A-320 IAE IDG drain mast oil leak

[Jimmy Hoffa Rocks]

For maintenance engineers and piltots please

During pre flight inspections on the A 320 IAE motors found a small oil leak out of the IDG hole of the drain mast.

According to the Airbus, with this oil leak, you must do a test with the engines in idle, to see if there are more than 3 drops of oil per minute.

Before doing a flight the engines in idle test with qualified maintenance engineers this seems the only way to be sure.

Does anyone have any more info on this ?

More info than what the FCOM says on the IAE drain mast, sump, etc,

Thanks in advance for your help:ugh::confused:

[Zaphod Beblebrox]

I have limited knowledge of the IAE engines however on the CFM models leaks of oil and or fuel can be common. This is most likely to occur after an extended shut down period or overnight. I have had to motor an engine on several occasions prior to push back to ensure the leak has stopped.

Maintenance has several theories on CFM leaks. Our fleet is mixed and we have some IAE but I have not flown that version. Some Maintenance techs are of the opinion that they observe more leaks in windy conditions. If the aircraft is parked with its tail to the wind the fans spin backwards. The theory is that there may be some very slow movement of the inner spool which causes the seals to lie the wrong way. They are cold and less pliable. This is especially noticeable in the winter. Once the engine is started the seals are aligned properly and the tighten up and the leaking stops.

In your situation it may be that the IDG was over-serviced. It is a normal overnight maintenance check at a lot of carriers and sometimes the IDG oil filler neck is not easy to get to or it is easy to over-service. The old Prat's were very sensitive to CSD overfills.

I can attest however that both IAE and CFM use a leak rate check after the engine has been run of determine if the engine and aircraft are able to be dispatched. That is the only maintenance action required.

[grounded27]

The leak may come from the cavity between the IDG and the gearbox, usually a carbon seal, they can leak staticaly. You are correct, if the approved doccument allows for 3 drops per minute at idle, a run while monitoring by qualified personell would be required. If this is the leak I am thinking of it would be most likely engine oil, not IDG oil. 3 drops is hard to measure, often with similar leaks we would tape a bag to the dripping line to collect the leakage.

[Tinwacker]

How much oil did you observe coming from the drain mast..??

I don't have the FCOM at hand so do not know what instruction was placed for you to comply with - call the engineer I guess..
Being practical the oil leak would have to be positive and not a weep or stain, before I run the engine.
The oil will come from the cavity but could be either gearbox or IDG seals, both have a limit of 3 d/min or 10cc/hr.
Shouldn't be over servicing as the servicing of the IDG will have a fill tube and a drain tube attached to ensure the correct quantity.
As mentioned, after an engine run seals will be bedded in and if it was statically leaking no oil will show in the collector can attached to the drain mast, then good to despatch.
Even if you were worried about this oil dripping, 25hrs or 10 cycles should get you home after re-checking the IDG oil level.
AMM 71-70-00-600-010 for light reading..
Finally call Maintenance Control if the leak was well over limit, as 6 d/min is still 20cc/hr and depending on your flight range will get you back to base for final fix, unless you are stuck in Bali.....:ok: