January’s issue of Vanity Fair magazine published an article on the 2006 mid-air collision of Gol Flight 1907 and a Legacy business jet N600XL high above the Amazon rainforest. I’ve just spent the past few hours researching this accident and listening to the cockpit voice recordings. On December 11, 2008, the final accident report released by aviation authorities and placed blame on positive air traffic control procedures, undetected loss of functionality of the airborne collision avoidance system (TCAS), Brazilian controllers on the ground, and the two American Legacy pilots.

The chain of events that led these two airplanes to collide is nothing short of fantastic, which is why Vanity Fair’s author, William Langewiesche, wrote a crash investigator told him “the Devil himself must have been at play.” Think about it: the most advanced avionics ever created — in both cockpits of the $25 million Legacy 600 and the two-week-old Gol Boeing 737 — put these jets on an incredibly precise high-altitude collision course from nearly 2,000 miles apart.

Langewiesche started his piece:

There were so many opportunities for the accident not to happen—the collision between a Legacy 600 private jet and a Boeing 737 carrying 154 people. But on September 29, 2006, high above the Amazon, a long, thin thread of acts and omissions brought the two airplanes together. From the vantage point of the pilots, the Brazilian air-traffic controllers, and the Caiapó Indians, whose rain forest became a charnel house, the author reconstructs a fatal intersection between high-performance technology and human fallibility.

Apparently, the Gol 737 made an evasive bank just seconds before impact, but it wasn’t enough to save the airliner. The 737 and the Legacy 600 struck each other’s wings — missing a nose-to-nose collision by a mere 30 feet, infinitesimal in the vastness of the sky. The Legacy’s five foot tall winglet tore through the center of the 737′s wing essentially tearing it off, which sent the passenger jet into an out-of-control rotating nose dive. Lasting around 45 seconds, the dive put the 154 passengers and crew on 1907 into a horrifying 4 G death spin. Just seconds before crashing into the Amazon rainforest, the Boeing broke into three pieces. All 154 on board were killed. The cockpit voice recording from 1907 at the time of impact with the Legacy is chilling. The collision sounded like a car crash, and the pilots tried to remain calm while a multitude of horns and alarms sounded for the final minute of their lives. 

The Legacy, on the other hand, was severely damaged but the pilots managed to descend and land at a nearby Brazilian Air Force base. All of the seven passengers and crew lived through the mid-air collision, something no one is supposed to survive.

About half-way through the article, the story becomes gripping, especially if you listen to the cockpit voice recordings as you read (skip ahead to 1:23:46 on the N600XL tape). Wikipedia has photographs of the damaged Legacy after its safe landing, as well as a mockup the collision point.

This entry was posted on Saturday, December 27th, 2008 at 12 pm and is filed under flight, links, news, travel.