Emergency landing
An emergency landing is an expedited landing made by an aircraft in response to an emergency involving an imminent or ongoing threat to the safety or operation of the aircraft, or involving a sudden need for a passenger or crew on board to terminate the flight (such as a medical emergency).
It typically involves a forced diversion to the nearest or most suitable airport or airbase, an off-airport landing, or ditching if the flight cannot reach an airfield. Flights under air traffic control give priority over all other aircraft operations upon the declaration of the emergency.
Types of Emergency landing
There are several different types of emergency landings for powered aircraft: planned landing or unplanned landing.
1-Forced landing:
The aircraft is forced to make a landing due to technical problems. Landing as soon as possible is a priority, no matter where, since a major system failure has occurred or is imminent.
It is caused by the failure of or damage to vital systems such as engines, landing gear, or hydraulics, and so a landing must be attempted where a runway is needed but none is available.
The pilot is essentially trying to get the aircraft on the ground in a way that minimizes the possibility of injury or death to the people aboard. This means that the forced landing may even occur when the aircraft is still flyable, in order to prevent a crash or ditching situation.
2-Precautionary landing:
May result from a planned landing at a location about which information is limited, from unanticipated changes during the flight, or from abnormal or even emergency situations. This may be as a result of problems with the aircraft, or a medical or police emergency.
The sooner a pilot locates and inspects a potential landing site, the less the chance of additional limitations being imposed by worsening aircraft conditions, deteriorating weather, or other factors.
3-Ditching:
Ditching is the same as a forced landing, only on water. After the disabled aircraft makes contact with the surface of the water, the aircraft will most likely sink if it is not designed to float, although it may float for hours, depending on the damage.
4- Belly landing
It is an emergency landing with the gear in the “up” position. This is usually caused by equipment malfunction (the gear cannot be extended or cannot reach the locked position).
Sometimes the pilots would choose to perform a forced landing with the landing gear intentionally up if they consider this would lead to a safer outcome, especially when landing outside an aerodrome.
A situation where the aircraft lands with the gear up due to human error (i.e. the crew forgetting to extend it) is normally referred to as a “gear up landing”. While this would usually be followed by a rapid RFFS response it is not considered an emergency or belly landing because the crew would not anticipate anything abnormal until the moment the aircraft touches down.
5- Crash landing
A crash landing is a landing where the aircraft receives significant structural damage. Not all emergency landings are classified as crash landings – if the aircraft has remained intact (or has received minor damage) using the term would be inappropriate.
Emergency Landing Procedures
If there is no engine power available during a forced landing, a fixed-wing aircraft glides, while a rotary winged aircraft (helicopter) autorotates to the ground by trading altitude for airspeed to maintain control.
Pilots often practice “simulated forced landings”, in which an engine failure is simulated and the pilot has to get the aircraft on the ground safely, by selecting a landing area and then gliding the aircraft at its best gliding speed.
What do pilots and cabin crew say in an emergency landing?
The procedures for planned and unplanned evacuations (on land), and planned and unplanned ditching (on water). The announcements and procedures are almost verbatim as they would be found in a Flight Attendant Manual.
Ladies and gentlemen, Captain ________ has informed me that we need to prepare the cabin for a possible emergency landing. Your crew is fully trained to handle this situation. We have (approx. time) to prepare the cabin for landing, so your undivided attention is very important!”
Where is the safest place to crash land a plane?
If there is a suitable landing spot within the aircraft’s gliding or autorotation distance, an unplanned landing will often result in no injuries or significant damage to the aircraft, since powered aircraft generally use little or no power when they are landing.
Light aircraft can often land safely on fields, roads, or gravel river banks (or on the water, if they are float-equipped); but medium and heavy aircraft generally require long, prepared runway surfaces because of their heavier weight and higher landing speeds.
Attitude and Sink Rate Control
The most critical and often the most inexcusable error that can be made in the planning and execution of an emergency landing, even in ideal terrain, is the loss of initiative over
the airplane’s attitude and sink rate at touchdown.
When the touchdown is made on flat, open terrain, an excessive nose-low pitch attitude brings the risk of “sticking” the nose in the ground. Steep bank angles just before touchdown should also be avoided, as they increase the stalling speed and the likelihood of a wingtip strike.
Since the airplane’s vertical component of velocity is immediately reduced to zero upon ground contact, it must be kept well under control. A flat touchdown at a high sink rate (well in excess of 500 feet per minute (fpm)) on a hard surface can be injurious without destroying the cabin structure, especially during gear-up landings in low-wing airplanes.
A rigid bottom construction of these airplanes may preclude adequate cushioning by structural deformation. Similar impact conditions may cause a structural collapse of the overhead structure in high-wing airplanes. On soft terrain, an excessive sink rate may cause digging in of the lower nose structure and severe forward deceleration.