Tenerife 1977 – Runway Collision Disaster
Date of Incident: March 27, 1977
Location: Los Rodeos Airport (now Tenerife North), Canary Islands, Spain
🧭 What Happened
Two Boeing 747 aircraft — KLM Flight 4805 and Pan Am Flight 1736 — collided on the runway in dense fog at Los Rodeos Airport. The KLM aircraft initiated takeoff without clearance while the Pan Am jet was still taxiing. The impact and resulting fire killed 583 people, making it the deadliest accident in aviation history.
✈️ Aircraft Details
KLM Flight 4805: Boeing 747-206B, Registration PH-BUF, “Rijn”
Pan Am Flight 1736: Boeing 747-121, Registration N736PA, “Clipper Victor”
KLM Origin: Amsterdam Schiphol (AMS)
Pan Am Origin: Los Angeles (LAX) via JFK
Destination for Both: Gran Canaria Airport (LPA)
Fatalities: 583 total (248 KLM, 335 Pan Am)
Survivors: 61 (all from Pan Am)
🔍 Key Factors
- Dense fog reduced visibility to under 300 meters
- Airport congestion due to bomb threat diversion from Gran Canaria
- Runway used for taxiing due to blocked taxiway
- Miscommunication between KLM crew and ATC
- Nonstandard phraseology and simultaneous radio transmissions
- Captain’s premature takeoff decision without clearance
📆 Timeline of Events
- 13:15 UTC – Bomb explodes at Gran Canaria; flights diverted to Tenerife
- 16:56 UTC – KLM instructed to backtrack runway for takeoff
- 17:02 UTC – Pan Am instructed to follow and exit at taxiway C3
- 17:05 UTC – KLM requests departure clearance
- 17:06 UTC – KLM begins takeoff roll without clearance
- 17:06:50 UTC – Collision occurs between taxiway C3 and C4
🎙️ Cockpit Voice & Flight Data
“We are now at takeoff.” — KLM First Officer
“We’re still taxiing down the runway, Clipper 1736.” — Pan Am First Officer
CVR revealed confusion over clearance and overlapping transmissions. KLM crew believed they had takeoff clearance. Pan Am crew attempted evasive action but collision was unavoidable. Both recorders were recovered and analyzed by Spanish, Dutch, and U.S. authorities.
⚙️ Aircraft Systems & Failures
- No ground radar at Los Rodeos Airport
- Runway centerline lighting NOTAM’d as unserviceable
- Radio interference masked critical transmissions
- Pan Am missed taxiway C3 due to poor signage and geometry
🛡️ Aftermath and Reforms
- Standardized phraseology mandated globally (e.g., “takeoff” reserved only for actual clearance)
- Crew Resource Management (CRM) introduced to empower junior crew input
- Ground radar installed at major airports
- KLM accepted responsibility and compensated victims’ families
- Memorials erected in Tenerife and at Pan Am’s U.S. headquarters