Damages to A320 IDG

[Ericgkl]

Hello

I have an A320 IDG that is badly damaged. Pictures are in the URL below.
I am puzzled as to why this unit can be so badly damaged even though it was disconnected. What is likely to have been the root cause? Can this be considered as normal wear and tear?

https://docs.google.com/fileview?id=0B_FoPnbTgCjtNTExMzVhYjUtNjA5OS00YmRiLWIwYTAtY2M xZDFiZjI2NTc3&hl=en

[fredgrav]

it has to be assessed when and why it was disconnected ...

[Swannecker]

I expect it was disconnected as a result of Internal failure. I am sure your IDG Overhaul provider will beable to inform you of the likely cause of failure.....

[spannersatKL]

One observation, I would expect to see some residual oil amongst the 'fine' particles....non appears here? May be no Oil in it?

[lomapaseo]

Looks like it ran severely damaged.

Of course if the shaft was wobbling for quite some time, you might have cracked quite a few parts.

[tech_sales]

Guys, I am actually looking for a unit right now and i couldnt find any in OH/SV cond out there. New one are like half million each. There are plenty of A320s around but no IDG available in the market. Crazy. Just let me know if anybody can help! PN: 1708897

[Fargoo]

They're like the proverbial rocking horse poo at the moment and have been for quite a while.

Does your airline have a spare engine it can remove the IDG from or pool agreements with other airlines for loan parts? Can't see you getting a 2nd hand one as they are in such demand.

As for diagnosis of the above, hard to tell but it does all point to what SpannersKL said - lack of oil.

Terminal block cover cracked could simply be from overtightening on fit or more seriously impact damage when the IDG finally let go.

Not good.

The other part numbers you can try are 772181A or 1706903 (obviously you need to check interchangeability on your aircraft) but both these are rare and new ones have a looooong lead time.

Price - $443,000 new - if you could get one :eek:

You could try SR Technics AOG desk on +44 1279 680 757

or British Airways AOG desk on +44 20 8562 3007 email - aog.desk AT ba.com
Let us know how you get on :ok:

[411A]

Normally...such damage is the result of the pilots inability to take corrective (IE: disconnect) action in a timely fashion.
Some might just sit there and think:ugh: that...hmmm, IDG low oil pressure, and reach for the appropriate checklist, as though this was not an immediate actionable item.
Meanwhile, said IDG is rapidly grinding itself to bits...:{
At one airline where I worked, the individual responsible for IDG status (the Flight Engineer) was charged (salary deduction) for his inability to recognise the problem, and take timely corrective action (IE: IDG disconnect, pronto).

For example, with many L1011 operators, IDG disconnect actions are a memory item (for the F/E)...after a quick word to the Commander, who promptly will say...'disconnect NOW, you fool.'
IDG's are a hugely important item...especially on a two engine transport airplane.
IE: treat with utmost respect, and be prepared for the necessary action in the event of problems.
In addition...for charter opertators, many carry an extra IDG in the fly-away kit (as we do)...a sensible precaution, make no mistake.

NB.
Modern transport jet airplanes are....electric by their design so...make absolutely sure that you have the electrics available, to complete the flight properly, otherwise, you might find yourself up the creek without a paddle.

Was this true of old(er) time designs?
Yup, sure was.
The Lockheed ELECTRA, comes to mind.
Big time.
The name 'Electra' was not without some thought, and systems design, accordingly..:}
Elecrtrics?
Yup, and if not, dead as a doornail was a distinct possibility:sad:

[PJ2]

Ericgkl, tech_sales;

Not sure if the following is helpful in explaining if damage to the IDG can progress upstream from the disengage solenoid into the IDG drive itself. At first blush it would seem that the unit or the installation would self-protect from such catastrophic damage but perhaps not.

From FCOM 1.02.24 (or thereabouts in others' FCOMs), Abnormals:
ELEC IDG 1(2) OIL LO PR/OVHT

– IDG (affected).................................................. ...................... OFF
If the associated engine is running, the IDG (integrated drive generator) must be disconnected from the engine at, or above, idle to prevent damage to the disconnect mechanism. Press the IDG pushbutton until the GEN FAULT light comes on. However, do not press for more than 3 seconds, to avoid damage to the disengage solenoid.

The IDG FAULT light goes off, when the IDG is disconnected.

One generator remaining on an electric airplane is a serious matter.

However, the A320 (as most know) has the 5 KVA Emergency Electrical Generator which is hydraulically-driven by the Blue system, and two 23-amp/hour batteries to run the hot buses which are supposed to keep you alive for 30 minutes through the TRs.

And then, so long as the airplane has hydraulics you can fly it on differential thrust, rudder and manual stabilizer trim. I've talked with someone, (FAA certification guy) who's landed the airplane using this method and he said it worked fine and was easier than the sim... ;-)

PJ2

[cod liver oil]

PJ2,

wouldn't procedure call to light up the APU in the event that you lost an engine generator?

just curious
cod

[PJ2]

cod...absolutely, thanks for mentioning it - the QRH calls for it as well. And I think departing with a u/s APU requires some careful thought even though the MEL may permit it...

PJ

[Swedish Steve]

British Airways AOG desk

BA is short of IDGs at the moment.
One was robbed from an aircraft in the hangar this week due nil spares.

[JenCluse]

PJ2

Your FAA certification guy obviously had very many training runs in the sim to even attempt* a real landing in that grossly depreciated control mode. Hydraulics? Oh. You need hydraulics too?. Gosh, I wonder if that belly bomb/fire/tyre blow has managed to miss the hydraulics?

On my initial A320 way back, 10 out of twelve med/high time skippers pranged the sim in that mode. One long time DC9 skipper (old friend) was so out of touch with underslung engine pitch/pwr coupling that he couldn't crack it, was failed, took to the bottle, and finally killed himself after the wife walked out. That's another form of pwr coupling.

I won't go into why anyone would design an aircraft like this when the Vickers Viscount 900 /a.k.a. DC9/ aka Boeing 717 use(d) unpowered direct coupled floating servo controls and were totally and absolutely 100% controllable under all power (or non-pwr) situations, but I was so very glad to have the Oz pilot's dispute see me off the A-320. I said then, and stand by what I said now, having been a radio erk before I flew, that when things started to wear on those beautifully cockpit-ed (sic) aircraft, and the connectors, connections & hydraulics started to corrode, as well built as the aircraft were it would be good to be somewhere else other than on an Airbus.

Whoops. Sorry. Just had to get that off my chest.

Everyone back to the thread.

[PJ2]

JenCluse;

I'm happy you feel better, and I'm happy you're off the A320. Some just don't belong on the airplane.

As for cables and pulleys, I flew the DC8 and loved the airplane, same with the DC9, B727, Lockheed etc and flew the A320/A330/340 and loved those airplanes too. In the business, progress is as progress does; we can go along for the ride and learn to understand an airplane or quite reasonably choose cables, pulleys, tabs and servos forever. That's the magic of the business.

For me, as for many, the 320 worked extremely well, but I refused to listen to the mandates to engage the automation at 100ft and disengage it after landing. I know even then that the 320 doesn't work well for everyone.

As for the last kind of landing I described, of course it can be a mess - that's obvious, just like Sioux City was a mess. And if you have no hydraulics and no electrics, like in most airplanes, you're almost always toast.

But the emergency procedure was part of our initial training and, quite frankly, almost all of us got the thing onto the (intended) runway in one piece though a few gear replacements would've been needed! That was the sim. We all know that the airplane flies and behaves much better than the electronic sim version.

As for my FAA friend, I can only repeat what he said when we discussed the technique when the airplane first came out and all of us had questions and Airbus wasn't answering any of them. It was a long time before Airbus actually began listening to the end-users' questions and suggestions so we turned to those who did the actual testing and who didn't mind actually talking with the unwashed.

Yes, back to the thread!

PJ2

[Fargoo]

Swedish Steve said

BA is short of IDGs at the moment.
One was robbed from an aircraft in the hangar this week due nil spares.

Maybe our Miami parts hunter phoned our AOG desk and we're now making a packet from the one removed from the hangar aircraft :hmm:

Since he hasn't come back and thanked us for our efforts, I guess he found one somewhere :rolleyes: