Responsibility
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Responsibility
Could some one please tell me who is responsible for terrain clearance in controlled airspace???Could you also give me a reference of where it is written down.
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chinny
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chinny
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UK - CAP493
clearance.
So in short, it is ATC responsibility to ensure levels assigned provide terrain clearance.
13.1 - Controllers are to ensure that levels assigned to:
a) IFR flights in receipt of a radar control service
b) flights in receipt of a radar advisory service and
c) flights in receipt of a radar information service and receiving vectors;
provide adequate terrain clearance for the phase of flight as shown below.a) IFR flights in receipt of a radar control service
b) flights in receipt of a radar advisory service and
c) flights in receipt of a radar information service and receiving vectors;
Within the defined final approach area:
Achieved if levels are assigned in accordance with a procedure approved by the CAA.
Within the RVA or Radar Minimum Altitude Area:
Levels allocated must be in accordance with the information published on the RVA chart or RMAC.
Within 30 miles of the radar antenna associated with the unit providing the service:
1000 feet above any fixed obstacle within (a) 5 miles of the aircraft, and
(b) 15 miles ahead and 20° either side of the aircraft’s track.
When the aircraft is within 15 miles of the antenna, and provided an RVA chart, RMAC or approved procedure has been notified, the 5
miles in (a) and the 15 miles in (b) may be reduced to 3 and 10 miles respectively.
Outside the Phases above:
1000 feet above any fixed obstacle which lies within 15 miles of the centre line of any airway or advisory route (for flights on airways and advisory routes), or within 30 miles of the aircraft (for all other
flights).
Achieved if levels are assigned in accordance with a procedure approved by the CAA.
Within the RVA or Radar Minimum Altitude Area:
Levels allocated must be in accordance with the information published on the RVA chart or RMAC.
Within 30 miles of the radar antenna associated with the unit providing the service:
1000 feet above any fixed obstacle within (a) 5 miles of the aircraft, and
(b) 15 miles ahead and 20° either side of the aircraft’s track.
When the aircraft is within 15 miles of the antenna, and provided an RVA chart, RMAC or approved procedure has been notified, the 5
miles in (a) and the 15 miles in (b) may be reduced to 3 and 10 miles respectively.
Outside the Phases above:
1000 feet above any fixed obstacle which lies within 15 miles of the centre line of any airway or advisory route (for flights on airways and advisory routes), or within 30 miles of the aircraft (for all other
flights).
In sections of airways where the base is defined as a flight level, the lowest useable level normally provides not less than 1500 feet terrain
clearance.
So in short, it is ATC responsibility to ensure levels assigned provide terrain clearance.
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If your question is aimed at the UK, then the answer above will lead you in the right direction.
However, if you are talking about international standards, ATC only accepts repsonsibility for terrain clearance when providing a vector. I think ICAO Doc 4444 refers but, funny old thing, I don't have one of those in my bookcase at home.
Note, we are talking service provision here and not type of airspace.
However, if you are talking about international standards, ATC only accepts repsonsibility for terrain clearance when providing a vector. I think ICAO Doc 4444 refers but, funny old thing, I don't have one of those in my bookcase at home.
Note, we are talking service provision here and not type of airspace.
From Doc 4444 PANS-ATM
Note 3.— The objectives of the air traffic control service as
prescribed in Annex 11 do not include prevention of collision
with terrain. The procedures prescribed in this document do
not therefore relieve the pilots of their responsibility to ensure
that any clearance issued by air traffic control units is safe in
this respect, except when an IFR flight is vectored by radar.
See Chapter 8, 8.6.5.2.
8.6.5.2 When vectoring an IFR flight, the radar controller
shall issue clearances such that the prescribed obstacle
clearance will exist at all times until the aircraft reaches the
point where the pilot will resume own navigation. When
necessary, the minimum radar vectoring altitude shall include
a correction for low temperature effect.
There's an interesting twist here. UK controllers, at least in the southern flatland where the base of the TMA everywhere is at least 1000 ft above the highest obstacle anywhere, seem quite happy to issue instructions to route to waypoints that are not on an aircraft's FPL route. That's all fine if the instructions continue to come, but when the radio fails, who is responsible for making sure that the aircraft can safely return from that off-route waypoint to its cleared route?
One can argue that its doesn't matter, as you're not going to hit anything at FL70 around London on a DCT between any two point. But when crews used to this never-mind-the-clearance-just-do-as-we-say mentality go elsewhere, they could be in for a rude shock, just like the AA965 crew that didn't make it to Cali.
Note 3.— The objectives of the air traffic control service as
prescribed in Annex 11 do not include prevention of collision
with terrain. The procedures prescribed in this document do
not therefore relieve the pilots of their responsibility to ensure
that any clearance issued by air traffic control units is safe in
this respect, except when an IFR flight is vectored by radar.
See Chapter 8, 8.6.5.2.
8.6.5.2 When vectoring an IFR flight, the radar controller
shall issue clearances such that the prescribed obstacle
clearance will exist at all times until the aircraft reaches the
point where the pilot will resume own navigation. When
necessary, the minimum radar vectoring altitude shall include
a correction for low temperature effect.
There's an interesting twist here. UK controllers, at least in the southern flatland where the base of the TMA everywhere is at least 1000 ft above the highest obstacle anywhere, seem quite happy to issue instructions to route to waypoints that are not on an aircraft's FPL route. That's all fine if the instructions continue to come, but when the radio fails, who is responsible for making sure that the aircraft can safely return from that off-route waypoint to its cleared route?
One can argue that its doesn't matter, as you're not going to hit anything at FL70 around London on a DCT between any two point. But when crews used to this never-mind-the-clearance-just-do-as-we-say mentality go elsewhere, they could be in for a rude shock, just like the AA965 crew that didn't make it to Cali.
