Throughout a normal flight, a pilot controls an aircraft through the use of
flight controls including maintaining straight and level flight, as well as turns, climbing, and descending. Some controls, such as a
"yoke" or "stick" move and adjust the
control surfaces which affects the aircraft's attitude in the three axes of pitch, roll, and yaw. Other controls include those for adjusting wing characteristics (flaps, slats, spoilers) and those that control the power or thrust of the propulsion systems. The loss of primary control systems in any phase of flight is an emergency. Aircraft are not designed to be flown under such circumstances; however, some pilots faced with such an emergency have had limited success flying and landing aircraft with disabled controls.
Control system failures resulting in disabled controls have resulted in a number of
aviation incidents and accidents. Some incidents occurred where controls were not functioning correctly prior to take-off, others where the failure developed during flight. A loss of control can occur when an unrelated failure, such as an engine failure, causes damage to control related systems. For instances, in several incidents an engine broke apart, causing the failure of main and redundant
hydraulic systems, which disabled all control surfaces. Some or all controls can become inoperative from
extreme weather
Extreme weather includes unexpected, unusual, severe weather, severe, or unseasonal weather; weather at the extremes of the historical distribution—the range that has been seen in the past. Extreme events are based on a location's recorded weat ...
conditions, due to collisions, due to poor maintenance or mistakes made by maintenance workers, as a result of pilot error, due to failures of the
flight control system
A conventional fixed-wing aircraft flight control system (AFCS) consists of flight control surfaces, the respective cockpit controls, connecting linkages, and the necessary operating mechanisms to control an aircraft's direction in flight. ...
, or due to design or manufacturing flaws.
Control techniques
Normal flight
In
normal flight, maneuvering an aircraft requires some combination of controls, which are often interactive in their effect.
* For instance, to climb to a higher altitude, the pilot can increase thrust which will cause the aircraft to climb while maintaining airspeed.
** Alternately, the pilot may climb by pitching the aircraft up, though in this case airspeed decreases.
* Normally to make a turn, the pilot banks left or right by adjusting the ailerons on the wings to increase lift on one wing, and decrease lift on the other. The asymmetric lift causes asymmetric drag, which causes the aircraft to yaw adversely. To correct the yaw, the pilot uses the
rudder
A rudder is a primary control surface used to steer a ship, boat, submarine, hovercraft, airship, or other vehicle that moves through a fluid medium (usually air or water). On an airplane, the rudder is used primarily to counter adverse yaw ...
to perform a coordinated turn.
** In a multi-engined aircraft, the loss of thrust in one engine can also cause adverse yaw, and here again the rudder is used to regain coordinated flight.
Flight with disabled controls
A basic means of controlling an aircraft with disabled flight controls is making use of the position of the engines. If the engines are mounted under the
centre of gravity
In physics, the center of mass of a distribution of mass in space (sometimes referred to as the barycenter or balance point) is the unique point at any given time where the weighted relative position of the distributed mass sums to zero. For a ...
, as in underwing passenger jets, then increasing the
thrust
Thrust is a reaction force described quantitatively by Newton's third law. When a system expels or accelerates mass in one direction, the accelerated mass will cause a force of equal magnitude but opposite direction to be applied to that ...
will raise the nose while decreasing the thrust will lower it. This control method may call for control inputs that go against the
pilot's instinct: when the aircraft is in a dive, adding thrust will raise the nose and vice versa.
Additionally, asymmetrical thrust has been used for directional control: if the left engine is idled and power is increased on the right side this will result in a
yaw to the left, and vice versa. If
throttle
A throttle is a mechanism by which fluid flow is managed by construction or obstruction.
An engine's power can be increased or decreased by the restriction of inlet gases (by the use of a throttle), but usually decreased. The term ''throttle'' ha ...
settings allow the throttles to be shifted without affecting the total amount of power, then yaw control can be combined with pitch control. If the aircraft is yawing, then the wing on the outside of this yaw movement will go faster than the inner wing. This creates higher lift on the faster wing, resulting in a rolling movement, which helps to make a turn.
Controlling
airspeed
In aviation, airspeed is the speed of an aircraft relative to the air it is flying through (which itself is usually moving relative to the ground due to wind). In contrast, the ground speed is the speed of an aircraft with respect to the sur ...
has been shown to be very difficult with engine control only, often resulting in a fast landing. A faster than normal landing also results when the
flaps cannot be extended due to loss of hydraulics.
Another challenge for pilots who are forced to fly an aircraft without functioning control surfaces is to avoid the
phugoid
In aviation, a phugoid or fugoid () is an aircraft motion in which the vehicle Aircraft principal axes, pitches up and climbs, and then pitches down and descends, accompanied by speeding up and slowing down as it goes "downhill" and "uphill". Th ...
instability mode (a cycle in which the aircraft repeatedly climbs and then dives), which requires careful use of the throttle.
Because this type of aircraft control is difficult for humans to achieve, researchers have attempted to integrate this control ability into the computers of
fly-by-wire
Fly-by-wire (FBW) is a system that replaces the conventional aircraft flight control system#Hydro-mechanical, manual flight controls of an aircraft with an electronic interface. The movements of flight controls are converted to electronic sig ...
aircraft. Early attempts to add the ability to real aircraft were not very successful, the software having been based on experiments conducted in flight simulators where jet engines are usually modelled as "perfect" devices with exactly the same thrust on each engine, a linear relationship between throttle setting and thrust, and instantaneous response to input. More modern computer systems have been updated to account for these factors, and aircraft have been successfully flown with this software installed. However, it remains a rarity on commercial aircraft.
Accidents and incidents involving commercial aircraft
Incidents where disabled, damaged, and/or failed control systems were a significant or primary cause of the accident.
Controls damaged by engine failure
In these incidents, a failure of propulsion systems (engine, fan, propeller, pumps) caused damage to control systems. (Engine mounting failures are covered under structural failures, below.)
*
Eastern Air Lines Flight 935, a
Lockheed L-1011 TriStar
The Lockheed L-1011 TriStar (pronounced "El-ten-eleven") is an American medium-to-long-range, wide-body trijet airliner built by the Lockheed Corporation. It was the third wide-body airliner to enter commercial operations, after the Boeing 747 ...
, on September 22, 1981. Suffered an uncontained failure of the No. 2 engine on takeoff from Newark, New Jersey. The crew were able to land the aircraft safely at
John F. Kennedy International Airport
John F. Kennedy International Airport is a major international airport serving New York City and its metropolitan area. JFK Airport is located on the southwestern shore of Long Island, in Queens, New York City, bordering Jamaica Bay. It is ...
with some limited use of the outboard spoilers, the inboard ailerons and the horizontal stabilizer, plus the differential engine power of the remaining two engines.
*
Reeve Aleutian Airways Flight 8, a
Lockheed L-188 Electra
The Lockheed L-188 Electra is an American turboprop airliner built by Lockheed Corporation, Lockheed. First flown in 1957, it was the first large turboprop airliner built in the United States. With its fairly high power-to-weight ratio, huge pro ...
, on 8 June 1983. Flying over
Cold Bay, Alaska, the plane's number 4 engine propeller detached itself from the engine and cut a hole in the plane as it flew underneath it. The resultant damage inflicted by the propeller caused an explosive decompression, severed cables connected to the plane's throttles and control surfaces and left the flight deck crew of three with only autopilot that had no lateral control. After managing to wrench the ailerons and elevators into minimal working condition, the crew tried to land at Anchorage at high speed. They had to make a go-around, but landed on the second attempt, saving all 10 passengers on board.
*
LOT Polish Airlines Flight 5055, an
Ilyushin Il-62
The Ilyushin Il-62 (; NATO reporting name: Classic) is a Soviet Union, Soviet long-range Narrow-body aircraft, narrow-body jetliner conceived in 1960 by Ilyushin. As a successor to the popular turboprop Ilyushin Il-18, Il-18 and with capacit ...
M, on 9 May 1987. According to the Polish investigatory commission, the cause of the crash was the disintegration of an engine shaft due to faulty bearings inside engine No. 2, which seized, causing extensive heat. This in turn caused the consequent damage to engine No. 1,
rapid decompression
An uncontrolled decompression is an undesired drop in the pressure of a sealed system, such as a pressurised aircraft cabin or hyperbaric chamber, that typically results from human error, structural failure, or impact, causing the pressurised vess ...
of the fuselage, and a fire in the cargo hold, as well as the loss of elevator controls and progressive electrical failures. The crew decided to return to
Warsaw Okecie Airport using only
trim tab
Trim tabs are small surfaces connected to the trailing edge of a larger Flight control surfaces, control surface on a boat or aircraft, used to control the trim of the controls, i.e. to counteract hydro- or aerodynamic forces and stabilise the ...
s to control the flight of the aircraft. They lost their struggle to land about 5 km from the runway in the Kabacki Forest. All 172 passengers and 11 crew members perished.
*
United Airlines Flight 232
United Airlines Flight 232 was a regularly scheduled United Airlines flight from Stapleton International Airport in Denver to O'Hare International Airport in Chicago, continuing to Philadelphia International Airport. On July 19, 1989, the DC-1 ...
, a
McDonnell Douglas DC-10
The McDonnell Douglas DC-10 is an American trijet wide-body aircraft manufactured by McDonnell Douglas.
The DC-10 was intended to succeed the Douglas DC-8, DC-8 for long-Range (aeronautics), range flights. It first flew on August 29, 1970; i ...
, on 19 July 1989. A fan disk in the No. 2 engine fractured, severing most of the flight controls.
Dennis Fitch, a
deadheading DC-10 instructor who had studied the case of
JAL Flight 123, was able to help the pilots steer the aircraft using throttle differential. Despite the break-up of the aircraft on landing, 175 of 285 passengers and 10 of the 11 crew members survived.
*
Baikal Airlines Flight 130, a
Tupolev Tu-154
The Tupolev Tu-154 (; NATO reporting name: "Careless") is a three-engined, medium-range, narrow-body airliner designed in the mid-1960s and manufactured by Tupolev. A workhorse of Soviet and (subsequently) Russian airlines for several decades, ...
, on 3 January 1994. When starting the engines before takeoff, the pilots noticed a warning light signaling dangerous rotation of the starter in engine #2. Believing the warning to be false, they decided to take off anyway. During the initial climb, the starter failed and a fire broke out in the #2 engine. The fire damaged all three hydraulic lines, rendering the plane uncontrollable. After 12 minutes of the crew trying to control the sliding trajectory of the plane, it eventually crashed into a dairy farm near Mamony town at 500 km/h, killing all 124 people aboard and one man on the ground.
Controls damaged by structural failure
In these incidents, a failure of structural components (bulkheads, doors, struts, mounts, spars, hull) subsequently damaged control systems.
*
American Airlines Flight 96, a
McDonnell Douglas DC-10
The McDonnell Douglas DC-10 is an American trijet wide-body aircraft manufactured by McDonnell Douglas.
The DC-10 was intended to succeed the Douglas DC-8, DC-8 for long-Range (aeronautics), range flights. It first flew on August 29, 1970; i ...
, on 12 June 1972. The failure of the rear cargo door caused an
explosive decompression
An uncontrolled decompression is an undesired drop in the pressure of a sealed system, such as a pressurised aircraft cabin or hyperbaric chamber, that typically results from human error, structural failure, or impact, causing the pressurised v ...
, which in turn caused the rear main cabin floor to collapse and severed flight controls. The pilots had only limited
aileron
An aileron (French for "little wing" or "fin") is a hinged flight control surface usually forming part of the trailing edge of each wing of a fixed-wing aircraft. Ailerons are used in pairs to control the aircraft in roll (or movement aroun ...
s and
elevator
An elevator (American English) or lift (Commonwealth English) is a machine that vertically transports people or freight between levels. They are typically powered by electric motors that drive traction cables and counterweight systems suc ...
s; the rudder was jammed. The number two engine also ran down to idle at the time of decompression. The aircraft landed safely at
Detroit-Metropolitan Airport.
*
Turkish Airlines Flight 981
Turkish Airlines Flight 981 (TK981/THY981) was a scheduled flight from Istanbul Yeşilköy Airport to London Heathrow Airport, with an intermediate stop at Orly Airport in Paris. On 3 March 1974, the McDonnell Douglas DC-10 operating the fl ...
, a
McDonnell Douglas DC-10
The McDonnell Douglas DC-10 is an American trijet wide-body aircraft manufactured by McDonnell Douglas.
The DC-10 was intended to succeed the Douglas DC-8, DC-8 for long-Range (aeronautics), range flights. It first flew on August 29, 1970; i ...
, on 3 March 1974. Similar to American Airlines Flight 96, the flight experienced an
explosive decompression
An uncontrolled decompression is an undesired drop in the pressure of a sealed system, such as a pressurised aircraft cabin or hyperbaric chamber, that typically results from human error, structural failure, or impact, causing the pressurised v ...
, when flying over the town of
Meaux
Meaux () is a Communes of France, commune on the river Marne (river), Marne in the Seine-et-Marne Departments of France, department in the Île-de-France Regions of France, region in the Functional area (France), metropolitan area of Paris, Franc ...
, France, caused by a rear cargo door failure. The rear main cabin floor collapsed and severed all flight controls. While the plane went into a vertical dive, the captain called for "Speed!", meaning increasing engine thrust to push the plane's nose up. The plane began to level out, but had lost too much altitude and slammed into the
Ermenonville Forest. All 346 people on board were killed upon impact, and it became the worst single aircraft disaster without survivors, and the fourth deadliest
aviation death count ever.
*
Delta Air Lines Flight 1080, a
Lockheed L-1011 Tristar
The Lockheed L-1011 TriStar (pronounced "El-ten-eleven") is an American medium-to-long-range, wide-body trijet airliner built by the Lockheed Corporation. It was the third wide-body airliner to enter commercial operations, after the Boeing 747 ...
, on April 12, 1977, suffered a structural failure of a bearing assembly controlling the aircraft's left stabilizer, which caused it to jam in a full trailing edge up configuration. The plane pitched abruptly upwards and the pilots could not counteract the pitching force even when pushing the control column fully forward. This caused the plane to lose speed and nearly stall. The pilot managed to regain control by using the Tristar's tail engine at maximum power and lowering the thrust on the wing engines in order to generate differential thrust, together with the cabin crew moving the passengers forward to alter the center of gravity. The airliner landed at
Los Angeles International Airport
Los Angeles International Airport is the primary international airport serving Los Angeles and its Greater Los Angeles, surrounding metropolitan area, in the U.S. state of California. LAX is located in the Westchester, Los Angeles, Westcheste ...
, with all 41 passengers and 11 crew being unharmed.
*
American Airlines Flight 191
American Airlines Flight 191 was a regularly scheduled domestic passenger flight from O'Hare International Airport in Chicago to Los Angeles International Airport. On the afternoon of May 25, 1979, the McDonnell Douglas DC-10 operating th ...
, a
McDonnell Douglas DC-10
The McDonnell Douglas DC-10 is an American trijet wide-body aircraft manufactured by McDonnell Douglas.
The DC-10 was intended to succeed the Douglas DC-8, DC-8 for long-Range (aeronautics), range flights. It first flew on August 29, 1970; i ...
, on 25 May 1979. The failure of the #1 engine mounting pylon and subsequent separation of the engine from the aircraft resulted in severed hydraulic lines and electrical system damage. The left wing
slats
Super Low Altitude Test Satellite (SLATS) or Tsubame was a JAXA satellite intended to demonstrate operations in very low Earth orbit (VLEO, below 200 km), using ion engines to counteract aerodynamic drag (physics), drag from the atmosphere ...
retracted due to the loss of hydraulic pressure and aerodynamic forces, while the right wing slats remained extended. The damaged electrical system prevented the slat retract indicators and
stick-shaker on the
yoke
A yoke is a wooden beam used between a pair of oxen or other animals to enable them to pull together on a load when working in pairs, as oxen usually do; some yokes are fitted to individual animals. There are several types of yoke, used in dif ...
from functioning, so the crew was not alerted to the slat retraction nor impending stall. All 271 on board were killed, as well as two on the ground at
O'Hare International Airport
Chicago O'Hare International Airport is the primary international airport serving Chicago, Illinois, United States, located on the city's Northwest Side, approximately northwest of the Chicago Loop, Loop business district. The airport is ope ...
in
Chicago
Chicago is the List of municipalities in Illinois, most populous city in the U.S. state of Illinois and in the Midwestern United States. With a population of 2,746,388, as of the 2020 United States census, 2020 census, it is the List of Unite ...
,
Illinois
Illinois ( ) is a U.S. state, state in the Midwestern United States, Midwestern United States. It borders on Lake Michigan to its northeast, the Mississippi River to its west, and the Wabash River, Wabash and Ohio River, Ohio rivers to its ...
.
*
Japan Air Lines Flight 123
Japan Air Lines Flight 123 was a scheduled domestic passenger flight from Tokyo to Osaka, Japan. On August12, 1985, the Boeing 747 flying the route suffered a severe structural failure and explosive decompression 12 minutes after takeoff. After f ...
, a
Boeing 747
The Boeing 747 is a long-range wide-body aircraft, wide-body airliner designed and manufactured by Boeing Commercial Airplanes in the United States between 1968 and 2023.
After the introduction of the Boeing 707, 707 in October 1958, Pan Am ...
, on 12 August 1985. A faulty repair years earlier had weakened the aircraft's rear pressure bulkhead, which failed in flight. The
vertical stabilizer
A vertical stabilizer or tail fin is the static part of the vertical tail of an aircraft. The term is commonly applied to the assembly of both this fixed surface and one or more movable rudders hinged to it. Their role is to provide control, sta ...
and much of the aircraft's
empennage
The empennage ( or ), also known as the tail or tail assembly, is a structure at the rear of an aircraft that provides stability during flight, in a way similar to the feathers on an arrow.Crane, Dale: ''Dictionary of Aeronautical Terms, third ed ...
was blown off during the decompression. The decompression also ruptured all four hydraulic lines which controlled the aircraft's mechanical flight controls. The pilots were able to continue flying the aircraft with very limited control, but after 32 minutes the aircraft crashed into a mountain, killing 520 of the 524 people aboard in the deadliest single aircraft disaster in history.
*
American Airlines Flight 587
American Airlines Flight 587 was a regularly scheduled international passenger flight from John F. Kennedy International Airport, New York City, to Las Américas International Airport, Santo Domingo, Dominican Republic. On November 12, 2001, t ...
,
Airbus A300
The Airbus A300 is Airbus' first production aircraft and the world's first Twinjet, twin-engine, double-aisle Wide-body aircraft, (wide-body) airliner. It was developed by ''Airbus Industrie GIE'', now merged into Airbus SE, and manufactured f ...
, November 12, 2001. This was the second-deadliest aviation accident in U.S. history, with 251 passengers and 9 crew members killed, as well as five people on the ground. According to the NTSB, the aggressive use of the rudder controls by the first officer stressed the composite vertical stabilizer until it separated from the aircraft. The complete loss of the vertical stabilizer meant the loss of all rudder control. As the pilots struggled to control the aircraft, it entered a
flat spin. The resultant forces caused the engines to separate from the aircraft, and it slammed into the ground 14 seconds later.
*
Air Transat Flight 961, an
Airbus A310
The Airbus A310 is a wide-body aircraft, Aircraft design process, designed and manufactured by Airbus Industrie GIE, then a consortium of European aerospace manufacturers.
Airbus had identified a demand for an aircraft smaller than the Airbus ...
, on 6 March 2005, catastrophic structural failure: the rudder detached from the aircraft with a loud bang and the aircraft began a
dutch roll
Dutch roll is an aircraft motion consisting of an out-of- phase combination of "tail-wagging" (yaw) and rocking from side to side (roll). This yaw-roll coupling is one of the basic flight dynamic modes (others include phugoid, short period, ...
. The pilots regained enough lateral control, albeit with difficulty, to land the aircraft safely at Varadero-Juan Gualberto Gomez Airport.
*
National Airlines Flight 102
National Airlines Flight 102 (N8102/NCR102) was a cargo flight operated by National Airlines (N8), National Airlines between Camp Shorabak, Camp Shorabak (formerly Camp Bastion) near the city of Lashkargah in Afghanistan and Al Maktoum Airport i ...
, a
Boeing 747
The Boeing 747 is a long-range wide-body aircraft, wide-body airliner designed and manufactured by Boeing Commercial Airplanes in the United States between 1968 and 2023.
After the introduction of the Boeing 707, 707 in October 1958, Pan Am ...
experienced a
load shift, damaging the
aft pressure bulkhead, severing the hydraulic lines that controlled the
elevators
An elevator (American English) or lift (English in the Commonwealth of Nations, Commonwealth English) is a machine that vertically transports people or freight between levels. They are typically powered by electric motors that drive tracti ...
. This disabled the elevators, which were stuck in a pitch-up attitude. This caused the plane to
stall and crash, killing all 7 occupants on board.
Control system mechanical failures
In these incidents, there was a failure of control system components themselves (e.g. cables, hydraulics, flaps, slats, ailerons, rudder, stabilizer, trim tabs, auto-pilot). (Control system fatigue failures are here, but improperly installed or incorrectly adjusted controls in the next section.)
*
United Airlines Flight 585,
Boeing 737
The Boeing 737 is an American narrow-body aircraft, narrow-body aircraft produced by Boeing at its Boeing Renton Factory, Renton factory in Washington (state), Washington.
Developed to supplement the Boeing 727 on short and thin routes, the t ...
, March 3, 1991. The hydraulic servo that controlled the rudder had an un-commanded actuation, resulting in a
"hardover" where the rudder unexpectedly reversed. All 20 passengers and 5 crew members were killed when the pilots were unable to regain control, and the aircraft slammed into the ground and exploded.
*
USAir Flight 427,
Boeing 737
The Boeing 737 is an American narrow-body aircraft, narrow-body aircraft produced by Boeing at its Boeing Renton Factory, Renton factory in Washington (state), Washington.
Developed to supplement the Boeing 727 on short and thin routes, the t ...
, September 8, 1994. A second rudder hardover crash killed all 127 passengers and five crew members on board.
*
Eastwind Airlines Flight 517,
Boeing 737-200
The Boeing 737 is an American narrow-body aircraft produced by Boeing at its Renton factory in Washington.
Developed to supplement the Boeing 727 on short and thin routes, the twinjet retained the 707 fuselage width and six abreast seating ...
, June 9, 1996. A third rudder hardover incident. This time, the crew were able to regain control and land the aircraft successfully. All 53 occupants on board the 737-200 survived with one flight attendant injured. This flight was instrumental in resolving the cause of the 737 rudder issues, because it was the first flight to land safely, allowing investigators to interview the pilots and study the aircraft.
*
Alaska Airlines Flight 261
Alaska Airlines Flight 261 was a scheduled international passenger flight from Licenciado Gustavo Díaz Ordaz International Airport in Puerto Vallarta, Puerto Vallarta, Jalisco, Mexico, to Seattle–Tacoma International Airport in Seattle, Washi ...
, a
McDonnell Douglas MD-80
The McDonnell Douglas MD-80 is a series of five-abreast single-aisle airliners developed by McDonnell Douglas. It was produced by the developer company until August 1997 and then by Boeing Commercial Airplanes. The MD-80 was the second gener ...
, on January 31, 2000. The acme nut/jack screw assembly, which adjusted the pitch of the horizontal stabilizer, failed. As a result, the pilots lost control of aircraft pitch, and the flight crashed into the Pacific Ocean killing all 5 crew and 83 passengers on board.
*
Northwest Airlines Flight 85, a
Boeing 747-400
The Boeing 747-400 is a large, long-range wide-body airliner produced by Boeing Commercial Airplanes, an advanced variant of the initial Boeing 747.
The ''Advanced Series 300'' was announced at the September 1984 Farnborough Airshow, target ...
, on 9 October 2002. Midway through a flight from
Detroit Metropolitan Wayne County Airport to
New Tokyo International Airport, the aircraft suffered a rudder hardover event due to metal fatigue, jamming the lower rudder fully to the left. By manipulating the upper rudder, the crew was able to perform a successful landing at
Ted Stevens Anchorage International Airport
Ted Stevens Anchorage International Airport is a major airport in the U.S. state of Alaska, located southwest of downtown Anchorage. The airport is named for Ted Stevens, who served as a senator of Alaska from 1968 to 2009. It is included in ...
with no loss of life.
*
Air Moorea Flight 1121
Air Moorea Flight 1121 was a de Havilland Canada DHC-6 Twin Otter which crashed into the ocean shortly after takeoff from Moorea Airport on Moorea Island in French Polynesia on 9 August 2007 killing all 20 people on board.
It was bound for Ta ...
, a
de Havilland Canada DHC-6 Twin Otter
The de Havilland Canada DHC-6 Twin Otter is a Canadian STOL (Short Takeoff and Landing) utility aircraft developed by de Havilland Canada in the mid-1960s and still in production today. Built by De Havilland Canada from 1965 to 1988, Viking ...
, on 9 August 2007. Deterioration of the elevator cable from frequent takeoffs and landings, and likely jet-blast from larger aircraft, caused the cable to snap one minute after takeoff. The plane then nosedived and crashed into the ocean near
Moorea-Temae Airport soon afterwards, killing all 19 passengers and the sole pilot.
Control failures due to maintenance errors
In these incidents, the failure of control system components was caused by improper installation or adjustment of control systems components by maintenance personnel.
*
Air Astana Flight 1388
Air Astana Flight 1388 was a repositioning flight from Lisbon to Almaty, with a refueling stop in Minsk. On 11 November 2018, shortly after takeoff, it experienced severe control issues. After 90 minutes, it landed safely at Beja Airbase, with ...
, an
Embraer ERJ-E190, November 11, 2018. The aircraft suffered severe control issues from an incorrectly installed aileron cable shortly after taking off from Alverca Air Base,
Portugal
Portugal, officially the Portuguese Republic, is a country on the Iberian Peninsula in Southwestern Europe. Featuring Cabo da Roca, the westernmost point in continental Europe, Portugal borders Spain to its north and east, with which it share ...
. The flight crew struggled to control the plane for about 90 minutes. During that period, they lost control of their aircraft multiple times but found they could gain more control by activating direct mode for flight controls which disconnects the FCM (flight control module). This greatly increased controllability of the pitch and yaw-
axes
Axes, plural of ''axe'' and of ''axis'', may refer to
* ''Axes'' (album), a 2005 rock album by the British band Electrelane
* a possibly still empty plot (graphics)
See also
* Axis (disambiguation)
An axis (: axes) may refer to:
Mathematics ...
, but control of the roll axis was still limited. After 90 minutes and two unsuccessful landing attempts, the flight crew managed to land the plane at
Beja Airport. Everyone aboard survived the incident, but one suffered a leg injury.
*
Emery Worldwide Airlines Flight 17, a
McDonnell Douglas DC-8, February 16, 2000. Crashed shortly after taking off from
Sacramento Mather Airport. The crash killed all three crew members. The investigation found that a control rod to the
right elevator control tab detached, causing a loss of pitch control while taking off. The disconnection was caused by the failure to properly secure and inspect the attachment bolt during prior maintenance.
*
Air Midwest Flight 5481, a
Beechcraft 1900D, on 8 January 2003. On takeoff from
Charlotte/Douglas International Airport, the aircraft pitched up and stalled, despite the captain attempting to push the yoke for full elevator down. The aircraft smashed into a US Airways hangar 37 seconds later, killing all 21 passengers and crew aboard and injuring one person on the ground. The NTSB found out that the plane had been overweight and that during maintenance, the tension turnbuckles that governed elevator movement had been set incorrectly by an inexperienced mechanic. This caused the elevators to lose control authority upon takeoff.
Controls damaged by explosive device/weapons
*
Philippine Airlines Flight 434
Philippine Airlines Flight 434, sometimes referred to as PAL434 or PR434, was a scheduled flight on December 11, 1994, from Manila to Tokyo with a quick stopover in Cebu on a Boeing 747-283B that was seriously damaged by a bomb, killing one pas ...
, a
Boeing 747
The Boeing 747 is a long-range wide-body aircraft, wide-body airliner designed and manufactured by Boeing Commercial Airplanes in the United States between 1968 and 2023.
After the introduction of the Boeing 707, 707 in October 1958, Pan Am ...
, on 11 December 1994. The hydraulics were damaged by a bomb in the passenger cabin.
*
DHL shootdown incident in Baghdad on 22 November 2003. The
Airbus A300
The Airbus A300 is Airbus' first production aircraft and the world's first Twinjet, twin-engine, double-aisle Wide-body aircraft, (wide-body) airliner. It was developed by ''Airbus Industrie GIE'', now merged into Airbus SE, and manufactured f ...
DHL aircraft, hit by a
surface-to-air missile
A surface-to-air missile (SAM), also known as a ground-to-air missile (GTAM) or surface-to-air guided weapon (SAGW), is a missile designed to be launched from the ground or the sea to destroy aircraft or other missiles. It is one type of anti-ai ...
, was the first jet airliner to land safely without any hydraulics using only engine controls.
*
Azerbaijan Airlines Flight 8243 on 25 December 2024. The
Embraer E190 crashed during an attempted emergency landing near
Aktua International Airport in Kazakhstan killing 38 out of 67 onboard. The crash is a suspected shootdown event, with the aircraft entering a
phugoid
In aviation, a phugoid or fugoid () is an aircraft motion in which the vehicle Aircraft principal axes, pitches up and climbs, and then pitches down and descends, accompanied by speeding up and slowing down as it goes "downhill" and "uphill". Th ...
cycle.
Controls damaged by pilot error
In these incidents, pilot error resulted in control system damage.
*
Pan Am Flight 845, a
Boeing 747
The Boeing 747 is a long-range wide-body aircraft, wide-body airliner designed and manufactured by Boeing Commercial Airplanes in the United States between 1968 and 2023.
After the introduction of the Boeing 707, 707 in October 1958, Pan Am ...
, on 30 July 1971. When taking off from
San Francisco International Airport
San Francisco International Airport is the primary international airport for the San Francisco Bay Area in the U.S. state of California. Owned and operated by the City and County of San Francisco, the airport has a San Francisco mailing ...
, the plane struck the
approach lighting system
An approach lighting system (ALS) is a lighting system installed on the approach end of an airport runway and consisting of a series of lightbars, strobe lights, or a combination of the two that extends outward from the runway end. ALS usually ...
after taxiing onto a much too short runway. After the impact, the plane continued into the takeoff roll, though its fuselage, landing gear, and 3 out of 4 hydraulic systems were badly damaged. After making a full circle over the Pacific Ocean for an hour and 42 minutes and dumping fuel, the plane made a hard emergency landing at San Francisco, ending on its tail. All 218 passengers survived with a few minor injuries.
*
Aerosucre Flight 157, a
Boeing 727-2J0F, on 20 December 2016. The plane was overweight and in an incorrect takeoff configuration when it took off from
Germán Olano Airport, where it overran the runway and struck a perimeter fence, a tree and a
sentry box
A sentry box is a small shelter (building), shelter with an open front in which a Picket (military), sentry or person on Security guard, guard duty may stand to be sheltered from the weather. Many boxes are decorated in national colours.
Compare: ...
. The 727 also crossed a road, almost killing several people on the ground who narrowly avoided being struck by it before becoming airborne. The plane lost its right main landing gear, power from engine 3, and all of its hydraulic systems, as well as having damage to the inboard right flap. The plane struggled to maintain flight as it entered a right turn before crashing into the ground. Initially, 2 out of the six people on board survived, but one later died of his injuries.
*
American Airlines Flight 587
American Airlines Flight 587 was a regularly scheduled international passenger flight from John F. Kennedy International Airport, New York City, to Las Américas International Airport, Santo Domingo, Dominican Republic. On November 12, 2001, t ...
,
Airbus A300
The Airbus A300 is Airbus' first production aircraft and the world's first Twinjet, twin-engine, double-aisle Wide-body aircraft, (wide-body) airliner. It was developed by ''Airbus Industrie GIE'', now merged into Airbus SE, and manufactured f ...
, November 12, 2001. A pilot's excessive rudder inputs caused the vertical stabilizer to fracture and separate from the aircraft. See complete entry in
structural failures above.
Controls damaged by mid-air collision
These incidents describe mid-air collisions that mainly damaged control systems of at least one of the aircraft, which may or may not have been recoverable.
*
Eastern Air Lines Flight 853, December 4, 1965: collision with
TWA Flight 42. Flight 853, a
Lockheed Super Constellation
The Lockheed L-1049 Super Constellation is an American aircraft, a member of the Lockheed Constellation aircraft line. The aircraft was colloquially referred to as the Super Connie.
The L-1049 was Lockheed's response to the successful Douglas DC ...
, collided with Flight 42, a
Boeing 707
The Boeing 707 is an early American long-range Narrow-body aircraft, narrow-body airliner, the first jetliner developed and produced by Boeing Commercial Airplanes.
Developed from the Boeing 367-80 prototype, the initial first flew on Decembe ...
, damaging the 707's wing and the Constellation's tail. The damage to Flight 853 left the Constellation controllable only by adjusting the throttles. Despite the damage, the crew was able to perform a crash landing on a mountain, with 50 of the 54 occupants surviving the crash. The captain survived the crash and escaped, but died trying to save a passenger who remained in the wreckage. The 707 made a successful emergency landing at
John F. Kennedy International Airport
John F. Kennedy International Airport is a major international airport serving New York City and its metropolitan area. JFK Airport is located on the southwestern shore of Long Island, in Queens, New York City, bordering Jamaica Bay. It is ...
.
*
Pacific Southwest Airlines Flight 182
Pacific Southwest Airlines Flight 182 was a scheduled flight on September 25, 1978 by Pacific Southwest Airlines (PSA), from Sacramento to San Diego ( SAN), with a stopover at Los Angeles ( LAX). The aircraft involved was a Boeing 727-214 ( r ...
, September 25, 1978. The
Boeing 727
The Boeing 727 is an American Narrow-body aircraft, narrow-body airliner that was developed and produced by Boeing Commercial Airplanes.
After the heavier Boeing 707, 707 quad-jet was introduced in 1958, Boeing addressed the demand for shorter ...
collided with a
Cessna 172
The Cessna 172 Skyhawk is an American four-seat, single-engine, high wing, fixed-wing aircraft made by the Cessna Aircraft Company.[Aeroméxico Flight 498
Aeroméxico Flight 498 was a scheduled commercial flight from Mexico City, Mexico, to Los Angeles, California, United States, with several intermediate stops. On Sunday, August 31, 1986, the McDonnell Douglas DC-9 operating the flight was clippe ...](_blan ...<br></span></div> single engined aircraft over San Diego, CA. The damage to the 727's right wing control surfaces and control system hydraulics made the aircraft uncontrollable. All 135 people aboard the 727, both pilots in the Cessna, and 7 people on the ground were killed, for a total of 144 fatalities.
*<div class=)
, August 25, 1986,
McDonnell Douglas DC-9
The McDonnell Douglas DC-9 is an American five-abreast, single-aisle aircraft designed by the Douglas Aircraft Company. It was initially produced as the Douglas DC-9 prior to August 1967, after which point the company had merged with McDonnell ...
. In an accident strikingly similar to PSA 182, a private, single engined
Piper Cherokee Archer strayed into the TCA control area, and collided with the DC-9's vertical stabilizer, separating it and much of the rudder. Without the vertical stabilizer, the DC-9 entered an inverted dive and slammed into a residential area, killing all 58 passengers and 6 crew, plus 15 fatalities on the ground. The pilot and two passengers in the Piper were decapitated when they slammed into the DC-9's vertical stabilizer. This incident and PSA 182 led to the creation of tightly regulated
Class B airspace around the nation's busiest airports.
Accidents and incidents involving military aircraft
Controls damaged by structural failure
* On 4 April 1975, A
Lockheed C-5 Galaxy
The Lockheed C-5 Galaxy is a large military transport aircraft designed and built by Lockheed Corporation, Lockheed, and now maintained and upgraded by its successor, Lockheed Martin. It provides the United States Air Force (USAF) with a heavy ...
(registered as ) making the first flight of
Operation Babylift
Operation Babylift was the name given to the mass evacuation of children from South Vietnam to the United States and other Western countries (including Australia, France, West Germany, and Canada) at the end of the Vietnam War (see also the Fall ...
, had the failure of the rear loading ramp, causing the cargo door to open explosively. This caused an
explosive decompression
An uncontrolled decompression is an undesired drop in the pressure of a sealed system, such as a pressurised aircraft cabin or hyperbaric chamber, that typically results from human error, structural failure, or impact, causing the pressurised v ...
, and in turn, severed control cables to the tail, causing two of four hydraulic systems to fail, including those for the rudder and elevator, and leaving the flight control with only the use of one
aileron
An aileron (French for "little wing" or "fin") is a hinged flight control surface usually forming part of the trailing edge of each wing of a fixed-wing aircraft. Ailerons are used in pairs to control the aircraft in roll (or movement aroun ...
,
spoilers, and power. The crew had to wrestle at the controls by adjusting the power setting and using the remaining one aileron and spoilers in order to return to
Tan Son Nhut Air Base
Tan Son Nhut Air Base () (1955–1975) was a Republic of Vietnam Air Force (RVNAF) facility. It was located near the city of Saigon in southern Vietnam. The United States used it as a major base during the Vietnam War (1959–1975), stationing ...
, but ended up crash landing in a
rice paddy, killing 138 of the 314 people on board.
Controls damaged by explosive device/weapons
In the
Charlie Brown and Franz Stigler incident
The Charlie Brown and Franz Stigler incident occurred on 20 December 1943, after a successful bomb run on Bremen, 2nd Lt. Charlie Brown (pilot), Charles "Charlie" Brown's Boeing B-17 Flying Fortress, B-17F Flying Fortress ''Ye Olde Pub'' of the ...
on 20 December 1943, a Boeing B-17F Flying Fortress of the 527th Bombardment Squadron was tasked with carrying out a bomb run on
Bremen
Bremen (Low German also: ''Breem'' or ''Bräm''), officially the City Municipality of Bremen (, ), is the capital of the States of Germany, German state of the Bremen (state), Free Hanseatic City of Bremen (), a two-city-state consisting of the c ...
,
Germany
Germany, officially the Federal Republic of Germany, is a country in Central Europe. It lies between the Baltic Sea and the North Sea to the north and the Alps to the south. Its sixteen States of Germany, constituent states have a total popu ...
, in formation with other B-17Fs. Before the bomber released its bomb load, accurate
flak
Anti-aircraft warfare (AAW) is the counter to aerial warfare and includes "all measures designed to nullify or reduce the effectiveness of hostile air action".AAP-6 It encompasses surface-based, subsurface ( submarine-launched), and air-bas ...
shattered the Plexiglas nose, knocked out the #2 engine and further damaged the #4 engine, which was already in questionable condition and had to be throttled back to prevent
overspeed
Overspeed is a condition in which an engine is allowed or forced to turn beyond its design limit. The consequences of running an engine too fast vary by engine type and model and depend upon several factors, the most important of which are the d ...
ing. This caused the plane to fall back from the formation and left it vulnerable to enemy attack. The B-17F was then attacked by over a dozen enemy fighters (a combination of
Messerschmitt Bf 109
The Messerschmitt Bf 109 is a monoplane fighter aircraft that was designed and initially produced by the Nazi Germany, German aircraft manufacturer Messerschmitt#History, Bayerische Flugzeugwerke (BFW). Together with the Focke-Wulf Fw 190, the ...
s and
Focke-Wulf Fw 190
The Focke-Wulf Fw 190, nicknamed ''Würger'' (Shrike) is a German single-seat, single-engine fighter aircraft designed by Kurt Tank at Focke-Wulf in the late 1930s and widely used during World War II. Along with its well-known counterpart, the ...
s) of
JG 11 for more than ten minutes, causing the pilot to lose consciousness and putting the B-17F into a steep dive. The pilot later regained consciousness and recovered the plane from the dive. Further damage was sustained from the attack, including to the #3 engine, reducing it to only half power (meaning the aircraft had effectively, at best, 40% of its total rated power available). The bomber's internal oxygen, hydraulic, and electrical systems were also damaged, and the bomber had lost half of its rudder and port elevator, as well as its nose cone. The crew on board were also wounded with one of them being killed. After being escorted by a
Luftwaffe
The Luftwaffe () was the aerial warfare, aerial-warfare branch of the before and during World War II. German Empire, Germany's military air arms during World War I, the of the Imperial German Army, Imperial Army and the of the Imperial Ge ...
Messerschmitt Bf 109 G-6 to be out of German airspace, the B-17F landed at
RAF Seething.
Controls damaged by mid-air collision

*On 1 February 1943, the ''
All American''
B-17F was in formation with other bombers of the
414th Bombardment Squadron to return to their base near
Biskra
Biskra () is the capital city of Biskra Province, Algeria. In 2007, its population was recorded as 307,987. Biskra is located in northeastern Algeria, about from Algiers, southwest of Batna, Algeria, Batna and north of Touggourt. It is nickna ...
,
Algeria
Algeria, officially the People's Democratic Republic of Algeria, is a country in the Maghreb region of North Africa. It is bordered to Algeria–Tunisia border, the northeast by Tunisia; to Algeria–Libya border, the east by Libya; to Alger ...
when two
Messerschmitt Bf 109
The Messerschmitt Bf 109 is a monoplane fighter aircraft that was designed and initially produced by the Nazi Germany, German aircraft manufacturer Messerschmitt#History, Bayerische Flugzeugwerke (BFW). Together with the Focke-Wulf Fw 190, the ...
s attacked the lead bomber and the ''All American.'' The first Bf 109 was downed by the bombers but the second continued its attack, flying towards the ''All American'' until its pilot was shot dead by machine gun fire and the Bf 109 collided with the ''All American'', shearing off the bomber's left
horizontal stabilizer
A tailplane, also known as a horizontal stabilizer, is a small lifting surface located on the tail ( empennage) behind the main lifting surfaces of a fixed-wing aircraft as well as other non-fixed-wing aircraft such as helicopters and gyroplan ...
and leaving a huge hole at the tail section. The only thing holding the B-17F together was the metal frame connecting the tail section and the rear gunner.
This caused the rudder, electricals, and oxygen systems to be damaged, removing the tail wheel and leaving only one operating elevator cable when the other control cables were destroyed. Despite the mid-air collision, none of the crew on board were injured and the B-17F remained airborne. The other bombers slowed down to maintain formation with the ''All American'' to protect it from potential attacks from other
Messerschmitt Bf 109
The Messerschmitt Bf 109 is a monoplane fighter aircraft that was designed and initially produced by the Nazi Germany, German aircraft manufacturer Messerschmitt#History, Bayerische Flugzeugwerke (BFW). Together with the Focke-Wulf Fw 190, the ...
s, which never happened. The B-17F managed to land back at the base with the tail section dragging the landing strip.
Accidents involving experimental flights
Extreme cold

On October 10, 1928, U.S. Army photographer
Albert William Stevens and Captain
St. Clair Streett, the chief of the U.S.
Army Air Corps Materiel Division's Flying Branch, flew the
XCO-5 experimental biplane to achieve an unofficial altitude record for aircraft carrying more than one person: ; less than short of the official single-person altitude record. Stevens snapped photographs of the ground below, warmed by electrically heated mittens and many layers of clothing. At that height the men measured a temperature of , cold enough to freeze the aircraft controls.
[ When Stevens was finished with his camera, Streett found that the aircraft's controls were rendered immobile in the cold, with Streett unable to reduce throttle for descent. The aircraft's engine continued to run at the high power level necessary for maintaining high altitude. Streett contemplated diving at full power, but the XCO-5 was not built for such strong maneuvers—its wings could have sheared off. Instead, Streett waited until fuel was exhausted and the engine sputtered to a stop, after which he piloted the fragile aircraft down in a gentle glide and made a ]deadstick landing
A deadstick landing, also called a dead-stick landing or volplaning, is a type of forced landing when an aircraft loses all of its propulsive power and is forced to land. The "stick" does not refer to the flight controls, which in most aircraf ...
.[ An article about the feat appeared in '']Popular Science
Popular science (also called pop-science or popsci) is an interpretation of science intended for a general audience. While science journalism focuses on recent scientific developments, popular science is more broad ranging. It may be written ...
'' in May 1929, entitled "Stranded—Seven Miles Up!"[Armagnac, Alden P. ''Popular Science'', May 1929]
"Stranded—Seven Miles Up!"
Retrieved on November 22, 2009.
Maintenance or pilot error
*The aircraft designer Roy Chadwick
Roy Chadwick, CBE, FRSA, FRAeS (30 April 1893 – 23 August 1947) was an English aircraft design engineer for the Avro Company.
Born at Marsh Hall Farm, Farnworth, Widnes, the son of the mechanical engineer Charles Chadwick, he was the chief ...
was killed on 23 August 1947 during a crash on take-off of the prototype Avro Tudor 2, ''G-AGSU'', from Woodford airfield. The accident was due to an error in an overnight servicing in which the aileron
An aileron (French for "little wing" or "fin") is a hinged flight control surface usually forming part of the trailing edge of each wing of a fixed-wing aircraft. Ailerons are used in pairs to control the aircraft in roll (or movement aroun ...
control cables were inadvertently crossed.
* X-15 Flight 3-65-97, a NASA
The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the federal government of the United States, US federal government responsible for the United States ...
test flight piloted by Michael J. Adams, on 15 November 1967. Adams was killed after an electrical disturbance caused the degradation of flight controls in his North American X-15
The North American X-15 is a Hypersonic speed, hypersonic rocket-powered aircraft which was operated by the United States Air Force and the National Aeronautics and Space Administration (NASA) as part of the List of X-planes, X-plane series of ...
upon ascent. At 230,000 feet, the X-15 entered a Mach 5 spin. Adams used the minimal manual controls he had along with backup controls to attempt an emergency landing at Rogers Dry Lake
Rogers Dry Lake is an endorheic desert salt pan in the Mojave Desert of Kern County, California. The lake derives its name from the Anglicization from the Spanish name, Rodriguez Dry Lake. It is the central part of Edwards Air Force Base as its ...
, but only managed to throw the aircraft into a pilot induced oscillation and a Mach 3.93 inverted dive. The plane began to break up 10 minutes and 35 seconds after takeoff, destroying the X-15 and killing Adams instantly.
Propulsion-controlled flight research
NASA personnel at Dryden Flight Research Center
The NASA Neil A. Armstrong Flight Research Center (AFRC) is an aeronautical research center operated by NASA. Its primary campus is located inside Edwards Air Force Base in California and is considered NASA's premier site for aeronautical rese ...
worked on the design of an aircraft control system using only thrust from its engines. The system was first tested on a McDonnell Douglas F-15 Eagle
The McDonnell Douglas F-15 Eagle is an American twin-engine, all-weather fighter aircraft designed by McDonnell Douglas (now part of Boeing). Following reviews of proposals, the United States Air Force (USAF) selected McDonnell Douglas's desi ...
in 1993, piloted by Gordon Fullerton. The system was then applied to a McDonnell Douglas MD-11
The McDonnell Douglas MD-11 is an American trijet wide-body aircraft, wide-body airliner manufactured by American manufacturer McDonnell Douglas (MDC) and later by Boeing.
Following McDonnell Douglas DC-10, DC-10 development studies, the MD-11 ...
airliner, and Fullerton made its first propulsion-controlled landing in August 1995. Later flights were made with the center engine at idle speed so the system could be tested using the two wing-mounted engines, simulating the more common airliner layout.[Tucker, p. 29.]
Notes
References
Bibliography
* Gero, David. ''Aviation Disasters''. Patrick Stephens Ltd (Haynes Publishing). Yeovil, Somerset. 1997 1 85260 526 X
*
* Tucker, Tom. Monographs in Aerospace History, No. 16
{{refend
Aviation accidents and incidents
Aircraft controls
Emergency aircraft operations