Fun morning at LCY

[Dudley]

This airport is definitely a fun place to go. This morning the weather was right down to minima, approach on 10 with 6 kts TWC on the RW but 10 to 15 on the Approach.
ROD of 1600 FPM all the way down, with no Auto-Pilot right down to decision...
It is a little stessful but it is definitely FUN.

Any impression from other people ???

[RAFAT]

Why no A/Pilot?

[This message has been edited by RAFAT (edited 07 January 2001).]

[Boeing Freak]

Dudley?

Thats a strange name for a Frenchman!

[ATCO Two]

Hi Dudley,

I was the Thames Radar controller that morning. Not much fun for us either, especially the multiple go arounds and runway changes. Still it all ended (fairly) happily.

[Dudley]

RAFAT

I fly the Dash 8 and unfortunately, the autopilot is only approved for G/S up to 4.5 degrees. It is the same limit for the flight directors. Therefore we do approaches to LCY with no A/P and no flight directors... Can be fun in bad weather...

[This message has been edited by Dudley (edited 07 January 2001).]

[Sir_Fly-a-Lot]

It might not be approved, but it works fine..

[RAFAT]

Dudley,

We both fly the same machine and I must admit to my question being a leading one.

The DHC-8 AFM states that Autopilot (coupled) and Flight Director (manual) approaches are authorised only for Glideslope angles of 2.5 to 4 degrees, ie. outside these limits, the Autopilot or the manual flying pilot cannot use the Flight Guidance Computer Command Cues in APP mode. Importantly however, these are APP mode, not Autopilot system limitations, and it does not mean that the Autopilot cannot be used to fly an approach, if used in Hdg and Pitch/VS modes, ie. using raw data without coupling the Autopilot to the ILS via APP mode. Remember that not all descent profiles are flown between 2.5 and 4 degrees, and the Autopilot doesn't have to be disengaged in these circumstances does it.

Furthermore, as the AFM limitations are only with reference to Glideslope angles, this suggests that the Localiser may be armed and used, and the Glideslope flown using the Autopilot in a Pitch or VS mode.

Obviously no one objects to you keeping your hand in and doing it manually, but in dodgy weather with strong winds and cloud cover down to minima, I'd rather let the automatics do the work.

[This message has been edited by RAFAT (edited 12 April 2001).]

[Sir_Fly-a-Lot]

Dudley,
RAFAT is right, there is no reason not to use the Autopilot and Flight Director. According to our procedures it is recommended to use AP in V/L as for a Loc. only approach, using V/S to set the required ROD. Actually, even in APP it works just fine, allthough it's not certified.
Cheers, SF.