Engine oil, propeller speed factors in Buffalo Airways crash near Deline: preliminary report

A drop inengine oil and a propeller malfunction may have been the first indications that something was wrong in the Buffalo Airways C-46 Commando airplane that made a crash landing outside of Deline, N.W.T. in September.

The cargo flight was on its way from Yellowknife to Norman Wells on Sept. 25 when it diverted toDeline and declaredan emergency landing.

TheCivil Aviation Daily Occurrence Reporting System (CADORS) has issued a preliminary report on the incident. The aviation occurrance information Transport Canada collects in CADORSis considered "preliminary, unsubstantiated and subject to change."

According to the CADORS report,the BuffaloAirwaysaircraft, which had four crew members aboard,was 140 nautical miles southeast of the Norman Wells Airport when the crew noticed a drop in the right engine oil quantity indicatorin conjunction with a propeller overspeed.

The propeller pitch was adjusted, says the report, but the engine oil quantity continued to drop.

CADORSsays one of the crew members sawoil escaping from the engine breather vent at "an abnormally high rate."

The right propeller speed was uncontrollableand the crew preformed the "prop overspeed drill," the reportstates, butthe propeller still didn't respond.

The crew decided to divert to Tulita,but couldn't because of the descent rate. They changed course for Deline, where the visibility was only a 1/2 mile with a 300 foot ceiling.

The crew was able to land the aircraft at the Deline Airport, butthey did not deploy thelanding gear, in order to conserve airspeed.

The reports says the C-46landed on its belly near the midpoint of the runway and finally came to a stop more than 200 metres beyond it.

None of the crew members was injured, but the aircraft was destroyed.

Buffalo Airways' initial investigation showed thatthe engine oil scavenge pump had failed, the CADORS report concludes.

CBC contacted Buffalo Airways for comment on this preliminary report, but has not yet heard back.