Too many questions!
That's why I asked FlightPathOBN what he uses as terrain clearance parameters for his Missed Approach procedures.
Alternatively, here was I thinking that RNP approaches and their Missed Approaches would provide adequate terrain clearance OEI. Perhaps that is not the case.
For standard missed approach, the TERPS/ PansOps criteria.
For RNP, 8260.52, the standard missed approach is all engine. The criteria are based on the following assumptions: (page 4-1 8260.52)
• Aircraft climb at a rate of at least 200 ft/NM (3.29%) in the missed
approach segment.
• A 50-ft height loss is inherent in MA initiation.
The standard MA construction is a continuation of the final approach course. The OEA expands at a 15° splay from the FAS RNP value to a value of 1.0, using a 40:1 OCS slope ratio. Missed approach RF turns that are speed limited must limit bank angles to 15° maximum.
For RNP EO missed, this is a custom design that looks at all segments, with emphasis on turns/bank angles.
OCH determination. 4.7.2.1 First, determine the height of the highest approach obstacle penetrating the final approach OAS or the horizontal plane from Dveb to the origin of the Z surface.
4.7.2.2 Next, reduce the heights of all missed approach obstacles to the height of equivalent approach obstacles by the formula given below:
ha = [(hma*cot Z) - (XZ-X)]/(cot VPA+cot Z)
where:
ha = height of the equivalent approach obstacle
hma = height of the missed approach obstacle
cot Z = cotangent of the Z surface angle
cot VPA = cotangent of the VPA
XZ = origin of the missed approach surface (Z) relative to LTP (Fictitious LTP if appropriate). It is
positive before the LTP/FTP and negative after.
X = Obstacle distance from threshold
and
Missed Approach MOC is:
50 m (164 ft) (Cat H, 40 m (132 ft)) for turns more than 15 degrees and
30 m (98 ft) for turns 15 degrees or less
and a few other borish calcs...
RNP EO procedures are sim and flight checked. THE EO tracks in RNP will be on the specific operators approach charts. Here is a generic example (
page 8)
According to the rule makers, retraction of the undercarriage must wait until the airplane has achieved a steady rate of climb of 100 ft/min, at Vref, approach flap, gear down, one engine inoperative. A tough nut to crack in 8 seconds. The U/C then needs another 5-7 seconds to retract.
Hence the
AC120...
"EOPs are NOT TERPS Or PANS-OPS Criteria
EOPs Do Not Provide Takeoff Data
EOPs Do Not Provide Standard ATC Departure
EOPs Are Not Developed or “Flight Checked”
EOPs Are Not Promulgated Under CFR Part 97
EOPs Are Not “Approved” By The FAA they Are “Accepted”