Forum: F-16 Procedures

r2d2 wrote:

The autopilot must also sense the position (i.e. the bank angle) of the a/c. In fact, according to my opinion, the prime duty of the autopilot will be ''to correct'' the bank angle. Stopping (dampening?) the natural roll is a part of the process.

I share the same opinion r2. I do wonder however what sort of impact the autopilot has on stability.
I understand some Airbus models suffer from roll oscillations with the roll autopilot engaged. The F-15 porpoises in pitch with the autopilot on and the Dassault Falcon 7x will still pitch and roll in turbulence.

With the autopilot engaged I guess an integrator is introduced in the roll channel, so I presume roll response is affected to some degree?
The Super Hornet has a FPAH with Roll Hold (Flight Path Angle Hold) autopilot mode, in which the pitch response to pilot input is said to be more sluggish, yet the roll response is similar to the pilot controlled CAS mode.

Considering FPAH/Roll strives to maintain the pilot selected roll attitude, its a wonder how capable an autopilot can be. How do they cope with gusts, turbulence, sudden asymmetries?

Obi

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Thought I'd add a couple of papers to this very interesting, albeit dormant, discussion; a fairly recent edition of MIL-STD-1797A and "Piloted Simulation of an F-16 Flight Control System Designed Using Quantitative Feedback Theory" (Stuart N. Sheldon. Veda Incorporated).

Contains a wealth of info on flying qualities, FCS as well as roll characteristics on a number of (great) aircraft types; YF-16, F-16, F-4, F-5, F-14, F-15.

B. Bolsøy
Oslo

Thanks energo Thumb

It will take a while to digest that info, the parts I understand that is.

Great find. Cheers

Obi_Offiah wrote:

Thanks energo Thumb

It will take a while to digest that info, the parts I understand that is.

Great find. Cheers

You're welcome. Guiness

B. Bolsøy
Oslo

Forum: F-16 Procedures

Manual trim in F-16