Three people were taken to a hospital after a small plane crashed in the front yard of an East Knoxville home on Tuesday afternoon Caitie McMekin/News Sentinel


The crew of a small plane that crashed in Knoxville on Dec. 19 was simulating a left engine failure when the left engine actually failed, according to a preliminary report from the National Transportation Safety Board. 

What happened next is still under investigation, but the plane ultimately crashed into some trees and landed atop a car in a driveway of a house in the Morningside neighborhood of East Knoxville.

The three men inside the plane — Gerald Marotta, Mike Spinazzola and Robert Gintz — were bloodied, but they survived. No homes were hit. There was no fire and no explosion.

The NTSB's preliminary report relays the stories told by the three men about what happened that day. Based on those accounts, two aviation experts criticized the crew's actions and argued that the flight should have never happened in the first place.

Although the experts disagreed on the primary cause of the crash, they agreed it was "amazing" that the men survived and that no one on the ground was hurt.

Show Thumbnails
Show Captions

The engine failure

The plane — a twin-engine Piper PA-23-250 Aztec that was built in 1973 — was headed back to Knoxville Downtown Island Airport after an instructional flight.

The report describes the occupants of the plane by their certifications: Spinazzola was the pilot, Gintz was the flight instructor and Marotta was sitting in the back, according to Federal Aviation Administration records.

Gintz tested Spinazzola by simulating a left-engine failure. He lowered the amount of fuel flowing to that engine.

Spinazzola crossed the runway threshold about 500 feet above ground level — too high to start landing, according to the NTSB report. At that point, the flaps on the airplane's wings were fully extended, which increases drag so the plane can descend at a sharper angle and land in a shorter distance.

Gintz called for a go-around; Spinazzola was turning when he said he "had lost the left engine."

Gintz told investigators he saw that the left propeller had stopped. He took over the controls.

'Achilles' heel'

Gintz tried to retract the flaps, "but was unable due to the one hydraulic pump being operated by the left engine," the NTSB report reads.

Early models of the Piper Aztec came equipped with one hydraulic pump operated by the left engine. When that engine dies, the pump no longer works, and the only way to control the flaps and the landing gear is to to use a "cumbersome" hand pump that "looks like a bicycle pump" and "comes out of the floor of the airplane," said Edward M. Booth Jr., an aviation lawyer and pilot in Jacksonville, Fla. 

"That's usually not a workable option," Booth said.

Gintz chose not to use the hand pump, according to the NTSB report.

Booth described the plane's reliance on one engine as its "Achilles' heel" and said "nearly all" Aztec planes in the sky have been retrofitted with a hydraulic pump on the right engine to remedy that problem.

"To me, it’s unheard-of to be operating a piece of equipment like this today without the retrofit," he said.

In Booth's opinion, the airplane didn't have enough power to climb on only one engine with the landing gear and flaps deployed and creating "so much drag." 

"I have to think the flight instructor did a masterful job of maintaining some semblance of control" to avoid landing upside down, Booth said.

But he questioned why the crew flew the plane with only one hydraulic pump and why the flight instructor simulated an engine failure on the critical engine.

'Unable to reach the controls'

Robert Katz, a pilot of 36 years and a flight instructor based in Dallas, disagrees with Booth. He argues the airplane could have continued to fly if Gintz had flown the plane at a higher speed.

According to the report, Gintz told investigators he thought it best to keep the speed at 80 mph — the minimum speed to control the plane — instead of increasing the speed to what is called Vyse: the speed at which an airplane will climb most rapidly on only one engine.

The report goes on to quote a section of the Aztec's operating manual about landing after an engine fails. "Maintain a best rate of climb airspeed," the last bullet point reads.

The report also quotes the FAA's Flight Training Handbook. 

"When the decision is made to continue flight, the single-engine best-rate of climb speed should be attained and maintained. Even if altitude cannot be maintained, it is best to continue to hold that speed because it would result in the slowest rate of descent and provide for the most time for executing the emergency landing."

Katz criticized Gintz for telling investigators he was "unable to reach the controls" to restart the left engine.

"He is the one that’s responsible for the safe operation of this flight," Katz said, "and if he takes off knowing that he can’t reach the controls, well that’s careless and reckless before he even leaves the ground."

The crew members could not be reached for comment.

Read or Share this story: