Imagine Finding Yourself In A Freefall from 28,000 Feet!

No, not from an airliner, military jet, or other aerial conveyance other than a Cessna 337D Super Skymaster. The private pilot who onwed N2685S had around 3,100 hours of flight time, and on April 1, 1997, he embarked on an aerial photography flight with a young woman as his photography assitant.

This was a rather unusual aircraft configuration where the airplane had a twin boom supporting both the horizontal elevator and a pair of vertical stabilizers. In addition, it was a twin engine aircraft, but one engine was a conventional engine on the front and a pusher engine on the back of the airplane.  It was, to say the least, an unusual airplane.

Specificatons:

• Crew: 1 pilot;
• Passengers: up to 5 passengers;
• Length: 29 feet, 9 inches;
• Wingspan: 39 feet, 9 inches;
• Height: 9 feet 4 inches;
• Powerplan: 2 continental I)-360-C 210 hp piston engines;
• Empty weight: 2,655 pounds;
• Gross weight: 4,400 pounds;
• Cruise speed: 191 mph;
• Range: 1,058 mils;
• Service ceiling: 18,000 feet.

The aircraft had been modified to carry a through-the-floor camera for aerial photography missions. The owner/pilot hired a young woman to operate the camera for him when he went on a mission. It was also equipped with an oxygen system for the pilot and passengers to use above 10,000 feet.

The particular flight in question took place on April 1st, 1997, and departed Waynesburg, Pennsylvania airport (WAY), and photographed a number of locations enroute to North Lima, Ohio airport 4G4.  There they fueled up and took back off for their home base (WAY) at approximately 1:45 pm Eastern time. It was VMC (Visual Meterological Conditons) that day, so as they climbed through 10,000 feet they put on their oxygen masks and continued to climb.

Somewhere around 20,000 feet the pilot asked his passenger how she was feeling. At the time she told him she felt fine, but a little while later she told the pilot she was feeling dizzy. The pilot did not respond to her, so she assumed he was tuned into some ATC transmissions. So, she closed her eyes, hoping that would provide her some relief. According to her statement, that was the last thing she remembered.

A map showing the location of the Cessna 337D accident.

ATC had cleared the pilot to 25,000 feet, but soon became concerned when the aircraft continued to climb to 27,700 feet, then leveled off for a few minutes, then descended to 26,000 feet where radar contact was lost. At this point the aircraft had entered an uncontrolled descent and began breaking apart. 

It's left and right tail booms, the right door, outboard left wing, vertical and horzontal stabilizers all departed the airframe and rained down over a 3-mile radius around the city of Hickory, Pennsylvania. The remainder of the fuselage came to rest about 30 feet in the air in a hickory tree. The pilot was dead, and the passenger was unconscious, but remarkably had only suffered minor cuts and bruises!

The Cause - "Oxygen isn't Air!"

The young female photography assistant remembered the pilot reaching back to turn on the oxygen tank valve, and then she felt the flow of cool air into her mask, and she noted that the indicator in the oxygen line had flipped from red to green which indicated a postive flow.

As it turned out, the pilot had been mistakenly given a tank of compressed air instead of pure oxygen when he landed at the 4G4 airport. The autopsy determined that he had died of hypoxia prior to impact. For some reason, the young photography assistant was better able to survive the prolonged oxygen deprivation. How people react to hypoxia can vary greatly, and is largely dependent on body type, overall health and personal history. Had they remained airborne much longer before entering the death spiral, her fate would eventually have been the same as the pilots.

The remarkable question is how she was able to survive the fall and impact with the tree. Studiies have shown that heavier individuals are 80% more likely to die in a crash than someone of average weight. This is partially due to being predisposed to other health issues, but the primary reason lies in seatbelt safety. The greater a persons weight the less effective the seatbelt is. Accident investigators found that the passenger was wearing her seatbelt, and that it had functioned properly, contributing to her survival.

Based on Newton's Second Law of Motion, a fast change in momentum will result in a larger force placed on a falling object upon impact. Softer landing surfaces slow down impact momentum, which in turn leads to less force being placed on the aircraft and the person inside. Since the aircraft's fuselage landed in a hickory tree rather than the hard grpund below, it decreased the force on the passenger, and thereby increased her odds of survival.

In writing this story I used the Aviation Safety Network narrative. The lesson to take from this accident is to always double check when you are relying on someone you don't know is providing something you will definately need!

Post Script: 'Many years ago in the late 1960s I was given the task of flying a cadaver from Battle Creek, Michigan in a Cessna 337 airplane to it's home. It was just myself and the cadaver in a body bag stretched accross the front and middle seat backs for the trip. I didn't give it much thought until as I climbed out the cadaver began making sounds! Of course, it was just the body exhaling, but it scared the heck out of me at first!'

I hope you enjoyed this trip through some of the history of aviation. If you enjoyed the story, please share it with all of your friends. And, if you are new to this blog, sign up to receive your own weekly blog post here: Subscribe here!

Until next time, keep your eyes safe and focused on what's ahead of you, Hersch!