AIM Text
- Certain airports have established pre‐taxi clearance programs whereby pilots of departing instrument flight rules (IFR) aircraft may elect to receive their IFR clearances before they start taxiing for takeoff. The following provisions are included in such procedures:
- Pilot participation is not mandatory.
- Participating pilots call clearance delivery or ground control not more than 10 minutes before proposed taxi time.
- IFR clearance (or delay information, if clearance cannot be obtained) is issued at the time of this initial call‐up.
- When the IFR clearance is received on clearance delivery frequency, pilots call ground control when ready to taxi.
- Normally, pilots need not inform ground control that they have received IFR clearance on clearance delivery frequency. Certain locations may, however, require that the pilot inform ground control of a portion of the routing or that the IFR clearance has been received.
- If a pilot cannot establish contact on clearance delivery frequency or has not received an IFR clearance before ready to taxi, the pilot should contact ground control and inform the controller accordingly.
- Locations where these procedures are in effect are indicated in the Chart Supplement.
Source: FAA Aeronautical Information Manual · current edition · paragraph 5-2-1.
Research Notes
AIM 5-2-1 introduces Departure Procedures — the standardized framework for departing aircraft from controlled and uncontrolled airports.
Three departure procedure types:
- ODP (Obstacle Departure Procedure): Provides obstacle clearance from the airport. Published in textual form on the front of the approach plates booklet or graphically. Required when terrain/obstacles prevent standard climb gradient. Pilots fly the ODP without ATC clearance unless an alternative is issued.
- SID (Standard Instrument Departure): ATC-routing departure with specific waypoints, altitudes, and frequencies. Issued by ATC name. Combines obstacle clearance with traffic-flow routing.
- Diverse Vector Area (DVA): Areas around airports where ATC can vector aircraft without an published SID. The DVA provides obstacle clearance for ATC vectors.
Pilot's responsibility: Brief the departure procedure before takeoff. Know the climb gradient required and confirm the aircraft can achieve it under current conditions (weight, density altitude, etc.). Many departures specify required climb gradients ("climb 250 ft/NM") that exceed standard performance.
The 'no SID, no DVA' situation: Some smaller airports have neither SIDs nor DVAs. The pilot relies on the published ODP (or in extreme cases, climbs visually until clear of obstacles).
Reference: § 91.175; AIM 5-2; AC 90-72B (Departure Procedures); FAA-H-8083-16 (IPH) Chapter 4.