For a mystery writer like me, much of the why the plane overshot Minneapolis by 150 miles conjecture has been deeply unsatisfying. Like “The pilot and copilot got preoccupied with smarmy online videos/labor-management” theory or the “They fell asleep” hypothesis. Several people I spoke with posited the Lost Boys had been engaged in some traitorous conspiracy or sex act so enthralling they failed to notice the 16th largest metropolitan area in the United States.
I admit that last one intrigued me. Still, even as a great fan of sex, I cannot imagine any liaison that would cause me to miss not just Minneapolis, but St. Paul too.
But if you take off your headphones and don’t hear the alarm? I asked myself. I received no answer, so after a recent flight, I had a quick chat with one of those sweetie-pie pilots who stand near the galley to say bye-bye to disembarking passengers: Hey, could those two guys piloting that Northwest Airbus have slept through the clamor of an alarm, like I might sleep through the ringing of my bedside clock? No way, he told me. Those alarms are so loud that the only people they could not wake are the dead.
Hmmm. I checked the official FAA transcript of the conversation between Northwest 188 and the Minneapolis Air Route Traffic Control Center. That first explanation from the cockpit did not inspire in me a profound belief in the Boys’ forthrightness: “ah roger we got ah distracted and we’ve over flown ah minneapolis we are over head eau claire and would like to make a one eighty and do arrival from eau claire”
Sadly, there was no way to check out the getting distracted business, as many news accounts pointed out. The Detroit News explained: “New recorders retain as much as two hours of cockpit conversation and other noise, but the older model aboard Northwest’s Flight 188 includes just the last 30 minutes — only the very end of Wednesday night’s flight after the pilots realized their error over Wisconsin and were heading back to Minneapolis.”
Aha! That was it! Were I one of those aggressively tweedy whodunit authors from the 30s or 40s, I would have my detective-protagonist gather the pilots, an FAA honcho or two, a US Attorney, and a cross-section of pissed off passengers from 188 in the vicar’s drawing room to announce a solution.
So, for what it’s worth… The pilots must have known, as apparently everyone in the airlines business does, that those older cockpit voice recorders, like the one that Airbus A320 , record in a loop. That is, after some set length of time, in this case 30 minutes, the continuing recording process erases the previously recorded material and replaces it with new content.
The Lost Boys might have been distracted earlier in the flight, but once they were nearing Minneapolis, they must have became painfully aware. They suddenly understood that whatever they had been saying or doing should not be on that searchable tape. Whether the material was indeed criminal or merely vile or inappropriate enough to result in their decertification — maybe even prosecution — is not knowable. But clearly they decided it was worth the risk to get rid of the proof. Since they couldn’t destroy the near-indestructible black box the recording was in, they did the next best thing. They destroyed the account of whatever went on… by flying an extra 150 miles. With time as their accomplice, the inexorable, looping recording continued and any hard evidence against the two of them was no more.