VC10

[RetiredBA/BY]

On the BA VC10s aileron upset was used at weights above 132 kg ( wing bending relief) Did the RAF tanker VC10
have this requirement removed when refuelling pods were fitted ?

[BEagle]

No, it was still needed.

In the latter years of RAF service, complex rules about when to use aileron upset were introduced following BAe assessment of fatigue management. Graphs in the pilot handbook showing upset domain against weight and altitude; this meant some quite odd flight levels would be used to avoid protracted cruise burn penalty with upset applied - which were different for all 4 marks. I don't know the logic behind that, but it's what the boffins had calculated to keep our creaking old jets flying until 'FSTA' was due to be in service.

In its final time, the VC10K2 (third hand Standard VC10, ex-BOAC and ex-Gulf Air) could be limited to as low as FL170 after take-off at max AUW until fuel was burnt off... This in 1999 I was able to fly a K2 from MPA to ASI, then 8:30 the following day direct to Brize. Such was the reliability of the VC10K by then that we really didn't want to risk more landings than were strictly necessary! I vaguely remember that we climbed to FL170, then as weight reduced crept up to FL250, then stayed there until we could make a higher level without needing to re-apply upset. The other pilot (OC 101) suggested AAR to top up as we headed north, but the navigator (Snake to those who know him) and I showed that this would be pointless as we'd be stuck at FL170 for ages.

Such was the clever :hmm: design of the VC10K2 that it was very nose heavy at MTOW and the TPI was right on the edge of the TOCW limit. Buffet speeds were also higher than for the Supers and we didn't have 14.5 flap. Also aileron upset began to apply as soon as the flap lever was in the 'up' position on the K2, whereas for the others it applied only when the flaps travelled through about (10?)°. The centre of pressure moves forward when aileron upset applies, so on clean-up you had a n-u pitch moment due to aileron upset, a n-u pitch moment due to acceleration (which was slow due to the high TPI) and a higher flaps up safety speed to reach - all combining to make the aircraft quite a handful if the pilot didn't concentrate on trimming... A mate of mine once elected to let a student crew depart from RAFG whilst monitoring from the 5th seat. The student captain (probably with a hangover, knowing him...:uhoh:) didn't trim properly and ended up with 45° AoB in IMC needing both hands on the yoke to contain the pitch moment until some 'helpful words of advice' were proffered! He Learned About Instructing From That!

[sangiovese.]

IIRC upset in the C1K started as the flaps went through 14.5, ahh the K2 and the 1.15g margin to buffet graphs at max AUW

:ooh:

In fact pre SFI changes upset in the C1 was above 290 000lbs and FL240 (gawd that was pre 98ish!)