CO is a by-product of the incomplete combustion of carbon-containing materials, such as aviation fuel
While Carbon Monoxide poisoning can occur with or without environmental control operating, heating units are the most likely source of the problem
Most heaters in light aircraft work by air flowing over the manifold
Use of these heaters, while exhaust fumes are escaping through manifold cracks and seals, is responsible every year for several nonfatal and fatal aircraft accidents from carbon monoxide poisoning
It is possible to have a large amount of CO in your blood just by your environment to include polluted air and spending time around smokers, thereby reducing your tolerance before takeoff
Even the direction of the wind relative to a running engine in the air during certain maneuvers, but more likely on the ground around other aircraft, can be a source
Recognizing Carbon Monoxide Poisoning:
Carbon Monoxide Symptoms
Carbon Monoxide Poisoning Symptoms:
Compounded with additional cues, knowing the symptoms, and recognizing them in your passengers, can be a key indicator
Carbon Monoxide has an affinity of 240 times that of oxygen, which means it will more readily attach itself to your blood cells
Low concentrations over time can produce high blood concentration impeding the ability for blood to transport oxygen
As little as 10% Carboxyhemoglobin (Carbon Monoxide in the blood) decreases peripheral and night vision
Symptoms will mirror that of hypoxia as an increase of CO in the blood implies you are suffering from hypemic hypoxia
Victims could expect: [Figure 1]
Sense of pressure in the head
Drowsiness
Dizziness
Roaring/ringing sensation of the ears
Confused and unable to think clear
Drunk appearance
Vomiting
Incontinent
Convulsions
Bounding pulse
Cherry red lips
Dilated pupils
Incapacitation
Carbon Monoxide Detection:
Amazon, Carbon Monoxide Detector
Amazon, Hand-Held Carbon Monoxide Detector
Due to its result from incomplete combustion, there will usually be odors or colors which can provide cues
Example: the smelling exhaust is an indication of a leak and possible contamination
Since Carbon Monoxide is odorless, it may be challenging to detect Carbon Monoxide until you or your passengers are experiencing symptoms, at which point any delay can be life-threatening
Therefore, Carbon Monoxide detectors are cheap insurance which you would rather have and not need than need and not have
Choosing a Carbon Monoxide Detector:
As demonstrated in the case studies, carbon monoxide is a life-threatening poison
Especially when impaired, detectors can trigger a pilot's cognative ability to recognize the problem
Carbon Monoxide detectors come in many designs but generally speaking; you'll have the choice of either passive or electronic detectors
Pilots must pay special attention to the sources of carbon monoxide in the fall and winter months as damage may have occurred months before, but it does not manifest itself until cold weather arrives
Most important is a thorough preflight to find potential sources
Treat CO posioning as a constant possibility, as it often occurs throughout the year across all geographic locations
The NTSB determines the probable cause(s) of this accident to be: An inadequate annual inspection by maintenance personnel, a deteriorated muffler, and pilot incapacitation due to carbon monoxide
The NTSB determines the probable cause(s) of this accident to be: The pilot's severe impairment from carbon monoxide poisoning in flight, which resulted in a loss of control and a subsequent collision with trees and terrain
Carbon Monoxide Poisoning Knowledge Quiz:
Conclusion:
Carbon Monoxide Poisoning in a silent killer, mitigated through a few simple steps
Although deadly, realize its not a sudden large exposure that is of primary concern, but rather the slow onset of symptoms that go unrecognized
It is incumbent on the pilot to conduct a thorough preflight, which includes the exhaust/heating components to spot irregularities
After CO poisoning, it can take up to 24 hours to recover
Especially in winter months, refresh your knowledge on Carbon Monoxide and conduct an extra thorough preflight
Remember, the heater system may have gone unused for months
Symptoms are not linear and a pilot's cognative ability will be effected first
Detectors are not infalible and may produce false positives
Unless easily determined to be a false positive, normalization of deviance develops when warnings are present but ignored with a quick explaination or denial of the problem
Additionally, ensure the Carbon Monoxide detector is in serviceable condition
