Pilots’ Reaction to Wind-Shear Alert Questioned

Documents filed in the investigation of the USAir crash here last July raise questions about the response of the pilots to a wind-shear condition that apparently hurled the DC-9 to the ground, killing 37 of the 57 aboard.

While mystery still shrouds the causes of the more recent USAir crash in Pittsburgh, Pa., that claimed 132 lives, sources close to the probe here say investigators are all but certain that a powerful thunderstorm--and the violent winds that it spawned--was the major factor in the Charlotte crash.

Still uncertain, however, is how well the cockpit crew--pilot Michael Greenlee, 38, and co-pilot James Phillip Hayes, 41--reacted to the growing emergency as Flight 1016 prepared to land at Charlotte-Douglas International Airport.

Questions also have arisen whether air traffic controllers adequately relayed information about the worsening weather to the cockpit crew.

Both Greenlee and Hayes survived the crash and are scheduled to testify today at the National Transportation Safety Board hearings that began here Monday.

According to investigators’ reports, Hayes was at the controls as the jetliner descended toward Charlotte after a 31-minute flight from Columbia, S.C.

National Weather Service meteorologists testified Monday that there were major thunderstorms in the area at the time, but an air traffic controller at the airport then testified that none of these storms seemed to pose a special hazard to any particular flight.

A weather message broadcast by the airport tower to all planes in the area at 6:23 p.m. made no mention of the thunderstorms.

The Air Line Pilots Assn. argued Monday that the cockpit crew was not aware of any impending problems, but the cockpit voice recorder suggests otherwise.

After Hayes noted the heavy rain they were encountering, Greenlee told Hayes that they might have to abort the landing and fly a right-turn “go-around” for a second attempt. Hayes agreed.

Greenlee then said there was “a chance of a shear.”

He was referring to the possibility of wind shear--a sudden shift in the direction and velocity of localized gusts.

A particularly dangerous form of wind shear is a microburst--a violent downdraft in the center of a thunderstorm. A plane flying through a microburst near the ground first encounters strong head winds; then strong tail winds deprive it of the lift needed to keep it aloft.

That, investigators say, is apparently what happened to Flight 1016.

At 6:40 p.m., the airport control tower issued a warning: “Wind shear alert.” The dangerous winds were reported to the right of Flight 1016. The warning was repeated 12 seconds later.

Two planes on the ground elected to delay their takeoffs, but Greenlee and Hayes continued their approach.

As the DC-9 hurtled into the storm, sensors in the cockpit and on the ground indicated that strong tail winds from the microburst began affecting the craft.

“Take it around, go to the right!” Greenlee ordered. “Max power!”

For some reason, as yet unexplained, Greenlee then ordered Hayes to “push it down,” apparently telling his co-pilot to lower the plane’s nose--an unorthodox procedure in either a go-around or a wind-shear situation.

According to investigators, Hayes applied full power, but he also raised the nose--standard procedure in such circumstances. The plane, which was beginning a turn to the right, rose a little, then started to sink again.

In another unorthodox move, Greenlee then placed his hand over Hayes’ on the throttles, attempting to take over the controls without telling Hayes that he was doing so.

Each pilot later claimed to have been in control of the plane, raising the specter that there was confusion in the cockpit.

Investigators said that “both pilots described feeling as though the aircraft had dropped out from under them.”

The plane slammed into the ground about 2,200 feet to the right of the runway, carving a 1,100-foot swath through a grove of trees before breaking up and bursting into flame.