The Danger with Rapid Rotations
Discussion came up over coffee about the rate of rotation used by some pilots. F/O said he was consistently amazed at the fast rate of rotation of one captain in his company flying 737NG variants and couldn't understand why there had not been a tail-strike so far. He felt that a comment would not be received gracefully so merely gritted his teeth.
Some years ago I transferred to another company flying the 737-200. The chief pilot criticised my rotation rate as being far too slow (in his opinion) and warned this could compromise obstacle clearance with engine failure. I was surprised at this as no one had criticised the rotation rate before because I had stuck strictly to the one potato - two potato up to 15 degrees.
Over the next few sectors I then observed carefully the rotation rate of the crusty old chief pilot of my new company and stopwatched him consistently on 2.5 seconds from Vr call to 15 degrees. As it was a -200 then wasn't much danger of tail strike but a high speed stall at that rate of rotation was a danger particularly at Flaps 1 take off.
The CP did not believe me when I said he had been timed at 2.5 seconds from Vr call to 15 degrees up and I realised he honestly thought he was doing the job at the FCTM ideal of 3 degrees per second.
So apart from the possibility of a tail strike, how dangerous are rapid rotations? In the early years of 737-200 operation, there were several documented instances of sudden pitch up and wing drop on Flap 1 rapid rotations especially if there was traces of frost or ice. This led to Boeing advice that if ice was around it was better to use greater flap settings or improved climb speeds to give a greater stall margin and also to ensure rotation rates were as per FCTM.
I believe that some pilots are quite unaware of their fast rotation rates aalthough one would think a diligent instructor would spot their bad habit during simulator training. For all the 737 variants there is a momentrary pitch force change around 10 dgrees body angle due to the tailplane encountering ground effect and it often results in a slight hesitation at 10 degrees before normal stick force returns. Some pilots will either unconsciously or deliberately force the rotation through that area and maintain this additional pull right through to the nominal 15-18 degrees. This results in a rapid rotation before the pilot is aware of it. A rapid rotator should be picked up in the simulator because it is a habit that is hard to crack. It begs the question should a pilot who is a rapid rotator be subject to a comment by the other pilot who may consider the manoeuvre potentially dangerous? Or do you play the shrug your shoulders game and keep quiet? Comments welcome.