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Old 29th Mar 2011, 23:59
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Zeffy
 
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CAAP 235-4(0)

1.1 Engine out SIDs (EOSIDs)
Standard Instrument Departures (SIDs) or departure procedures (DPs) are designed in accordance with U.S. Standards for Terminal Instrument Procedures (TERPS) or ICAO Pans-Ops. These are based on normal all-engine operations and assume that the aircraft are capable of maintaining a climb profile.
These departure procedures are normally published as specific routes to be followed or as omni-directional departures, together with procedure design gradients and details of significant obstacles. They are normally established for each runway where instrument departures are expected to be used and they define a departure procedure for the various categories of aircraft used.
In the event of an engine failure, continued adherence to departure procedures may not be possible as SIDs or DPs do not necessarily assure that engine-out obstacle clearance requirements are met.
An engine failure during takeoff is a non-normal condition, and therefore, takes precedence over noise abatement, air traffic, SID’s, DPs, and other normal operating considerations.
The fundamental difference between SIDs and EOSIDs is that SIDs provides the minimum performance considerations to meet the departure requirements assuming an all engine operation whereas EOSIDs are based upon engine out performance in relation to obstacle clearance. EOSIDs can be in the form of a straight departure and or a series of turns.
The guidance is quite similar to 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.
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