PPRuNe Forums - View Single Post - Air Vanuatu Twin Otter elevator cable snap
Old 9th Oct 2016, 07:26
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westhawk
 
Join Date: Jun 2005
Location: USA
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Frequent takeoff and landing is believed to have been a major factor in the crash, because of wear and tear on the elevator cables, inspected only at fixed time-intervals, regardless of usage.
In the case of the Air Moorea DHC6, I seem to recall how it was typically parked on the ramp possibly contributing to cable wear as well. Apparently jet blast from taxiing large aircraft would regularly strike the elevator from behind, causing it to move violently. Additionally, the salty tropical environment is not kind to the steel cables. Closer/more frequent inspection and corrosion protection treatments are more than just a good idea in such an operating environment.

An elevator cable break may be more recoverable in some circumstances and airplane types than others. Though I've demonstrated a trim only (elevator free) landing in a C-172 with good results, I'd be less sure about doing this in a larger airplane with higher control force required and/or slower trim. Particularly if it was unplanned and had not been previously practiced under controlled conditions at a safe altitude.

If near the ground and out of trim, things could easily go south before the effect of cranking the trim wheel affected the pitch attitude. Given the typical delay in trim effect while flying stick/elevator free, PIO may result in some airplane types and loading conditions. Anyone thinking that just because it's relatively easy to control one aircraft in one set of conditions would do well to consider that it might not be so easy in other conditions. It pays to know ahead of time!
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