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PIA Boeing 747 - Approach into London Heathrow
An ATC (Air Traffic Control) account of a PIA 747s approach into
London Heathrow. - [With ATC Sounds]
by Alan Moss, Air Traffic Controller, London Heathrow
Sound recorded and added by Jamie J. Alnasir
As the aircraft enters UK airspace, it is handed to Area Control which
is based at the London Area and Terminal Control Centre (LATCC) at
West Drayton, London. (3miles North of Heathrow). Here, all UK
airspace as for North as Scotland is controlled. As the aircraft
crosses into UK airspace it starts its descent. Coming down to
Flight Level (FL) 215 (21500ft) it is handed to Terminal Control.
Terminal control provides ATC for the London Terminal Manoueuvring
Area (LTMA) which is a block of airspace covering most of the South
East of England up to FL215 and is some of the worlds busiest
It approaches from the East into TC North east's airspace, and is
given directions to the designated holding stack to the North East of
Heathrow - Lambourne (LAM). When it is clear of all
conflictions, (Gatwick, Luton and Stansted outbounds) descending to
FL80 to FL120 (holding levels) it is transferred to heathrow Approach,
which is where I work.
Approach is split into 4 positions
(INT) director South on Freq 134.97.
Intermediate (INT director North and North Support on Freq 119.72
Final Director on Freq 120.4. (Listen
to Sound )
INT north looks after the Bovingdon (BNN) and Lambourne (LAM) holds.
The Ockham (OCK) and Biggin (BIG) stacks are controlled by the INT
The director then decides on an order to get his aircraft in to
Heathrow. Whilst in the hold (if not already) the aircraft is
descended to FL80 and then brought off the stack on a radar heading.
The aircraft is also "Speed Controlled" by us and normally
flies downwind at 210/220 knots. The aircraft is then normally
descended to FL70 only as the outbound aircraft on SID's (Standard
Instrument Departures) are climbing to 6000 feet.
When downwind and away from the outbound traffic, the final descent
can begin. At Heathrow, Continuous Descent Approaches (CDAs) are
carried out. This means that the aircraft starts its final
descent when it has a certian track distance to run. Basically,
a CDA means that less fuel is used by the aircraft who hopefully won't
have to level off before the ILS. It is also better for the
local communties as there is less noise and pollution on the ground.
As a rule, we allow 1000 foot of descent for every 3 track miles to
go. Therefore, the final descent form FL70 is started at
approximately 25 miles form touchdown. We remind pilots of there
track distance at least 3 times, so that they may smoothly descend
When it has approx 20 miles to run, it is given the instruction to
"Report Callsign Only to Director on 120.4" The
aircraft then calls the final director who will pack the aircraft in
as close as is possible for the landing runway. The minimum
distance between aircraft types depends on its Wake Vortex Category.
For the LTMA, we have 5 grades.
HEAVY - B747'2/767's/MD11's/A 340 etc
Upper MEDIUM - B757/IL62/VC10 etc
Lower MEDIUM - B737/A320 etc
SMALL - BA 146/Gulfstream 4 etc
LIGHT - Citation/BAe 125 etc
These categories are based on MTOW (Maximum take-off weight).
Obviously, a Citation following a B747 needs maximum spacing (7 miles)
whilst a B737 followed by an A320 needs the mimum of 3 miles spacing
due to wake vortex (Listen
We can use 2.5 mile spacing on final if there is NO Vortex
consideration. (i.e BAe 125 followed by a B747).
Leg turn and Final Approach
FINAL director now gives the aircraft a base leg turn, at right angles
to the final approach (Listen
to Sound ).
He also instructs the aircraft to reduce speed to 180 knots and
continue its descent to 4000 feet
When he judges so, he will then turn the aircraft onto an intercepting
heading for the ILS localiser. Ideally, this will be at about 15
miles from touchdown, but can be as far out as 22miles. This
must be within 30 degrees of the final approach track (i.e. For
runway 09L, a heading of 120 degrees from the North, or 060 degrees
from the South.
The aircraft is told "Report Localiser Established on Runway 09
When the aircrafts reports established it is then "Cleared to
descend on the ILS" (Listen
At the same time, up to 3 aircraft can be establishing, with maybe 4
or more flying the ILS.
The controller must then tell the aircraft to "Reduce speed to
160 knots until 4 DME" (Listen
DME is the Distance Measuring Equipment and is coupled with the ILS to
give distance from touchdown and replaces Outer/Inner markers.
This speed restriction ensures that the aircraft will not catch up the
aircraft in front, or impede the aircraft just 3 miles behind!
Any erosion of seperation is a safety issue and the aircraft will have
to break off the approach if within the vortex rules.
Now there is nothing for us to do. The aircraft is then
instructed to "Contact Heathrow Tower on 118.7" (Listen
to Sound ).
Heathrow Tower then receive the aircraft, and they have been watching
the sequencing on a computerised radar picture in the Visual Control
Room (VCR). Normally, they are informed of there position and
told to continue approach "you are number 3, continue approach
In the UK, landing clearance can ONLY be given to one aircraft at a
time. When Cleared to land and given the wind, the aircraft
rolls down the landing runway. When under control and slowing
down, the controller instructs the aircraft to "Vacate Right and
contact Ground Control on 126.42"
The aircraft then calls ground and is given instructions to navigate
the labyrinth of taxiways which is Heathrow airport. It is then
given a stand number, and is marchalled in by a team of engineers.
The aircraft then is cleaned, emptied, turned around and returns to
Pakistan often only 2 hours later!!"