Investigation Summary
Thirteen minutes into the flight, while climbing through 29,200 feet, the crew noticed elevator control issues. Unbeknownst to them, a leak in a hot air pipe in the unpressurized aft section had reached temperatures of 300°C, melting the insulation of electrical cables. This caused short circuits and sparks that ignited a fire in the cargo bay. Because this area lacked fire detectors, the crew was initially unaware of the fire's severity, only reporting smoke in the cabin minutes later. By the time they initiated an emergency descent and fuel dump, the fire had weakened the rear fuselage structure. Just as the airport came into view, the empennage detached, sending the aircraft into a vertical dive.
Final Conclusions
The investigation concluded that the primary cause was a design flaw involving the proximity of high-temperature air pipes to electrical wiring in a section of the aircraft not equipped with fire sensors. The resulting fire destroyed the control cables and eventually the structural attachments of the tail unit.
Video Analysis
The Crash of Interflug Flight 450: East Germany's Deadliest Aviation Disaster — This video examines the 1972 crash of an Ilyushin Il-62 near Königs Wusterhausen. It details how a hot air pipe leak triggered a catastrophic cargo bay fire, leading to structural failure and the loss of all 156 people.
Watch on YouTube ↗If playback is blocked, the owner has disabled embedding — use the link above.
Systems & Failure Modes
Aft Cargo Bay
The location of the initial fire, which lacked smoke or heat sensors, delaying crew awareness.
Elevator Control System
The fire damaged the control cables running through the rear of the plane, leading to the initial reports of handling issues.
Hot Air Pipes
Leaking pipes carrying high-temperature air ignited the surrounding electrical insulation.
Interesting Facts
- 01It is the deadliest aviation accident to ever occur on German soil.
- 02The aircraft had only 3,520 flight hours at the time of the accident.
- 03The aft cargo bay where the fire started was not equipped with fire detectors.
- 04The fire reached temperatures sufficient to melt aluminum and weaken the steel structure of the tail.
- 05All 156 people on board (145 passengers and 11 crew) perished.
Safety Actions & Advisories
Il-62 Design Modifications
Source ↗Following the crash, the Ilyushin Il-62 was modified to include fire detectors in previously unmonitored compartments and improved insulation for electrical wiring near hot air ducts.