Gordon Gekko wrote:@horton, do you mean they had loaded the cargo then offloaded it? Or they never loaded it in the first place? If the former, the cargo manager should be fired as loading an aircraft is really basic math. He cost me the shareholder lost earnings as time was wasted and the craft delayed. Given the tight turn around times KQ has on its craft, that means a knock on effect on delayed connections for passengers resulting in needless accommodation costs.
Erm GG, it's not as "basic"as you would think. Too many variables, they offloaded 400 kgs from the B737-800. Here is a few things, B738 has an MTOW(max Takeoff weight) of 79050kgs. But is is at ISA( standard atmosphere conditions) where temperature is 15degrees C, sea level etc. The B738 has a max thrust of 26,000 pounds of thrust per engine again under STD conditions. And the temp has a 2 degrees c lapse rate per 1000ft Above mean sea level.
The variables come into play involving field elevation, temperature, runway length, obstacles etc etc
Out of Nairobi, we are at 5330ft, at 24 C on average, and ur already starting off on the back foot, coz if u apply the STD lapse rate, nbo should be at 5 degrees.
So on that day, they had planned for takeoff at an assumed temp of 24, which is more conservative than what the met guys give. The temp of 24, gave them a TO weight of 79T at the planning stages;However temp increased unexpectedly to 28C on that afternoon, quite unusual for the temp to increase so profoundly, but once in awhile, it does happen, as they say, hard to predict women and weather nbo has a condition know as "hot and high" airports so at 28degrees with such a high field elevation they had to reduce the TO weight by removing non-urgent cargo that went in the later flight. The 4degree increase led to a weight reduction of 400kgs to remain legal for TO. So it was more of a technical thing than anything else.
Just for info, to increase weights, pilots have the following at their disposal:
-lower flap setting
-use longer runway
-use higher rotation speeds, also known as ICP(improved climb performance
-use a runway that doesn't have an obstacle
-wait for the temperature drops
-switch of bleeds, to give the engines the "ooommpfhh" to carry a few 100kgs.
They do the above before they decide to reduce cargo etc.
So the thing was it was a technical restriction and if the temp didn't inadvertently increase, it would have gone.