TCAS/Stability

[rob152]

Hi fellow flyers,

I've got a big assignment to do for my aerodynamics subject at college and one of the questions is "Explain the main function of an automatic flight control system for maintaining aircraft stability and describe the major components". I have no issues with this but my lecturer suggested that I might be able to incorporate a previous project I done on the TCAS system (mainly because I got very high marks for this!), I'm, personally, not convinced that there is any direct relationship between TCAS and aircraft stability being maintained by AFCS, what do you guys think?

Apologies if this is inappropriate for this particular forum but I am a wannabe!

Cheers,

Rob152:confused:

[celtflyer]

Not sure, But I understand that high speed protections on the airbus speed tape i.e the double green horizontal bar are approximately 5 kts above VMO/MMO barbers pole, so once the protections occur you will get a nose pitch up regardless of stick input to reduce speed "HOWEVER" If there happens to be a TA or RA on the TCAS you will have sidestick usage at the risk of getting in to alternate law abnormal attiudes.
So I reckon there has to be a tie in with the Electronic flight control system (EFCS) which includes the 7 computers 2XElacs/3xSEC/2XFac's and the Tcas system allowing input or no input depending on a RA but only if your into protected regimes.
Just my humble opinion, not 100% sure.

[Mad (Flt) Scientist]

That suggestion (of your lecturer) seems nigh-on incomprehensible.

Aircraft stability and AFCS appears to be pertaining to matters such as use of a yaw damper, up to full fly-by-wire stability augmentation, depending upon the degree of AFCS authority and amount of stability you want to maintain.

TCAS is, as I'm sure you know if youy already studied it, and autonomous and/or cooperative warning system for avoid ground impact or midair collision. Almost entirely dominated by considerations of aircraft performance (what RoC/RoD can I obtain/maintain) and almost entirely unaffected by stability and handling concerns.

The only MINOR link I could get was if someone has an autopilot mode actually directly engaged with TCAS (such that the aircraft would automatically respond to a TA or RA, without pilot input). AFAIK no-one does that; I believe all responses to TCAS RAs and TAs has to be crew-initiated. (But I'd be intrigued to learn otherwise)

[MrBernoulli]

And I believe that most operators INSIST that the pilot/s of an aircraft subject to an RA must disconnect any autopilot (except, perhaps an autothrottle) and fly the RA manoeuvre MANUALLY.

[BEagle]

This might be of help:
http://www.wingfiles.com/files/systems/a320.pdf

A large download, however!

[Down Three Greens]

AIRBUS are looking into an automatic response to TCAS i.e. coupled to the autopilot. One of the main reasons being are the TCAS response is more effectively controlled as I am sure that many of us have over responded to a TCAS resolution advisory or reversed RA in the sim. It is still under evaluation however.

DTG