Flight Crew Air Transport Pilot (ATP)
Confusion; Communication Breakdown; Situational Awareness
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural MEL / CDL; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Overcame Equipment Problem; General Maintenance Action
Aircraft; Human Factors; MEL; Procedure
We were dispatched with MELs 27-61-1 and 27-62-1-2 [deferrals]. These relate to the Auto Speedbrake System with Load Alleviation. Part of the Dispatch Procedures requires that the Speedbrake lever is moved [by Maintenance] in its full range to ensure the Load Alleviation System (LAS) is not restricting its travel. Under the remarks and exceptions [in the MEL]; there is a comment to ensure that full range of travel exists. However; there is no requirement under the (O) section that we [flight crew] accomplish this task. During our flight we were asked to expedite our descent. I extended the Speed Brakes and encountered resistance at the 50% position. This is normally the position to which the LAS would return the speed brake lever if we exceeded certain weight and airspeed parameters. We were below the applicable weight (not to mention that the system was deferred); so this was an unexpected restriction. I was able to move the speed brake lever beyond 50% if I applied roughly 30 LBS of force; but it would snap forward when I released it. The exception to this was [the handle] would stay in the fully extended position if pulled fully aft. We speculated that the MEL maintenance procedures may not have been properly performed; or that the [LAS] restriction would be removed upon landing.After landing; the Load Alleviation System (LAS) restriction was still in place. I overpowered the LAS and fully extended the speed brakes. The rollout was uneventful. After block in; a mechanic discovered that; indeed; the LAS actuator was extended and was restricting the travel of the lever. If we had been going to a short runway and had not extended the speedbrake lever in flight; the first indication of an abnormality would have been at a critical time. If we would have had to perform a Rejected Take-Off (RTO); we probably would not have had the same stopping performance. Because of this; I recommend that the MEL remark about ensuring full speedbrake lever travel; that we attributed to the Dispatch Maintenance Procedures be put under the (O) section. I strongly encourage making it an explicit operational crew requirement to ensure this event doesn't happen again.
Before departure; we reviewed applicable MELs 27-61-1 Speed Brake Load Alleviation System (LAS) and 27-62-1-2 Auto Speed Brake System. I specifically concentrated on the Operations Procedures (O) section and Operations Limitations section. Upon arrival the Captain needed speed brakes for descent and when applying noticed excess force required to apply past 50% deployed. Upon landing when deploying speedbrakes; the same thing happened. Maintenance at [our destination] determined the excess force portion of the [LAS] system was not de-activated in the process of complying with the MELs. The Captain filed an event report to suggest the flight crew verify normal speed brake operation for this MEL. We then realized both MELs in the Remarks and Exceptions section has a note to verify speed brake handle forces are verified normal from full down to full up position; but that neither MEL has this step in the Operations Procedures; which may have contributed to our not checking this prior to block out from [our departure airport].
Two pilots reported MEL (M) Maintenance Procedures 27-61-1 for Speed Brake Load Alleviation System (LAS) and 27-62-1 Auto Speed Brake System deferrals on a B767-300 aircraft were not properly complied with causing restricted Speed Brake lever movement in flight. Pilots recommended an (O) Operations Procedure be added to MEL for lever movement verification. The excess force portion of the LAS System had not been de-activated in the process of complying with the MELs.