View Full Version : High Speed climbs?
Gravox
21st Nov 2002, 14:52
Why is it that wide bodied "heavy" aircraft consistantly request a high speed climb?
Tankengine
21st Nov 2002, 21:55
Because they need more than 250 kts to fly clean above flaps up speed. A 744 likes about 280kts min clean at max weight.
In any case , why not? A high speed climb is more efficient anyway! :D
CallButton
21st Nov 2002, 22:40
Sometimes it is just to make up time or save fuel (by climbing at a more efficient speed).
Other times the 250kt restriction below 10,000ft is actually below the min clean maneouvring speed of the aircraft i.e. you have to wait until above 10,000ft before you can accelerate and retract all your flap so it makes sense to ask for a high speed climb.
Waste Gate
23rd Nov 2002, 05:51
Also, regardless of min. clean manoeuvreing speed, a 250 knots below 10000 ft speed requirement applies at most of the Australian airports "heavies" operate from.
Even though you may be able to fly "clean" at, say, 220 knots, a lifting of the restriction and subsequent climb at 320 knots ore more may be beneficial in some circumstances.
WG.
Gnadenburg
23rd Nov 2002, 06:05
Wonder the real use in a high speed climb, which I assume is in the 330kt to 350kt range, depending on airline type, as opposed to a cruise climb, around 300kts.
In a cruise climb you will get up into the higher TAS or tailwind levels quicker. Negating the speed increase in a high speed climb.
Some smart F/O can use a bit of calculus to prove they are "same,same but different" in end result.