I have asked in this forum several times about the minimum oil quantity that is required to be in the engines to ensure a safe flight.

I got no answers here, so I went online and I wish to share it with you so you all know when to refill oil or at least why they need to be above a certain minimum for safe flying.

 

B747-400 GE engines: min. engine oil: 16 QTS on the ground with engines off

 

B777 RR engines: min. engine oil before engine start: 18QTS

 

hope it helps virtual pilots

Thanks for your research :)

Sorry for bringing up this old thread. I've also done some digging. It seems the figure for 744 RR engines is 19.8 quarts (see p.20 in https://www.easa.europa.eu/sites/default/files/dfu/TCDS_RB211-524_issue 02.pdf). I'm not sure whether I interpreted the units correctly though (it seems to suggest 39.6 lmp pt in the document).

 

Just my two cents.

my data was from the GE engined 744, so thanks for your research!

It’s interesting that Boeing use to have a min oil quantity as a limitation but sometime ago it got removed and was left up to the operator to decide. For example our company SOPs got changed to Minimum OIL QTY for flight.

However in our Maintenance Engineers SOP manual it stated OIL QTY will be checked full before flight. It was then up to the Captains discretion if departing to a destination without an engineer present for the turn-around.

However all ETOPs flights require engineering signoffs and full oils including the APU.

IM