Collins FD-108 gain programming?

[quid]

It's been over 15 years since I've used the FD-108, and I don't remember the gain programming.

If I remember correctly, first stage starts at radio altitude around 1200'. Second stage (ILS extend) at 200.

If there is not radio altimeter, GP extend is triggered by the MM.

If there is no RA, first stage starts at LOC capture, and runs for about 75 seconds, then goes into GP extend if there is no MM.

I have one source that says there is NO first stage down programming, and the only reduction is at the MM.

I'm trying to help a friend, and I'd appreciate your assistance.

[mpenage]

Its about ten years since I worked on FD-108/109/110 so here goes, on the 108 I think, there were 2 Gain Programs, the first at RA<1500 or GS capture it ran for about 120 sec and reduced the GS sensitivity by about 50%. This program could be overriden by MAN GS. Program 2 came in at MM or 200 RA and ran for about 10 sec reducing sensitivity by another aprox 20%. Dont Quote me on the exact figs. My memory cannot always be trusted!

[askop]

I might to be able to help. I have a CDROM for the avionics on the DC9. I dont know if uses FD108 eqpt, but if you believe so I might be able to help. I'll take a look at it when I get home from work.



[This message has been edited by askop (edited 02 February 2001).]

[quid]

Thanks for the answers, guys, but I have learned there are many possible configurations for the FD-108, and unless we know what those are, there is no simple answer to my question.

[Century]

FD 108 guru Rob Simpson can help you contact him at [email protected]