Aviation Reads - Back to Basics Performance: SID segments and Go-Around Performance

Disclaimer! This is NOT an opinion piece, but rather a collection of various readings and clippings which serve to spur further exploration in the topic. These are not full articles but simply excerpts from the bulk of reading material that is available.  As much citation and references were taken with regards to the topic. Legitimacy and accuracy of the clippings are read at your own discretion.
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Performance
SIDs segments and Go-around performance

SID

There are two basic types of departure routes: straight and turning. Departure routes are based on track guidance acquired within 12 miles (20 km) from the departure end of the runway (DER) on straight departures and within 6 miles (10 km) after completion of turns on departures requiring turns. The design of instrument departure routes and associated obstacle clearance criteria are based on the definition of tracks to be followed by the airplane. When flying the published track, the pilot is expected to correct for known wind to remain within the protected airspace. ATS stands for air traffic services.

Standard Instrument Departure (SID) routing are designed to allow efficient traffic flow, avoidance of noise sensitive areas and deconfliction from both arrival traffic and the traffic from other aerodromes. They also ensure obstacle clearance provided that the standard minimum climb gradient of 200'/nm (3.3%) or, when published, a specified higher climb gradient is met. The standard 3.3% SID gradient exceeds the certification requirements for engine out climb capability in virtually all transport category aircraft. Consequently, in the engine failure case, following the SID routing does not necessarily ensure obstacle clearance.

Engine Out Obstacle Clearance Profile

The Net Takeoff Flight Path for the engine failure case is divided into four segments. Three of these are climbing segments with specified minimum gradients which are dependent upon the number of engines installed on the aircraft and one is a level acceleration segment. A brief description of the four segments is as follows:

1. First Segment - depending upon the regulations under which the aircraft is certified, the first segment begins either at lift-off or at the end of the takeoff distance at a screen height of 35' and a speed of V₂. On a wet runway, the screen height is reduced to 15'. Operating engines are at takeoff thrust, the flaps/slats are in takeoff configuration and landing gear retraction is initiated once safely airborne with positive climb. The first segment ends when the landing gear is fully retracted.engine
   
   
2. Second Segment - begins when the landing gear is fully retracted. Engines are at takeoff thrust and the flaps/slats are in the takeoff configuration. This segment ends at the higher of 400' or specified acceleration altitude. In most cases, the second segment is the performance limiting segment of the climb.
   
   
3. Third or Acceleration Segment- begins at the higher of 400' or specified acceleration altitude. Engines are at takeoff thrust and the aircraft is accelerated in level flight. Slats/flaps are retracted on speed. The segment ends when aircraft is in clean configuration and a speed of V_FS has been achieved. Note that the third segment must be completed prior to exceeding the maximum time allowed for engines at takeoff thrust.
   
   
4. Fourth or Final Segment - begins when the aircraft is in clean configuration and at a speed of V_FS. Climb is re-established and thrust is reduced to maximum continuous (MCT). The segment ends at a minimum of 1500' above airport elevation or when the criteria for enroute obstacle clearance have been met.

Each segment of the one engine inoperative takeoff flight path has a mandated climb gradient requirement.
For example, a gross second segment climb gradient capability of 2.4%, 2.7% or 3.0% is required for two, three and four engine aircraft respectively. Similarly, the required gross gradients for the fourth segment are 1.2%, 1.5% and 1.7% respectively.

Missed Approach PANS OPS doc 8168

Source:
- https://www.skybrary.aero/index.php/Emergency_Turn
- https://www.skybrary.aero/index.php/Engine_Failure_During_Takeoff_-_Multi-Engine_Transport_Category_Jet_Aircraft
- https://www.skybrary.aero/index.php/Required_Navigation_Performance_(RNP)

- An Illustrated Dictionary of Aviation Copyright © 2005 by The McGraw-Hill Companies, Inc. All rights reserved
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- www.v-prep.com