One element that was alluded to regarding FW aeros is that an aircraft would have published 'g' limits that should not be exceeded when performing such manoeuvres. Which helicopters have published 'g' limits? Which helicopters are fitted with 'g' meters to monitor the fatigue on the aircraft when performing aerobatic manoeuvres?
I was lucky enough to fly all the Lynx display manoeuvres and the aircraft was limited to a max of 2.7 'g' IIRC and fitted with a 'g' meter. All manoeuvres were recorded in the F700 and the fatigue penalty calculated and applied - thus reducing the life of the components.
I think the 18 hour gearbox that TET refers to may well have been before the 'g' limits were applied.
Does the rest of the helicopter aerobatic world follow similar procedures and if not, why not?
In a FW, 'g' has predictable, calculable effects on the designed life of the airframe - the structure itself is pretty straightforward.
On a helo we have TRGBs and IRGBs on the end of long moment arms which were never designed with aerobatic stresses in mind and engines and MRGBs that were certainly never expected to be rolled upside-down.
The ability of rotor systems to produce massive accelerations in pitch and roll, thus enabling many of these manoeuvres to be flown without chopping tails off would appear to have outstripped the capability of the rest of the airframe to absorb said accelerations.
Having just watched the Red Bull video, the pilot is flying extremely gently in an effort to avoid generating high 'g' and his rolls are beautifully smooth, thus minimising twist on the tail boom. He modifies his recoveries from the wingovers/pedal turns etc to avoid having to pull through the vertical on the recovery, preferring to roll to a nearer horizon and then recover - again minimising the 'g'. There is certainly nothing wacky or dangerous in that display - very nice job
