Narrative:

I pulled up the flight documents for aircraft X:- aircraft was on MEL xx-xx left pack inoperative- the first officer and I reviewed the MEL for left pack inoperative and concluded that all applicable items were complied with. - We reviewed and discussed the [appropriate procedures] - we then reviewed the procedure under 'left pack inoperative' and how we would prepare the aircraft prior to takeoff.- when cleared for takeoff we repositioned the switches as described in [the aforementioned procedure]- after selecting toga for takeoff I noticed that the N1 number was higher than I thought it was on the [performance data sheet] paperwork; however; it did match the numbers that were in the FMC. - After takeoff we continued with the procedure- at cruise we discussed the situation and realized this was more than just a left pack inoperative and was actually a 'bleeds off' takeoff and we should have had a [performance data sheet] reflecting that condition. - When we arrived [at our destination]; I discussed the situation with the 'outbound crew' and mentioned to them that I thought this situation should have a bleeds off takeoff [performance data sheet]. He looked at his paperwork and noticed it did not show bleeds off but instead was identical to my [performance data sheet]; a normal bleeds on [performance data sheet].dispatch failed to realize that the MEL would result in a bleeds off take-off thus requiring a different/adjusted [performance data sheet]there is no mention in the in the MEL that the operator should request a bleeds off takeoff [performance data sheet]lessons learned:- there is no reference in the MEL that the procedures outlined in xx-xx left pack inoperative will result in a bleeds off takeoff and to ensure you have a [performance data sheet] reflecting that condition.- in my discussions with dispatch; it appears there is no indication to them that this procedure will result in a bleeds off takeoff and to supply a [performance data sheet] reflecting that condition.- there needs to be a bullet point in the MEL xx-xx procedure under left pack inoperative that reminds the crew they need a bleeds off [performance data sheet]

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Original NASA ASRS Text

Title: B737 Captain reported confusing MEL information related to takeoff procedure with one air conditioning pack inop.

Narrative: I pulled up the flight documents for Aircraft X:- Aircraft was on MEL XX-XX Left Pack Inoperative- The First Officer and I reviewed the MEL for Left Pack Inoperative and concluded that all applicable items were complied with. - We reviewed and discussed the [appropriate procedures] - We then reviewed the procedure under 'Left Pack Inoperative' and how we would prepare the aircraft prior to takeoff.- When cleared for takeoff we repositioned the switches as described in [the aforementioned procedure]- After selecting TOGA for Takeoff I noticed that the N1 number was higher than I thought it was on the [Performance Data Sheet] paperwork; however; it did match the numbers that were in the FMC. - After Takeoff we continued with the procedure- At cruise we discussed the situation and realized this was more than just a Left Pack Inoperative and was actually a 'Bleeds Off' Takeoff and we should have had a [Performance Data Sheet] reflecting that condition. - When we arrived [at our destination]; I discussed the situation with the 'Outbound Crew' and mentioned to them that I thought this situation should have a Bleeds Off Takeoff [Performance Data Sheet]. He looked at his paperwork and noticed it did not show Bleeds Off but instead was identical to my [Performance Data Sheet]; a normal Bleeds On [Performance Data Sheet].Dispatch failed to realize that the MEL would result in a Bleeds Off Take-Off thus requiring a different/adjusted [Performance Data Sheet]There is no mention in the in the MEL that the Operator should request a Bleeds Off Takeoff [Performance Data Sheet]Lessons Learned:- There is no reference in the MEL that the procedures outlined in XX-XX Left Pack Inoperative will result in a Bleeds Off Takeoff and to ensure you have a [Performance Data Sheet] reflecting that condition.- In my discussions with Dispatch; it appears there is no indication to them that this procedure will result in a Bleeds Off Takeoff and to supply a [Performance Data Sheet] reflecting that condition.- There needs to be a bullet point in the MEL XX-XX procedure under Left Pack Inoperative that reminds the crew they need a Bleeds Off [Performance Data Sheet]

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.