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View Full Version : Full out-of-trim/stabiliser excursion


twistedenginestarter
31st Jul 2002, 08:55
The IL86 crash is being blamed on the stabiliser. It is not clear whether the plane might have been wrongly trimmed or that the stabiliser ran away after take-off.

Does anybody know what, typically, airworthiness requirements are? I thought for example that you can hold a 747 against fully forward and full aft trim. I'm not sure about other aircraft but my suspicion is you can resist all mis-trim as long as you realise very quickly what is happenning. If you don't apply immediate, possibly very heavy, correction you can be in a stall before you know it.

411A
2nd Aug 2002, 00:53
Older types (707 for example), the elevator was not large/powerfull enough to fully resist a grossly mis-trimmed stabilizer. Newer types, with hydraulic assist/operation, are generally not so constrained. Certification rules have changed over the years.