Narrative:

Aircraft dispatched with auto throttles inoperative. I had just completed a simulator check with auto throttles inoperative and knew it would be a very busy leg even with good weather. Captain had never flown 737 without auto throttles in either simulation or on line. We reviewed MEL and thoroughly discussed all aspects/phases of the flight. A 737 captain was in the jump seat for the leg. Cruise altitude was FL390. Completely unrelated to the airspeed event described below; upon leveling at FL390 in smooth air; we noted that we had about ten knots below the red line and ten knots above the yellow hook. It occurred to us; that without the added protection afforded with auto throttles; that any unexpected turbulence could easily result in an over speed or under speed and/or departure from controlled flight. We requested a descent to FL370 which made for a much more comfortable margin. Prior to the descent; the captain determined that the HUD was extremely helpful in power management and determined it best that he fly the descent; approach and landing. I then became pilot not flying. Upon arrival approach left us at 4;000 ft just outside FAF about 10 miles from the field. We requested a vector for descent and received clearance to descend to 2;000 ft on a 340 degree (approximate) heading; across the final approach course. Flaps 10 was selected for the descent. At that point I suggested to the captain that if approach tried to give us a right turn to final that we request a left 270 as a right turn to final would have set us up for an angling; unstable approach. Approach did clear us for the right turn and we requested a 270 to final which clearly irritated the approach controller. During the turn; the captain came off the HUD momentarily to clear the turn as I worked the radios and checklist. About 10-15 degrees into the turn both the jumpseater and I simultaneously noted the airspeed bleeding off and below the target MCP speed (175 KTS) and the ten flap bug speed (approximately 170). We both called 'airspeed' immediately and noted it at 165 KTS; which was about ten knots above the min man (hook speed). Captain immediately added power and speed quickly returned to MCP target speed (175 KTS). Visual approach concluded with no further issues. We discussed this at length and noted that we had a lot going for us. Good weather; daylight; non-fatigued; observant jumpseater. Cockpit was completely sterile and we had thoroughly briefed approach; to include the possibility of a no auto throttles go round. We were alert for; and proactive for the possibility of an unstable approach. After landing; we did the 'what ifs': what if we were at the end of a long day; night; marginal weather; no jumpseater; challenging high altitude airport; language barriers; and/or another minor aircraft issue. The potential for an unhappy outcome is obvious. Our conclusions are that: 1. We should not dispatch aircraft without auto throttles; or if absolutely necessary; for one leg only for the repair. 2. If aircraft are dispatched without auto throttles; the MEL should specify certain limits on length of leg; weather; type of approaches (ie. Not CAT ii/III) and should have dispatch altitude limits to increase the performance margins for unanticipated turbulence. Consideration should be given to not dispatching into airports in known high workload environment/hit list airports. 3. We get very little training or guidance in flying the 737 without auto throttles. If dispatching without auto throttles is to be allowed; we need operations manual guidance that helps us consider where we can be tripped up on the various phases of flight.

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Original NASA ASRS Text

Title: A B737 First Officer reported being dispatched with an inoperative auto throttle system and described the situations that developed. It was suggested that this MEL should have restrictions or simulator training for this situation be enhanced.

Narrative: Aircraft dispatched with auto throttles inoperative. I had just completed a Simulator Check with auto throttles inoperative and knew it would be a very busy leg even with good weather. Captain had never flown 737 without auto throttles in either simulation or on line. We reviewed MEL and thoroughly discussed all aspects/phases of the flight. A 737 Captain was in the jump seat for the leg. Cruise altitude was FL390. Completely unrelated to the airspeed event described below; upon leveling at FL390 in smooth air; we noted that we had about ten knots below the red line and ten knots above the yellow hook. It occurred to us; that without the added protection afforded with auto throttles; that any unexpected turbulence could easily result in an over speed or under speed and/or departure from controlled flight. We requested a descent to FL370 which made for a much more comfortable margin. Prior to the descent; the Captain determined that the HUD was extremely helpful in power management and determined it best that he fly the descent; approach and landing. I then became pilot not flying. Upon arrival approach left us at 4;000 FT just outside FAF about 10 miles from the field. We requested a vector for descent and received clearance to descend to 2;000 FT on a 340 degree (approximate) heading; across the final approach course. Flaps 10 was selected for the descent. At that point I suggested to the Captain that if Approach tried to give us a right turn to final that we request a left 270 as a right turn to final would have set us up for an angling; unstable approach. Approach did clear us for the right turn and we requested a 270 to final which clearly irritated the Approach Controller. During the turn; the Captain came off the HUD momentarily to clear the turn as I worked the radios and checklist. About 10-15 degrees into the turn both the jumpseater and I simultaneously noted the airspeed bleeding off and below the target MCP speed (175 KTS) and the ten flap bug speed (approximately 170). We both called 'airspeed' immediately and noted it at 165 KTS; which was about ten knots above the min man (hook speed). Captain immediately added power and speed quickly returned to MCP target speed (175 KTS). Visual approach concluded with no further issues. We discussed this at length and noted that we had a lot going for us. Good weather; daylight; non-fatigued; observant jumpseater. Cockpit was completely sterile and we had thoroughly briefed approach; to include the possibility of a no auto throttles go round. We were alert for; and proactive for the possibility of an unstable approach. After landing; we did the 'what ifs': What if we were at the end of a long day; night; marginal weather; no jumpseater; challenging high altitude airport; language barriers; and/or another minor aircraft issue. The potential for an unhappy outcome is obvious. Our conclusions are that: 1. We should not dispatch aircraft without auto throttles; or if absolutely necessary; for one leg only for the repair. 2. If aircraft are dispatched without auto throttles; the MEL should specify certain limits on length of leg; weather; type of approaches (ie. not CAT II/III) and should have dispatch altitude limits to increase the performance margins for unanticipated turbulence. Consideration should be given to not dispatching into airports in known high workload environment/hit list airports. 3. We get very little training or guidance in flying the 737 without auto throttles. If dispatching without auto throttles is to be allowed; we need Operations Manual guidance that helps us consider where we can be tripped up on the various phases of flight.

Data retrieved from NASA's ASRS site as of April 2012 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.