HEAVY WEIGHT TAKE OFF

This is about my recent flight to JFK, New York, 10 Jul 09. Very heavy weight takes off on the Airbus 340-600. Even though 4 engines used to accelerate the longest aero plane in the world down the long hot Abu Dhabi International Airport runway, it took slightly over a minute to get airborne. The lift off speed was at 167 knots or at about 307 km per hour for 368,000 kg big bird. The Maximum Take Off Weight for this aircraft is 380,000 kg. The lift off speed or the rotation speed (Vr) must be followed strictly in order to avoid any catastrophic disaster. If pilot try to rotate or make the aircraft airborne before reaching the correct Vr speed, necessary ‘lift’ to lift the plane off the ground is not sufficient yet. What will happen then? Rotation means the pilot pulling the control stick aft ward to command the flight control surfaces through the flight control computer to move the control surfaces, the elevator in this case to pitch the plane up. Fly by wire aircraft, does not use cables or push rods anymore. The nose will pitch up but as the lift force for lift off is not sufficient yet due to the low speed, the plane will stay on the ground. Bear in mind A340-600 is 75.3 meters long, the main wheels located at the midpoint. When the nose pitches up, the tail section relatively will go down and due to the length of the plane, it easily strikes the runaway! The plane will get airborne though when it reaches the correct speed. The Tail Strike can damage the structure or make a hole which forms a leak for the aircrafts pressurization. When that happened, no other choice but have to return for landing .This incident happened to an Emirate aircraft 4 months back during take off in Melbourne.

The pitch limit angle is presented as V in this PFD, Primary Flight Display during take off.