The technical investigation team recovers the cockpit section of Pan Am 103

What caused the crash ?

Investigations about the Pan Am 103-crash were conducted at an official level by the Air Accident Investigation Branch , AAIB, in UK and Scotland. Other technical experts helped the AAIB. The conclusion was, that an intentional explosive device was the cause of the crash. But other people have during the years brought forward other theories for the crash.


This is a purely technical page, and shall not concern itself with any criminal investigations. To read about the criminal investigation, go to the criminal investigation page .

Overview and quick-menu - press to go to section:
  • Investigation crew and personell 
  • The black box 
  • A giant 3D-puzzle 
  • Pan Am 103 scrapnell graveyard 
  • Mach stem waves 
  • Finding the bomb 
  • Explosive residue 
  • Other theories of damage 
  • Read and view the full and official AAIB-report of the crash

    Personnell conducting the AAIB investigation

    The investigation expenses of the AAIB exceeded 5 million British pounds already in the first year!
    M.M.Charles from the AAIBwas chief-of-staff in the AAIB investigation. Take a look at a list of those activly involved in the investigation.
    Personnell list

    Scottish fireman at the crash scene in LockerbieJames Thomas Thurman was the leading forensic expert, that analyzed the tiny piece of timer circuit board, that was allegedly recovered from the wreckage of Pan Am 103. He, together with forensic crash expert Korsgaard, could not determine, whether the device was triggered by a barometer or just a simple timer device. However he could trace the scrap of the circuit board to a Swiss manufacturer, Meister et Bollier of Zurich, known as the MEBO AG. Amazing - !

    Alan Faraday, head of the Forensic Explosives Laboratory at the Royal Armament Research and Development Establishment, proved specimens from the wreckage to show evidence of two types of chemicals used to manufacture Semtex, a plastic explosive. However, it was not proven, that these chemicals actually came from the bomb. They could be traces of other cargo, since the aircraft had been used for military transport before. In fact, the traces of chemical ingrediens used in making semtex was so small an amount, it could very likely been scraps from army uniforms or even traces from medical chemicals such as heartpain-pills....

    The black box

    The black box, wich isn't black at all, but is bright orange, contains the flight data recorder of every aircraft. It contains cockpit-instruments measurings and readings, pilot's talking over the radio, steardesses announcing to fasten seat-belts etc.

    The black box of Pan Am 103 was found early on December the 22nd. It landed close to the Lockerbie Tundergarth countryside at Banks Hill. Stuart Dodd (14) took his dad's tractor together with his brother Robbie Stuart (13) to search for debris on the fields, and they found the box laying on Chris Grahams land, close to some woods.

    The Data recorder was from 1972, but due to the technical lessons from the crash of Pan Am 103, data flight recorders today are equipped with new, seperate power links, in order to record also after the main power has been ruptured due to crash in midflight.

  • View the recordings of the Black Box for the crash of Pan Am 103
  • Investigators had their trouble with listening to the sounds of the black box's voice recordings. Due to mechanical failure, the recorder didn't vipe out the old sounds completely, before recording a new session. Investigators had to filter those old noises and conversations away, before they could listen to the session just before the power rupture.

    A giant 3-D puzzle

    How does one find out what really happened when a plane has crashed ? The only way is to find all the pieces of the aircraft and put them together again in order to see, first of all, how the aircraft disintegrated (broke into pieces). It is just like a GIANT 3D-puzzle. After this, the technical staff of investigators go through all the disintegrational points as to find out why they broke apart. In the case of Pan Am 103 it was easy to see, where the plane first disintegrated.....i.e. where the bomb went off. The plane started disintegrating just at the "neck" between the cockpit and the fuselage. The forensic puzzle took place at a massive hangar at the British Ministry of Defense depot in Longtown, near Carlisle in north England. There all the remains recovered from the surroundings of Lockerbie were sorted out, no matter how small the shrapnels might be. Sometimes big sacks of mud and rubble were sifted through nets to find tiny pieces of airplane debris. Those pieces came mostly from the famous crater at Sherwood Crescent, where the fuel explosion dismantled everything into confetti.

    The graveyard of PanAm 103

    Many have emailed me and asked: "What has become of the plane today?" Well, the wreckage of Lockerbie jet lies in Lincolnshire scrapyard in the UK

    At the end of a Lincolnshire country lane marked "private", weeds coil around 350 tonnes of white and blue metal strewn over a field which has become the graveyard of PanAm Flight 103, bombed out of the sky over Lockerbie. Moss covers the aircraft's cockpit, which is lying on its side among the debris, propped against one of the Boeing 747's giant engines. Nearby is part of a tail-fin. PanAm's livery is fading, but its blue globe logo remains visible. Under Scottish law the breaker's yard owner is not allowed to dispose of the wreckage until the case closes.

    It was transported to the yard from an army base at Longtown near Carlisle by a fleet of eight trucks in 1989. The destination was not publicised to prevent sightseers gathering.Freight containers ring the field, which is around 1,000 square feet. In some places the debris is piled 10 feet high. Bushes and trees sprout between the pieces of silver grey aluminium wreckage.

    The cockpit's interior is said to be largely intact, with instrument panels, dials and the pilot's joystick all in place. Rain and time have discoloured the exterior. Also in the field is a helicopter which has broken in half, as well as the fuselages of smaller aircraft.The breaker's yard owner was at first paid by insurers, but since PanAm went bankrupt the estimated £1,000 monthly bill has been paid by Dumfries and Galloway police.

    What was the crash like when it happened:

    The technical investigators found out, that the blast, which brought down Pan Am 103 wasn't a very big one. The plane wasn't blown to pieces by the was the mach stem waves that ruptured the plane into pieces together with the gravitational and aerodynamical forces in flight. What are mach stem waves ? Read what the technical crew thinks might have happened with Pan Am 103 in its last seconds before impact:

    Mach stem waves: the ultimate plane shredder

    Mach stem waves: a technical explenation 

      Finding the bomb

    The biggest puzzle on earth: at the crash scene in LockerbieAir planes just don't crash like that without a cause. Radar readings, analysis of the cockpit-voice recorder all indicated the crash to be due to a sudden power break or rupture. Analysis of wheather and winds as well as fracture trail, indicated that Pan Am 103 must have broken up/disintegrated already in descent in midair.That doesn't nescessarily mean the plane has been blown up. Aircrafts can disintegrate if they descent violently because of other reasons, too.

    However, the investigation team concluded in their report, that the crash of Pan Am 103 was triggered by a socalled IED (intentional explosive device), in plain english: a bomb. Or at least, this is what they assume was the most plausible explenation. It is not 100 % the truth...but it is the explenation, that comes closest to the truth. Let's take a look at the indication for the crash to have been triggered by an IED/bomb:

  • The CVR (cockpit voice recorder) recorded a loud sound just miliseconds before power rupture. It could be the sound of a bomb. But it could also be the sound of the aircraft disintegrating. No final conclusion was made as to the origin of this sound, only technical correct speculations.
  • If a bomb started the disintegration, the wreckage of this direct impact would be first on the ground, at the beginning of the wreckage trail. The lower, forward cargo deck was indeed one of the pieces lying at the beginning of the wreckage trail.
  • Engine no. 2 shows heavy damage due to powerful airflow disturbance as well as intake of foreign objects, among them a cable similar to the closure curtain of a cargo container. This means engine no.2 had been hit by some sort of strong blast as it still was working. In fact, later they found out engine no.2 actually "ate" about 8 passengers, including seat and seatbelts!
  • Burned marks on a luggage container, and the one next to it shows a blast fraction.
  • An electronic timing device allegedly found inside piece of suitcase from the blasted luggage container.The device doesn't nescessarily have to be a timer for a bomb - but that is what FBI assumes.
  • There was no indications of prior technical problems with the aircraft. Neither to be found in the aircraft repair-reports, flightrecorders, crew conversation or other proofs of flight history. At least, that's what Boing says.

  • Technical investigations assume the IED was found in a brown Samsonite luggage, inside a Toshiba Cassete Recorder, a socalled Ghettoblaster, probably packed with 10 to 14 ounzes of semtex. However there was no direct indications of semtex, wich is a plastic explosive. Two traces of socalled ingrediens of semtex where found in cargo area (RDX and PETN), but this does not automatically proove them to be fragments from semtex.
    Traces of RDX and PETN can be found in many other chemical substances, too. And even just a soldier having used explosives, brushing dust from his clothes could be the explenation for the finding of RDX and PETN. After all, PA 103 had been used recently by military forces as part of agreement between commercial airliners and the US government.
    So there is in fact no legal proof of explosive devices aboard!

    Any traces of explosive material are not nescessarily proven to be related to a bomb blowing up Pan Am 103....but it is a high possibility they actually are. The "bomb" is nevertheless a very plausible explenation of crash cause.
    In a court of law, the traces of semtex wouldn't stand the evidence.

     More and more planes seems to become victims of explosive devices. It is the nightmare of any airline-carrier, because a bomb strikes from nowhere out of the blue. You cannot predict air-crashes due to intentional bombs. But maybe you can predict the bomb, when it is brought aboard. Most bombs are hidden inside the luggage on board. Read about a research project which found out some interesting technical facts of such problems....
  • Research-project experimenting bombs inside airplane luggage containers

  • Other theories of damage

    Beeing an American plane, carrying CIA personell among others, a bomb can be no big surprise. But it doesn't have to be a bomb. Other weird things can make an aircraft disintegrate and crash as well. Seagulls sucked into the engines. Meteorites hitting the aircraft. Oops!-missiles or deliberate missiles. UFO's trying to abduct the plane. Metal fatigue. Bad weather. Bad luck. Most of the mentioned incidents are very unlikely to be the cause of the crash of Pan Am 103. But some theories other than a bomb are within reason.

    Crash expert John Barry Smith put forward another theory about the crash. It is his opinion, that the crash was triggered by a defect cargo door. He claims, that other Boeing 747-aircrafts have had similar problems, and even thinks that other crashes involving 747-aircrafts can be connected to this cargo door problem. Some air accidents are factually caused by week cargodoors. In his opinion, the crash of Pan Am 103 was not a criminal act, but inevitable sooner or later.

    Discussions of technical causes for the crash:

  • Technical discussion: bomb or no bomb ?
  • Some technical wizards have other explenations. In connection with the crash in Lockerbie, several people noticed intense magnetic disturbances in their TV-sets or radio's. Could electromagnetic disrupture have something to do with the crash ?
    (Probably not....but read it anyway!)

  • Lockerbie crash caused from Alaska ???
  • Much crap has been written during the investigation....but seldom has truth been so far away as in this article from 1996:

  • Two bombs aboard Pan Am 103 ?
  • Pan Am 103 was not the only plane crashing due to evil intention of man...

  • Other crashes of airplanes caused by terrorist activities and tried covered up

  • Bombs - if it indeed was a bomb that brought down Pan Am 103 - don't come out into the open from the unknown.
    Why was the bomb aboard ? And who put it there ?
    Let's take a look at the criminal investigation of Pan Am 103...