There are many advantages to SETO as I’ve said before.
Reduced engine run time (especially useful for “power by the hour” leasing contracts).
More fuel available at destination (the safety advantage you scoffed at). Twice in my career I’ve ended up with less fuel at destination than I wanted with everything looking fine at ToD, both times I was very happy to have the extra 100-200kg I’d saved on the ground on departure.
Cooler brakes at places like EDDS and EDDF.
And reduced fuel costs and environmental benefit.
Our data is produced by knowing the average fuel burn for the time from first movement to setting T/O power for a two engine taxi and subtracting the actual fuel used by both engines and APU burn. It’s pretty accurate.
Your point about the fuel saving not being just the difference between eng 1 and eng 2 burn at the start of the take off roll is noted and correct but the saving is still significant and our data is cleverer than that.
It’s not always appropriate to perform SETO. It’s prohibited for us with contamination and some MEL’s. For workload management I start early before crossing runways (eg LEBL).
We perform the after start checklist as normal for both one and two engine taxi, then start no. 2 using read and do from the QRH, no memory actions.
The QRH also contains extra info like checking the accumulator pressure prior to push as it won’t be supplied until the y elec pump goes on as part of the after start flow to ensure brakes are available in case of tow bar separation in the push. Also turn no corners between y elec pump off and five secs after eng 2 master on as the yellow system could be unpowered potentially causing temporary loss of the NWS.
This job is all about risk / reward management. Done with thought SETO rewards far outweigh any small increase in risk.
ATB
LD
Last edited by Locked door; 11th Apr 2024 at 15:18.