All Nippon Jetliner’s 2011 Nosedive More Dangerous Than First Thought • Investigators’ Final Report Likely to Refocus Industrywide Interest in Similar High-Altitude Incidents

The Wall Street Journal

By Andy Pasztor

Oct. 5, 2014 3:09 a.m. ET


An All Nippon Airways Co. co-pilot who accidentally put his plane into a violent dive and roll in 2011 came closer to losing control of the Boeing Co.  737 than previously believed, according to data released by investigators.

The Japan Transport Safety Board’s final report about the serious incident over the Pacific Ocean reveals there were multiple warnings of an impending aerodynamic stall, while the plane carrying 117 people exceeded its maximum operating speed a number of times. The jet also exceeded its structural load limit.

An earlier report disclosed many of the co-pilot’s errors and the plane’s excessive speed. But it suggested there was only a single activation of the “stick shaker,” a last-ditch safety alert that the plane is about to lose lift and may be on the verge of a crash.

Investigators found that the plane’s excessive-speed warning was also activated more than once during the episode.

The report is likely to refocus industrywide interest in high-altitude upsets, or incidents in which jetliners slow dramatically or end up with the nose or wings at unusually steep upward or downward angles.

After the co-pilot mistakenly operated a rudder-control switch at 41,000 feet, instead of a different switch that unlatched the cockpit door, the jetliner plummeted 1.2 miles in slightly more than 30 seconds and briefly flew nearly upside down. The recently released report provides some new details about the extent of the danger.

Two flight attendants were pinned to the cabin floor slightly injuring them. One attendant told investigators that after she felt “earthquake-like vertical shaking,” she slumped to the floor on her knees from downward forces so strong she couldn’t raise her arm.

The 100-page document also highlights the 38-year-old co-pilot’s delayed and confused response, which investigators attributed to gaps in training, undue reliance on automation and seeming anxiety to let the captain back into the cockpit. According to the report, “excessive dependence on autopilot” exacerbated “lack of full awareness about the need to monitor” flight controls.

The co-pilot couldn’t recall the stick shaker’s activation, according to the report, which describes his reaction to the emergency as “partially inappropriate or insufficient.”

He failed to recognize there was a problem for 17 seconds, and then alternately pushed forward and pulled back on the controls. The captain, returning from a bathroom break, was locked out of the cockpit while the plane nose-dived and executed back-to-back rolls in opposite directions. The maneuvers lasted about 90 seconds, though passengers may not have fully realized what was happening because it was dark outside.

ANA said it “took action following the incident to prevent any recurrence, and we are continuing to take additional measures in line with the report’s recommendations.”

Japan’s safety board urged the carrier to ensure compliance with single-pilot operation protocols and enhance training to cope with high-altitude stall warnings.

The report should get a lot of attention in the industry since it details “a real poster child event about complacency” and an inappropriate response after being started, said Rory Kay, an ex-737 captain and former senior pilot-union safety official who now works as a training captain on Boeing jets. Pilots should “treat high-altitude stalls totally differently than those at low altitude,” he said. Thinner air up high means jet engines take longer to rev up power and a sudden upward nose command is more likely to create control problems.

Once the plane was back on the correct course and altitude, neither pilot disclosed the extent of the problem to air-traffic controllers, who in turn never pushed for answers. The jet, en route to Tokyo’s Haneda airport from Okinawa, made a normal landing.

The crew’s failure to promptly alert mechanics about the specifics of the event, according to the report, meant the plane continued to carry passengers for four more flights before all required inspections for possible structural damage were conducted. The checks didn’t detect any problems.

The nose of the ANA jetliner was pointed 35 degrees down from level flight, a much steeper angle than passengers typically experience. The plane was subjected to forces nearly 2.7 times the force of gravity.

The co-pilot, who hasn’t been identified, remains an All Nippon employee but isn’t currently assigned to flight duties, according to the carrier.

The report, among other things, determined that the co-pilot’s training didn’t include dealing with high-altitude flight upsets or any “upset recovery training accompanied with a stall warning.”

Before the upset, the ANA co-pilot failed to follow company procedures requiring him to put on his oxygen mask when he was left alone at the controls.

Investigators found that the co-pilot’s initial preoccupation with opening the cockpit door prevented using “calm judgment” to continue monitoring controls and then to fly the plane manually. Upon returning to the cockpit, according to the report, the captain took over the controls because he found the co-pilot’s condition “fairly unsettled.”

The ANA event occurred two years after the crash of Air France Flight 447, a widebody Airbus A330 that stalled at high altitude. That crew’s failure to understand and counteract a rapid descent ended in the death of all 228 people aboard. The crash was seminal event that sparked world-wide emphasis on stall recovery training, particularly at cruise altitudes.

Many airlines quickly revised simulator training to include lessons learned from the Air France accident.

There have been more recent instances of high-altitude upsets. An American Airlines Boeing 757, cruising at 35,000 feet over Venezuela on August 30, lost some 7,500 feet in about one minute. There were no injuries and the flight continued on to Brazil. An American spokeswoman couldn’t immediately be reached for comment.

Japanese investigators said the ANA co-pilot, who was relatively inexperienced, had less than 2,800 flight hours in another 737 version and only 197 hours in the Boeing 737-700 involved in the incident. As previously reported, the cockpit-door unlock switch on his earlier aircraft was similar to the location, size and shape of the rudder switch on the 737-700 model.

--Megumi Fujikawa contributed to this article.

Source:  http://online.wsj.com