On 21 December 1988, one of the most tragic incidents in the history of civil aviation took place. But the lessons of that tragic day and the impact of “Pan Am 103” or “Lockerbie” remain valuable and deserve attention. Santrauka 1988 m. gruodžio 21 d. ivyko vienas tragiškiausiu incidentu civilines aviacijos istorijoje. Tačiau šios tragiškos dienos pamokos ir Pan Am 103 arba kitaip Lockerbie katastrofa turi išliekamaja verte. But the lessons of that tragic day and the impact of “Pan Am 103” or “Lockerbi e” remain valuable and deserve attention . Keywords: incident, aviation security, bomb, disruption, lesson. 1. Introduction On 21 December 1988, Air Malta Flight 180 arrived in Frankfurt as scheduled and discharged its passen gers and baggage into the Frankfurt International Airpor t distribution system. A brown Samsonite suitcase with an Improvised Explosive Device (IED) was entered into the Frankfu rt Airport automatic baggage distribution system at a mid- field entry point. PAA-103A was not departing until some time later (around 4 hours); the suitcase with the IED was retained in the Frankfurt Airport automatic baggage system until a command was subsequently given to the baggage computer system to discharge all bag s of PAA-103 А at Gate 46. The brown Samsonite suitcase, together with other suitcases, was driven from Gate 46 to Gate 44 for X-ray. The baggage (after the X-ray control was completed) was delivered to PAA-103A and placed in the hold of a B-727. Fig 1. PAN AM Flight 103, December 21, 1988 The fatal journey of flight PAA-103 began from Frankfurt International Airport on the afternoon of 21 December 1988. Soon after that, air traffic controller Alan Topp, who watched Flight PA103 as it crossed Scottish airspace, saw that the aircraft’s transponder stopped replying so me- where over Lockerbie. The ATC controller tried agai n to communicate with Clipper 103, but there was no repl y. Not one, but several radar returns on his screen at last altogether disappeared. A ULD-3 container in the forward cargo hold contained that brown Samsonite suitcase. It was loc ated on the left side of the aircraft, forward of the wing. A detonated bomb ripped a hole in the side of the container near the left side of the aircraft and a hole in the aircraft skin. When scientists found a fragment of a printed circuit board on part of the luggage container from Pan Am 103 into which the explosive device had been loaded, th ese enquiries took on a greater significance. Aviation, 2009 13(3): 78–86 - 80 - The Royal Armament Research and Development Establishment of the United Kingdom (RARDE) made extensive enquiries. Police also established that t he fragment of printed circuit board came from a Toshi ba radio cassette recorder. Other debris recovered, in cluding a fragment from the owner’s instruction manual, sub se- quently allowed forensic scientists to identify the model as a Toshiba RTSF16 radio cassette recorder. A fragmen t of printed circuit board was found in a grey shirt mad e by Slalom, and the forensic scientists concluded that it had an intimate involvement in the explosion. In their report they stated: “This fragment represents the only rec overed piece of modification in the Toshiba radio which wo uld have been necessary to convert it into a delayed ac tion bomb”. The improvised explosive devices recovered by the German police were thereafter examined by forensic scientists, but they did not find any components th at matched the fragment of circuit board recovered fro m the bomb which destroyed Pan Am 103. The print-out and record sheet therefore confirmed the presence o f a suspicious item – an unaccompanied bag transported to London Heathrow from Malta. It was established by the investigation that Pan Am Flight 103 had been destroyed by an Improvised Explosive Device (IED): - a Toshiba radio cassette recorder, Model No RTF16 contained the IED inside. - the presence of chemicals found in Semtex was confirmed by forensic examination. - the bomb was placed inside a Samsonite suitcase a long with clothing purchased in Malta. - on Wednesday, 7 December 1988 the clothing was purchased by a man who was described as Libyan by Anthony Gauci (a witness). The Aviation Disaster Family A ssis- tance Act and the Foreign Air Carrier Family Support Act were enacted in 1996 and 1997 correspondingly. The artful concealment used by Lockerbie terrorists made the detection of explosives very difficult for scree- ners. Explosive detection systems and explosive tra ce detection were designed after “Lockerbie” as an att empt to develop equipment for the reliable detection of explosives and explosive devices. It became possibl e due to increased funding of research and development of this detection equipment. Cargo security was amended by new standards for screening and practices based on the “known” and “u nk- nown” shipper concepts. Another lesson of Lockerbie yet to be implemented by civil aviation is contained in the recommendatio ns of the aircraft accident report: “The following safety recommendations were made during the course of the investigation: 4.5 That airworthiness authorities and aircraft manufacturers undertake a systematic study with a view to identifying measures that might mitigate the effects of explosive devices and improve the tolerance of aircraft structures and systems to explosive damage” (Charles 1990). As a result, much research was done to improve the structure of aircraft and harden the cargo hold and containers against the consequences of IED blasts. Efforts in this area continue. This material also gives an example of system approach to AVSEC QC and QA activities/ AVSEC auditor responsibilities in making conclusions, whi ch may influence present and future state of security in relative civil aviation environment. References Anderes, V. 2008. Global Impact of Pan Am 103: 20 years after Lockerbie. ASI. Case study PAN AM Flight-103 December 21, 1988. 1989. Jordan Regional