Obstacle Clearance surveys
Guest
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Obstacle Clearance surveys
B737 on I/T charter lines up for take off from small Greek island. The captain briefs the engine failure procedure for which the company published runway analysis requires early curve left through 90 deg. to hdg (say) 350. Flap retract height 800ft. There is no other note on the chart. Local knowledge indicates there is another island with spot height 1200 ft, and dead on track 350 deg.- distance 8 miles.
From observation I was sure there would be an outside chance of clobbering the hill while on third segment at 800ft level and accelerating. Should I trust the engineers? Have they taken that spot height into account when giving max take off weights for that runway? I have no idea, except that the spot height worries me in IMC.
So I asked them. It transpires that the island with its 1200 ft spot height is beyond the survey distance provided on the State published obstacle clearance chart for that airport. So yes, Captain - there may well be a chance of clipping the spot height beyond the official surveyed chart distance - but that is your problem, Captain - not ours, because we have met the legal requirement in giving you a safe weight out to the survey limit..
According to the performance engineers, obstacle clearance beyond the survey distance of the take off individual runway analysis chart, becomes the pilot's responsibility.
Clearly this is not on - especially as few runway analysis charts show the survey distance for which the charts are valid.
In my view, the runway analysis charts should give full one engine inoperative obstacle protection up until a safe height is reached from where the crew can make an instrument approach using the relevant charts. This is the policy of the regulator in Australia - but obviously disregarded in some other ICAO states. In the simulator I often see the aircraft one engine inop at max structural, still cleaning up at 800 ft 10 miles from the departure end.
Appreciate your views, as it is my experience that few pilots are aware of the relevant survey distance limits of each runway that they depart from. What are the responsibilities of the performance engineers in this regard?
From observation I was sure there would be an outside chance of clobbering the hill while on third segment at 800ft level and accelerating. Should I trust the engineers? Have they taken that spot height into account when giving max take off weights for that runway? I have no idea, except that the spot height worries me in IMC.
So I asked them. It transpires that the island with its 1200 ft spot height is beyond the survey distance provided on the State published obstacle clearance chart for that airport. So yes, Captain - there may well be a chance of clipping the spot height beyond the official surveyed chart distance - but that is your problem, Captain - not ours, because we have met the legal requirement in giving you a safe weight out to the survey limit..
According to the performance engineers, obstacle clearance beyond the survey distance of the take off individual runway analysis chart, becomes the pilot's responsibility.
Clearly this is not on - especially as few runway analysis charts show the survey distance for which the charts are valid.
In my view, the runway analysis charts should give full one engine inoperative obstacle protection up until a safe height is reached from where the crew can make an instrument approach using the relevant charts. This is the policy of the regulator in Australia - but obviously disregarded in some other ICAO states. In the simulator I often see the aircraft one engine inop at max structural, still cleaning up at 800 ft 10 miles from the departure end.
Appreciate your views, as it is my experience that few pilots are aware of the relevant survey distance limits of each runway that they depart from. What are the responsibilities of the performance engineers in this regard?
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This will vary from airport to airport and depends on airline policy. AIP charts usually go out to a distance of approximately 72,000 feet.
Try insisting that your performance engineers issue an engine failure procedure which finishes at a fixed point, i.e. At 3 miles, right turn back to the VOR and hold. At least this way you know that you will clear all the terrain beneath you.
BTW, the 72,000 feet clearance also applies on straight out departures.
Mutt
Try insisting that your performance engineers issue an engine failure procedure which finishes at a fixed point, i.e. At 3 miles, right turn back to the VOR and hold. At least this way you know that you will clear all the terrain beneath you.
BTW, the 72,000 feet clearance also applies on straight out departures.
Mutt
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Sounds more like a country thing. We operate out of a Greek airport which has no obstacles (according to the airport). We often wondered about the fact we were often at eye level with the cross on the local town's church on heavyweight take-offs. We sent our own surveyers out there to take a look, and now we have something more like accurate obstacle data for the airport.
The other end of the runway has a vertical drop off a cliff into the sea - Lovely!
A prize for guessing which airport.
The other end of the runway has a vertical drop off a cliff into the sea - Lovely!
A prize for guessing which airport.
