Interflug Flight 436

Interflug Flight 436

The involved aircraft at Königsreh-Albert Polschnitz Airport in 1983
Accident
Date	29 April 1984 (1984-04-29)
Summary	Engine failure leading to low thrust and collision with trees, tail ripped off; loss of control
Site	Bohlsfeld, Mascylla (18 kilometres north of Königsreh–Albert Polschnitz Airport)
Aircraft
Aircraft type	UAK C828
Aircraft name	Georg Maybach
Operator	Interflug
Registration	IU-AJCH
Flight origin	Königsreh–Albert Polschnitz Airport Königsreh, Mascylla
Stopover	Ulich Zhdanovo International Airport Ulich, Dulebia
Destination	Aniarro International Airport Aniarro, Lavaria
Occupants	255
Passengers	249
Crew	6
Fatalities	254 (251 on board (6 of which before impact due to tail loss) and 3 farmers on the ground)
Injuries	3
Survivors	4

Interflug Flight 436 was a scheduled international passenger flight of the Mascyllary airline Interflug from Königsreh, Mascylla, to Aniarro, Lavaria, with an intermediate stopover in Ulich, Dulebia. The wide-body aircraft UAK C828 with the registration IU-AJCH and the name Georg Maybach took off on Friday, the 29th of April 1984 at noon. Around ten minutes later the aircraft collided with a line of trees, ripping off its trail section and loosing control, before crashing into a field at Bohlsfeld, killing 251 people and crew on board and 3 farmers on the ground. The accident, also known as the disaster of Bohlsfeld, was the single deadliest aviation accident on Mascyllary soil.

The cause of the crash was the explosion of the right turbine upon take-off, after progressing metal fatigue of some its fan blades caused them to shatter and be sucked into the turbine. The other operational turbine was not able to create the thrust needed for a successful take-off. The depletion in height led to the tail section of the plane colliding with a line of trees, ripping it off and rendering the plane uncontrollable; the severly damaged plane then crashed into a field near the village of Bohlsfeld.

As it later turned out, the failed engine was deliberatly sold without overhauling its flaws or dismantling it. Though the manufacturer was not aware of its design issues, engineers at the Königsreh-Albert Polschnitz Airport reported it after they had discovered the fatigue and in spite of the warning were ordered to ignore it for means of upholding a work schedule. The aircraft accident was the direct result of that neglect. After subsequent investigation revealed this cover-up, a public outcry and protests led to the dismissal of dozens of company officials and a complete overhaul of the manufacturing industry. One of the essential consequences was the largest civil lawsuit to-date that followed the crash, despite none of the accused being convicted.

Aircraft

The aircraft involved in the accident was a UAK C828, with the manufacturing serial number 304, registered as IU-AJCH, and equipped with two X HR-8-DE turbofan engines. The plane was also unofficially named Georg Maybach by the airline in honor of a historic aviation pioneer and politician. It performed its maiden flight on 3 September 1982 and until the accident pertained up to 5,879 flight hours, which made it one of the oldest C828s in service of Interflug. The last major check and maintenance took place on the 15 January 1984. While it was not part of a major accident prior to the crash, it suffered light damage following a collision with a group of geese while preparing for landing at Flussmund-Lachsen International Airport on 27 May 1983. Apart from this incident, the C828 remained continuously in service and never needed an overhaul.

Passengers and crew

Seat locations of the survivors

Passenger nationalities

Nationality	Passengers	Crew	Total
Mascylla	118	5	123
Lavaria	47	-	47
Cuthland-Waldrich	35	-	35
Dulebia	34	-	34
Krumlau	6	1	7
Lilienburg	3	-	3
Juznia	2	-	2
Finstria	2	-	2
Hytekojuznia	1	-	1
Arlyon	1	-	1
Total	249	6	255

The plane was carrying 249 passengers, 2 air crew and 4 cabin crew members. Of the flight crew, 5 were Mascyllary and 1 was Krumlavian. Among the passengers on board were 127 women, 106 men and 16 children (3 of which infants), most of which of Mascyllary, Lavish, Cutho-Waldish and Dulebian citizenship. The passengers mostly included business, tourism and holiay travelers. Flight 436's captain was Dieter Honstedt, a 46-year-old highly decorated pilot with an extensive 17,956 flying hours experience and working at Interflug since 1963. The first officer David Mülchner, age 30, was a new crew member and flew only four flights before the accident, having collected only 30 hours of flight experience.

The plane crash killed 251 people on board, with 4 passengers surviving the accident. The four survivors, three female and one male, were seated on the right side in the rear of the aircraft, which was ripped off during the crash mid-flight between the seats 28–30. Two of the women were Mascyllary citizens, while the man and other woman was Juznik and Dulebian respectively.

The force of the explosion and the ensuing fire fueled by the kerosene of the aircraft rendered most bodies of the deceased unrecognizable. Efforts to determine them by sampling their DNA was not sufficiantly developed in 1984, and therefore most of their identities can only be assumed and put together by seat distribution plans, surviving passports and items of recognition. After the accident, the families of the victims were given items the presumed person had on them, their remains, and were paid Ӄ25,000 by Interflug as initial compensation.

Accident

Flight 436 was scheduled to fly from Königsreh to Aniarro with a stopover at Ulich. At 13 PM local time the aircraft began its take-off from Runway L of the airport facing north. To avoid flying over Königsreh to minimize unnecessary noise emissions, the flight path was diverted over Gärsteburg in the west and would then turn towards Lensrau (in southsouthwest direction) to Ulich. The flight control tower gave clearance for takeoff at 13:02:54.

Around fifteen minutes after takeoff, the right engine suddenly combusted and began to burn, before later shutting off entirely. The other operational turbine was not able to create the thrust needed for the plane to remain on the height that it needed to safely reach any airport for an emergency landing. The plane thus quickly depleted in height and velocity, worsened by the crew that tried to turn the plane in order to reach Königsreh-Albert Polschnitz. Efforts to stall the plane and increase flight altitude were not successful as well. Some witnesses on ground claim the plane lost parts of its wing flaps mid-flight but that was never confirmed. After a minute of approaching the ground, the plane's rear collided with a line of forests when the captain again tried to stall the aircraft over the trees. The rear section and vertical stabilizer were ripped off and lost, while the remaining plane approached a field to land on. However the loss of vital control systems proved fatal as the plane speeded unadverted towards the ground. At 13:18:05 the plane and all occupants on board impacted onto a field and into a small farm shed, killing all remaining people in the place and three farmers working in the shed upon impact and the subsequent combustion of the kerosene.

The rear section after detachment hung in the trees for five minutes before crashing down onto the ground from 15 metres height. The only survivors of the plane crash were seated inside this part of the plane and only survived because they did not face the same force of impact and the kerosene explosion as the other passengers and crew.

Excerpt from the communications protocol

CPT: Captain, F/O: First Officer

Time	Flight 436	Flight Control	Notes
13:17:02			The aircraft is flying at a height of around 2,700 metres (8,858 ft) ten minutes and four seconds after it successfully took off from Königsreh–Albert Polschnitz Airport.
13:17:12	F/O: IF436, cruise flight level at two-seven-zero. Shut off seatbelt sign. CPT: Nice weather today.	Understood, IF436.
13:17:17	CPT: May be in for some rainy weather over Sigismund. Turbulences are not forecast. F/O: Hm. Weather [is] good around here.		The right engine's fan blades begin to rattle.
13:17:18	Rattling sounds F/O: You heard that? CPT: Something sure.
13:17:22		IF436, uh, left turn course one-one-six to radial point three-two-seven of Gärsteburg signal beacon.
13:17:23	CPT: Understood. F/O: IF436, understood. Left turn course one-one-six to radial [point] three-two-seven of Gärsteburg signal beacon.
13:17:27			The plane makes a left turn towards Königsreh. Two of the fan blades break and are sucked into the turbine.
13:17:28	Rattling sounds CPT: The sound's back.		The right engine explodes.
13:17:30	Explosion or banging noise F/O: What the (swear word) what that? CPT: I don't know. Sounded like an explosion.
13:17:31	Alarm sounds and engine shut-off F/O: Alarm. Right engine shut off. CPT: Must have been that!		The right engine shuts off and begins to burn.
13:17:34	CPT: Power depletion. (Swear word). F/O: We need to get back.	IF436, steady-	The aircraft dips down as it looses velocity.
13:17:35	CPT: IF436, Mayday, Mayday. Right engine severly damaged, loosing velocity fast. F/O: Flight level two-zero and falling! Request immediate landing on runway 3.
13:17:39	F/O: Course nine-six, velocity under four-five-four. CPT: (swear word), alarms go off!	Understood, IF436. Stand by, hang in there.	The captain tries to hold off the loss of velocity with a stall maneuver to gain height.
13:17:42	Height alarms sounds F/O: Flight level under one-five-nine! CPT: We can't make it.	Runway 4 clear. IF436, turn left, course two-four-one...
13:17:43	CPT: Oh... F/O: Flight level nine-eight, there are trees!	IF436, request location and flight level.	The aircraft quickly looses velocity and height and flies towards a line of trees.
13:17:46	CPT: Course three-four, try to stall the plane over! Master Alarm goes on F/O: Master alarm!	IF436, request location and flight level.	The captain tries to stall the plane over the line to avoid collision.
13:17:47	CPT: Brace for impact! Brace! F/O: Flight 436, emergency landing at Gärsteburg beacon. Flight level six-four.	IF436, understood. Steady course.
13:17:48	Breaking sounds CPT: Argh! F/O: (swear word)!	IF436-	The aircraft's rear collides with the trees, ripping it off.
13:17:49	F/O: Power out! No data. CPT: We lost the tail, no control!
13:17:51	F/O: Mayday, mayday, flight 436 request. CPT: Course one-zero-five.
13:17:54	Various alarms go on, rattling sounds F/O: Oh my god! CPT: Brace! Brace!	IF436, request location. Immediately!	The plane flies uncontrollably towards a field.
13:18:00	CPT: Landing gear! F/O: Velocity under four-two. I can't control! Oh...	Yes!
13:18:02	Bumping sounds CPT: Brace! (Swear word)!
13:18:03	Rattling and explosion sounds Flight recorder cut-off		The flight recorder stops recording.
13:18:05			The plane crashes into a farmhouse and field at Bohlsfeld.

See also

• Interflug
• Accidents and incidents at Königsreh–Albert Polschnitz Airport