in it's final days, one could imagine that process being brought fwd. One does hope one gets saved, but it is a bit big for a gate and a museum would struggle to maintain it's upkeep.

[Bengo]

From looking at the AD, and without any knowledge of the current life (in cycles or anything else) of the RAF Fleet it is not possible to say whether the RAF will be noticeably affected. The worst case is an inspection within 90 Flight cycles or 30 days from 2 Feb, the best is 7,000 flight cycles or 10 years. Much depends on the exact variant and on when an assortment of LM Service Bulletins having been applied. It would be a surprise if the RAF Fleet is not a relatively low-time/cycle bunch of aircraft so even if they need to be inspected there is a good chance that fatigue damage has not set in.

The AD also notes that AMOC may be applicable, and that will be for the MAA to have a view on, if Marshalls were to propose something.

Since there was a NPRM last year I guess that the various responsible agencies have been thinking about this and it would be no surprise if someone had taken the opportunity to have an informal look at a suitable airframe or two during the servicing cycle.
N

[SASless]

a museum would struggle to maintain it's upkeep.

The RAF is strugglng to maintain its upkeep!

What is the historical value of a Tri-Star? It ain't exactly a Vulcan...Lancaster...or even a C-47 in word or fame.

Make beer cans out of the things and be done with them!

[Rigga]

"...worst case is an inspection within 90 Flight cycles or 30 days from 2 Feb, the best is 7,000 flight cycles or 10 years. Much depends on the exact variant and on when an assortment of LM Service Bulletins having been applied."

The lower parameters normally refer directly to the particular aircraft that have the mandate raised against them. The 7000FC and calendar limits would normally be thresholds to start a repeat inspection regime on low-time aircraft, such as some his/hers private jets.

I would be extremely surprised if the RAF Timmys are below the 7000FC/10Yr threshold, but would not be surprised if the Marshalls Spar/Conversion Mods provided some sort of AMOC to extend the interval of the inspections, but not the intensity of them.

Either way, its up to the NDT techies to get the right findings to keep them going - or to stop them!

This is a Black or White situation, no grey allowed.

If found sufficiently cracked these jets won't fly operationally without some already defined repair action. If any Marshall's AMOC reduces the issue then any subsequent repair requirements will take that much longer to design/complete.

In aircraft maintenance there is always a penalty for any perceived shortcut or advantage - never forget that.

[Kitsune]

Given that the RAF was forced to buy the TriStars from BA to help justify Thatcher's privatisation, they must have done than enough more cycles etc. to trigger the inspections. Having seen the torrents of fuel that pour out of ruptured tanks due to overstressed rear spars in both the Brize incident and the Cathay Pacific incident at Narita in the '90's, (both 'hard' landings), the rear spar is something that is well worth checking methinks...:eek:

[NutLoose]

There were not all BA, some were Panam. The one that had the spar problems had them replaced, they were lying on the hangar floor for ages looking frightning..

[Bongodog1964]

Aren't the RAF Tristars L1011-500's ? all the quoted documents refer to other models

[Sook]

L-1011-385-3 is the official designation for the -500.