Jet Shook, Killing Ex-White House Aide, After Pilots Shut Off Key System, Report Says

A business jet carrying a former White House official this month pitched up and down in midair, causing her death, after pilots turned off a system that stabilizes the plane, the National Transportation Safety Board said in a preliminary report.

The pilots noticed several warnings related to system failures of the aircraft’s flight control as it traveled from Keene, N.H., to Leesburg, Va., on March 3, and they followed steps on a checklist, which advised them to turn off a switch that controls a stabilizer function in the aircraft, according to the report.

When the switch was turned off, it prompted the nose of the plane to swing upward, the report says. The plane then pointed down and jerked upward again in a roller-coaster-like motion before a pilot used both hands to regain control of it, the N.T.S.B. said.

“As soon as the switch position was moved, the airplane abruptly pitched up,” the report says. One of the pilots, in his account to investigators, estimated that the plane had oscillated up and down for a “few seconds.”

Shortly after the scare, the crew members were told by a passenger that the former White House official, Dana Hyde, 55, of Cabin John, Md., had been injured. Ms. Hyde, who was a senior adviser at the State Department under President Barack Obama and served as counsel on the 9/11 Commission, was taken to a hospital after the plane landed.

She died in the hospital from her injuries, the authorities said.

The people onboard the plane, a Bombardier Challenger 300, were subjected to forces about four times the pull of gravity, according to the report.

The authorities initially said that the plane had encountered “severe turbulence.” But the flight crew members told investigators that they “did not experience any remarkable turbulence during the flight,” the report says.

The jet was diverted to Bradley International Airport in Windsor Locks, Conn.

Last year, the Federal Aviation Administration issued a directive to pilots flying the Bombardier Challenger 300 that instructed them to conduct extra safety tests before flights. The directive was prompted by several reports that the horizontal stabilizer caused the noses of planes to tilt down when pilots tried to make the plane climb, according to a rule from the F.A.A. in June last year.

Bombardier said in a statement on Sunday that it was “deeply saddened by this tragic event,” adding, “We extend our sincerest sympathies to all those affected by this accident.”

Bombardier said it was “carefully studying” the preliminary report from the N.T.S.B.

Ms. Hyde’s husband, Jonathan Chambers, said in a statement that they and their younger son had been flying home that day, after visiting schools in New England, when their plane “suddenly convulsed in a manner that violently threw the three of us.”

“Dana was the best person I ever knew,” he said, adding that she “never forgot her small-town eastern Oregonian roots.”

Ms. Hyde was a special assistant to the deputy attorney general in the Clinton administration, according to Columbia University. She later served as associate director of the Office of Management and Budget during the Obama administration. She also helped establish the African Leadership University and worked at Jerusalem Venture Partners, a venture capital firm. “That’s a real résumé,” her husband said.

Mr. Chambers said his wife was “a wonderful mother to our boys.”

In a eulogy for Ms. Hyde delivered by Mr. Chamber’s older son, he dismissed the idea of living each day as if it were your last.

“I now realize that’s wrong,” the son said, according to Mr. Chambers. “You should live each day as if it’s the last of someone you love.”