Partially true BOAC. But, as is often the case, things aren't so simple. I was trying to keep it simple & my statement that you shouldn't be touching down below Vref +5 was technically incorrect - sorry.
The following is basicly what the FCTM says (in my words) -
*If you are carrying a gust correction, touchdown should occur at Vref + the gust additive.
*If there is no gust additive touchdown should occur between Vref & Vref -5. This is stated in the 'Landing' chapter of the FCTM.
*Touchdown should occur at no less that Vref -5. To use Boeing's words - touchdown at lower speeds seriously reduces aft fuselage/runway clearance.
The speed will start to bleed off as the power is reduced during the flare. With the A/T engaged, the thrust reduction starts at 27', if memory serves me correct. With A/T not engaged, the FCTM states that the thrust levers should be smoothly reduced towards idle at the commencement of the flare, aiming to have the thrust levers reach the idle stops at the same time as main wheel touchdown.
So 50' is perhaps a little high.
Also, the indications are that you can expect a 5 to 10 kt reduction in speed during the flare maneuver. So perhaps it would have been more accurate to have stated that if you are carrying Vref + 5, you maintain that until the commencement of the flare.
I must say that in my experience most people carry too much speed, too far into the flare - particularly with flap 40. So BOAC's technique has merit. However, if you use the correct speed, get the thrust off at the correct point in the flare & then actually flare the aircraft, it will land quite nicely - main gear first, rather than in a 3-point attitude where the nose gear touches down at the same time or immediately after main gear touchdown.
However, if you have misjudged the height of the flare don't keep flaring to get a smooth touchdown or you risk a tail strike or even going off the far end. Just put it on.
Last edited by Oakape; 8th Jun 2010 at 12:11.