Obstacle Departure Procedures and Assigned Headings.

by CarlValeri on November 10, 2012

Question From Matt:

On an instrument flight plan in VMC (visual meteorological conditions), before I depart from a runway the tower gives me a specific heading to fly. When I look in the back of the 10-9 page there is a Obstacle Departure Procedure (ODP) for that runway. Now, should I fly the heading and ignore the ODP?

Great question Matt. Occasionally I get this question while briefing the departure. This is one of those scenarios that leads to much confusion because the explanation depends on your operations and we can’t point at one specific place in the regulations for an answer.

The short answer is that you should fly the heading. Now let’s discover why we should fly the assigned heading.

Background:

In 2000, the FAA combined into a single product both textual IFR departure procedures and graphic standard instrument departures (SIDs). This combined product introduced the new term departure procedures (DPs) to the pilot and Air Traffic Control (ATC) community. The FAA for a short period stopped using the terms IFR departure procedure and SID but simply use the term Departure Procedure (DP).

By doing this the FAA realized this was confusing and did not harmonize with the international aviation community. So the FAA reintroduced the term SID while also continuing to use the term ODP (Obstacle Departure Procedure).

Due to complexity of some Obstacle Departure Procedures a Graphical procedure may be published. Furthermore, all RNAV dependent ODP’s will always be in Graphic format. If in graphical format the ODP may be filed in your flight plan as if it was a SID (Standard Instrument Departure).

Matt is using the Jeppesen charts which is a commercial product with information organized in a logical manner. The 10-9 page Matt is referencing has the taxi diagram obstacle departure procedure depicted in textual format if one exists. The 10-9 is normally printed with the taxi diagram on the front page and the runway data on the reverse.

For our discussion I will use the government AeroNav charts but the same rules apply when viewing the Jeppesen charts. The big difference is the government charts normally will have information located on more than one page where Jeppesen consolidates the relevant information on one page.

What is An Obstacle Departure Procedure?

An Obstacle Departure Procedure (ODP):

  • Defines procedures that provide obstacle clearance.
  • Are only used for obstruction clearance.
  • Do not include ATC related climb requirements.
  • Use the least onerous route of flight to the en route structure or at an altitude that allows random (diverse) IFR flight.
  • Only one ODP is established for a runway.
  • Is considered to be the default IFR departure procedure and is intended for use in the absence of ATC radar vectors or a SID assignment.
  • Uses ground based NAVAIDS, RNAV, or dead reckoning guidance wherever possible, without the use of radar vectors for navigation.

Where Do We Find Obstacle Departure Procedures?

If you are using Jeppesen charts then look at the back of the “dash 9” page and you will find a description under the title “OBSTACLE DP” For government charts ODP procedures are listed in the front of the approach chart booklets under the heading “Takeoff Minimums and Obstacle Departure Procedures”. Each procedure is listed in alphabetical order by city and state.

The ODP listing in the front of the booklet will include a reference to the graphic chart located in the main body of the booklet if one exists. Remember pilots do not need ATC clearance to use an ODP and are responsible for determining if the departure airport has a published Obstacle Departure Procedure..

When MUST We Use An Obstacle Departure Procedure?

91.175 of the Code Of Federal Regulations states: (click link to read entire text of the regulation.)

(f) Civil airport takeoff minimums. This paragraph applies to persons operating an aircraft under part 121, 125, 129, or 135 of this chapter.

(3) Except as provided in paragraph (f)(4) of this section, no pilot may takeoff under IFR from a civil airport having published obstacle departure procedures (ODPs) under part 97 of this chapter for the takeoff runway to be used, unless the pilot uses such ODPs.
(4) Notwithstanding the requirements of paragraph (f)(3) of this section, no pilot may takeoff from an airport under IFR unless:
(i) For part 121 and part 135 operators, the pilot uses a takeoff obstacle clearance or avoidance procedure that ensures compliance with the applicable airplane performance operating limitations requirements under part 121, subpart I or part 135, subpart I for takeoff at that airport; or
(ii) For part 129 operators, the pilot uses a takeoff obstacle clearance or avoidance procedure that ensures compliance with the airplane performance operating limitations prescribed by the State of the operator for takeoff at that airport.

When Should We Use a Textual ODP?

An ODP must be developed when obstructions penetrate the 40:1 departure OCS, using a complex set of ODP development combinations to determine each situation and required action. Textual ODPs are only issued by ATC controllers when required for traffic. If they are not issued by ATC, textual ODPs are at the pilot’s option to fly or not fly the textual ODP, even in less than VFR weather conditions, for FAR Part 91 operators, military, and public service.

As a technique, the pilot may enter “will depart (airport) runway via textual ODP” in the remarks section of the flight plan, this information to the controller clarifies the intentions of the pilot and helps prevent a potential pilot/controller misunderstanding. For example if you are departing Newark Airport and want to depart using the textual departure procedure for runway 4 Right then then in the remarks section you should include “will depart KEWR runway 4R via textual ODP”.

Conclusion:

If you are flying part 91 and a textual Obstacle Departure Procedure exists for the runway you are using and ATC assigns you a heading then you must follow the ATC instruction and fly the assign heading after departure. With that said, as pilot in command you are responsible for the safety of the flight and if you feel the vector is not safe then advise ATC you want to follow the written Obstacle Departure Procedure for the runway. Furthermore, it is not required but highly recommended you fly the textual ODP

Thanks again for the question Matt. Safe Flying!

Recommended Reading:

AC 120-91 – Airport Obstacle Analysis

Departure Procedure Climb Gradient And Calculating Your Rate Of Climb

FAR/AIM 2013

Instrument Procedures Handbook. Chapter 2 Takeoffs And Departures.

Pilot Supplies:


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