Document
OAS-25A (4/18)
Interagency Aviation
SAFETY ALERT
No. IA SA 24-01 Date: September 20, 2024 Page 1 of 2 Subject: Aircraft Ventilation During Retardant Loading Operations Area of Concern: Airtanker Operations Distribution: Airtanker Base Personnel and Airtanker Aircrews Discussion : A Sentry device (ADS-B Portable Receiver and carbon monoxide monitor) located in the cockpit of a large airtanker (LAT) recently detected high levels of carbon monoxide (CO) during the retardant loading process at the Colorado Springs Airtanker Base (COS). The Sentry is programmed to provide a red warning light and audible alarm when CO levels are more than 200 PPM. This warning was received during the retardant loading process at two different pits and on more than one occasion.
The CO detection at COS prompted the need for air quality testing on different airtanker types, both internally and externally vented tanked aircraft, and at other airtanker bases to determine the extent of the issue and to try to isolate any potential cause(s). In addition to CO testing, other tests are also being conducted to detetmine if the presence of other gases that are known to interfere with the electrochemical sensors within CO detectors are causing a false indication. A National Incident Management Organization (NIMO) Team is leading and coordinating all air quality testing and monitoring among several internal and external stakeholders.
Until results can confirm the source and types of gases that are being detected, the following measures must be taken to ensure safety: Airtanker Bases: • Confirm airtanker operators are implementing mitigations for potential CO exposure such as aircraft venting in addition to ensuring emergency procedures are appropriate for their aircraft type.
• Daily briefings must include a reminder of the required CO mitigations during the retardant loading process (e.g. aircrew must ensure proper ventilation during the loading of internally vented aircraft).
Airtanker Flight Crews: • Implement company approved protocols for CO monitoring, detection, and emergency procedures.
• Ensure approved aircraft venting procedures are appropriate for the aircraft type during all retardant loading operations.
No. IA SA 24-01 Date: September 20, 2024 Page 2 of 2 • Ensure all aircrewmembers are familiar with the physical symptoms of CO exposure and are able to treat in-flight CO poisoning with continuous 100% oxygen (O2).
NOTE : The requirements within this Interagency Aviation Safety Alert (IASA) will remain in effect until additional information becomes available. An updated Safety Alert may be published to communicate additional information related to the ongoing testing or any changes to requrements or recommendations.
/s/ Keith Raley /s / Lori Clark Keith Raley Lori Clark Chief, Aviation Safety, Training, Program Branch Chief - Aviation Safety Management Evaluation, and Quality Management Systems DOI, Office of Aviation Services USDA, Forest Service