Originally Posted by
John Citizen
Is this a common bush technique which works well in other turboprops (Twin Otter) but not so well in a Dash 8 ?
I was told to never even think about twisting the grips to go past the low pitch stops in the Twin Otter in flight. I only heard rumour that someone had tried it and there was a loss of aircraft control more to do with aerodynamics of airflow, perhaps over the tail. Perhaps right in the flare, this procedure might get done on offstrip landings.
I dont think people realise you can be in beta RANGE without selecting reverse, they are not the same animal.
I think every person who has flown a PT6 powered aircraft has been in Beta RANGE totally legally. Beta RANGE is when the prop speed is controlled by the power lever, i.e. taxi, and often on final approach. Beta range is not the same as reverse range, however the reverse range can also be considered in the beta range.
Alfa RANGE is when the prop levers control blade angle.
Correct,
At the finer pitch range at low power settings, the aircraft is in what is known as Approach Beta which simply means that Power lever movement is controlling blade angle. It could be from 10-17 degrees blade angle but I don't have the manual handy at the moment.
Originally Posted by
Hugh Jarse
I'm not going to comment on the crew actions, but in response to the second paragraph of your last post I have to say that with the Dash 1 to 300, it's common knowledge among its pilots that "if you can see it, you can land on it". By that, I mean that if your landing runway is in view, any combination of flight idle, condition levers max, gear and flap will get you safely (and stable) to your proposed touchdown point without exception.
In over 6000hrs on the Dash, I never had to go around because of being too high/fast. The aeroplane is just so versatile and easy enough to fly to enable a stable approach in many unusual situations.
Thinking about it now, the accidents that I can remember off the top of my head were on the Fokker 50 and Saab 340 which has a GE engine. I flew the ATR and it seems similar in being able to get down quickly with those prop blades at flight idle.
In this accident, it appears that the scenario was different with a desire to get below a CB cloud combined with an overspeed.