December 19, 2019

Carbon Monoxide in Aircraft


Transport Canada-Civil Aviation (TCCA) has recently issued a Civil Aviation Safety Alert (CASA) to remind pilots of the hazards of carbon monoxide (CO) in the cockpit of their aircraft. This is a timely reminder given the season.

CO is an odourless gas that reduces blood’s ability to carry oxygen throughout the body. There are no tell-tale signs that CO is present in the air unless dedicated and effective detection devises are used. Given that most single-engine airplanes have their engine in front of the cockpit, and that twin-engine aircraft often have a combustion-type heater in the nose of a twin (e.g. Janitrol), it is essential that careful inspection of the aircraft systems be regularly conducted, with repairs carried out as need.

The Safety Alert reminds pilots of Airworthiness Directive (AD) CF-90-03R2, issued almost three decades ago, which requires repetitive inspections of exhaust-type heat exchangers. TCCA also mentions that the detailed visual inspections (DVIs) that the AD calls for is not capable of detecting small leaks. TCCA suggests that a pressure/leak test also be conducted when carrying out the inspection required by the AD.

Much has been written about the best way to detect the presence of CO in the cockpit of an aircraft. The card-type detectors sold for a few dollars that one can stick onto the instrument panel or other easily visible place in the cockpit are considered by many experts to be inadequate. In addition, some are advertised as being effective for only 90 days after the package it comes in is opened. How often do they actually get replaced?

The full CASA can be seen below.