Old 27th May 2019, 00:18
  #32 (permalink)  
Join Date: Mar 2002
Location: West of zero
Posts: 240
Aser, indeed...

From 11 years ago:
This is something I posted in a discussion on an R44 accident that was labelled LTE.
There is one phenomenon I’ve never seen addressed in these “LTE / LTA” accident investigations that most of us, certainly those who have spent time giving primary instruction are familiar with. It has no “official” name but my vote would be FOC, for

Freezing on the Controls.

From my own primary flight training efforts I recall (with cheeks burning) those occasions where despite my pushing that left pedal for all my 200 lbs. was worth the nose merrily kept trundling to the right – until the instructor took over, I lifted my trembling right leg off the pedal, and miraculously another 2 or 3 inches of pedal travel materialized.

I experienced an even more extreme example of this while giving instruction a few years later. My student was a slightly-built PPL rated gentleman in his 60s; I was in my 30s and outweighed him by over 50 lbs. Nevertheless, on several occasions after I called “I have the controls” I could not budge any of them – not the pedals, not the collective, not the cyclic – because of how tensed up he was. I terminated the lesson early because I was afraid we’d crash while wrestling for the controls; next morning he flew with another instructor who outweighed me by about 40 lbs. thanks to his weight-lifting hobby, and despite my warnings about this student he thought the pedals had jammed the first time he tried to take over.

These experiences have led me to believe that in a lot of cases where the accident report read “despite application of full left pedal” it should have read “despite the application of what the pilot believed to be full left pedal but was somewhat less than that”. Typical scenario: low-time and/or out-of-practice pilot, already somewhat tense, tail- or cross-wind hover, a little gust and the nose whips right, pilot really tenses up then pushes the left pedal, but against his tensed-up, immovable right leg, pilot now believes he has full pedal in and why doesn’t this spin stop? The remedy here would be enough clarity of mind to consciously lift the right foot off the pedal, but in a high-pressure and rapidly-changing situation, that’s an awful lot to expect from a relative neophyte. If the investigators asked “did you have your right foot on the floor?” and the pilot answered in the affirmative I’d have to believe he really had full left pedal in, but so far I’ve never seen this confirmed either way in accident reports.

As for my personal experience in type: in 250 hours in the R44 including hovering in and out of ground effect in any relative wind angle, I’ve never encountered the pedal stops. The tail rotor authority was always excellent. Please note that “twitchy in yaw” is not the same as “poor tail rotor authority”.

If the subjects of discussion are “Gazelle” and “fenestron stall” replace left with right and vice versa in the above.
Then recently I saw an in-cockpit video of a B206 accident, which rolled over after spinning out of control during taxi. A fraction of a second before ground contact the camera happened on the pilot's feet and the pedals were neutral.

All this led me to conclude that the first step in an LTE/LTA scenario should be: take your right foot off the pedal.

My roughly 1300 hours of flying B206L models at high-ish DA (up to 10,000 ft) showed that what we were told during training was correct: "Lead power application with up to full left pedal".
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