Originally Posted by
crispyking
I'm no heli expert, and only a low-hour PP without any instrument rating.
I imported the flight path kml into google earth and tried flying it with the (admittedly rough) SR-22 simulation at the approximate speed. That seems like it is one very steep 180 degree turn at that speed.
I'm guessing that IMC was almost certainly anticipated by the pilot by that point and the climb into clouds and 180 turn was an expected (if not fairly routine?) manoeuvre for an IFR-rated pilot. It certainly looks like the turn was initiated with plenty of altitude to clear the hills (which the pilot would have known if he was familiar with the route). It seems like a fairly routine SVFR flight into IMC at that point (if that can ever be called "routine". I'm no expert -- can any S76 IFR pilots comment?)
The question for me is: why was the 180 turn so steep? I'm guessing that it was at near 90 degrees of bank which gives a useless (horizontal) lift vector and I'm guessing would entirely explain the descent and CFIT.
Possibilities:
- He didn't transition to instruments and lost attitude awareness. Seems implausible for an IFR-rated pilot. Just watch the artificial horizon, ASI and altimeter.... Is this kind of IMC transition really that hard for an IFR-rated pilot?
- The artificial horizon was malfunctioning or lagging, and he was unaware of his bank angle...
- He deliberately made an aggressive 90-degree bank turn (because now everyone is really late) without anticipating (in time) the lift-vector consequences... It has happened before (e.g. Siggi Hoffmann BO105). He probably would have realized it within a second or two, but too late to recover...
Any thoughts?
A Climb into cloud and a 180 degree turn is not the norm for an IR rated pilot, no.
as for lift vectors ? Nope
your questions?
1. He was svfr and most likely caught out by going imc low level and the turn was probably his last attempt at getting back visual. Not just a case of jumping straight on instruments in that situation at that height.
2. nope
3. nope. Siggy Hoffman was a different issue not lift vector issue if I remember correctly. More a cyclic limit factor known about in the 105.
best not to speculate and wait for the report