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| Author |
cruise settings in 747-400 |
p51d
Posts: 120
Joined: 06.05.06
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| Posted on 10-10-2007 17:39 |
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i'm finding that i have to have power set to full in order to stay at the typical cruise speed of 0.85 mach in the 747-400. why is this!? i have tried several altitudes in the 30,000's but can't seem to get it right!? |
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| Author |
RE: cruise settings in 747-400 |
jackfolla
Posts: 509
Joined: 11.04.06
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| Posted on 10-10-2007 17:40 |
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Hi BJ mxc, above 29000 ft switch over to Mach hold. The typical cruise setting for a B747-400 above 30000 is 0.85 to 0.86.
Airspeed drops the higher you go because air pressure drops and thus less wind to push into the pitot. But you will notice (if looking at a propper GPS such as Reality-XPs Garmin 530N, www.reality-xp.com) that you ground speed stays the same or actually increase.
The typical cruise altitute for the Queen of the skys (Read B747-400) is between 30000ft and 37000ft, depending on weight and distance travelled. The FMC in the PMDG B747-400 and B747-400F will guide you to the optimal altitute but keep in mind that at 30000ft your semi-circular rule changes from 1000ft seperation to 2000ft so you have to climb 4000ft at a time. Maybe SkyDancer or any other real pilot can explain the semi-circular plan better, if it is unclear or unknown.  |
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