After the tragic collision between a Russian Tu-154 and a DHL cargo Boeing 757 at 35,400 ft over southern Germany on July 1, AIN questioned whether regulations, or any other body of accepted procedures, clearly state which command took precedence–that of the onboard traffic alert collision avoidance system (TCAS) or that of the human controller. Seeking input from our readers, we posted the following question on AINonline.com: “You are flying at 35,000 ft at night. Suddenly, ATC tells you to descend immediately due to traffic, but at the same moment your TCAS tells you to climb. What do you do and why?”
The question evoked response in greater numbers than any in recent memory. A total of 81 answers were tallied. (Seventy-nine readers responded via e-mail, while a pair of ink-pen jockeys wrote in the old-fashioned way.) Sixty-two respondents (77 percent) said they would climb in response to their TCAS. What surprised us here is that 14 (17 percent)–including one with a Honeywell e-mail address–advised they would obey the controller. Finally, five rugged individualists (6 percent) said they would maintain their current altitude and turn–some said “either left or right.”
More In Safety
