Approach Climb Gradient
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Approach Climb Gradient
Hoping to get some performance help. I searched the forums, but couldn't quite find the answer to my questions concerning twin-engine approach climb gradient performance requirements.
I fly almost exclusively off of US DoD approach plates, so I don't have the luxury of being provided a required missed approach climb gradient, an alternate, higher MDA/DH that provides a 2.5% climb path clear of obstacles, or a company provided OEI escape maneuver.
Question 1: Am I doing this math correctly? Published missed approach requires 360ft vertical climb/min for every 60kts of groundspeed. I calculate a missed approach climb gradient of approx 5.9% [(360 ft/NM)/(6076 ft/NM)].
Question 2: At my intended landing weight my flight performance manual shows my aircraft is capable of achieving a greater than 2.5%, but less than 5.9%, One Engine Inop Go-Around climb gradient. Am I overweight to initiate this approach under IMC on two engines?
Thanks!
I fly almost exclusively off of US DoD approach plates, so I don't have the luxury of being provided a required missed approach climb gradient, an alternate, higher MDA/DH that provides a 2.5% climb path clear of obstacles, or a company provided OEI escape maneuver.
Question 1: Am I doing this math correctly? Published missed approach requires 360ft vertical climb/min for every 60kts of groundspeed. I calculate a missed approach climb gradient of approx 5.9% [(360 ft/NM)/(6076 ft/NM)].
Question 2: At my intended landing weight my flight performance manual shows my aircraft is capable of achieving a greater than 2.5%, but less than 5.9%, One Engine Inop Go-Around climb gradient. Am I overweight to initiate this approach under IMC on two engines?
Thanks!
Join Date: Jan 2009
Location: CHINA
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Firstly, the 5.9% climb gradient is based on all engines. If the A/C flight this missed approach procedure, the landing weight maybe reduced very much. So, the only method is to design the one engine out missed approach procedure, to increase the landing weight meanwhile meet the requirement of the regulations.
the minimum FAR 25 approach climb gradients are 2.1% for Twins, 2.4 for Trijets, and 2.7% for Quads;
these limits were derived from flight tests, but for OPS specs approval on the procedure the operator must assure that those certification limits are met...i.e part 121/135 requires that FAR 25 WAT limits are met in order to achieve that minimum gradient... most likely, if there are no annotation to the flight manual, you will meet the requirements---the tabular or graphical data for landing performance i.e either will include a direct measure of gradient or contain a warning annotation such as "shaded/cross-hatched data does not meet approach climb gradients"
the confusing part is how much protection does the procedure provide ?...that's tough stuff so for that I refer you to another recent and intersting thread with a similar theme
http://www.pprune.org/tech-log/44698...-vs-eosid.html
However, as a pilot your responsibility is mainly to assure that either the minimum gradient is met in an approved manner or that any annotations in the AFM/POH are respected, that the best one can hope for the rest is on the operators, certification authorities, and designers...lets hope they've all spoken to, and heard one another
I'm getting to be so boring
here watch this
these limits were derived from flight tests, but for OPS specs approval on the procedure the operator must assure that those certification limits are met...i.e part 121/135 requires that FAR 25 WAT limits are met in order to achieve that minimum gradient... most likely, if there are no annotation to the flight manual, you will meet the requirements---the tabular or graphical data for landing performance i.e either will include a direct measure of gradient or contain a warning annotation such as "shaded/cross-hatched data does not meet approach climb gradients"
the confusing part is how much protection does the procedure provide ?...that's tough stuff so for that I refer you to another recent and intersting thread with a similar theme
http://www.pprune.org/tech-log/44698...-vs-eosid.html
However, as a pilot your responsibility is mainly to assure that either the minimum gradient is met in an approved manner or that any annotations in the AFM/POH are respected, that the best one can hope for the rest is on the operators, certification authorities, and designers...lets hope they've all spoken to, and heard one another
I'm getting to be so boring
here watch this