Landing is the final phase in flight, in which the aircraft returns to the ground. The average vertical speed in a landing is around 2 meters per second (6.6 ft/s); greater vertical speed should be classed by crew as "hard". Crew judgement is most reliable to determine hard landing, as determination based on recorded acceleration value is difficult and not advisable, partially because there is no recording of true vertical acceleration.
Hard landings can be caused by weather conditions, mechanical problems, over-weight aircraft, pilot decision and/or pilot error. The term hard landing usually implies that the pilot still has total or partial control over the aircraft, as opposed to an uncontrolled descent into terrain (a crash). Hard landings can vary in their consequences, from mild passenger discomfort to vehicle damage, structural failure, injuries, and/or loss of life. When an aircraft has a hard landing, it must be inspected for damage before its next flight.
When the final approach isn't stabilised, the crew should abort and go around, as expressed by the Australian Transport Safety Bureau after investigating the hard landing of a Malaysia Airlines Airbus A330 in Melbourne Airport coming from Kuala Lumpur on March 14, 2015.
For helicopters, a hard landing can occur after mechanical or engine damage or failure when the rotor(s) are still intact and free to turn. Autorotation, in which airflow over the rotors keeps them turning and provides some lift, can allow limited pilot control during descent. As an unpowered descent, it requires considerable pilot skill and experience to safely execute.
A hard landing of a spacecraft such as a rocket stage usually ends with its destruction and can be intentional or unintentional. When a high-velocity impact is planned (when its purpose is to study consequences of impact), the spacecraft is called an impactor.
- RALPH MICHAEL GARBER, LAWRENCE VAN KIRK, "Conditional Inspection", Aero, Boeing (14)
- Guillaume Aigoin, Characterising hard landings / EASA EOFDM Conference, 12 January 2012, page 7: "The vertical parameter is neither vertical nor an acceleration … It is the normal load factor in the aircraft reference frame is not sufficient for assessing contact severity!"
- Richard N. Aarons (Jun 22, 2017). "Unstabilized Approach?". Aviation Week Network. ATSB: When In Doubt, Go Around.
- "Hard landing involving an Airbus A330, 9M-MTA, Melbourne Airport, Victoria on 14 March 2015", Aviation safety investigations & reports, ATSB, 5 April 2017
- Stabilized Approach and Flare Are Keys to Avoiding Hard Landings / Flight Safety Foundation, FSF Digest, August 2004