Thursday, August 13, 2009

No Hydraulics

"I didn't want them to die." That's what DC-10 instructor pilot Dennis Fitch said in a post-crash interview. He was deadheading on United Airlines Flight 232 on July 19, 1989 when a compressor fan failed in the DC-10's number 2 engine, shooting titanium fragments out of the engine nacelle and rupturing the hydraulic lines of all three of the airplane's hydraulic systems.

For a pilot, it's hard to imagine any situation more scary than losing all flight controls. The flight crew, Captain Alfred Haynes, First Officer William Records, and Flight Engineer Dudley Dvorak, immediately responded to the engine failure, shut down the number 2 engine, and began assessing the situation. Dvorak reported a loss of hydraulic pressure in all three hydraulic systems -- an almost unimaginable event. The airplane began banking and oscillating as the crew struggled to maintain control by using differential thrust from the number 1 and 3 engines. Dennis Fitch made his way to the flight deck to offer assistance. Captain Haynes assigned Fitch to throttle control, which was all the crew had to maintain any semblance of control of the DC-10.

The crew diverted to Sioux Falls, Iowa, the nearest suitable airport for landing in the area. Using only differential thrust from the two wing engines, Fitch managed to point the jet toward the airport and establish a descent toward the runway. The final moments of the flight were harrowing, and the crew can be heard on the cockpit voice recorder working all the way down until impact. A distinct increase in engine noise can be heard in the final seconds before impact as Fitch pushed both throttles to maximum power in an effort to make the descent rate survivable. The DC-10 slammed the ground, broke into several pieces, and fire erupted.

One-hundred and ten passengers and one flight attendant were killed in the crash. There were 185 survivors. All four flight crew members survived the crash.

Dennis Fitch saved 185 lives that day. His heroic efforts under unimaginable fear and stress during a situation so seemingly hopeless are what yielded survivors when it was more likely for all those aboard to die. "It tore my heart out to know people died behind me," Fitch said. My heart is with those lost and their families. I hope Fitch reminds himself that he saved more lives than were lost that day.

National Transportation Safety Board (NTSB) Investigator Jim Wildey is an unsung hero of this crash. Wildey devoted his time and energy to investigating the cause of the compressor fan failure which resulted in the fatal loss of the airplane's three hydraulic systems and subsequently flight controls. Wildey discovered a tiny area of metal fatigue on the failed piece of the engine which caused the piece to disintegrate in flight and send titanium shards into the aircraft's hydraulic lines. Wildey determined that the crack was detectable and should've been discovered by United Airlines maintenance technicians during a routine engine inspection prior to the crash. The oversight error by the maintenance technicians was cited as a critical piece of the cause of the crash of Flight 232.

Because of Wildey's efforts and findings, new rules are in place to prevent this type of accident from ever occurring again. Maintenance inspections are more strict, hydraulic systems are built to preserve hydraulic fluid when punctured, and an Airworthiness Directive was issued to prevent other DC-10s with the same fault from suffering the same fate.

The loss of all flight controls is almost unimaginable to most pilots. But that's exactly what Dennis Fitch, Captain Haynes, First Officer Records, and Flight Engineer Dvorak were faced with on July 19, 1989. Fitch kept flying. He never gave up, even when the situation was grave. Other pilots can learn from him. When faced with danger, we must keep thinking, we must keep flying.