Casualties unknown

Engine Oil Breather Line Failure Leads to Forced Landing and Stall (N138WW)

Mesa, AZ, US

On February 25, 1991, a North American T-28B (registration N138WW) operated by Worldwide Aeronautical Ind,inc was involved in an aviation accident near Mesa, AZ. Investigators recorded the probable cause as: Failure of the engine upper crankcase oil breather line, which allowed engine oil to vent overboard, resulting in oil loss and engine seizure. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.

Sourcesthe U.S. National Transportation Safety Board (NTSB) historical archivePrimary reportUpdated 2026-07-04Data APIEditorial standards

An aircraft experienced a total loss of engine power after the engine upper crankcase oil breather line failed, causing oil to vent overboard. The pilot attempted a road landing but diverted to an open area, where a stall on short final resulted in a hard landing.

Incident Overview

During cruise flight, the engine upper crankcase oil breather line of the aircraft failed. This failure allowed engine oil to vent overboard. The resulting lack of oil caused the engine to seize, leading to a total loss of engine power.

Forced Landing Attempt

Following the power loss, the pilot set up a power-off approach to a road. However, due to excessive vehicular traffic on the road, the pilot altered the aircraft's course and attempted to land in an open area.

Stall and Hard Landing

On short final approach to the open area, the pilot observed high tension wires. To avoid a collision, the pilot pulled the nose of the aircraft up. The aircraft cleared the wires, but the maneuver slowed the airspeed, causing the aircraft to stall. The subsequent landing was hard.

Probable cause

Failure of the engine upper crankcase oil breather line, which allowed engine oil to vent overboard, resulting in oil loss and engine seizure.

Frequently asked questions

What happened in the 25 Feb 1991 North American T-28B accident near Mesa, AZ?

An aircraft experienced a total loss of engine power after the engine upper crankcase oil breather line failed, causing oil to vent overboard. The pilot attempted a road landing but diverted to an open area, where a stall on short final resulted in a hard landing.

What aircraft was involved and where did it happen?

The accident on 25 Feb 1991 involved a North American T-28B, registration N138WW, operated by Worldwide Aeronautical Ind,inc, at Mesa, AZ.

What was the probable cause of the accident?

Failure of the engine upper crankcase oil breather line, which allowed engine oil to vent overboard, resulting in oil loss and engine seizure.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001212X16482. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.