If you wish to contribute or participate in the discussions about articles you are invited to join SKYbrary as a registered user

 Actions

Misaligned Takeoff

From SKYbrary Wiki

Article Information
Category: Runway Excursion Runway Excursion
Content source: SKYbrary About SKYbrary
Content control: SKYbrary About SKYbrary

Description

The situation in which an aircraft is not properly aligned on the assigned takeoff runway at the beginning of the takeoff phase of flight.

Discussion

There are multiple factors that can cause an aircraft to execute a misaligned takeoff. The most significant of these factors are:

Environmental Factors

Environmental factors have a significant effect on the risk of a misaligned takeoff. These include the following:

  • Rain/fog/snow: These can reduce the visibility making it more difficult to see signage, surface lighting, and surface markings from the cockpit, thus making it difficult to determine the correct initial position for takeoff.
  • Night: In nighttime conditions, the visibility is restricted to only taxiway/runway lighting and the limited area that the aircraft lights can illuminate.

Human Factors

There are several human factors issues that can have a negative effect on the risk of a misaligned takeoff. These include:

  • Distraction: Distraction can come in many forms.
    • Communication with the tower or ATC while entering the runway for takeoff
    • Late completion of a required pre-takeoff checklist
  • An issue in the cockpit that requires the crew’s attention (e.g. caution or warning message or light)
    • Fatigue: Any level of fatigue will make the individual/crew less alert and increase the risk of misaligning the aircraft on the runway prior to takeoff

Airport/Aircraft Factors

Aircraft and airport factors play a large role in determining the risk of a misaligned takeoff.

  • Lighting
    • Aircraft lights ineffective or not used : This restricts the visual picture available to the aircrew.
    • Runway centerline lights: These assist the crew in determining the correct takeoff position
    • Taxiway lead in lights that go all the way to the runway centreline
    • Recessed or above ground runway edge lighting: These reinforce if the lights are edge lights or centerline lights. Recessed edge lighting can give the impression and feel of centerline lighting.
    • Non-standard lights or light pattern in the takeoff area can increase the risk of a misaligned takeoff
  • Airport surface environment
    • Width of runway at takeoff area: Extra surface area in the takeoff area can make it more difficult for the crew to determine the correct takeoff position
    • Displaced threshold/intersection takeoff: These remove many of the normal visual references used to determine the correct takeoff position
    • Takeoff area conspicuity (e.g. runway numbers, “piano keys”): These greatly assist the aircrew in determining/confirming takeoff position
    • Runway centerline conspicuity, both lighting and painted area

Related Articles

Runway Excursion

Accident and Incident Reports

Further Reading

ATSB ATSB Research Report AR-2009-033 "Factors influencing misaligned take-off occurrences at night"