PPRuNe Forums - View Single Post - Air-Refuelling Systems Advisory Group 2010
Old 7th Apr 2010, 22:15
  #42 (permalink)  
D-IFF_ident
 
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Diff would like to see a quantitative analysis of the closure rates Ben There experienced, and the subsequent rates of acceleration/deceleration and seperation parameters. Otherwise it's just another breakaway; a copy of the mishap report might help.

IIRC there have been some collisions between boom tankers and receivers, but I am not aware of any recorded cases where a 'soft kill' of the tanker, by the crew overboosting its engines, have resulted in saving lives. Although I would be keen to read such a report. IT's less of an issue on P&D missions of course.

Notwithstanding the thrust limits set by engine manufacturers (NOT by Boeing or Airbus - who only make the aeroplane to which the engines are bolted), an Airworthiness Authority would have to consider very carefully whether allowing crews to operate outside of design parameters met ALARP principles, to start with. I suspect they would want the crews to stick to the limits; and I would argue that the 'fire or medal' argument is a matter of philisophical difference between operators.

Personally, I have trained and evaluated a number of Tanker and Receiver crews, in Boom and P&D ops, and I believe that while exceptionally qualified operators, like Ben There, might benefit from being able to ride the knife-edge, the average pilot, on an average day, etc, would benefit from protection beyond the edge of the envelope. NB that the Bus allows operation to the limits, just not beyond them.

Specifally for the A330MRTT; there are 3 engine types available and all allow access to maximum rated thrust applicable to the given environment, with protection against shelling-out as Ben There did.

FFP mate - if you press TOGA on your TRC and 'firewall' your throttles - you get TOGA (MCT factored for ram air effect?) same deal on a 'Bus with CF6's - only no visible TRC, just push the thrust levers forwards to the stops. From what Ben There says - if you do the same on the KC135, you get a Class 1 mishap!

You also make a good point that it's the deficiencies of the KC-135 autopilot that brings about the sort of situation Ben There found himself in. Therefore, if Boeing are offering the same standard of automation as the KC-135, then perhaps he has a point, but we would need to assess the, as yet unbuilt, Boeing product before his argument has any merit at all.

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