KLM Cityhopper Flight 433 was a
Saab 340B
The Saab 340 is a Swedish twin-engine turboprop aircraft designed and initially produced by Saab AB and Fairchild Aircraft. It is designed to seat 30-36 passengers and, as of July 2018, there were 240 operational aircraft used by 34 different op ...
, registered as PH-KSH, which crashed during an
emergency landing
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 term ...
on 4 April 1994 and killing 3 occupants, including the captain. Flight 433 was a routine scheduled
flight
Flight or flying is the process by which an object moves through a space without contacting any planetary surface, either within an atmosphere (i.e. air flight or aviation) or through the vacuum of outer space (i.e. spaceflight). This can be a ...
from
Amsterdam
Amsterdam ( , , , lit. ''The Dam on the River Amstel'') is the capital and most populous city of the Netherlands, with The Hague being the seat of government. It has a population of 907,976 within the city proper, 1,558,755 in the urban ar ...
, the
Netherlands
)
, anthem = ( en, "William of Nassau")
, image_map =
, map_caption =
, subdivision_type = Sovereign state
, subdivision_name = Kingdom of the Netherlands
, established_title = Before independence
, established_date = Spanish Netherl ...
, to
Cardiff
Cardiff (; cy, Caerdydd ) is the capital city, capital and List of urban areas in the United Kingdom, largest city of Wales. It forms a Principal areas of Wales, principal area, officially known as the City and County of Cardiff ( cy, Dinas a ...
,
Wales
Wales ( cy, Cymru ) is a country that is part of the United Kingdom. It is bordered by England to the east, the Irish Sea to the north and west, the Celtic Sea to the south west and the Bristol Channel to the south. It had a population in ...
. The accident was caused by inadequate pilot training and faulty failure sensor, leading to loss of control during
go-around
In aviation, a go-around is an aborted landing of an aircraft that is on final approach or has already touched down. A go-around can either be initiated by the pilot flying or requested by air traffic control for various reasons, such as an unsta ...
.
Accident
The aircraft took off from Runway 24 at
Schiphol Airport
Amsterdam Airport Schiphol , known informally as Schiphol Airport ( nl, Luchthaven Schiphol, ), is the main international airport of the Netherlands. It is located southwest of Amsterdam, in the municipality of Haarlemmermeer in the province ...
at 2:19 pm
local time
Local time is the time observed in a specific locality. There is no canonical definition. Originally it was mean solar time, but since the introduction of time zones it is generally the time as determined by the time zone in effect, with daylight s ...
, with the captain as the
pilot flying. At 2:30, the pilots received a false warning of low oil pressure in the right engine, caused by a
short circuit
A short circuit (sometimes abbreviated to short or s/c) is an electrical circuit that allows a current to travel along an unintended path with no or very low electrical impedance. This results in an excessive current flowing through the circu ...
. While the first officer consulted the emergency checklist, the captain unilaterally set the right engine's power to idle, probably to reduce the risk of damage. However, the oil pressure gauge was still showing above 30
PSI, indicating that oil pressure was within safe limits and the warning was false. The checklist recommended continuing normal flight operations under the circumstances.
However, the captain did not return the engine to the previous throttle
A throttle is the mechanism by which fluid flow is managed by constriction 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' ...
setting, leaving the aircraft effectively flying on one engine. As the Saab approached flight level
In aviation and aviation meteorology, a flight level (FL) is an aircraft's altitude at standard air pressure, expressed in hundreds of feet. The air pressure is computed assuming an International Standard Atmosphere pressure of 1013.25  ...
170 (17,000 feet), the loss of power degraded the aircraft's climb performance. The crew misinterpreted this, and decreasing oil pressure from the retarding right engine, as confirmation that the engine was faulty.[ A Pan-Pan call was made at 2:33, requesting to return to Schiphol.
The captain had not anticipated the consequences of flying with one engine at idle, and was unable to stabilize the final approach onto Runway 06; the situation was aggravated by an 8 knot ]tailwind
A tailwind is a wind that blows in the direction of travel of an object, while a headwind blows against the direction of travel. A tailwind increases the object's speed and reduces the time required to reach its destination, while a headwind has ...
. He also disengaged the autopilot
An autopilot is a system used to control the path of an aircraft, marine craft or spacecraft without requiring constant manual control by a human operator. Autopilots do not replace human operators. Instead, the autopilot assists the operator' ...
, while the first officer neutralized the rudder
A rudder is a primary control surface used to steer a ship, boat, submarine, hovercraft, aircraft, or other vehicle that moves through a fluid medium (generally air or water). On an aircraft the rudder is used primarily to counter adve ...
trim, both of which had been compensating for the asymmetric thrust. During this time the aircraft fell below the glideslope and airspeed
In aviation, airspeed is the speed of an aircraft relative to the air. Among the common conventions for qualifying airspeed are:
* Indicated airspeed ("IAS"), what is read on an airspeed gauge connected to a Pitot-static system;
* Calibrated ...
decreased to 115 knots, below the target approach speed of 125 knots. In response, the captain increased torque
In physics and mechanics, torque is the rotational equivalent of linear force. It is also referred to as the moment of force (also abbreviated to moment). It represents the capability of a force to produce change in the rotational motion of th ...
on the left engine, causing the aircraft to veer to the right of the runway. The crew did not apply additional rudder deflection to correct it, instead relying on the ailerons
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 around ...
.
At a height of 45 feet, the captain decided to perform a go-around
In aviation, a go-around is an aborted landing of an aircraft that is on final approach or has already touched down. A go-around can either be initiated by the pilot flying or requested by air traffic control for various reasons, such as an unsta ...
, and commanded full throttle to the left engine, while leaving right engine at idle. The crew continued to only use the ailerons to counteract the thrust imbalance. The aircraft rolled to the right and pitched up, while airspeed decayed to 105 knots, activating the stall warning. Some rudder deflection was applied afterwards, and full deflection was applied 8 seconds later, but the aircraft was unrecoverable as airspeed decreased to 93 knots and the right bank increased to 80 degrees.
At 2:46, the aircraft crashed in a field just outside the airport, 560 meters from the runway. Of the 24 people on board, 3 were killed—the captain and 2 passengers. Out of the 21 survivors, 9 suffered serious injuries, including the first officer. Due to amnesia
Amnesia is a deficit in memory caused by brain damage or disease,Gazzaniga, M., Ivry, R., & Mangun, G. (2009) Cognitive Neuroscience: The biology of the mind. New York: W.W. Norton & Company. but it can also be caused temporarily by the use ...
caused by the crash, the first officer could not recall the accident.
Aircraft and crew
The aircraft involved was a Saab 340B
The Saab 340 is a Swedish twin-engine turboprop aircraft designed and initially produced by Saab AB and Fairchild Aircraft. It is designed to seat 30-36 passengers and, as of July 2018, there were 240 operational aircraft used by 34 different op ...
, registration PH-KSH, which had first flown in 1990. The aircraft was powered by two General Electric CT7-9B turboshaft engines and had flown 6,558 hours at the time of the accident.
The captain, 37-year-old Gerrit Lievaart, had been with KLM Cityhopper
KLM Cityhopper is the regional airline subsidiary of KLM, headquartered in Haarlemmermeer, North Holland, Netherlands. It is based at nearby Amsterdam Airport Schiphol. As a subsidiary of Air France–KLM, it is an affiliate of SkyTeam. The ai ...
since 2 March 1992. He had a total of 2,605 hours flying time, including 1,214 hours on a Saab 340. However, training records revealed that he had failed two engine-out checks, and on his most recent one had been given a "standard minus," the lowest passing grade. The first officer, 34-year old Paul Stassen, had been with KLM Cityhopper since 27 January 1992. He had a total of 1,718 hours flying time, including 1,334 hours on a Saab 340.
Accident investigation
The final report from the Netherlands Aviation Safety Board The Netherlands Aviation Safety Board ( nl, Raad voor de Luchtvaart) was an agency of the Government of the Netherlands. It investigated aviation accidents and incidents. Its head office was located in Hoofddorp in the Haarlemmermeer municipality.
...
found that pilot error
Pilot error generally refers to an accident in which an action or decision made by the pilot was the cause or a contributing factor that led to the accident, but also includes the pilot's failure to make a correct decision or take proper a ...
, through inadequate use of flight controls during unequal throttle go-around, resulting in loss of control, was the primary cause of the accident. In addition, the report included recommendations directed at KLM, regarding contributing factors,[ addressing: improved training on ]crew resource management
Crew resource management or cockpit resource management (CRM)Diehl, Alan (2013) "Air Safety Investigators: Using Science to Save Lives-One Crash at a Time." Xlibris Corporation. . http://www.prweb.com/releases/DrAlanDiehl/AirSafetyInvestigators/ ...
; improved pilot assessment techniques; and improved guidance on flying with an idle engine.[ In addition, the report found that the crash was generally survivable, with the captain's death attributable to not wearing his shoulder restraints.][
]
In popular culture
The crash of KLM Cityhopper Flight 433 was covered in 2019 in "Fatal Approach", a Season 19 episode of the internationally syndicated Canadian TV documentary series ''Mayday
Mayday is an emergency procedure word used internationally as a distress signal in voice-procedure radio communications.
It is used to signal a life-threatening emergency primarily by aviators and mariners, but in some countries local organiz ...
''.
References
External links
Fatal Events Since 1970 for KLM
CVR transcript KLM Cityhopper Flight 433 – 04 APR 1994
*
Final report of the investigation into the probable causes of the accident with the KLM Cityhopper flight KL433, Saab 340B, PH-KSH at Schiphol, Amsterdam Airport on 4 April 1994
'
Archive
. Netherlands Aviation Safety Board The Netherlands Aviation Safety Board ( nl, Raad voor de Luchtvaart) was an agency of the Government of the Netherlands. It investigated aviation accidents and incidents. Its head office was located in Hoofddorp in the Haarlemmermeer municipality.
...
(Raad voor de Luchtvaart) 1995. In book series Aircraft accident report 94-05 �
Available on the shelf
at the Delft University of Technology
Delft University of Technology ( nl, Technische Universiteit Delft), also known as TU Delft, is the oldest and largest Dutch public technical university, located in Delft, Netherlands. As of 2022 it is ranked by QS World University Rankings among ...
*
{{DEFAULTSORT:Klm Cityhopper Flight 433
Aviation accidents and incidents in the Netherlands
Aviation accidents and incidents in 1994
Accidents and incidents involving the Saab 340
KLM Cityhopper accidents and incidents
1994 in the Netherlands
April 1994 events in Europe