Dc10-30 Pafam

[BigJoeRice]

I was clearing out some old DC10 manuals and came across a blurb for PAFAM (Performance and Failure Assessment Monitor) in the maintenance training notes. I seem to recall it was some sort of runway touchdown point predictor (?) and I was wondering if anybody had actually used it and did it help with the landings.

[finncapt]

Long time since I flew the beastie but wasn't it something to do with centre line guidance in low vis take off/landing ground roll?

[finncapt]

Had a look on google and maybe I'm getting muddled up with something else.

We had them on our -30s but I can't remember if they were de-activated or not.

I'll be interested to read if anyone can remember.

[Day_Dreamer]

Touchdown point prediction indicator.
We had them in 1979on the DC 10-10 and 10-30 but they were later deactivated.

[BAe146s make me cry]

PAFAM

Maintenance Manual Ref: ATA22-41

Performance And Failure Assesment Monitor. Duplicated ILS, Rad Alt, Pitch Computer, Roll Computer, & Yaw Rate Gyro, INS (thru AMSU), CSU-1, Linear Accelorometer, Ground Spoiler Control Unit, Numerous VALID's, CADC & Flying Control position inputs to the PAFAM computer. The PAFAM also has reversion inhibits for all A/P & Yaw computers.

The PAFAM drives a display electronics unit which in turn drives
Capt's & F/O's CRT displays with adjustable dim/bright mounted below glareshield. The display shows a trapezoid (runway profile as viewed on approach) and displays PAFAM's computed moving cross for 'Runway & predicted place of touchdown'.

Sorry if I got a bit over-Techy. PAFAM was disabled on our a/c.
One of our old skipper's used it (way back when) and wasn't too impressed. Not sure if that was a majority crew opinion or just him!

Regards

BAe146??? :{:{:{
Ex-DC-10 Certifying Technician

[BigJoeRice]

"BAe146s make me cry"

Nice one. We had it installed at World but I moved on before I had a chance to play with it. Seems like the rest of aviation probably had the same opinion as your Captain as I never really heard of it after the DACO course circa 1979.

Thanks.

[WorldDC10]

We don't have them on the 7 DC10-30's we have at World.

Always found that keeping the needles centered and looking out the window helps predict where the landing will occur:)

[BAe146s make me cry]

On older DC-10-30 examples (eg: MSN47816, MSN47831), If you have a quick look in the Avionics Compartment, there will probably be 2 x vacant LRU trays (U1-104 & U1-155, PAFAM & PAFAM Display Electronics respectively) located on Center Bay, Shelf 3, Main Radio Rack.

The 2 x PAFAM displays were located upper inboard on Capt & F/O inst panels (under glareshield). Today, you'll find the display slots would have been blanked off upon system deactivation (panels replaced maybe). C/B (AC Bus1, phase A) pulled/locked out, Wiring coiled & stowed.

After any system deactivation, no reason to carry the deadweight if
the modification permits.

BAe146??? :{:{:{

[BigJoeRice]

"WorldDC10"

This was on the original World DC10-30 fleet from the factory back in 1979, so yes, probably not on today's fleet mix. As you say, pilots probably found it wasn't that helpful, plus it was a complicated system as you can see from BAe146's posts, so why keep the weight and the maintenance headaches..

"BAe146s make me cry"

Looks like it was another one of those good ideas at the time but...

Thanks to all for the comments.