Roll-rates

[XPMorten]

Hi all,

For simulation purposes I'm having problems finding
any good documentation on actual rollrates (degrees/sec) on
airliners. Can't find anything in the AOM/POH's.

The pilots we have testing the models give us an indication,
but for some reason they seem to disagree ALOT.. .
e.g on the 757 the estimates vary from 20-30 deg/s to 90 deg/s!

Of most interest is the 757 and MD80, but other types are
of interest as well.

Can anyone help?

Cheers,

M

[Mephistopheles]

If you are interested the max roll rate for the A330/A340 is 15 degrees/second with the sidestick at max deflection & limited to 67 degrees in normal law with spiral stability introduced at 33 degrees. The rate is a bit more in direct law.

[františek dobrota]

For A320 same as above, but for direct or alternate law roll rate increase to aprox. 30 deg. per sec.

[H Peacock]

Albeit a sort of small airliner, the Bombardier Global Express can achieve almost 200deg/sec! Big ailerons and a great set of multifunction spoilers! I'll borrow a stopwatch and try to find an exact answer.

[fantom]

Oh well, if it's a contest, the Gnat was 270 deg/sec at RAF Valley and the stops were removed for the Reds to allow 360/sec.

Next.

[ChristiaanJ]

XPMorten,
You may have to be a bit more specific.

There are vast differences between max raw roll rates with fully manual control inputs and what you get in various A/P modes or with FBW.

[Mad (Flt) Scientist]

Might be useful to have flight conditions and aircraft weights and inertias too. And configurations.

And one reason I *hope* for pilots disagreeing about maximum roll rates on a given civilian airliner is that they shouldn't actually have ever done it!

[XPMorten]

Thanks for the reply's guy's :)

I'm looking for hands on (non AP) rollrates. The purpose
is to try to get the "feel" of the simulation right.
Any info on any configuration/weight will help.
We can set up the acf to match the situation you might
have information on and calibrate it there.
Like Mad flt says, if MAX CW deflection is hardly ever used,
rollrates in the "normal envelope" will do fine.

Found this that gives an indication on the B764;
http://cf.alpa.org/internet/alp/2001/feb01p22.htm

The first was a check of roll rate in bank-to-bank rolls from 30 degrees to 30 degrees at ½ wheel deflection. Flying the clean airplane at 350 knots, bank-to-bank took 4 seconds, for a roll rate of 15 degrees per second. Here is where a sharp control input initiated an aeroelastic response from the airframe. A later check of this same maneuver with flaps 30 at Vref=136 gave a bank-to-bank time of 6 seconds, or a roll rate of 10 degrees per second. This excellent response at slow speed in the landing configuration is another indication of the exceptional handling qualities of this airplane.

Cheers,

M

[Fat Dog]

Oh well, if it's a contest, the Extra 300L has a roll rate of 400 deg/sec...

Next.

:)

[Clarence Oveur]

Why would real world roll-rates matter in a simulation, where joystick settings are probably as varied as there are users?

[XPMorten]

Why would real world roll-rates matter in a simulation, where joystick settings are probably as varied as there are users?

The joystick etc sensitivity settings are done from within the simulator.
- We give recommended settings for our models which is only a couple of parameters.
- The envelope in which you can adjust sensitivity is probably only
a few deg/s, so if the model is off, you cant adjust your way back in.
In other words, if the model is off, you'll notice.

Offcourse spring force, controls travel etc will vary from what equipment you
have. But the point is that for a given % of deflection on any joystick
or yoke you should have an in the ballpark rollrate.

An similar example from real is the 75 and 76. The 767 has half the Control Wheel deflection (45 deg) as the 757 does (85 deg). So the 767 will FEEL
more sensitive than the 757, but they probably have similar roll rates for the
same PERCENT of control wheel deflection.

M