Hello,
If one engine fails lets say at FL410, driftdown is required to lets assume level 210 with speed 247 kts. For non Etops operations (B738), lets assume we have a suitable enroute alternate too within 60 mins flying time with single engine. My question is how this sixty minutes is calculated. If one engine fails (ENG no 1), then can Eng no 2 use left main tank fuel? This may sound stupid but this is really bothering me. There is no transfer in air for 738s. We are not opening the crossfeed valve (checklist doesnt say so) so how Eng no 2 uses fuel from tank no 1? Also why fuel burn increases other than the fact of Low Altitude? If Eng no 2 can use fuel from tank 1 then why theres a fuel restriction for single engine operation? Thanks for answering.
Yours sincerely.