SUMMERSIDE, P.E.I. - A veteran aviator who was flying his small aircraft over Prince Edward Island watched in shock Saturday as his friend's homemade, open cockpit aircraft turned nose down and spiralled 260 metres into a farmer's field, killing the 70-year-old pilot.

Dick Lubbersen, the owner of a commercial air service at Slemon Park airport, said he was just 170 metres above the bright red, Spezio Tuholer, open-cockpit plane when it started the fatal dive.

Lubbersen said his friend and former boss -- who RCMP have not named pending notification of family members -- was in the homemade aircraft, preparing to land after a brief flight on a crystal clear day over the Island.

"It was quite a shock," said the pilot, who said his friend had "an enormous amount of experience as an aviator" and had successfully landed the aircraft before without power.

He heard a brief radio transmission from the pilot before the dive began indicating there was "a problem."

"He was a very experienced pilot and was able to land that aircraft dead stick, and had done so on a couple of occasions in the past few years," he said during a telephone interview.

Dead stick is an aviation expression meaning the pilot lands the aircraft by gliding it into the runway without power.

The small, private plane spiralled several times before crashing nose down near North St. Eleanors at 12:40 p.m.

RCMP Sgt. Denis Morin said Transport Canada and the RCMP will investigate the reasons for the crash.

"It (mechanical problems) is definitely something we're looking at which might be the cause of the accident," said Morin.

After the crash, Lubbersen called the airport and emergency responders rushed to the farmer's field where the plane fell.

He landed his own aircraft and was at the site of the crash himself within minutes, as his friend's body was taken from the site.

He said that just a few years ago he had helped his friend rebuild the fabric wings of the aircraft, and that he was with the man recently when he retired from his job.

"This man loved to fly. When you have your own airplane you love to fly. One thing about a home built (aircraft) is that it costs less for insurance and it's not as expensive to purchase or build one as a factory produced aircraft," he said.

Many people in the aviation community across North America knew the victim, said Lubbersen.

The pilot said it was especially difficult having to inform the pilot's widow of the crash.

"We're grief stricken here. We're sad."