Full out-of-trim/stabiliser excursion
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ENTREPPRUNEUR
Joined: Jun 2001
Posts: 577
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From: The 60s
Full out-of-trim/stabiliser excursion
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.
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.
Joined: Mar 2000
Posts: 8,571
Likes: 3
From: Arizona USA
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.
