flap maneuvering speed and minimum maneuvering speed

[Driver170 42]

Right guys i'm confused, this seems contradictive...

 

I have quoted 2 paragraphs from the FCTM.

 

The first mentions at V2 + 15 you have 40* bank capability

 

The second mentions at V2 + 15 maximum bank is 30* capability

 

 

Takeoff

After zero fuel weight, V1, and VR are entered into the FMC, airspeed bugs are automatically displayed at V1, VR and the minimum flap retraction speed for the next flap position. Command speed is set at V2 using the MCP. V2 is the minimum takeoff safety speed and provides at least 30° bank capability (15° + 15° overshoot) for all takeoff flaps. An airspeed bug is automatically set 15 knots above command speed. V2 + 15 knots provides 40° bank capability (25° + 15° overshoot) for all takeoff flaps.

 

 

 

Immediate Turn after Takeoff - All Engines

Obstacle clearance, noise abatement, or departure procedures may require an immediate turn after takeoff. Initiate the turn at the appropriate altitude (normally at least 400 feet AGL) and maintain V2 + 15 to V2 + 25 knots with takeoff flaps.

Note: Amaximum bank angle of 30° is permitted at V2+15 knots with takeoff flaps.

[Spin737 102]

Permitted =\= Capability

[Driver170 42]

Don't understand matt can you explain please?

[downscc 1,327]

Permitted does not equal capability... just because the airplane will do it doesn't mean you should try it. I'd never bank beyond 30 deg in a Part 121 operation but it's nice to know the airplane has my back at 30 deg and I'm not at the edge of the safety envelop.

[BlueStar 323]

Don't understand matt can you explain please?

You can bank to any angle you wish without worries as long as you keep the AOA at three o'clock or greater. :-))

 

Billy Bluestar

[G550flyer 1,013]

 

 

Don't understand matt can you explain please?

 

Just remember that aviation is all about a safety factor. You don't want to diminish the safety buffer. The DC10 said the same thing about having 33 degree bank protection with flaps at takeoff while at v2/v2+10. Still, you don't want to exceed 15 degrees of bank. This extra bank capability protects you in case you had a issue in which the plane rolls more than 15 degrees inadvertently. Just remember that aircraft certification is not based on flying a plane perfect to be safe. It has a built in buffer to meet worse case scenarios. The DC10 could easily exceed 22 degrees of pitch while maintaining V2+10. The flight manual restricted the pitch limit to 22 degrees. Though the jet is capable of going higher, you don't want to have a engine failure with the pitch that high. So for a safety buffer, you restrict the jet to 22 degrees and let it accelerate. 

[Driver170 42]

 

 

 
Just remember that aviation is all about a safety factor. You don't want to diminish the safety buffer. The DC10 said the same thing about having 33 degree bank protection with flaps at takeoff while at v2/v2+10. Still, you don't want to exceed 15 degrees of bank. This extra bank capability protects you in case you had a issue in which the plane rolls more than 15 degrees inadvertently. Just remember that aircraft certification is not based on flying a plane perfect to be safe. It has a built in buffer to meet worse case scenarios. The DC10 could easily exceed 22 degrees of pitch while maintaining V2+10. The flight manual restricted the pitch limit to 22 degrees. Though the jet is capable of going higher, you don't want to have a engine failure with the pitch that high. So for a safety buffer, you restrict the jet to 22 degrees and let it accelerate. 

 

Always have a good answer to things keep it up