Yes, I know that no FAA lawyer dies when a aircraft has a
CFIT during an IDP after an engine failure.

Any competent pilot will consider such "details" and adjust
gross weight, weather or other parameters because pilots
[and passengers] die, not FAA lawyer.



"Bee" wrote in message
...
| Jim Macklin wrote:
| A normal IDP requires 152 ft/nm, about 350 ft. min @ 120
| KIAS.
| Many airports have obstacles that require a steeper
climb,
| so they publish "non-standard TO minima"
| Some airports cannot be departed safely in IMC due to
local
| terrain.
| Altitudes required to clear an obstruction include a
margin,
| 2,000 feet in mountainous regions and 1,000 feet in
other
| areas.
| The IDP gradient at Aspen is based on the angle from the
| departure end to the critical obstacle, a rate that is
well
| above the engine-out performance of most airplanes.
[460
| ft/nm will be close to 1,000 ft/min and most turboprops
| won't do that on one engine, it is the worst your plane
can
| do that is the performance you need to consider.]
| Once past the critical obstacle, a climb at standard
rates
| will be safe. [Again, those rates may be above the
| performance of many smaller, low powered aircraft.]
|
| From AC 120-91:
|
| 7. TERPS CRITERIA VERSUS ONE-ENGINE-INOPERATIVE
REQUIREMENTS.
|
| a. Standard Instrument Departures (SID) or Departure
Procedures (DP)
| based on TERPS or ICAO Procedures for Air Navigation
Services—Aircraft
| Operations (PANS-OPS) are based on normal (all engines
operating)
| operations. Thus, one-engine-inoperative obstacle
clearance requirements
| and the all-engines-operating TERPS requirements are
independent, and
| one-engine-inoperative procedures do not need to meet
TERPS
| requirements. Further, compliance with TERPS
all-engines-operating climb
| gradient requirements does not necessarily assure that
| one-engine-inoperative obstacle clearance requirements are
met. TERPS
| typically use specified all-engines-operating climb
gradients to an
| altitude, rather than certificated one-engine-inoperative
airplane
| performance. TERPS typically assume a climb gradient of
200 feet per
| nautical mile (NM) unless a greater gradient is specified.
For the
| purposes of analyzing performance on procedures developed
under TERPS or
| PANS-OPS, it is understood that any gradient requirement,
specified or
| unspecified, will be treated as a plane which must not be
penetrated
| from above until reaching the stated height, rather than
as a gradient
| which must be exceeded at all points in the path.
Operators must comply
| with 14 CFR requirements for the development of takeoff
performance data
| and procedures. There are differences between TERPS and
| one-engine-inoperative criteria, including the lateral and
vertical
| obstacle clearance requirements. An engine failure during
takeoff is a
| non-normal condition, and therefore takes precedence over
noise
| abatement, air traffic, SIDs, DPs, and other normal
operating
| considerations.