View Full Version : Comair 737-200 T/O
Can anybody please tell me why Comair's 737-200 uses alot more runway on the T/O than most other 737-200?I've noticed this lately at JHB!
goblin
17th May 2003, 03:57
Hi there
Did you maybe notice any of the aircraft's registration? Some have old -9 P&W engines - or maybe they are just carrying heavier loads than the competition.;)
Gunship
17th May 2003, 09:50
Certain Crew Members needed a "bit of adjustment" around the waist line the last time I have seen somebody for REAL from Comair in cockpit ... :p
REAL ORCA
17th May 2003, 15:11
Eina!. Gunns I owe you one!!
The Comair aircraft do of course carry heavier loads and no, it has nothing to do with the weight of the pilots either!
At higher airfields elevations like JHB and WHK with long runways you are given an option in the T/O performance data to use a set of parameters which is called the Improved Climb Performance data. This in short allows you to lift more weight by increasing your V1, V2 and Vrotate speeds and still make your climb gradients as required by law. This obviously increases your T/O roll distance - It is the penalty you have to pay. This is obviously only nessasary if your weight is above a spesific limit because you do put more "pressure" on tyres and should a T/O rejection occur at V1, it is guaranteed (spelling) to :ooh: .
To answer your question - The Comair aircraft probably had a heavier load and was using Improved Climb data whilst the other aircraft was using normal performance data.
Maybe the Boffins would like to expand on this subject.
REAL ORCA has hit on one possible reason, another one could be the use of "reduced takeoff thrust". JNB has an extremely long runway on which a B737 wouldnt be field length limited. In order to increase engine life you can trade that excess runway length into a takeoff power reduction of up to 25%.
Makes for longer takeoff rolls, but perfectly safe.
Mutt