Max maneuvering speed indicator

[kbehrent]

On Vans airspeed indicators, they mark the max speed in which full controls can be applied without breaking something as a "Blue" limit line. Is there a way to do the same on the 4500?

Thanks,
Kevin

[Trevor Conroy]

Kevin, since that is not a standard marking in the aviation world (other than for twin engine airplanes which means something totally different) we do not have a "blue line". However, I'd use the bottom of the yellow arc for that number. Vno is defined as the maximum speed in still air where abrupt or full control movements can be made. So I'd take that Vno number from Van's and make it the top of your green/bottom of the yellow arc.

[kbehrent]

That's sounds reasonable.

Thanks

[kbehrent]

Trevor,

Actually I've thought about this and even tried to make this work with the 4500 and quickly realized that it's really needed. If I went with your recommendation, I would only have a green arc from 56 mph to 118 since Van's declared the Maneuvering Speed-Max (See below) to be 118 mph. I would than have a hugh yellow arc from 118-210 with reline at 210. The difference between the VNO and max maneuvering speed is the full use of controls (1 at a time). The blue line identifies the max speed in which full control inputs could be applied with out damaging the aircraft. The Green arc represents the speed range that can handle the full G limits of the aircraft without damage. Yellow arc being speed in calm conditions where turbulence could over stress the airframe. All three of these are different conditions and should be represented. Making the entire range from 118-210 a yellow arc is really incorrect and not very representative of the capabilities/limits of the aircraft. I suspect that most will not do this and would leave out the "Blue Line" and that's really a shame as well.

Regarding not being standard, it can be found in other GA aircraft as a tick mark, not necessarily as a "Blue line". A friend of mine has it in his C-182.

I would really suggest adding this tick mark as a new feature. Van's felt it necessary to include in their airspeed indicators. I can't imagine it would be that difficult to add.

According to Van, here is how they like things ranged marked for the RV-9A:
Bottom of White Arc: (@ indicated stall speed w/full flaps): 49 mph
Top of White Arc: (@ stall speed w/full flaps): 90 mph
Bottom of Green: (@ stall speed without flaps): 56 mph
Top End of Green Arc: (Max structural cruise speed): 180 mph
Blue Line: (Maneuvering speed-max permitted speed at which "full control" inputs can be applied. Speed at which full elevator control would impose loads exceeding limits): 118 mph
Yellow Arc: (Caution range, to be flown only in calm air or light turbulence conditions): 180-210 mph
Red Line VNE TAS: Max permissible speed under any conditions: 210 mph