Commercial Fixed Wing
Flight Crew Air Transport Pilot (ATP)
Situational Awareness; Time Pressure; Human-Machine Interface; Communication Breakdown; Confusion
Deviation / Discrepancy - Procedural Published Material / Policy
General None Reported / Taken
Manuals; Procedure; Human Factors; Airport
While waiting for departure off Runway 24 in MHT--on Taxiway Juliet; behind another flight that had a delay--we were holding short of Taxiway Juliet 1 anticipating we would be cleared to takeoff with a back taxi as had a CRJ before us. We asked Tower if we could back taxi full length; and he responded 'unable.' Tower asked us if we would be good from Juliet 1 and--assuming we would be OK due to the short distance between Juliet 1 and the runway full length--we said it should be no problem. Tower then cleared us for takeoff while my First Officer was still running new numbers from Juliet one taxiway. While on runway and cleared for takeoff the new numbers came up on ACARS as invalid. In my judgment I had asked the First Officer if he thought we were OK for takeoff and he replied 'I think we should be good' or words to that effect. We continued a normal takeoff and the aircraft rotated well within the balanced distance of runway. Assuming the short distance that was given up by the Taxiway Juliet 1 and Runway 24 threshold I didn't think the data would have been invalid.I should have cleared the runway when no valid numbers were available.
The presumed distance difference between the end of Runway 24 and J1 is approximately 100 FT. The PM/Captain informed the PF/First Officer to inform ATC that we could indeed take this intersection for departure.After informing ATC the Captain commanded me to perform a Takeoff check 'above and below the line.' I took it upon myself to send for new ACARS data for the intersection. The Captain; during this time; also deleted the Flex [reduced thrust] Assumed Temp out of the FMS. While taxiing into position the new ACARS Data came back as 'Invalid Runway DATA.' I asked the captain what he would like to do. He stated that it was most likely an error in the input and we were 'fine' with this departure. We performed a normal takeoff without incident. Threats include but not limited to: Time pressure. Poor decision making. Poor Leadership skills from the Captain; poor followership skills from the First Officer; taking off from an intersection without valid runway data. From this event I have re-learned the importance of not letting time pressure influence the decisions you make. I have also learned that when dealing with an un-standard Captain that it is important to bring the Captain up--to the best of your ability--to a standard and professional level. A 10 minute delay is not worth the increase in risk associated with this particular operational incident. The company could stress the importance of valid runway data for takeoff in addition to sufficient ACARS information for all airports in our system.
When their access to the full length of the runway was blocked by a delayed flight the Captain of a commercial fixed aircraft opted to accept a takeoff clearance from an intersection a nominal distance from the end of the runway. When the First Officer unilaterally requested ACARS takeoff data from that intersection a response of 'invalid runway DATA' was returned. The Captain elected to command a takeoff and the First Officer complied.