A300 grounding by FAA

[Kut Lunch]

Just seen on CNN that all early airbus A300's have been grounded until the thrust reversers are deactivated in-flight.
Anybody heard more??
Is this to do with the vertical stabiliser and crash out of New York??:confused:

[LGW Vulture]

Kut

Nothing to do with A300-600.

AD stems from CF6-50 thrust reverser deployment in flight, which happened to Northwest DC-10 a while back.

Thus, only aircraft with these engines, most notably DC-10 and A300 B2/B4 are affected.





If life were only bizjets...........

[tinyrice]

So are DC10-30's also grounded?

[sky9]

No; they are American :D

[tinyrice]

Actually no. It's because they're not covered by FAA AD 2002-08-51E issued 08Apr2002. It only covers A300 B2 and B4 aircraft.

[stanley]

A300 are ok to fly as long as the thrustreversers are locked out

[WorkingHard]

If the DC10 has the same engines and configuration ( I have knowledge of neither) would anyone like to speculate why the rules are not applied even handedly?
sky9 you have a theory?

[Flip Flop Flyer]

I have searched the FAA website but have found nothing. Maybe someone could point me in the right direction ? I work for an european airline which relies rather heavily on a fleet of A300B4s. That prompts the question whether a FAA directive would have any effect on non-N registred aircraft. Presumeably a world-wide grounding of the A300B2/4 fleet would have to come from the french DGCA, and not the FAA. In the same way that the DGCA would not be able to impose a worldwide grounding of, say, the 737 classics.

But first of all, can we have this rumour substantiated. We have a US affiliate which also operates A300s and any grounding, or TOW restrictions due inop thrust reversers, would have rather nasty implications for our customers.

Puzzled :confused:

[stanley]

the european CAAs sent out a directive to deactivate the reversers before flight .no other restrictions .

[Nopax,thanx]

It's to do with a dodgy valve, apparently. Subject item was installed on a DC-10 in 1999, but had been incorrectly assembled. Caused an uncommanded deployment of the reversers (possibly only partial, as the aircraft did not suffer an extreme loss of control, as the Lauda Air 767 tragically did a few years ago)

Now, why it did not fail on installation is a mystery, but that's the situation as it is at the moment. Presumably once any suspect valves have been identified and isolated, the restriction can be lifted.

[Flight Detent]

No mention of the B747s fitted with the CF6-50 engine?

I happen to know that AHK operates three of them into European airspace, via the Middle East, from Hong Kong.

Cheers

[Volume]

The thrust reverser is not part of the engine but part of the nacelle. Airbus A300 B2/B4 Nacelle was adapted from one type of DC10 (the long range version if I remember correctly), designed and built by Rohr.
Therefor the 747 equiped with CF6-50 are not affected, beacuse nacelle design and manufacturer are different.

[LGW Vulture]

Excellent information Volume......thanks

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

The optimist says, I hope he maintains airplanes I fly on
The pessimist says, I hope he doesn't make entries in the tech log with spelling like that!!!!!!!

[lomapaseo]

>It's to do with a dodgy valve, apparently. Subject item was installed on a DC-10 in 1999, but had been incorrectly assembled. Caused an uncommanded deployment of the reversers (possibly only partial, as the aircraft did not suffer an extreme loss of control, as the Lauda Air 767 tragically did a few years ago)

Now, why it did not fail on installation is a mystery, but that's the situation as it is at the moment. Presumably once any suspect valves have been identified and isolated, the restriction can be lifted.
<

Not exactly correct. The valve in question is a redundancy against deployment and as such its failure "allowed" the in-flight deployment to occur in combination with another fault. The authorities expect at least one redundancies to work all the time. In this case the faulty valve, was installed with an unknown latent failure against its single most important task. Such a latent failure in combination with at least one other form of revreser lockout is sufficinet to provide against an unanted deployment, However, should the primary means of guarding against in-flight deployment fail, then this valve has to work and it apparently didn't due to its unknown latent failure.

Either there must be a routine way of checking for hidden failures (lots of luck) or the reliability of each device must be of a high magnitude to make it unlikely that unwanted deployment will occur. So far the industry has not met this requirement with most current reverser so the authorities are requiring all new designs to add yet another line of redundant defense (which will probably also have some latent failures)

On another issue, since the problem was discovered in a Boeing product, it's typical that the corrective action was already employed in the DC10 fleet.

It probably took the JAA a tad more time to figure out that even with the diference in the nacelle reverser design, that with the same dodgy valve, an unwanted deployment could still ocur on an Airbus even though there had never been a failed valve found in that fleet.

[blue ice]

As I understand it the A300 was dealt with first as it is a twin and the control problems associated with a T/R deployment would make it more of a challenge that if the same thing happened with the old diesel 10.

The difference between the 747 and the DC10/A300 has nothing to do with the nacelle, or T/R structure.

The 747 T/R is exactly the same structure as the A300/DC10.

The ACTUAL diffence is the installation of a mechancal throttle interlock on a 747 'build' T/R halves and the installation of a T/R pneumatic limit switch on the engine, which limits the max N1 in reverse.

The mechanical interlock cam is fitted to both T/R halves and releases the throttle mechanical interlock in the same way as the pneumatic interlock on the RHS of the A300/DC10 T/R. This means the eng cant accel in reverse until both sides have deployed, unlike the A300/DC10 which rely on a pneumatic interlock on the RHS only, hence poss acceleration with one side out of position

[LGW Vulture]

Mr Moderator

I feel a move to the Engineers and Technicians forum is now well and truly overdue!

Lord.... spare us the main forum.


Q. What do you call an Engineer in a suit?

A. The Accused!



..........If life were only bizjets!

[Nopax,thanx]

Thanks for the insight, lomapaseo...that would explain why the faulty valve didn't show until recently. Much more action to follow, I guess.