Interagency Aviation Accident Prevention Bulletin 21-05 Drought Conditions and Increased Risk for Water-Scooping Aircraft

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Overview

The Interagency Aviation Accident Prevention Bulletin 21-05 Drought Conditions and Increased Risk for Water-Scooping Aircraft () is a public-domain DOI Office of Aviation Services aviation safety document, republished here as a free chaptered HTML edition with a linked table of contents and the official PDF.

Publisher: DOI Office of Aviation Services
Document
Pages: 2

Key points

Prolonged drought conditions have led to historic low water levels in many reservoirs, lakes, and streams in the western states.
Obstacles such as submerged rocks and tree stumps now pose significant hazards for water-scooping aircraft.
Water source selection is critical for safe scooping operations, requiring assessment of various factors including depth and hazards.
Fire Boss aircraft typically require a minimum of 4 feet of water depth, while CL-415/CL-215 aircraft require at least 6 feet, with pilots preferring 7 feet.
Approved scoop sites should be reviewed at the beginning, mid-season, and end of the season to ensure safety.

Frequently asked questions

What hazards are associated with water-scooping operations during drought conditions?

Drought conditions can expose submerged obstacles such as rocks and tree stumps, which create significant hazards for scooping aircraft.

How should water sources be assessed for scooping operations?

Water sources should be surveyed for suitability, including factors like winds, water conditions, depth, and natural or man-made hazards.

What is the minimum water depth required for Fire Boss and CL-415/CL-215 aircraft?

Fire Boss aircraft require a minimum of 4 feet of depth, while CL-415/CL-215 aircraft require at least 6 feet, with most pilots preferring 7 feet.

How often should approved scoop sites be reviewed?

Approved scoop sites should be reviewed at the beginning of the season, mid-season, and end of the season to ensure they are clear of hazards.

What should be done if new hazards are identified at a scoop site?

Any new hazards appearing within a designated scoop/dip site should be reported and communicated during briefings.

Document

OAS-43A (12/12)

Interagency Aviation

Accident Prevention Bulletin

No. IA APB 21-05 September 15, 2021 Page 1 of 2 Subject: Drought Conditions and Increased Risk for Water-Scooping Aircraft Area of Concern: Flight Safety Distribution: All Aviation Activities Discussion: Due to prolonged drought conditions, many reservoirs, lakes, and streams in the western states are at or near historic low water levels. As water levels fall, obstacles such as rocks, tree stumps or logs that were once submerged are now closer to the surface where they can create a significant hazard for scooping aircraft and bucketed helicopters.

Recently, a Fire Boss float was damaged while scooping from a lake when it struck a submerged tree stump. Fortunately, the pilot was able maintain control and fly the aircraft safely back to the airport.

A reservoir storage graph (below) contains data for nine different reservoirs in Oregon. The graphs illustrate a comparison of the water level percentages of the reservoirs in February 2021 and August 2021. Based on these conditions, bodies of water previously approved for scooping operations or dipsites should be reassessed for new hazards and risks prior to use.

No. IA APB 21-05 September 15, 2021 Page 2 of 2 Water source selection is critical to the safe operation of scooping and bucket operations.

The NWCG Standards for Water Scooping Operations , PMS 518 identifies that water sources should be surveyed for suitability, including winds, water conditions, length, width, depth, natural and man-made hazards, recreation, and ingress/egress routes. Depth can be assessed by the position of the high- water mark along shores, or other visual cues such as boat dock position or types of boats being operated. Adequate depth in the event a water scooper needs to reject a take-off and settle into displacement taxi, is also critical.

Fire Boss aircraft typically require a minimum of 4 feet of depth and a CL- 415/CL-215 requires 6 feet of depth. That said, most pilots would prefer at least 7 feet.

Accident Prevention Recommendations: • Conduct a low-level reconnaissance to ensure dip/scoop site is clear of obstacles and hazards.

• Obtain a Predictive Services report on water conditions and reservoir levels and ensure it is briefed. Water condition reports are available at https://water.weather.gov/ahps/.

• At a minimum, approved scoop sites and dip sites should be reviewed at the beginning of the season, mid-season, and end of season.

• Monitor and be aware of snow-pack levels over the winter and note start of season levels.

• Report any new hazards appearing within a designated scoop/dip site and ensure communication with all resources at briefings.

/ s/ Keith C. Raley /s/ Lori Clark Lori Clark Keith C. Raley Branch Chief - Aviation Safety Management Chief, Aviation Safety, Training, Program Systems Evaluation, and Quality Management USDA, Forest Service DOI, Office of Aviation Services