737 questions over coffee
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737 questions over coffee
Appreciate your advice.
With 20K engines in the 737-300 what is the expected thrust at MCT 35,000 ft ISA . I recall a figure around 4000 lbs per engine which is (one presumes), why it takes a relatively long time to build up speed using MCT from 0.74 to reach Barber Pole in level flight. Roughly how long should it take to reach Barber Pole from 0.74 at say 50 tonnes at MCT at 35,000 ft in level flight?
Regarding Mach Tuck in the 737. In the Classics there is a Mach 0.74 limit if the mach trim is inoperative. Has anyone had experience of mach tuck if speed is advertently permitted to exceed 0.74? If so, how quickly did the aircraft nose over? If the autopilot was engaged at alt hold with mach trim inoperative and beyond 0.74 , would the AP be able to still maintain alt hold against the progressive nose over tendency?
Presumably there would be a critical Mach where, with mach trim inoperative, the pilot would be unable to prevent a further nose over (Mach Tuck) and a serious (uncontrollable ?) dive could occur.
If RTO is actuated during high speed rejected take off or during max manual braking during the landing, the anti-skid system would operate. In the real aircraft (as distinct from simulator), does anti-skid always cause marked airframe vibration on a dry or wet runway? If so, does this vibration stay at the same amplitude throughout the RTO or max manual braking deceleration? Or should the vibration caused by rapid operation of the anti-skid system, reduce as speed slows?
Last question! What is expected idling thrust ECG with both aircon packs Auto during ground ops? This assumes engine anti-icing off and idle 23%. N1. Nothing in the FCOM. So how is the pilot expected to know if the EGT readings are in the normal range?
With 20K engines in the 737-300 what is the expected thrust at MCT 35,000 ft ISA . I recall a figure around 4000 lbs per engine which is (one presumes), why it takes a relatively long time to build up speed using MCT from 0.74 to reach Barber Pole in level flight. Roughly how long should it take to reach Barber Pole from 0.74 at say 50 tonnes at MCT at 35,000 ft in level flight?
Regarding Mach Tuck in the 737. In the Classics there is a Mach 0.74 limit if the mach trim is inoperative. Has anyone had experience of mach tuck if speed is advertently permitted to exceed 0.74? If so, how quickly did the aircraft nose over? If the autopilot was engaged at alt hold with mach trim inoperative and beyond 0.74 , would the AP be able to still maintain alt hold against the progressive nose over tendency?
Presumably there would be a critical Mach where, with mach trim inoperative, the pilot would be unable to prevent a further nose over (Mach Tuck) and a serious (uncontrollable ?) dive could occur.
If RTO is actuated during high speed rejected take off or during max manual braking during the landing, the anti-skid system would operate. In the real aircraft (as distinct from simulator), does anti-skid always cause marked airframe vibration on a dry or wet runway? If so, does this vibration stay at the same amplitude throughout the RTO or max manual braking deceleration? Or should the vibration caused by rapid operation of the anti-skid system, reduce as speed slows?
Last question! What is expected idling thrust ECG with both aircon packs Auto during ground ops? This assumes engine anti-icing off and idle 23%. N1. Nothing in the FCOM. So how is the pilot expected to know if the EGT readings are in the normal range?
Last edited by Tee Emm; 28th Feb 2014 at 07:56.
Yes it does display Mach Tuck but it is much less than the 200 series, and very gentle nose down. It was fully controllable. Sorry dont know about with the autopilot on.
I would suspect that the AP would maintain the altitude until the AP force limits are exceded and it disengaged. Probably not a good situation.
Have not done a high speed RTO but done a few max effort landing in both the 200 and 300 in dry conditions. The 200 did judder at the lower speeds but at the higher speeds were fine. The 300 was smooth as a babies right to the stop, however lateral control felt like landing on a very wet runway. The first time was a shock at how well the brakes work. The jet had come to a stop before reverse had got to accel past the detent, the cause was partly the 'startle' factor but the rest was how awesome the brakes worked.
I would suspect that the AP would maintain the altitude until the AP force limits are exceded and it disengaged. Probably not a good situation.
Have not done a high speed RTO but done a few max effort landing in both the 200 and 300 in dry conditions. The 200 did judder at the lower speeds but at the higher speeds were fine. The 300 was smooth as a babies right to the stop, however lateral control felt like landing on a very wet runway. The first time was a shock at how well the brakes work. The jet had come to a stop before reverse had got to accel past the detent, the cause was partly the 'startle' factor but the rest was how awesome the brakes worked.
