Casualties unknown

1999-06-07: Piper PA-31 Navajo C-GRNE — Between Province of Manitoba — and Brandon Flying Club, CA

and Brandon Flying Club, CA

On June 7, 1999, a Piper PA-31 Navajo C-GRNE operated by Between Province of Manitoba was involved in an aviation accident near and Brandon Flying Club, CA. Investigators recorded the probable cause as: The arrival and departure controllers did not adequately monitor the flight paths of the two aircraft on radar; the departure controller authorized descent without passing relevant traffic information; the arrival controller assumed the Mooney was a VFR… This summary draws on records from the Transportation Safety Board of Canada (TSB).

Sourcesthe Transportation Safety Board of Canada (TSB)Primary reportUpdated 1785068748Data APIEditorial standards

A Piper PA-31 Navajo and a Mooney M20C experienced a loss of separation 5 nm west of Winnipeg International Airport, with 0.53 nm lateral and 300 ft vertical spacing, below the required 3 nm or 1000 ft.

Occurrence

On an unspecified date, a Piper PA-31 Navajo (registration C-GRNE) was arriving at Winnipeg International Airport under instrument flight rules (IFR). The arrival controller vectored the aircraft for a visual approach to runway 36. A Mooney M20C (registration C-GKGY) departed from runway 36 on an IFR flight plan and was given a left turn to heading 270° and cleared to climb to 6000 feet. The two aircraft passed within 0.53 nautical miles laterally and 300 feet vertically, less than the required minimum separation of 3 nautical miles lateral or 1000 feet vertical as per Canadian Aviation Regulation 801.08.

Contributing Factors

The arrival and departure controllers did not adequately monitor the flight paths of the two aircraft on radar. The departure controller authorized the arrival controller to descend the Navajo to 3000 feet without passing relevant traffic information about the Mooney. The arrival controller assumed the Mooney was a visual flight rules (VFR) flight and would remain at or below 2500 feet, and therefore saw no requirement to provide additional separation. The data controller alerted the arrival controller to the conflict, but separation had already been lost. No conflict-alerting tool was available to warn controllers.

Safety Actions

On 15 August 2000, the Transportation Safety Board of Canada issued Aviation Safety Advisory No. A000035-2 to NAV CANADA regarding the use of alternate procedures without built-in defences. NAV CANADA responded, stating that the company's basic principle is that action must be taken to ensure another type of separation exists before previously used separation becomes insufficient. A safety-related publication, *Squawk 7700*, was issued on 26 October 2000 outlining dangers of failing to abide by standard operating practices.

Probable cause

The arrival and departure controllers did not adequately monitor the flight paths of the two aircraft on radar; the departure controller authorized descent without passing relevant traffic information; the arrival controller assumed the Mooney was a VFR flight and therefore took no action to provide separation.