Land and hold short operations
From Wikipedia, the free encyclopedia
Land and Hold Short Operations (or LAHSO, pronounced "La-So") is an Aeronautical term referring to a situation in which a landing aircraft is forced to land and hold (stop short and fast) on the runway to avoid collision with another object, or to avoid hazardous conditions on the runway.
The name for this category of procedures was previously SOIR (Simultaneous Operations on Intersecting Runways), but the guidelines for LAHSO incorporates all of the SOIR definitions and expands upon them now.
[edit] Types
There are three main types of LAHSO.
- LAHSO of Intersecting Runway: In this LAHSO, a landing plane is instructed to land and hold on the runway before the intersection of it and another runway, which will have another aircraft taking off or landing when they arrive.
- LAHSO of Intersecting Taxiway: In this LAHSO, a landing plane is instructed to land and hold on the runway before the intersection of it and a Taxiway, which will have other aircraft taxiing for landing or takeoff when they arrive.
- LAHSO of Point on Runway: In this LAHSO, a landing plane is instructed to land and hold on the runway before a designated point. This form of LAHSO is the newest, and is used when safety precautions are needed due to hazards concerning other runways, taxiways, or any of a number of other hazards for a landing plane that may be present on their runway (ice, for instance).
[edit] Notes
- A heightened level of situational awareness is necessary for these procedures.
- Although used in the US, many countries do not permit the use of LAHSO clearances, and some airlines' operating procedures do not allow the acceptance of LAHSO clearances in those countries that do permit it.
- In the US, pilots have the authority to decline a land-and-hold-short clearance. Air traffic control must then re-vector the aircraft to provide adequate spacing.
