Emergency landing
View on Wikipediafrom Wikipedia
 | This article needs additional citations for verification. (August 2008) |
An emergency landing is a premature landing made by an aircraft in response to an emergency involving an imminent or ongoing threat to the safety and 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, or an off airport landing or ditching if the flight cannot reach an airfield. Flights under air traffic control will be given priority over all other aircraft operations upon the declaration of the emergency.
Types
[edit]There are several different types of emergency landings for powered aircraft: planned landing or unplanned landing.
- 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, hydraulics, or landing gear, 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 which 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.
- 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.
- 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 damage.
Procedures
[edit]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.
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. Glider pilots routinely land away from their base and so most cross-country pilots are in current practice.
UAV forced landing research
[edit]Since 2003, research has been conducted on enabling unmanned aerial vehicles to perform a forced landing autonomously.[1]
Notable examples
[edit]Large airliners have multiple engines and redundant systems, so forced landings are extremely rare for them, but some notable ones have occurred. A famous example is the Gimli Glider, an Air Canada Boeing 767 that ran out of fuel and glided to a safe landing in Gimli, Manitoba, Canada on July 23, 1983. In June 1982, British Airways Flight 9, a Boeing 747 en route from Kuala Lumpur to Perth flew into a plume of volcanic ash and lost power in all four engines, three of which subsequently recovered, eventually diverting to Jakarta. On April 28, 1988, Aloha Airlines Flight 243 experienced an explosive decompression when approximately 35 square metres (380 sq ft) of aluminium skin separated from the fuselage. The flight was successfully diverted to Kahului Airport with only one casualty, flight attendant Clarabelle "C.B." Lansing who was sucked out when the cabin depressurized.[2]
_after_crashing_into_the_Hudson_River_(crop_2).jpg)
Less than a month later, another 737, TACA Flight 110, lost both engines due to bad weather but was able to make a successful deadstick landing on a grass levee on the grounds of NASA's Michoud Assembly Facility outside New Orleans, with minor injuries to the passengers and minor damage to the aircraft. Investigations drove the engine manufacturer, CFM International, to modify the engine design to prevent future power loss.
One year later, United Airlines Flight 811, a Boeing 747, suffered a cargo door failure in-flight, separating a section of fuselage with 9 passengers and resulted in cabin depressurization. The plane made a successful emergency landing at Honolulu International Airport.[3] More recently, Air Transat Flight 236, an Airbus A330, ran out of fuel over the Atlantic Ocean on August 24, 2001, and made a successful forced landing in the Azores. On November 1, 2011, a Boeing 767 LOT Polish Airlines Flight 016 made a belly landing after a central hydraulic system failure at Warsaw, Poland's Frederic Chopin International Airport, with no injuries.[4]
A less successful crash landing involved Southern Airways Flight 242 on April 4, 1977. The DC-9 lost both of its engines due to hail and heavy rain in a thunderstorm and, unable to glide to an airport, made a forced landing on a highway near New Hope, Georgia, United States. The plane made a hard landing and was still carrying a large amount of fuel, so it burst into flames, killing the majority of the passengers and several people on the ground.
Airliners frequently make emergency landings, and almost all of them are uneventful. However, because of their inherent uncertain nature, they can quickly become crash landings or worse. Some notable instances include United Airlines Flight 232, which broke up while landing at Sioux City, Iowa, United States on July 19, 1989; and Air Canada Flight 797, which burned after landing at Cincinnati/Northern Kentucky International Airport on June 2, 1983, after a fire started in the cabin.
Shannon Airport in Ireland has a high number of emergency landings from trans-Atlantic flights, as it is the first major airport after the eastbound ocean crossing.[5][6]
On April 29, 2007, a bird was ingested into the right engine of a Boeing 757 departing Manchester (UK) airport, just as the plane rotated off the runway (flight Thomson 253H). The pilot subsequently made a successful precautionary landing.[7]
See also
[edit]References
[edit]- ^ Daniel Fitzgerald. "UAV Forced Landing Research". Daniel Fitzgerald. Archived from the original on 2007-09-27.
- ^ NTSB, Aloha Airlines, Flight 243, Boeing 737-200, N73711, National Transportation Safety Board
- ^ NTSB, Explosive Decompression – Loss of Cargo Door in Flight, United Airlines Flight 811 Boeing 747-122, N4713U, National Transportation Safety Board
- ^ "Newark flight makes emergency landing in Poland". CNN. November 1, 2011.
- ^ "Record number of emergency landings at Shannon as planes forced to divert". 31 December 2016.
- ^ "Shannon Airport handles six unscheduled landings". The Irish Times.
- ^ "Pilot lands jet after bird strike". BBC News. 29 April 2007. Retrieved 2009-05-14.. For an amateur video of the incident, see [1].
Emergency landing
View on Grokipediafrom Grokipedia
Fundamentals
Definition
An emergency landing is a premature, unplanned landing of an aircraft necessitated by an imminent threat to the safety of the aircraft or its occupants, such as mechanical failure, medical emergencies, or environmental hazards, where the priority is to achieve ground contact as soon as possible, often under sub-optimal conditions.[1][3] Key characteristics of an emergency landing include the declaration of an emergency by the pilot, typically via a Mayday radio call to air traffic control, which signals grave and imminent danger and requests immediate assistance and priority handling.[4] This often results in a deviation from the planned flight route and may involve potential damage to the aircraft or injury to occupants, distinguishing it from routine landings by its high urgency and elevated risk level.[1][3] The definition encompasses various forms, such as on-airport, off-airport, and water landings (ditching).[1] Investigations into emergency landings that culminate in accidents or serious incidents are standardized internationally under ICAO Annex 13, first adopted by the ICAO Council on April 11, 1951, to ensure consistent procedures for determining causes and preventing recurrences.[5] Success rates—measured by minimal injury or damage—vary by aircraft type, with commercial airliners generally achieving higher outcomes than smaller general aviation planes due to robust design and support systems.[2]Causes
Emergency landings in aviation are triggered by a range of factors that compromise the safety or operability of an aircraft, often necessitating immediate action to prevent further risk. These causes are typically classified into mechanical failures, medical emergencies, environmental hazards, human factors, and other incidents, with mechanical issues being among the most frequent according to aviation safety analyses.[6] Mechanical failures, such as engine shutdowns, hydraulic system malfunctions, or structural damage, frequently lead to emergency landings by impairing critical flight controls or propulsion. Engine failures can result from bird strikes, where birds are ingested into the engines, causing loss of thrust; fuel exhaustion due to miscalculations or leaks; or internal component breakdowns. A notable example is the 2009 incident involving US Airways Flight 1549, where a bird strike led to dual engine failure shortly after takeoff from New York, forcing a ditching on the Hudson River. Hydraulic issues may disable landing gear or flight surfaces, while structural damage from impacts or fatigue can compromise airframe integrity, all requiring pilots to select suitable landing sites promptly.[3][7] Medical emergencies involving passengers or crew members account for a significant portion of diversions, often involving sudden incapacitation that demands rapid descent and landing for treatment. Common scenarios include heart attacks, severe allergic reactions, or decompression sickness from cabin pressurization issues, with cardiac events being the leading cause of aircraft diversions in such cases, occurring in approximately 58% of in-flight medical emergencies that result in landings. As of 2025, in-flight medical emergencies occur in approximately 1 in 212 flights, though only 1.7-7% lead to full diversions, highlighting the role of onboard medical kits and crew training in mitigation.[8][9][10] Environmental hazards pose uncontrollable threats that can force emergency landings by affecting aircraft performance or visibility. Severe weather, including thunderstorms with high winds or lightning, icing that accumulates on wings and reduces lift, and turbulence causing structural stress or control difficulties, are primary culprits; turbulence is a leading cause of nonfatal injuries in commercial aviation. Volcanic ash clouds, which abrade windshields, engines, and instruments, have historically led to multiple engine failures and emergency descents, as seen in incidents where aircraft encountered ash plumes from eruptions. These factors underscore the importance of pre-flight weather monitoring to avoid hazardous conditions.[11][12] Human factors, though less common than mechanical or environmental issues, can precipitate emergency landings through errors or intentional acts that disrupt normal operations. Pilot error, such as misjudging fuel loads or failing to extend landing gear, contributes to around 80% of aviation incidents when combined with fatigue, stress, or communication breakdowns. Security-related events like hijackings or bomb threats, while rare in modern aviation—with global incidents dropping to near zero annually post-2001 due to enhanced screening—have historically forced diversions to secure locations, often involving coordinated ground responses.[13][14] Other causes include cargo fires from hazardous materials, sudden pressurization losses leading to hypoxia, navigation errors due to system glitches, and rare events like space debris impacts that damage critical components. These miscellaneous factors, while infrequent, can escalate quickly and require immediate landing protocols. Recent trends indicate a rise in bird strikes post-2020, with U.S. civil aircraft reporting 22,372 incidents in 2024—a 14% increase from 2023—attributed partly to resuming flight volumes after the COVID-19 downturn and urban expansion near airports attracting more wildlife.[15]Types
On-Airport Landings
On-airport emergency landings occur when pilots elect or are compelled to touch down at a designated airport facility, typically involving a return to the departure airport after issues during takeoff or a diversion to the nearest suitable alternate airport. These scenarios prioritize rapid coordination to secure priority clearance, allowing the aircraft to bypass standard traffic queues and proceed directly to landing. For example, engine failure shortly after departure often prompts such returns or diversions to ensure controlled operations on prepared runways.[3][16] Air traffic control (ATC) plays a pivotal role by vectoring the aircraft toward the active runway, clearing all conflicting traffic, and initiating the deployment of emergency services such as rescue and firefighting teams upon declaration of the emergency. Pilots, in turn, configure the aircraft for the approach—often opting for high-speed landings to maintain momentum in cases of partial power loss or short-field techniques to utilize available runway length effectively—while adhering to ATC directives for separation and sequencing.[17][1][18] The primary advantages of on-airport landings include immediate access to full airport rescue and firefighting infrastructure, as well as smoother, paved surfaces that reduce the risk of structural damage or injury compared to unprepared sites. These factors contribute to exceptionally high success rates; for precautionary on-airport landings, where issues are anticipated in advance, the fatality rate stands at approximately 0.06 percent, reflecting near-total survivability in controlled environments.[2][19] Challenges in executing on-airport emergency landings encompass maneuvering through congested airspace, where multiple aircraft may complicate priority routing, and contending with suboptimal weather conditions at the target airport that could limit options for alternates. To mitigate low-visibility scenarios, standard protocols incorporate the Instrument Landing System (ILS), which provides precise vertical and lateral guidance to enable safe approaches down to runway visual ranges as low as 1,800 feet (550 meters) for Category I operations.[20][21][22]Off-Airport Landings
Off-airport landings, also known as forced or precautionary landings away from established airfields, occur when pilots must select and utilize unprepared terrain due to emergencies such as engine failure or fuel exhaustion. These maneuvers demand rapid assessment and execution to prioritize occupant survival over aircraft preservation, contrasting with on-airport procedures that benefit from runways and air traffic control support. Pilots typically aim for sites that allow a controlled touchdown, using the aircraft's structure to absorb impact energy.[3][2] Site selection is critical and focuses on key criteria to maximize safety: sufficient length (ideally 500–1,000 feet for light general aviation aircraft), width to accommodate wingspan, minimal slope (flat or slightly downhill preferred to aid deceleration), and absence of obstacles like power lines, trees, or rocks. Suitable surfaces include open fields, highways, or beaches, with pilots prioritizing a clear approach path even if the touchdown area is imperfect; visual reconnaissance from the air, supplemented by GPS or onboard mapping tools, guides the choice. Proximity to populated areas is favored to facilitate post-landing assistance, while energy-absorbing features like tall crops or soft soil can mitigate impact forces. Hazards such as uneven ground, livestock, or foreign objects must be avoided, as they can exacerbate damage during rollout.[23][2][24] Techniques for off-airport landings emphasize minimizing groundspeed and impact severity, often involving a gear-up configuration on rough or soft terrain to prevent landing gear collapse and reduce the risk of the aircraft flipping or catching fire from ruptured fuel lines. Pilots execute a low-angle approach, touching down at the lowest controllable airspeed just above stall, with full flaps deployed for better control and a nose-high attitude to protect the propeller and cabin. These methods evolved from early 20th-century bush piloting in remote regions like Alaska, where pilots during and after World War II adapted improvised landings on gravel bars, beaches, and frozen surfaces without formal runways, honing skills in short-field operations and obstacle avoidance that remain foundational today. Survival gear, such as emergency kits with signaling devices and first-aid supplies, should be stowed aft to maintain balance and accessibility post-landing.[25][3][26][27][28] Risks in off-airport landings primarily stem from terrain irregularities, which can cause the aircraft to cartwheel, nosedive, or erupt in post-impact fire, compounded by factors like high sink rates or pilot hesitation leading to stalls. Federal Aviation Administration studies on general aviation indicate a fatality rate of approximately 10% for forced off-airport landings, implying a survival rate of about 90% when proper techniques are employed, though outcomes worsen in mountainous or obstructed areas due to delayed egress or injury from uneven surfaces. Psychological pressures, such as reluctance to commit to a site, further elevate hazards by prompting unsafe maneuvers.[3][2][29] Notable examples illustrate the challenges and successes of off-airport landings in remote settings, such as Alaskan wilderness operations where bush pilots routinely face engine-outs over tundra or rivers. Such incidents underscore the emphasis on carrying comprehensive survival equipment in high-risk areas, including cold-weather gear and emergency locators, to bridge the gap until help arrives.[30][31]Ditching
Ditching refers to the controlled emergency landing of a land-based aircraft on a water surface, distinguishing it from planned water operations of seaplanes or amphibious aircraft.[32] The term "ditching" originated in the early era of aviation, particularly during the seaplane age and transoceanic flights of the 1930s and 1940s, when landplanes were forced to make unplanned water contacts akin to abandoning a vessel in a ditch.[32] Modern instances include commercial flights like Pan American World Airways Flight 6 in 1956, where a Boeing 377 Stratocruiser successfully ditched in the Pacific Ocean after engine failures, with all 31 aboard surviving.[33] Preparation for ditching emphasizes rapid cabin securing and passenger readiness to mitigate post-impact hazards. Crew instruct passengers to don life vests without inflating them until after exiting the aircraft, secure loose items to prevent injury during impact, and assume brace positions.[34][32] These protocols evolved significantly after World War II, informed by incidents involving Pan American's flying boat Clippers, such as the 1942 ditching of the Yankee Clipper, which highlighted the need for structured evacuation drills and improved fuselage integrity.[35] Ditching procedures focus on hydrodynamic stability to minimize structural damage and facilitate evacuation. Pilots approach parallel to swells or into the wind for optimal control, retracting landing gear and deploying full flaps to achieve a touchdown speed just above stall—typically 10-20% higher than normal landing speed to maintain lift without stalling.[34][3] Aircraft with hull-like designs, such as U.S. Navy flying boats from the mid-20th century (e.g., the PBY Catalina), exhibit superior flotation and reduced breakup risk compared to conventional landplanes due to their reinforced, boat-shaped fuselages.[36] Key risks during and after ditching include rapid sinking, often within minutes due to fuselage breaches, leading to drowning as the primary cause of fatalities.[37] Cold water immersion poses severe threats like hypothermia and cold shock, impairing escape and survival, while in tropical regions, shark encounters have historically compounded dangers amid blood and debris.[34][38] Survival rates for ditching events from 1989 to 2022 stand at approximately 76% overall, with 95% surviving the initial impact but post-evacuation factors determining outcomes; commercial jet ditchings, such as US Airways Flight 1549 in 2009, achieve near-100% survival when executed in populated areas with swift rescue.[37][39]Procedures
Preparation
Upon identifying an emergency situation, such as engine failure or other critical malfunction, pilots immediately declare the nature of the distress to air traffic control (ATC) via radio to alert ground services and receive assistance. For conditions involving grave and imminent danger requiring immediate aid, the international distress signal "Mayday" is transmitted three times, followed by the aircraft's identification, current position, number of souls on board, and intended actions, such as the selected landing site. In cases of urgency where assistance is needed but the situation is not immediately life-threatening, the signal "Pan-Pan" is used in the same manner to indicate a potential emergency without full distress protocols.[17] Pilots then conduct a rapid systems assessment and configuration to optimize the aircraft for landing while minimizing risks. If sufficient time and altitude permit, fuel dumping is initiated to reduce the aircraft's weight, thereby lowering landing speed and the potential for post-impact fire, with systems designed to jettison fuel at a rate of at least 1% of maximum takeoff weight per minute from designated wing points. Aircraft controls are adjusted by extending flaps to increase lift and decrease stall speed for better maneuverability, and landing gear is prepared for deployment unless a gear-up landing is deemed safer for off-airport terrain, as per the aircraft flight manual. Simultaneously, the cabin crew briefs passengers on emergency procedures, instructing them to adopt brace positions—such as head down against the seatback, hands protecting the head, and feet flat on the floor—to reduce injury risk during impact.[40][3][41] Decision-making focuses on selecting the most suitable landing site within the aircraft's operational envelope, prioritizing factors like wind direction, terrain suitability, and obstacle clearance to ensure the safest possible outcome. For powered glides or remaining flight endurance, pilots calculate estimated endurance time (EET) using the formula EET = Fuel Remaining / Fuel Burn Rate, which helps determine reachable airports or fields before fuel exhaustion. This assessment adapts to the specific emergency trigger, such as engine failure limiting glide range, to identify options like nearby runways or open fields.[42][3] Crew coordination is critical under crew resource management (CRM) principles, where roles are clearly divided to maintain aircraft control and efficient response. The captain typically assumes the pilot flying (PF) role to direct the aircraft, while the first officer serves as pilot monitoring (PM), handling radio communications with ATC, executing checklists, and relaying updates. Cabin crew members manage passenger conduct, securing the cabin and preventing panic through calm instructions and monitoring for compliance with safety directives.[43]Execution
The execution of an emergency landing encompasses the dynamic phases from the final approach to touchdown, emphasizing precise control to ensure a survivable outcome. During the approach phase, pilots establish a stabilized descent at the aircraft's best glide speed, which maximizes the lift-to-drag ratio to extend gliding range while conserving energy. For instance, in a Cessna 172, this speed is 65 knots indicated airspeed (KIAS), allowing the aircraft to cover approximately 1.5 nautical miles per 1,000 feet of altitude lost.[3] Energy management is paramount to prevent stalls, requiring pilots to avoid excessive deceleration or configuration changes that could reduce airspeed below this threshold, thereby maintaining a sink rate under 500 feet per minute for controllability.[3] Fundamental to this phase is the physics of gliding flight, where the glide ratio—defined as the horizontal distance traveled divided by the altitude lost—determines reachable landing sites. This ratio equals the maximum lift-to-drag (L/D) value, as lift balances weight and drag opposes forward motion in unpowered flight:
For light general aviation aircraft like the Cessna 172, the glide ratio is typically 8:1 to 9:1 at best glide speed. In commercial jets, it reaches 15:1 to 17:1, enabling extended glides from cruise altitudes; for example, a Boeing 747-200 can travel about 150 kilometers from 10,000 meters. Drag, governed by the equation $ D = \frac{1}{2} \rho V^2 C_D S $ (where is air density, is velocity, is the drag coefficient, and is wing area), must be minimized relative to lift $ L = \frac{1}{2} \rho V^2 C_L S $ (with as the lift coefficient) to achieve this efficiency.[44]
As the aircraft transitions to touchdown, the pilot executes a controlled flare to minimize vertical speed and groundspeed, aiming for a flat attitude upon impact. Spoilers, if available on the aircraft, are deployed immediately after main gear contact to spoil lift and augment drag, reducing stopping distance.[45] Reverse thrust, standard on turbine engines, is engaged promptly following main gear touchdown to redirect exhaust forward, providing deceleration proportional to engine power; its effectiveness increases if deployed within seconds of wheels-on.[46] Gear extension timing is dictated by the landing surface: on soft or uneven terrain, a gear-up configuration may be selected to slide rather than snag, preserving structural integrity, while gear-down is preferred on firm runways to absorb initial impact and protect the fuselage.[3]
Procedures vary by aircraft configuration. In single-engine aircraft, execution relies solely on aerodynamic gliding with no propulsion option, demanding immediate pitch adjustments to best glide upon power loss. Multi-engine aircraft protocols differ if only partial power is lost, involving shutdown of the failed engine and asymmetric thrust management, but revert to identical glide techniques in total power failure scenarios.[3] Post-2010 advancements have emphasized automation integration, such as autothrottle systems in modern airliners, which can maintain approach speeds autonomously during emergencies when pilots disengage other modes, enhancing precision under stress.[47] Execution adapts briefly for on-airport versus off-airport scenarios, with the former leveraging runway markings for alignment.[3]