UNSTABILISED APPROACH :Inappropriate ATC Speed Instructions

  The Flight Safety Foundation has found that a crew’s inability to control the aircraft to the desired flight parameters (airspeed, altitude, rate of descent) was a major factor in 45 % of 76 approach-and-landing accidents and serious incidents. Flight-handling difficulties have occurred in situations which included rushing approaches, attempts to comply with demanding ATC clearances, adverse weather conditions and improper use of automation.

At many airports, ATC speed controls are rigorously followed for expeditious handling of traffic.  At times the controllers fail to take into consideration presence of significant headwind or tailwind conditions present at altitude and give speed control instructions that are incompatible with the required vertical profile below FL100 and distance to go to land.

This places an unusually high workload on the pilot to achieve the desired flight path and affects the crew’s ability maintain situational awareness.

With modern aircraft designed to have efficient aerodynamic characteristic which needs longer distances for descent and deceleration there is an increased risk of an unstabilised approach developing, which may be difficult to correct and culminate in either a go around or a poorly handled landing with increased  risk of runway excursions.