Flight planning question

[Just another student]

Can any one help me with this question?

Planning a flight from Paris-London for a twin-jet aeroplane.
Preplanning:

MTOM = 62,800kg
MZFM = 51,250
MLM = 54,900
MTM = 63,050

Assume the following

Trip fuel = 1,800kg
Alternate = 1,400
Holding fuel (final reserve) = 1,225
DOM = 34,000
Traffic load = 13,000
Catering = 750
Baggage = 3500

Find the take-off mass.

Answer given as 51,515 kg


The answer that I keep on getting is 51 425kg, which is one of the answers given.

I'm working it out as follows

DOM+Traffic+Trip fuel+Alternate+Holding = 51,425 kg

Where am I going wrong?

Thanks for your help.

[oxford blue]

You've forgotten to add contingency fuel. 5% of 1800 is 90 kg. Add that to your total and you get the right answer.

You can't ignore contingency fuel. You are required by law to carry it. Even if it's not mentioned in the question, you're supposed to add it automatically.

[Just another student]

Doh :O ! I'll know for next time.

Thanks

[Jinkster]

Muppet ;)

"I am not ignorant as I do know 'Just Another Student' well - we all do make mistakes" :E