On 6 February 2023 a Coulson Aviation Boeing 737 converted as a large air tanker came down in Fitzgerald River National Park in southern Western Australia while conducting retardant drops. Both pilots survived with only minor injuries and the aircraft was destroyed. Authorities and Coulson have said investigations are underway to establish the sequence of events and causal factors.

From an operational perspective there are a handful of recurring hazards in large air tanker work that this event brings back into sharp focus. These are low altitude energy management, terrain and situational awareness when operating in smoke, the handling characteristics of converted aircraft during partial-load drops and go-arounds, and the human factors around briefings and tasking information.

Low altitude energy management is the clearest risk vector. Large air tankers fly deliberately low and slow to place retardant where it will do the most good. That leaves a small performance margin to deal with rising terrain, wind shear, gusts from fire driven convection, and engine response times when power is needed quickly. Converted jets and turboprops do not behave the same way as purpose built smaller firefighting aircraft. Pilots need to factor in engine spool-up time when planning a drop and the expected exit path out of the target. When a drop begins over descending terrain the aircraft may be operating at idle or near idle thrust to maximize accuracy and to meet the selected drop profile. If the exit requires a rapid climb over rising terrain the margin can evaporate in seconds. In this incident early reports noted the crash occurred shortly after a retardant drop and that investigators cautioned against assuming a single cause.

Terrain and visibility compound the problem. When smoke obscures horizon cues a crew must rely on briefings, the birddog or lead aircraft for geometry and on their instruments for low height awareness. That means pre‑flight and in‑pattern briefings must capture the exit terrain profile, preferred headings, minimum safe altitudes and what the birddog will and will not do. Failing to confirm the geometry of the exit and any rising ridgelines can put crews into a low energy state with little time to recover. Early news reporting and operator statements show both the tasking and the response were under review, and investigators were being deployed to gather flight and witness data.

Aircraft configuration and partial loads matter. Converted 737s and other large tankers use retardant delivery systems designed for rapid large volume discharge. A partial release changes aircraft weight and trim and operators sometimes reduce target drop speed after a partial release to preserve delivery accuracy. That trimmed lower speed reduces energy margins on the exit. The crew must brief and monitor any changed target speeds and be ready to command a disciplined, immediate go-around with appropriate power application. From the cockpit that is not a theoretical issue. Engine response lags exist. A conservative plan is to assume the engines will take more time to deliver needed thrust than a pilot might expect in a transport category jet in normal cruise procedures. That needs to be built into decision heights and abort criteria.

Crew resource management and tasking communication are equal partners in risk control. The person flying the aeroplane cannot be the only layer of defense. The pilot monitoring, the birddog and the tasking agency should all have clearly shared expectations about minimum safe heights, decision points and who calls a rejection. Public reporting around the crash shows both operator and authorities were cooperating with investigations, which is the right first step. The industry history of large tanker operations in Australia, including the tragic 2020 C-130 loss and the subsequent ATSB findings, makes it clear that information flow from tasking agencies to crews and clear risk registers are not optional if we want to reduce preventable losses.

What can operators, tasking agencies and pilots do now to reduce exposure? From a practical pilot and operator view I would highlight a few measures:

  • Standardize pre‑drop briefings so they always include exit geometry and a minimum drop height or decision height that is called and set on the radio altimeter. Make the decision height an explicit, non negotiable item in the brief.
  • Treat partial-load drops as a configuration change. Rebrief target speed and go‑around power settings before committing to a second pass.
  • Require a “show me” or reconnaissance run from the birddog in marginal terrain or low visibility so the tanker crew has a visual picture of the exit. If the birddog will not do one then the entry parameters should be more conservative.
  • Reinforce sterile cockpit discipline during drops so monitoring calls are crisp and all deviations are announced immediately by the pilot monitoring.
  • Ensure tasking agencies capture and pass on rejections, declinations and environmental assessments from other crews operating at the same fire ground. Do not assume a single crew’s assessment is sufficient intelligence for others. The ATSB investigation into the 2020 incident underlined how critical that communications chain is.

This incident is a reminder that aerial firefighting is inherently hazardous work. Converted large tankers bring valuable capacity to fight big fires, but they also bring specific handling and operational constraints that must be respected. Investigations will determine why the Fitzgerald River event unfolded as it did. Meanwhile operators, agencies and crews should treat the event as a prompt to reexamine briefings, energy management practices and information flows rather than wait for definitive findings. If we take conservative measures now the industry will preserve capability and keep crews safer in the field.

Acknowledgement: Coulson Aviation issued a company statement confirming the accident and that both pilots were medically assessed. News organisations reported the event and the ongoing investigations.