Slow Final Approach Speed

[eeper]

I was operating a ferry flight (757) into LHR yesterday. Obviously with no pax or cargo the Vref was very low giving a final approach speed of 115 knots.

I informed director of this as we turned onto the localiser and was grumpily informed by the (admittedly overworked) controller that I should have told him earlier.

At what stage do you chaps like to be informed of a slow final speed and what, for your purposes, constitutes a sufficiently low speed? Obviously this will vary from aircraft to aircraft, but, as a rough guide, are we talking about 10 knots slower or more? Do you have an average final speed that you use for all aircraft.

All answers gratefully received.

[U R NumberOne]

When to inform ATC will largely depend on where you are - the sequencing at Heathrow being much more speed dependent than at smaller airfields. But if I'm putting together a sequence of four or five, telling me when you're on a base leg or with 15-20 miles to run is enough time for me to sort things out behind you. The big consideration with the 757 is vortex - so a slow final approach speed can erode that separation quicker than might be anticipated.

The only time I'm really amazed by the 757s slow final speed is when helicopters catch it up on the ILS! :eek:

[Gonzo]

We get this quite a lot at Heathrow, especially with 757s. Of course, because of their particular vortex characteristics, a 757 is often followed by a 747 or 777. When doing Arrivals, I'm often told when the aircraft comes on my frequency that it will be slow inside 4DME, by this time Director will have already put the one behind you on the ILS or just about to establish so it's a bit late to do anything except get the one behind slowed down ASAP (not very easy if its a 777 or 747) or maybe switch one if it's looking exceptionally tight.

I'm sure my radar colleagues will jump in with more deatils, but I'd say that you should tell Intermediate Director (ie. 119.72 or 134.97). Any sooner than that is really not needed. I'd imagine a differential of 10 kts from the norm would be about right.

Gonzo.

[ 04 November 2001: Message edited by: Gonzo ]

[HEATHROW DIRECTOR]

I'm happy if you tell me as soon as you call me on 120.4 and I can use the info until I turn you onto the ILS but by the time you're locked on the one behind is already turning on, by which time it's a bit late to do much. If we're going for 2.5nm spacing it's imperative that we have good warning of slow final approach speeds. Many thanks for your consideration..

[OrsonCart]

Any flight that cannot adhere to the following at my unit certainly needs to tell ATC as soon as possible, ideally on first contact.

We use 220/210 downwind, 180 base and 160 to 4 DME if there is a flow of arriving and departing flights. (Which is the norm from 0700-2359.) This allows for uniform presentation to the tower controllers

[HEATHROW DIRECTOR]

OrsonCart... the man meant the reduction inside 4DME. Just about everyone will fly 150-170kts to 4DME but lightly loaded a/c sometime come back to dramatically low speeds close in, as you have probably noticed. If we get adequate warning during the intermediate approach we can add on half a mile so the one behind doesn't overtake over Hatton Cross!

[Gonzo]

Had to laugh last night when the French AF Falcon carrying Jospin into LHR last night for a chin wag with Blair reduced to 120kts at 7 miles out when it was told and read back 160kts to 4DME. Separation got down to around 1.5 miles against the 767 coming up behind, so my colleague in arrivals sent the Falcon around. I'm told that another FAF Falcon (we had three in last night) turned the wrong way while on base leg, and started heading out towards the Thames Estuary!

Gonzo.

[Warwick Hunt]

Reduction inside 4 miles is a huge problem. At some units the tower needs to take this into consideration as radar only provides the 'gap' to 4 miles and this is published in pt2.

The problem for them (The folk in the VCR) is that crew can fly the same plane differently, the plane may well be empty, there could be training on the flight deck, the weather may play a part as well.

Good point HD, a miss read thread?

So what is the problem at Heathrow, you have two runways and falling traffic!

Joke over, although a good debate though!

Bye the way, the post actually says final approach speed and no ref to 4 miles or inside, was that the reason for the Orson post?

[ 05 November 2001: Message edited by: Warwick Hunt ]

[FoxHunter]

We have the opposite problem with the MD11. At heavy weights the final approach speed may be as high as 165k. If the preceeding aircraft slows after 4 miles or the OM the separation becomes a problem.

[Ready]

When my landing weight is quite light, runway lenght and condition permitting, I use Flaps 20 for approach and landing instead of the regular Full Flaps.

It's in our SOP, save time and money and since I can approach 10-20 knots faster using that technique, I feel more in harmony with the flow. The option of going Full Flaps is always there if ATC wanted it for whatever reason.

[Zeitgebers]

In my company ( Charter, not LHR but most other UK airports ) if we are operating an empty positioning sector, the flight number has a 'P' suffix. ie XXX 458P. ( P for Positioning ) Empty aircraft = slow speed inside 4 miles ( 115 kts )
Hope this helps.