Flight Director importance
 

Hi,

how important is the role of the flight director these days with respect to landing a plane in poor vis?

Is it realistically possible to carry out a jet landing (where you dont bust out until 200ft agl and with 100m vis) without using a flight director?

cheers for any input!

The Flight director is a very useful aid, but it is important to practice raw data approaches to keep some degree of proficiency.

As for breaking out at 200ft AGL and 100M vis. I think you are in big trouble approaching manually with less than 550M vis.

Landing manually with 550m vis is easier with the Flight directors, but yes it is perfectly feasible to land without them.

On the 727 the flight director is a pretty good aid, depending on the type and if the pilot knows how it works. (don't laugh, they all seem different, and they are because the fleet is so diversified now a days)

We don't use it for a non precision approach but on an ILS it's very good at keeping you ahead of the a/c.

The minimums (give or take a few feet) I know for anything from 737 upwards...:

CAT 1 200 DH - 550m RVR , manual landing
CAT 2 100 DH - 350m TVR , manual/autoland(on most)
CAT 3a 50 DH - 200m RVR , autoland
CAT 3b 20 DH - 125m RVR , dual channel autoland

for take-off: min 125-150m RVR depending on aircraft

A visibility of 100m is below everything - for good reasons.
Attempting it without a flight-director sounds rather dangerous/foolish to me.

The visibilty/RVR is far more important than the ceiling.

It depends on a lot of factors. I haven't used the FD on my aircraft (Cat 1 only) for about four years now. This stemmed from the need to keep in raw data practice for my CAA IRT initial issue, but I have got into the practice of not using it.

I would like to point out that it is a particularly poor FD, and I found I could do a better job as it is reactive, whereas I can anticipate changes in drift down the approach. My company SOPs don't require it to be used, and a lot of my colleagues don't.

Landing in vis. less then 550 m will require an autoland.

Landings in weather above 550 m. can be flown manually whereas a flight director is a great help during the approach , but also during the last -looking outside- part as you can have a quick glance at mainly your pitch bar for a bit of pitch reference in this poor handflown weather.

Nobody will use the flight director to flare or actually land though , if that is what you mean.

Again in the weather you prescribe , it is not allowed to make a manual landing(<RVR550).

By the way wonderbusdriver (in 737 upwards) you forgot (?) the :
DH 0 FT / RVR 75 m. (triple A/P).

cheers

Thanks for that,

one last question: To be checked out on the A320 or 737 are you required to bring the plane to 200ft using 'just' the HSI / ILS display or are you allowed to use the FD along with the above.

Once again many thanks.

back to the top!

Air:

On the 737 (don´t know about the NGs) you would probably have to do it.(I did..)

On the 320 I´m not so sure, since the FD-Signals are "better" - probably depends on the company.(FD off is not normal on straight in apps)

All depends on the setup/quality of the computer that gives the FD signals. (and copmany philosophy also)

Nevertheless, you should be able to do raw-data APPs without FDs anyway.

Morse:
"...the ones I (!!) know..."
I forgot about Cat3C ?? (0/75rvr) actually.
Shouldn´t be too many aircraft around that can do it, though.
I know the A300 or A310 in my company was certified for it, but they stopped doing it quite a while ago.

I guess it depends on the carrier. For an initial issue type rating (737), we weren't required to do a raw data ILS (without FD). We had to fly a manual ILS, but we were allowed a FD. I still occasionally fly raw data ILS' - I did one into LHR the other day on a nice day. I tried to keep my head inside a smuch as possible, and kept it comfortably within IR limits to 200'. Great fun too! Don't forget we have a track line on the EHSI which makes it a lot easier.

(We did practice raw data ILS' in the sim, but just weren't actually tested on them. I was required to do a couple durimg my line training though).

[This message has been edited by BmPilot21 (edited 20 June 2001).]