Approach Segment gradient Vs PANS OPS missed app. gradient
Thread Starter
Joined: Sep 2003
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From: Paris
Approach Segment gradient Vs PANS OPS missed app. gradient
Hi all,
maybe one of you can explain me where i'm wrong in my understanding of regulations...
A 2 engines aircraft with one engine out should be able to climb at least 2.1 % Gradient.
However, according to PANS OPS, a missed approach procedure is constructed as to require a 2.5% Gradient in the intermediate missed approach segment...
Does that mean that an aircraft with one engine out climbing at 2.2% (for example..) during a go around following the published missed approach procedures would not meet the MOC (min obst. clearance) provided by the missed app. proc. ? and consequently can hit an obstacle?
I must have misunderstood something somewhere, please clarify me
maybe one of you can explain me where i'm wrong in my understanding of regulations...
A 2 engines aircraft with one engine out should be able to climb at least 2.1 % Gradient.
However, according to PANS OPS, a missed approach procedure is constructed as to require a 2.5% Gradient in the intermediate missed approach segment...
Does that mean that an aircraft with one engine out climbing at 2.2% (for example..) during a go around following the published missed approach procedures would not meet the MOC (min obst. clearance) provided by the missed app. proc. ? and consequently can hit an obstacle?
I must have misunderstood something somewhere, please clarify me
Joined: Sep 2004
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From: Devon
with a discontinued instrument approach climb calculations with decision height s below 200' we have to take into account the take off mass and fuel expected to be consumed in flight ,allowing a missed approach grad of climb with the crit eng off and with the speed and config used for a go around than it is 2.5% at least or the published grad whichever is greater
i hope this helps
i hope this helps
Joined: Jun 2004
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From: Australia
You haven't misunderstood anything iaf_22, that's exactly the way it is. Stinks doesn't it
You have 3 basic options available -
(1) For a OEI missed approach, use a higher minima, so that the lesser gradient lies above the obstacle-clear plane derived from PANS-OPS, OR
(2) Develop "Special" missed approach procedures for OEI operations, much as we do for the Takeoff case, OR
(3) Limit your landing weight to that at which the missed approach gradient, which may be higher than 2.5% (e.g. 7.0% for Hong Kong 07L), is achievable by the aircraft with OEI.
The first 2 are difficult to calculate, and option (2) is fraught with problems if you use the OEI Takeoff procedure for the same runway (but better than nothing although risky).
The best option is No. (3), which is what I provide data for in the Ops Manuals which I produce, safe, simple, and practical.
Regards,
Old Smokey
You have 3 basic options available -
(1) For a OEI missed approach, use a higher minima, so that the lesser gradient lies above the obstacle-clear plane derived from PANS-OPS, OR
(2) Develop "Special" missed approach procedures for OEI operations, much as we do for the Takeoff case, OR
(3) Limit your landing weight to that at which the missed approach gradient, which may be higher than 2.5% (e.g. 7.0% for Hong Kong 07L), is achievable by the aircraft with OEI.
The first 2 are difficult to calculate, and option (2) is fraught with problems if you use the OEI Takeoff procedure for the same runway (but better than nothing although risky).
The best option is No. (3), which is what I provide data for in the Ops Manuals which I produce, safe, simple, and practical.
Regards,
Old Smokey
Fleet Manager
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From: various places .....
iaf_22,
A lot of folk forget that we are comparing oranges with apples .. Certification Design Standards prescribe a bunch of things including lines in the sand minimum performance criteria for various conditions.
In the real world there are many occasions when the aircraft's weight has to be restricted to meet the requirement of the day ... having to schedule RTOW data for departure ... having to restrict TOW to make an OEI cruise capability to match a high enroute terrain requirement... or having to address a host of other limiting requirements along the way ... having to take a lesser payload to permit enough fuel to be uplifted for the sector distance ... etc., etc ...
A lot of folk forget that we are comparing oranges with apples .. Certification Design Standards prescribe a bunch of things including lines in the sand minimum performance criteria for various conditions.
In the real world there are many occasions when the aircraft's weight has to be restricted to meet the requirement of the day ... having to schedule RTOW data for departure ... having to restrict TOW to make an OEI cruise capability to match a high enroute terrain requirement... or having to address a host of other limiting requirements along the way ... having to take a lesser payload to permit enough fuel to be uplifted for the sector distance ... etc., etc ...
Joined: Jan 2000
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PANS OPS is predicated on normal operations. It would be impossible for a procedure designer to develop a generic OEI procedure.
Contingency operation planning responsibility falls on individual operators, I'm afraid - but your local procedure designer would probably help for a modest fee......
Contingency operation planning responsibility falls on individual operators, I'm afraid - but your local procedure designer would probably help for a modest fee......
Joined: Apr 2002
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From: boh
I think i understand but I had this question thrown at me.
"Certification approach climb gradient is 2.1% and the MISAP gradient is 2.5%. Could you show how this is possible..
Can i show this easily by just drawing it out......
"Certification approach climb gradient is 2.1% and the MISAP gradient is 2.5%. Could you show how this is possible..
Can i show this easily by just drawing it out......
