Take Off & Landing Clearance as Busy Airports
Join Date: Jun 2001
Location: Hampshire UK
Age: 70
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At the larger airports there are three methods of giving aircraft 'permission' to land. The first is of course "cleared to land", when the runway is completely unoccupied. The other methods are sometimes confused as is evident from the responses I have received from pilots during my 21 years at EGLL. They are the "land after procedure" and the "cleared to land after" procedure. The "cleared to land after" procedure can only be used at airports with runways longer than 2500m. It started out as a UK procedure but is now in use at several major European airports as an example of best practice adopted by the JAA. It originated for two reasons: firstly some companies required in their Ops Manuals that their aircraft had a proper landing clearance before a landing was made - (albeit a conditional one as I will explain), secondly its use avoided talking to the crews on very short final.
I will now highlight the differences between the two procedures quoting from the Manuals of AIr Traffic Services
Land After Procedure
A landing aircraft will not be permitted to cross the beginning of the runway on its final approach until a preceding departing aircraft is airborne.
A landing aircraft may be permitted to touch down before a preceding landing aircraft which has landed is clear of the runway provided that:-
a) the runway is long enough to allow safe separation between the two aircraft and there is no evidence to indicate that braking may be adversely affected
b) it is during daylight hours
c) the controller is satisfied that the landing aircraft will be able to see the preceding aircraft which has landed clearly and continuously, until it is clear of the runway, and
d) the pilot of the following aircraft is warned.
Responsibility for ensuring adequate separation rests with the pilot of the following aircraft.
Clear to Land After Procedure
When then runway is temporarily occupied by other traffic, landing clearance may be issued to an arriving aircraft provided that the Air Controller is satisfied that at the time the aircraft crosses the threshold, the following conditions will exist:-
a) Landing following landing
The preceding aircraft will be clear of the runway in use or at least 2500m from the threshold
b) Landing following departure
The departing aircraft will be airborne and at least 2000m from the threshold or if not airborne at least 2500m from the threshold
(These distances are reduced to 1500m in all cases when both aircraft concerned weigh less than 5700kg).
These special procedures are to be used by day only and under the following conditions:-
a) Reported met conditions are equal to or better than vis 6km and cloud ceiling 1000ft and the Air Controller is satisfied that the pilot of the next arriving aircraft will be able to continously observe the relevant traffic
b) When both aircraft are being operated normally (pilots responsible for notifying ATC if otherwise)
c) When the runway is dry and the braking action is good
d) When the Air Controller is able to assess separations either visually or by means of ATM (Aerodrome Traffic Monitor) information
RTF phraseology when runway temporarily occupied. "BAW123 after the landing/departing (type) cleared to land 27L".
The "Cleared to Land After" procedure may not be used when both aircraft are still in the air. (Impossible to judge whether preceding will be 2500m down the runway or clear when next arriving aircraft crosses the threshold). The CLA procedure is a landing clearance with the ATCO taking responsibility for separation. The LA procedure is not a landing clearance - the pilot is responsible for judging separation. CLA may be used after departing traffic - LA may not. Weather criteria are built into the use of CLA - none for LA.
The "land after" procedure can be used at all aerodromes. The "cleared to land after" procedure is only used at EGLL, EGKK, EGSS and EGCC (?)
I am sorry that this reply is so detailed. but I hope that it clarifies the differences between the procedures. I will be pleased to answer any other ATC questions that you might have.
I will now highlight the differences between the two procedures quoting from the Manuals of AIr Traffic Services
Land After Procedure
A landing aircraft will not be permitted to cross the beginning of the runway on its final approach until a preceding departing aircraft is airborne.
A landing aircraft may be permitted to touch down before a preceding landing aircraft which has landed is clear of the runway provided that:-
a) the runway is long enough to allow safe separation between the two aircraft and there is no evidence to indicate that braking may be adversely affected
b) it is during daylight hours
c) the controller is satisfied that the landing aircraft will be able to see the preceding aircraft which has landed clearly and continuously, until it is clear of the runway, and
d) the pilot of the following aircraft is warned.
Responsibility for ensuring adequate separation rests with the pilot of the following aircraft.
Clear to Land After Procedure
When then runway is temporarily occupied by other traffic, landing clearance may be issued to an arriving aircraft provided that the Air Controller is satisfied that at the time the aircraft crosses the threshold, the following conditions will exist:-
a) Landing following landing
The preceding aircraft will be clear of the runway in use or at least 2500m from the threshold
b) Landing following departure
The departing aircraft will be airborne and at least 2000m from the threshold or if not airborne at least 2500m from the threshold
(These distances are reduced to 1500m in all cases when both aircraft concerned weigh less than 5700kg).
These special procedures are to be used by day only and under the following conditions:-
a) Reported met conditions are equal to or better than vis 6km and cloud ceiling 1000ft and the Air Controller is satisfied that the pilot of the next arriving aircraft will be able to continously observe the relevant traffic
b) When both aircraft are being operated normally (pilots responsible for notifying ATC if otherwise)
c) When the runway is dry and the braking action is good
d) When the Air Controller is able to assess separations either visually or by means of ATM (Aerodrome Traffic Monitor) information
RTF phraseology when runway temporarily occupied. "BAW123 after the landing/departing (type) cleared to land 27L".
The "Cleared to Land After" procedure may not be used when both aircraft are still in the air. (Impossible to judge whether preceding will be 2500m down the runway or clear when next arriving aircraft crosses the threshold). The CLA procedure is a landing clearance with the ATCO taking responsibility for separation. The LA procedure is not a landing clearance - the pilot is responsible for judging separation. CLA may be used after departing traffic - LA may not. Weather criteria are built into the use of CLA - none for LA.
The "land after" procedure can be used at all aerodromes. The "cleared to land after" procedure is only used at EGLL, EGKK, EGSS and EGCC (?)
I am sorry that this reply is so detailed. but I hope that it clarifies the differences between the procedures. I will be pleased to answer any other ATC questions that you might have.
Join Date: Jun 2001
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>Take Off and Landing Clearances at Busy Airports<
Hi Mitchell,
If by "your original post" you mean the fact that a procedure was used whereby two aircraft were given almost simultaneous take off clearance from different points on the runway, then I can authoritatively state that there is no provision for this in the Manual of ATS. Having said that, during single runway operations when getting two aircraft away in a gap, I have on rare occasions launched the second aircraft seconds before the first aircraft's wheels have left the runway, but only when I was certain that the first aircraft was just about to rotate. When teaching single runway operations to trainees, the rule of thumb I use is that the departing aircraft should be rolling before the arriving aircraft reaches a two mile final. Adherence to this rule should obviate the need for "quick fire" take off clearances such as you experienced. I also teach trainees to swallow their pride and send the landing aircraft around at an early stage if it is not going to work, simultaneously cancelling the take off clearance of the departing aircraft. The worst case scenario is a departure climbing underneath a go around.
