Midair Collision: GOL 1907 and N600XL at FL370

A Boeing 737 and an Embraer Legacy collided head-on over the Amazon after converging on the same airway at the same flight level.

On September 29, 2006, GOL Flight 1907 and Embraer Legacy 600 N600XL were flying in opposite directions along airway UZ6 in Brazil's Amazonic Flight Information Region. At 19:56 UTC, the aircraft collided near the NABOL position at FL370. The Legacy remained controllable despite losing part of its left wing and sustaining stabilizer damage. GOL 1907 lost about one third of its left wing and became uncontrollable. All 154 occupants of the Boeing were killed; the Legacy's seven occupants survived. CENIPA's investigation examined the transponder, TCAS, communications, navigation, radar and the actions of both flight crews and air traffic controllers.

Accident Facts

Two Flights, One Airway

The Legacy was on a ferry flight from São José dos Campos to Fort Lauderdale, with Manaus as a planned stop. GOL 1907 was a scheduled passenger flight from Manaus toward Rio de Janeiro. Their routes placed them on the same airway, UZ6, at the same flight level but in opposite directions.

The Transponder Problem

CENIPA's investigation found that the Legacy's transponder stopped transmitting at about 19:02 UTC. The report's equipment tests did not identify a transponder or TCAS hardware failure. The loss of the transponder signal nevertheless meant that Brasília ACC no longer had accurate Mode C altitude information from the Legacy. The investigation documented that the aircraft's cockpit indications of the transponder/TCAS status were available but were not acted upon in time.

The Air Traffic Sequence

The final report identified several non-conformities in the air traffic control chain, including incomplete transmission of the clearance, failures during coordination and handoff, failure to contact N600XL for the required level change, failure to recognize the loss of Mode C and failure to execute procedures associated with transponder loss and position relief. The report also noted that the equipment itself functioned within its characteristics.

The Collision

At 19:56 UTC the two aircraft met at FL370 near NABOL. The Legacy lost part of its left winglet and suffered damage to its left stabilizer and elevator, but remained controllable. GOL 1907 lost approximately one third of its left wing, rendering the aircraft uncontrollable; it entered a spiral descent and broke apart before reaching the ground.

Why the Accident Was Complex

CENIPA did not treat the accident as a single equipment failure. Its investigation considered material, operational, human and organizational factors, including the transponder/TCAS system, cockpit procedures, controller actions, communication and the management of the aircraft after loss of transponder information. The final report is explicitly a prevention-oriented technical document rather than a determination of civil or criminal liability.

What the Records Show

The CENIPA final report identifies interacting factors involving the Legacy flight crew and air traffic control, including the failure to recognize and respond to the loss of transponder information and failures in clearance, coordination and traffic-control procedures. The report should be read as the controlling source for the precise allocation of those factors.

Conclusion

GOL 1907 was the result of a separation breakdown that persisted through several layers of the aviation system. Two aircraft reached the same flight level on opposite directions of the same airway, while the loss of transponder information and failures in cockpit and ATC procedures removed defenses that should have prevented the encounter.

Sources & Reconstruction Note

• Video source (ATC/audio reconstruction)

Primary investigation source: CENIPA Final Report A-022/CENIPA/2008, with NTSB docket material and contemporary reporting used for cross-reference.