AIM Text
- In order to enhance airport capacities, reduce taxiing distances, minimize departure delays, and provide for more efficient movement of air traffic, controllers may initiate intersection takeoffs as well as approve them when the pilot requests. If for ANY reason a pilot prefers to use a different intersection or the full length of the runway or desires to obtain the distance between the intersection and the runway end, THE PILOT IS EXPECTED TO INFORM ATC ACCORDINGLY.
- Pilots are expected to assess the suitability of an intersection for use at takeoff during their preflight planning. They must consider the resultant length reduction to the published runway length and to the published declared distances from the intersection intended to be used for takeoff. The minimum runway required for takeoff must fall within the reduced runway length and the reduced declared distances before the intersection can be accepted for takeoff.
- Controllers will issue the measured distance from the intersection to the runway end rounded “down” to the nearest 50 feet to any pilot who requests and to all military aircraft, unless use of the intersection is covered in appropriate directives. Controllers, however, will not be able to inform pilots of the distance from the intersection to the end of any of the published declared distances.
- An aircraft is expected to taxi to (but not onto) the end of the assigned runway unless prior approval for an intersection departure is received from ground control.
- Pilots should state their position on the airport when calling the tower for takeoff from a runway intersection.
- Controllers are required to separate small aircraft that are departing from an intersection on the same runway (same or opposite direction) behind a large nonheavy aircraft (except B757), by ensuring that at least a 3-minute interval exists between the time the preceding large aircraft has taken off and the succeeding small aircraft begins takeoff roll. The 3-minute separation requirement will also be applied to small aircraft with a maximum certificated takeoff weight of 12,500 pounds or less departing behind a small aircraft with a maximum certificated takeoff weight of more than 12,500 pounds. To inform the pilot of the required 3-minute hold, the controller will state, “Hold for wake turbulence.” If after considering wake turbulence hazards, the pilot feels that a lesser time interval is appropriate, the pilot may request a waiver to the 3-minute interval. To initiate such a request, simply say “Request waiver to 3-minute interval” or a similar statement. Controllers may then issue a takeoff clearance if other traffic permits, since the pilot has accepted the responsibility for wake turbulence separation.
- The 3-minute interval is not required when the intersection is 500 feet or less from the departure point of the preceding aircraft and both aircraft are taking off in the same direction. Controllers may permit the small aircraft to alter course after takeoff to avoid the flight path of the preceding departure.
- A 4-minute interval is mandatory for small, large, and heavy aircraft behind a super aircraft. The 3-minute interval is mandatory behind a heavy aircraft in all cases, and for small aircraft behind a B757.
Source: FAA Aeronautical Information Manual · current edition · paragraph 4-3-10.
The short answer
This AIM section gives FAA advisory guidance on intersection takeoffs—departing from a point other than the runway end to enhance capacity and reduce delays. It covers pilot responsibility to assess reduced runway/declared distances, stating your position to the tower, and wake-turbulence separation intervals behind larger aircraft.
Research Notes
Common Questions
Can I decline an intersection takeoff and use the full runway?
Yes. Controllers may initiate or approve intersection takeoffs, but if for any reason a pilot prefers a different intersection or the full length of the runway, or desires the distance between the intersection and runway end, the pilot is expected to inform ATC accordingly. Pilots must consider the resultant length reduction to the published runway length and declared distances before accepting an intersection.
What is the wake-turbulence wait for a small aircraft behind a large jet at an intersection?
Controllers separate small aircraft departing from an intersection on the same runway behind a large nonheavy aircraft (except B757) by ensuring at least a 3-minute interval. A 3-minute interval is mandatory behind a heavy in all cases and behind a B757; a 4-minute interval is mandatory for small, large, and heavy aircraft behind a super. The controller states, “Hold for wake turbulence.”
When is the 3-minute wake-turbulence interval not required?
The 3-minute interval is not required when the intersection is 500 feet or less from the departure point of the preceding aircraft and both aircraft are taking off in the same direction. A pilot may also request a waiver by saying “Request waiver to 3-minute interval,” accepting responsibility for wake turbulence separation, and controllers may then issue takeoff clearance if traffic permits.