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Terrain Clearance Section - what is it?

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Hi Phil,

 

Under the "Advanced" section.  See the attached picture.

 

Cheers,

Rudy

Terrain Clearance.png

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It is actually as fundamental as EDTO (ETOPS) or take-off speeds calculation, but ignored by most people flying flight simulators. Per legal requirements, to put is simply, you have to ensure that aircraft will be capable to operate by at least X margin (typically, 1000 feet) above terrain elevation along any point of your route (plus some width margin buffer) with one engine inoperative (for twins), given actual planned weight. If this criteria is not met, you either reduce takeoff weight to achieve it, or re-route to avoid high terrain. These requirements vary from authority to authority. You may find more about this subject by googling terms such as 'net level off altitude' and 'drift down analysis'. PFPX implementation is simple and does allow second method (full drift down analysis), but it is good enough. To manually determine compliance with this requirement you would take net level off weight chart from FPPM (for Boeing aircraft) and terrain elevation data; PFPX automates this process to a certain degree.

 

Another area which is really missing in PFPX is oxygen profile (you have to ensure that in case of decompression, aircraft will be capable to descent to X altitude within specific time limit, considering actual terrain profile along your route).

 

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nothing else to add. for oxy it can be interesting as different are offered for airlines. but we are far from simulation .... 

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Thanks for the answer!  Indeed a good explanation.  I tend to only worry about terrain >14,000' for oxygen/depressurisation procedures if needed.

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