AIM

4/3/14

5−2−6

Departure Procedures

DEPARTURE (OBSTACLE), or, CROWN ONE

DEPARTURE (RNAV) (OBSTACLE). Standard In-

strument Departures are air traffic control (ATC)

procedures printed for pilot/controller use in graphic

form to provide obstruction clearance and a transition

from the terminal area to the appropriate en route

structure. SIDs are primarily designed for system en-

hancement and to reduce pilot/controller workload.

ATC clearance must be received prior to flying a SID.

All DPs provide the pilot with a way to depart the air-

port and transition to the en route structure safely.

Pilots operating under 14 CFR Part 91 are strongly

encouraged to file and fly a DP at night, during mar-

ginal Visual Meteorological Conditions (VMC) and

Instrument Meteorological Conditions (IMC), when

one is available. The following paragraphs will pro-

vide an overview of the DP program, why DPs are

developed, what criteria are used, where to find them,

how they are to be flown, and finally pilot and ATC

responsibilities.

a.

Why are DPs necessary? The primary reason is

to provide obstacle clearance protection information

to pilots. A secondary reason, at busier airports, is to

increase efficiency and reduce communications and

departure delays through the use of SIDs. When an in-

strument approach is initially developed for an

airport, the need for DPs is assessed. The procedure

designer conducts an obstacle analysis to support de-

parture operations. If an aircraft may turn in any

direction from a runway within the limits of the as-

sessment area (see paragraph 5−2−8b3) and remain

clear of obstacles, that runway passes what is called

a diverse departure assessment and no ODP will be

published. A SID may be published if needed for air

traffic control purposes. However, if an obstacle pen-

etrates what is called the 40:1 obstacle identification

surface, then the procedure designer chooses whether

to:

1.

Establish a steeper than normal climb gradi-

ent; or

2.

Establish a steeper than normal climb gradi-

ent with an alternative that increases takeoff minima

to allow the pilot to visually remain clear of the ob-

stacle(s); or

3.

Design and publish a specific departure route;

or

4.

A combination or all of the above.

b.

What criteria is used to provide obstruction

clearance during departure?

1.

Unless specified otherwise, required obstacle

clearance for all departures, including diverse, is

based on the pilot crossing the departure end of the

runway at least 35 feet above the departure end of run-

way elevation, climbing to 400 feet above the

departure end of runway elevation before making the

initial turn, and maintaining a minimum climb gradi-

ent of 200 feet per nautical mile (FPNM), unless

required to level off by a crossing restriction, until the

minimum IFR altitude. A greater climb gradient may

be specified in the DP to clear obstacles or to achieve

an ATC crossing restriction. If an initial turn higher

than 400 feet above the departure end of runway

elevation is specified in the DP, the turn should be

commenced at the higher altitude. If a turn is speci-

fied at a fix, the turn must be made at that fix. Fixes

may have minimum and/or maximum crossing alti-

tudes that must be adhered to prior to passing the fix.

In rare instances, obstacles that exist on the extended

runway centerline may make an “early turn” more de-

sirable than proceeding straight ahead. In these cases,

the published departure instructions will include the

language “turn left(right) as soon as practicable.”

These departures will also include a ceiling and visi-

bility minimum of at least 300 and 1. Pilots

encountering one of these DPs should preplan the

climb out to gain altitude and begin the turn as quickly

as possible within the bounds of safe operating prac-

tices and operating limitations. This type of departure

procedure is being phased out.

NOTE

−

“Practical” or “feasible” may exist in some existing de-
parture text instead of “practicable.”

2.

ODPs and SIDs assume normal aircraft per-

formance, and that all engines are operating.

Development of contingency procedures, required

to cover the case of an engine failure or other

emergency in flight that may occur after liftoff, is

the responsibility of the operator. (More detailed

information on this subject is available in Advisory

Circular AC 120−91, Airport Obstacle Analysis, and

in the “Departure Procedures” section of chapter 2 in

the Instrument Procedures Handbook,

FAA−H−8261−1.)

3.

The 40:1 obstacle identification surface

(OIS) begins at the departure end of runway (DER)

and slopes upward at 152 FPNM until reaching the

minimum IFR altitude or entering the en route struc-