B767-300 and 300 ER
Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 64; Flight Crew Total 15000; Flight Crew Type 4000
Confusion; Distraction
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Weight And Balance; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Fuel Issue
Flight Crew Overcame Equipment Problem
Aircraft; Human Factors; MEL
This trip started with our ground transport showing up more than 30 minutes late. We were still able to arrive close to our scheduled arrival time. Arriving at the aircraft; I did not feel rushed. I try not to rush and take the time to look over paperwork carefully. We already had the flight departure paperwork when we arrived at the aircraft. The logbook was not on the aircraft so I spent some time looking over the paperwork. We were eventually told by maintenance that the logbook was being filled out for a previous write up and that we could begin preflight. I noticed a number of deferral stickers on the aircraft. When the mechanic arrived; he spent some time explaining a write up from the inbound leg regarding a fuel balancing problem in flight. He could find no problems with the fuel system and signed off the problem. I asked about the deferred parking brake and pulled the MEL up on my [Electronic Flight Bag]. I was concerned about not only having no parking brake during engine start/shutdown; but more critical in my mind at the time was the inoperative anti-skid. Auto brakes would also not be available. I briefed the threats related to inop anti-skid; particularly if an RTO (Rejected Takeoff) was required during takeoff. Between this MEL; an MEL for the right center hydraulic pump; an MEL for right runway turnoff light; and the previously discussed fuel balance issue; I felt a little behind looking up all the information and discussing the related threats. However; I still did not feel rushed. I noticed in the parking brake MEL the note 'The parking brake light and EICAS advisory will be continuously displayed. ACARS operation may be affected.' The info about 'ACARS operation may be affected' should have made me realize that some of the ACARS functions that seemed to not be working as usual were due to this MEL. I think I was so focused on the threat of no anti-skid that I didn't process the info I was receiving; like arrival ATIS info coming up instead of departure. Aircraft was loaded early with Hazmat and Weight and Balance paperwork brought to the aircraft. I don't remember if ACARS Weight and Balance even came up at this point. I filled out paperwork and read ZFW (Zero Fuel Weight) to my FO (First Officer); which he input and read gross weight. I confirmed this weight against Weight and Balance paperwork and read off takeoff gross weight and verbalized this was below planned weight. At this point I felt a little behind and was still concentrating on all the threats we would encounter with the loss of the parking brake and anti-skid systems. I don't remember inputting info into the ACARS for FDP data but considering the issues that I now see we were having with the ACARS; a manual request for data must have been made. Apparently when the data was requested; the ACARS must have retained the previous flights ZFW and fuel on board. When the data came back I finished the Weight and Balance paperwork and handed the load supervisor his copy. I asked my FO to double check the numbers on our Weight and Balance copy. I printed the FDP (Flight Data Processing) data and again confirmed the flight number; OFP (Operational Flight Program); and that the FDP data included [the parking brake MEL]; but again must not have noticed the weight difference on the first part of the data. I did notice the alerts for ZFW and GTOW less than planned but seeing this as a common alert misread how much lower. I was still preoccupied with the threat of starting engines while having to hold the brakes manually and the lack of anti-skid during a possible RTO; which I briefed. We departed with what seemed a normal takeoff and climb out. We still did not realize our error. Enroute to ZZZ; we did notice what the previous crew had written up regarding a fuel balance problem. The left totalizer fluctuated in quantity. We spent some time monitoring and cross checking calculated fuel against totalizer and fuel used. I wrote up the problem and notified dispatch as the ACARS would not bring up the maintenance function. This was another distraction that delayed our noticing the incorrect take off data. As we got closer to ZZZ; my FO sent for landing data. We discussed the lack of autobrake distance info in the data due to no autobrakes available. We discussed brake usage with no anti-skid and looked up info for brake application. There was some concern that the only info we would get back was for 'Max Man'; which we would not use with anti-skid inop. I compared the landing weight in the FDP data with the FMC data and that's where I noticed the discrepancy. The FDP data landing weight was off by more than 60;000 lbs. When I am in a 767; I print out the data to look more closely at the data to avoid the very mistake we made. I pulled out my previously printed TO data and was shocked to see our error. What I had thought to be a ZFW of approximately 8000lbs less than planned was actually 83;500 less. GTOW; instead of what I thought to be around 6000 lbs less than planned was actually 69;000 less. I looked over the data and compared it to the FMC and Weight and Balance paperwork. This was when I realized we missed seeing the incorrect ZFW info that we should have caught and corrected. I remember seeing the Weight and Balance info come up on ACARS but still don't remember requesting FDP data manually. I let expectation bias and numerous distractions cause me to miss a VERY critical part of preparation. I know the [operational] procedures include to verify accuracy of conditions used for performance data. I thought I always did this meticulously. I allowed distractions caused by what seemed a very unusual deferral with serious threats cause me to miss critical details that caused an even larger threat to my aircraft. I corrected the errors in the FDP landing data conditions and resent the request. The correct data now showed more than 7000 feet required for Max Man; again which we would not be doing. ZZZ ATIS was advertising landing runway XXR and departing XXC. Though total length for both runways is the same XXR has less runway beyond glideslope. We told ZZZ we would need XXC for operational necessity. I again briefed the landing with reduced braking and made a normal landing with no problems. Additionally; I corrected TO conditions and sent a new TO data request to compare to our incorrect data. V1 and Vr were 19kts higher. V2; R40; and R80 were 17kts higher. Power settings and MTOW were the same with trim a little further aft. Due to the incorrect speeds used with the original TO data; I inspected the tail and tail skid after landing. The areas were normal with no indication of damage. I still can't believe this happened. In retrospect; I should have not allowed distractions to take me out of my normal flow and procedures. I do confirm numbers in the FDP info with both the FMC and Weight and Balance paperwork. I allowed numerous distractions to cause me to not only miss critical mistakes; but also allowed expectation bias to cause me to misinterpret data that should have alerted me to those mistakes. I will make sure in the future to continue carefully checking data regardless of outside distractions. I believe a stronger note in the MEL regarding ACARS operation with [the parking brake MEL] may prevent some confusion and possibly help future crews recognize earlier some of the issues we experienced. 'ACARS operation may be affected' is pretty weak considering the many issues we noticed. Additionally; I believe there should be more guidance on determining a practical minimum runway with anti-skid inop. We do not do 'Max Man' braking without anti-skid but that is the only distance we see in the FDP landing data. Ultimately though; it is my job to trap these types of errors. I failed in that respect and will work that much harder in the future to avoid missing critical details; distractions or not.
I was the FO (First Officer) on [the flight] to ZZZ. On this flight I failed to notice that the ZFW (Zero Fuel Weight) that came back with the TO performance data was incorrect. This resulted in us taking off with inaccurate TO data. There were numerous factors that led to this event. First and most importantly was my in attention to detail that caused me to not notice the incorrect ZFW. Other contributing factors were the MEL for the inop brakes that was causing the ACARS to not populate data correctly. Much of the info from the previous flight was still present even after the CA (Captain) initialized the aircraft. I was struggling to get the clearance because of the unfamiliar procedures and the data had to be manually rendered because of the MEL issue. By the time I got the clearance resolved I was feeling way behind but I did not verbalize this to the CA. When the TO data came back I checked the OFP (Operational Flight Program) and the runway but not the ZFW. This led to us using the incorrect data that came back. There were several ways I could have prevented this event from occurring. Most importantly I should have been professional enough to admit to the CA that I was behind and that would have allowed us to slow down and get back together. Additionally; knowing that I was behind I should have paid special attention to critical safety of flight issues like the TO data. In the future I will ensure I do not allow that to occur again.
B767 flight crew reported failing to use correct weights for takeoff and landing planning.