PLANE MAY HAVE LOST POWER INVESTIGATORS STUDY LEFT ENGINE'S ROLE IN CRASH.

Byline: Karen Rubin Staff Writer

Aviation investigators combing the wreckage of a twin-engine Cessna that crashed in a park crowded with Fourth of July revelers determined Friday that the left propeller did not develop enough power during takeoff, authorities said.

National Transportation Safety Board investigators said it is too early to determine if the deadly crash - which killed four people and injured 12 - was caused by a left engine failure, but the damaged propeller was the first indication of possible engine failure.

Investigators said they will examine the plane's engines to see if they were operating properly.

``I can't speculate if the plane's left engine lost power, but the left propeller showed low power,'' said Jason Ragogna, the lead air-safety investigator. ``Our focus over the next two days is going to be to examine the right engine to determine whether it was operating at the time of the accident.''

On Thursday, the twin-engine Cessna 310i failed to climb moments after takeoff from Brackett Field in La Verne and crashed into a picnic area where some 700-plus people were spending the holiday at Frank G. Bonelli Regional County Park.

Among the dead were the pilot, Michael Brand, 44, and his co-pilot, Michael Alder, 49, both of Glendora; 12-year-old Jackie Ngo-Ton of La Mirada; and 15-month-old Brandon Truong of El Monte.

Brand was out for a spin with his buddy Alder, a licensed pilot, both with the intention of rejoining their families later in the day to watch fireworks.

But moments after take-off, Brand radioed the air tower and said he was having trouble climbing and gaining altitude.

Then three consecutive mayday calls crackled over the radio. The content of those calls was not disclosed.

The plane's left wing clipped a tree, pivoted left and sheared a 30-foot fir before slamming into the picnic area.

Brand, a real estate agent and known as an experienced pilot who had flown the military's Black Hawk helicopters, died later at a hospital.

Alder, a businessman who owned a plumbing company, was pronounced dead at the scene. He, too, was an experienced pilot, his son said.

A month ago, Brand and Alder had a scare when the two went to test fly the plane that Brand bought three months ago from another friend.

They were flying the plane when the landing gear initially failed to deploy properly, said Alder's son, Greg. After a few more tries, they were able to set down safely. After that, Brand had a technician run through everything on the plane.

Since the Cessna does not have a flight-data recorder, investigators will interview the air-traffic controller who heard Brand's mayday calls. Barry Schiff, a retired Trans World Airlines pilot and air safety consultant, said the plane's failure - sinking after take off and veering left - is consistent with a left engine failure.

``The mostly likely scenario is engine failure of one of the engines,'' Schiff said.

While a two-engine Cessna is capable of flying on one engine, it's difficult to control the plane and keep the craft's altitude.

Investigators will continue to examine the craft and will also examine maintenance records of the plane.

The Associated Press contributed to this report.