It means that runway information is not standardized even within JAA.
Two questions are affected:
(1) Will it affect max weights?
(2) Can reduced thrust be used?
It might affect weights of large heavy aircrafts. It will not affect the weights for a normal 737CL or NG because the runway at EDDM is 4000mtr.
Most airlines use computer runway analysis from EFB, FLT OPS or a vendor. These are based on Boeing Airplane Flight Manual-Digital Performance System and will give numbers that are less conservative than the QRH and cost saving reduced thrust when permitted by regulations.
Reports such as "runway dry and braking action good" or warnings such as "slippery when wet" are of little use unless the person who makes the note use the same terminology as aircraft certification rules and manufacturers performance definitions. Reduced thrust takeoff will save millions for your airline. It should be used when conditions permit. Unfortunately well intended non standard reports can make it difficult to determine if it is safe to make reduced thrust takeoffs. Not a problem if it happens a few times each year. Big problem if it happens on a daily basis.
Wet or damp runway – may use reduced thrust but reduce V1 on short runways
Standing Water (more than 3 mm depth) - reduced thrust not permitted
In the EDDM example a maximum assumed temp takeoff with wet runway would give a medium weight B737NG 2300 mtr stopping margin* and about 1300 mtr stopping margin at MTOW.
(*) Stopping margin = runway remaining after the aircraft stops following RTO at V1. No credit for reverse thrust on a dry runway/reverse thrust is on for wet as per FAA/JAA approved calculations.
Last edited by 80/20; 17th October 2004 at 09:39.