Number 228
June 1998
Carbon Monoxide Alert
Most pilots are aware that carbon monoxide (CO) is a colorless, odorless and tasteless gas contained in exhaust fumes. It is also a common by-product of chemical reactions which can occur upon heating of many petroleum products and silicone-based synthetic lubricants used as aircraft oils and hydraulic fluids. The carbon monoxide level in blood is measured through a specific blood-gas method and is reported as a percentage. The normal level of carbon monoxide produced by the body's metabolism is from 0.4-0.7%, but heavy smokers can have much higher levels. Elevated levels of carbon monoxide in the bloodstream can create the effects of hypoxia (oxygen deficiency). Here is one air carrier crew’s experience with CO:
Handy Detectors
A General Aviation pilot, thwarted by closed airport restaurants, initially thought that his nausea and dizziness during flight were due to skipping breakfast.
s I remember not being able to find my approach plates,
even though they were on the floor beside me. I tried three times to set my destination into the GPS. I was confused as to what to do and panic began to set in. Fortunately, I was able to acquire the airport and complete the approach visually. Upon landing, I discovered that my carbon monoxide detector was jet black! I now suspect my disorientation was a result of carbon monoxide exposure. Aviation supply shops have no “missing breakfast detector” available at any price. However, small, lightweight carbon monoxide detectors are available for less than $10, and change colors to inform aircraft occupants of the presence of this odorless gas.
s An electrical/hot plastic smell was noticed in the cabin, and the Flight Attendants reported feeling ill. Maintenance could not find any source of the odor. We started boarding passengers, but boarding was suspended when the odor returned. The Flight Attendants later went to the hospital…they had carbon monoxide levels of [up to] 1.2 [%]. Later that evening, the First Officer and I were tested for carbon monoxide and had levels of 0.5 [%] and 0.6 [%].
Several hydraulic leaks were discovered in the engine thrust reversers and in the tail cone. The APU was contaminated with hydraulic fluid as well as the air conditioning system. Headaches and nausea were the symptoms reported by another crew who suspected carbon monoxide exposure.
The Air Up There Is Rare
Another General Aviation pilot used oxygen delivered by nasal cannula to fend off altitude-related hypoxia.
s During a test flight, I received a clearance to climb and
maintain FL250. I was using supplemental oxygen. After about 20 minutes, I began to experience hypoxia, but I had no awareness of it at the time. This resulted in loss of altitude control by as much as 2,000 feet. Center asked me to report my current altitude, which I was unable to do due to mental confusion and inability to read my altimeter. I was given a clearance back to my home base. I wrote it down, but was unable to read it. With difficulty, and assistance from Center, I managed to descend to a lower altitude. I violated clearance limits more than once on the way down. Center was not happy. I neither felt the need for, nor requested, any assistance from Center. I now realize I was in serious trouble with acute hypoxia. The reporter believes that the oxygen flow rate may have been inadequate for the altitude flown. A full-size face oxygen mask might have provided more reliable delivery of correct amounts of oxygen. This reporter and other pilots of unpressurized aircraft that fly at high altitudes might consider high-altitude pressure chamber training, offered by the Air Force and the FAA. Hypoxia recognition is a beneficial by-product of this training. Information and application forms for this training may be obtained from local FAA Flight Standard District Offices. Courses are offered for small fees at appropriately equipped Air Force bases.
s After climb we noticed an unusual, faint odor in the cockpit. We tried to determine what the source of the odor might be. In the logbook, we found a previous write-up of an undetermined “ozone” smell in the aircraft. There were also two previous write-ups in reference to unexplained smoke detector activation in the lavatories.
The First Officer said he was not feeling well. I was also slightly nauseated, had a headache, and was extremely fatigued. Both Flight Attendants also complained of the same symptoms. After arrival, we all agreed we should seek medical attention. It was 3-1/2 hours after the flight arrived that we had blood drawn. The [carbon monoxide levels] ranged from 2.3 [%] to 2.5 [%]. I am aware that these values are above normal. I wonder what the values might have been if the tests were taken just after we landed. The source of the odors was not identified, but carbon monoxide probably caused the crew's symptoms. More information about hypoxia and carbon monoxide can be found in the Aeronautical Information Manual—Medical Facts for Pilots, Section 1, Para. 8-1-2 and 8-1-4.
ASRS Recently Issued Alerts On...
Canadair CA-RJ asymmetric wing flap failure Malfunction of both fuel tank check valves on a BA-31 Continuing confusion over a rewritten New Jersey SID Excessive rubber build-up on a Tennessee airport runway ATR-42 loss of cabin pressure due to inflight electrical failure
A Monthly Safety Bulletin from The Office of the NASA Aviation Safety Reporting System, P.O. Box 189, Moffett Field, CA 94035-0189
http://olias.arc.nasa.gov/asrs
April 1998 Report Intake
Air Carrier Pilots General Aviation Pilots Controllers Cabin/Mechanics/Military/Other 2071 719 82 97
TOTAL
2969
飞行翻译公司 www.aviation.cn 本文链接地址：美国ASRS安全公告CALLBACK cb_228.pdf
June 1998
Carbon Monoxide Alert
Most pilots are aware that carbon monoxide (CO) is a colorless, odorless and tasteless gas contained in exhaust fumes. It is also a common by-product of chemical reactions which can occur upon heating of many petroleum products and silicone-based synthetic lubricants used as aircraft oils and hydraulic fluids. The carbon monoxide level in blood is measured through a specific blood-gas method and is reported as a percentage. The normal level of carbon monoxide produced by the body's metabolism is from 0.4-0.7%, but heavy smokers can have much higher levels. Elevated levels of carbon monoxide in the bloodstream can create the effects of hypoxia (oxygen deficiency). Here is one air carrier crew’s experience with CO:
Handy Detectors
A General Aviation pilot, thwarted by closed airport restaurants, initially thought that his nausea and dizziness during flight were due to skipping breakfast.
s I remember not being able to find my approach plates,
even though they were on the floor beside me. I tried three times to set my destination into the GPS. I was confused as to what to do and panic began to set in. Fortunately, I was able to acquire the airport and complete the approach visually. Upon landing, I discovered that my carbon monoxide detector was jet black! I now suspect my disorientation was a result of carbon monoxide exposure. Aviation supply shops have no “missing breakfast detector” available at any price. However, small, lightweight carbon monoxide detectors are available for less than $10, and change colors to inform aircraft occupants of the presence of this odorless gas.
s An electrical/hot plastic smell was noticed in the cabin, and the Flight Attendants reported feeling ill. Maintenance could not find any source of the odor. We started boarding passengers, but boarding was suspended when the odor returned. The Flight Attendants later went to the hospital…they had carbon monoxide levels of [up to] 1.2 [%]. Later that evening, the First Officer and I were tested for carbon monoxide and had levels of 0.5 [%] and 0.6 [%].
Several hydraulic leaks were discovered in the engine thrust reversers and in the tail cone. The APU was contaminated with hydraulic fluid as well as the air conditioning system. Headaches and nausea were the symptoms reported by another crew who suspected carbon monoxide exposure.
The Air Up There Is Rare
Another General Aviation pilot used oxygen delivered by nasal cannula to fend off altitude-related hypoxia.
s During a test flight, I received a clearance to climb and
maintain FL250. I was using supplemental oxygen. After about 20 minutes, I began to experience hypoxia, but I had no awareness of it at the time. This resulted in loss of altitude control by as much as 2,000 feet. Center asked me to report my current altitude, which I was unable to do due to mental confusion and inability to read my altimeter. I was given a clearance back to my home base. I wrote it down, but was unable to read it. With difficulty, and assistance from Center, I managed to descend to a lower altitude. I violated clearance limits more than once on the way down. Center was not happy. I neither felt the need for, nor requested, any assistance from Center. I now realize I was in serious trouble with acute hypoxia. The reporter believes that the oxygen flow rate may have been inadequate for the altitude flown. A full-size face oxygen mask might have provided more reliable delivery of correct amounts of oxygen. This reporter and other pilots of unpressurized aircraft that fly at high altitudes might consider high-altitude pressure chamber training, offered by the Air Force and the FAA. Hypoxia recognition is a beneficial by-product of this training. Information and application forms for this training may be obtained from local FAA Flight Standard District Offices. Courses are offered for small fees at appropriately equipped Air Force bases.
s After climb we noticed an unusual, faint odor in the cockpit. We tried to determine what the source of the odor might be. In the logbook, we found a previous write-up of an undetermined “ozone” smell in the aircraft. There were also two previous write-ups in reference to unexplained smoke detector activation in the lavatories.
The First Officer said he was not feeling well. I was also slightly nauseated, had a headache, and was extremely fatigued. Both Flight Attendants also complained of the same symptoms. After arrival, we all agreed we should seek medical attention. It was 3-1/2 hours after the flight arrived that we had blood drawn. The [carbon monoxide levels] ranged from 2.3 [%] to 2.5 [%]. I am aware that these values are above normal. I wonder what the values might have been if the tests were taken just after we landed. The source of the odors was not identified, but carbon monoxide probably caused the crew's symptoms. More information about hypoxia and carbon monoxide can be found in the Aeronautical Information Manual—Medical Facts for Pilots, Section 1, Para. 8-1-2 and 8-1-4.
ASRS Recently Issued Alerts On...
Canadair CA-RJ asymmetric wing flap failure Malfunction of both fuel tank check valves on a BA-31 Continuing confusion over a rewritten New Jersey SID Excessive rubber build-up on a Tennessee airport runway ATR-42 loss of cabin pressure due to inflight electrical failure
A Monthly Safety Bulletin from The Office of the NASA Aviation Safety Reporting System, P.O. Box 189, Moffett Field, CA 94035-0189
http://olias.arc.nasa.gov/asrs
April 1998 Report Intake
Air Carrier Pilots General Aviation Pilots Controllers Cabin/Mechanics/Military/Other 2071 719 82 97
TOTAL
2969
飞行翻译公司 www.aviation.cn 本文链接地址：美国ASRS安全公告CALLBACK cb_228.pdf
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