A pilot died Monday after he was struck in the head by a moving airplane propeller, according to officials.

The single-engine plane pilot was struck in the head after he got out of his aircraft in the ramp area of Gillespie Field in El Cajon east of San Diego.

Gordon Woodard, 41, was taken to the hospital with critical injuries where he died later, according to airport spokesperson Ian Gregor.

Woodard realized the engine had stalled after pulling it out of the hangar.

"We believe he got out of the plane to manually start the propeller," said Gregor in a statement. "When the propeller engaged, it struck him in the head."

In the aviation industry, starting the engine manually is called "hot propping," and is generally considered very dangerous.

"If the aircraft is not able to start, whether it's here or it's somewhere else across country, we have a policy," said Tom Hannawa of the American Aviation Academy. "No touching of the propeller to start, no hand-propping to start the engine. it's a very dangerous practice."

A helicopter instructor along with a student witnessed the accident according to Hannawa.

"They were very traumatized," Hannawa said. "We're going to let them have as much time as they need to recover because it was a very traumatic experience for them."

Pilot Mark Hanten's hangar is next to the space used by Woodard.

"It just gives us pause to be a little more cautious when we fly," Hanten said.

Several pilots told NBCSanDiego they would never try to move the propeller by hand.

"Hopefully other people will learn from this mistake and it won't happen to somebody else," Hanten said.

The Federal Aviation Administration and National Transportation Safety Board will investigate this accident, Gregor said.

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