AgnusBymaster From United States of America, joined Feb 2001, 649 posts, RR: 0 Posted (10 years 4 months 3 days ago) and read 2121 times:
For those of you out there with knowledge of the 737-400, what is the typical climb speed (not vertical rate) used above 10,000 ft? I know the limit is 250 kts IAS below 10,000, but the manual for MSFS 2000 says to maintain 280 kts IAS in ascent above 10,000. Personally, I like to set the fuel load to 60-70% prior to takeoff, allowing me to accelerate to and maintain 340 kts IAS above 10,000 ft until I intercept my cruise mach number (I then set the autothrottle to that mach number). My climb rate is generally 2,700 ft/min to 7,000 ft and then 1,700 ft up to cruise.
For descent, the manual says to maintain 250 kts IAS. But, again, I like to do "cruise descents," maintaining the cruise mach number while I descend at about 1,700 ft/min, and then 340 kts, and then 250 kts below 10,000, slowing to about 145 for final approach.
Anyway, how am I doing? How does this compare to airline operating procedure? To make my flight times more realistic, should I hold my climb speed to 280 kts IAS, or is it OK to accelerate to 340 kts? In a real-life situation, would this cause too much stress on the airframe or be too wasteful of fuel?
AgnusBymaster From United States of America, joined Feb 2001, 649 posts, RR: 0 Reply 1, posted (10 years 4 months 2 days 9 hours ago) and read 2026 times:
Basically, what I'm asking is, is it OK to accelerate all the way up to the "bar" (340 kts IAS) above 10,000 ft, or should I maintain 280 kts IAS until I intercept Mach .74 If my fuel load permits, and I don't exceed 90% N1, I don't see why I can't do 340 kts IAS. However, in the real world, which procedure do airlines tend to follow?
Also, for an airline trying to get from pt. A to pt. B as quickly as possible, would it not be faster to do a "cruise descent" rather than a "power to idle" descent?
Skystar From Australia, joined Jan 2000, 1363 posts, RR: 3 Reply 2, posted (10 years 4 months 2 days 5 hours ago) and read 2024 times:
Noone would realically climb at 340kias indicated - this is a 737, not a 747 - it's not an efficient speed for climbing. There's a reason why it's not done in the real world.
2700fpm isn't much once the aircraft is cleaned up below 10,000.
A cruise descent is not necessarily faster - you could to a power to idle descent and descend at near Vmo, just starting the descent later.
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