B747-400
Flight Crew Last 90 Days 160; Flight Crew Total 9000; Flight Crew Type 5000
Communication Breakdown; Physiological - Other; Situational Awareness; Time Pressure
Deviation / Discrepancy - Procedural FAR
General None Reported / Taken
Company Policy; Human Factors
Diverted to a foreign airport for destination weather below minimums. Called Company Crew Desk to ask about duty day contractually and FAR's. Noted pages of contract we felt applied. 747 Crew Desk person said we had even 2 hours extra of crew duty day and must continue to our destination. We were all tired and asked again about if we were legal for FAR's and contractually. Crew Desk said yes. Took off without enough duty day to complete flight. Total duty day was 19:40 and limit was 19:30. Violation of FAR'S. It used to be the Crew Desk gave us valid information and we could trust it. Dispatcher also said we had enough day to complete flight. We had no idea we had violated FAR'S till next day when it showed up in the scheduling computer.
A fatigued B747-400 crew was told they had enough legal duty time remaining to complete the 19+30 hour duty; but discovered the following day the Company had lied and in fact they violated an FAR.