In the blink of an eye, Jimmy Leeward’s P-51 Galloping Ghost went from rounding the last turn at National Championship Air Races in Reno to sharply pitching upward, rolling over, and then diving straight down into box seats full of spectators. Strange as it is to say, there are reasons to be grateful — had his airplane hit the grandstands, there would have been hundreds, not dozens, of injuries.
Air shows are a big deal in America — attendance is around 17 million visitors to the 400 or so air shows each year, roughly around the same attendance as the NFL — and, apart from the causal attendees, there’s a sense of community around types of planes, types of shows, and locations. They know the history of the sport; the Ramstein disaster, for one, still lingers in the minds of many in the air show community, and the frequency of fatal and near-fatal crashes is not lost on anyone. The casualty numbers are lower, but they still look more like a major air disaster than a simple crash; Reno will likely take a similar place to Ramstein in the minds of the air show community, and may end the National Championship Air Races, at least in their current form.
As always, when a crash happens, the media attention shifts quickly to the National Transportation Safety Board’s “Go Team” investigation. Maybe it’s something about the allure of governmental rapid response teams, or maybe it’s the idea that, with an investigation and findings will come some sort of closure. The NTSB is a good organization with talented and dedicated personnel, and it’s no stretch to say that NTSB Aviation Accident Reports and other recommendations have saved countless lives, but one thing needs to be understood about the NTSB.
Coincidentally, a few hours before the crash I conducted the deposition of the former fleet operations manager for a company involved in a fatal maritime accident. The NTSB Marine Accident Report recommended that her company “review existing safety management program and develop improved means to ensure that your company’s safety and emergency procedures are understood and adhered to by employees in safety-critical positions.” The fleet operations manager argued that the NTSB’s finding that her company had at all contributed to the accident was merely “political.”
In one sense, she’s right: the NTSB’s findings are “political,” in that they are made by the government for the benefit of everyone, rather than made for accountability among those involved in the crash. The NTSB reviews accidents primarily for the purpose of making recommendations for the future and secondarily for determining fault. In contrast, civil litigation exists to determine who should pay for the losses arising from an injury, and thus cases are reviewed by the judicial system primarily for determining fault.
This difference in focus isn’t just a matter of word choice. There’s an entire field of ‘root cause analysis’ that assesses the way in which accidents and other failures are investigated. Its lessons have been applied to aircraft safety as well, including in the federal regulations governing military aircraft safety, which direct audits towards the cause, not just the symptom, of safety deficiencies.
That’s not to say the NTSB’s process is flawed or that their conclusions are wrong (although it’s always disturbing to me how the “party system” always gives the likely culpable parties a seat at the table but never gives any voice to the victims). It’s just important to understand that they answer a different question — what can we, as a government agency, recommend to prevent this in the future? — from the question asked in a lawsuit: who, if anyone, was responsible?
Initial reports have focused on the trim tab of the Galloping Ghost. A remarkable photo just before the crash taken by Tim O’Brien, himself an air show organizer, shows the plane missing one of its left side trim tab entirely. Still images from video taken of the crash show the trim tab in the process of falling off.
It wouldn’t be surprising if the flutter caused the trim tab to break off. (For those unfamiliar with flutter, Mike Danko dug up an old NASA video of trim tab flutter). That’s a known problem with P-51s; consider this report regarding the P-51 Voodoo Chile at the Reno National Championship Air Races just a couple years ago:
… Voodoo very abruptly pulled up; however, Hannah didn’t radio a distress call. … Steve Hinton flew over to take a look Voodoo. “You OK Bob?” called Hinton. “Yea, this thing just popped big time,” replied Hannah. What Hannah didn’t mention is that the g-load from the quick pull-up had caused him to black out. He finally managed to reach the throttle and reduced Voodoo’s power. At that point Hannah radioed that he “(wasn’t) out of it yet,” but he wasn’t thinking clearly. Later, he declared a mayday and made a perfect landing. … On the ground one could see what cause Voodoo’s problems during the race. The left elevator torque tube failed when the elevator trim fluttered and departed the plane. Fortunately, Bob Hannah’s skill and coolness in the cockpit saved day.
When the trim tab fell off Voodoo, the plane shot upwards and the 10G deceleration force caused Bob Hannah to black out entirely. That’s just as you would expect: the faster you go, the more the plane points upwards on its own, and the more you need to point the nose down to trim the airplane. Thus, at speed and level, the trim tab points up relative to the airflow over the elevator, causing the elevator to be deflected slightly down to maintain level flight.
At over 500 miles per hour, there are enormous airloads on the elevator trim tab to keep the elevator in a position that allows the pilot to maintain control, making damage to the trim tab more likely. Remove the trim tab and the non-trimmed elevator settings immediately deflect up, just like when pulling the stick back hard. That’s what causes the abrupt climb (and corresponding loss of consciousness) when the trim tab falls off.
Hannah regained consciousness at 9,000 feet and, as you can tell from the above, took some time to come back to his senses. You can see pictures of the damage here. It was even the same trim tab. The difference between Voodoo’s close call and Galloping Ghost’s tragedy may have been pure, dumb luck: Voodoo didn’t roll after losing the trim tab while Galloping Ghost did.
But that doesn’t necessarily mean flutter caused the trim tab to dislodge, or that the trim tab was the cause of the accident, or that the trim tab was the only cause of the accident. It’s quite possible something else caused the Galloping Ghost to climb rapidly, and in that process the flutter developed or the trim tab was damaged. As has been reported, some members of the crowd noticed “a strange gurgling engine noise” before Galloping Ghost pitched upwards. Further, as discussed below, it’s possible the trim tab failure could have been avoided, and more could have been done — such as ensuring the pilot was harnessed properly and plotting the race further from the stands — to prevent this tragedy.
So, where might liability fall?