The single biggest reason both pilots walked away from Coulson Tanker 139 has very little to do with luck and everything to do with something pilots and operators sometimes take for granted: redundant, simple egress hardware and the training to use it.

On 6 February 2023 Coulson Aviation’s Boeing 737-300 large air tanker N619SW impacted terrain while conducting a retardant drop in Fitzgerald River National Park. The aircraft was destroyed by post impact fire but both crew escaped with only minor injuries. Investigators and contemporary reporting confirm the two pilots exited the wreckage through a flight deck window after the main cabin door had buckled and one cockpit window could not be opened.

From a pilot point of view the sequence is painfully familiar. A high energy event, a jammed or structurally distorted primary egress, and then a short window to get clear before fire overwhelms the airplane. In this case the crew’s ability to use the flight deck number two window as an alternate escape route was decisive. The ATSB factual record notes the cabin door was buckled and the right‑side window could not be opened, while the captain was able to open the left window and both crew exited within a matter of moments.

Most transport category aircraft have a planned contingency for that exact scenario. On the 737 family, flight deck number two windows are designed to open in flight and on the ground and are paired with escape straps or lanyards stored in compartments above the windows. The published procedure is straightforward: open the window, open the escape strap compartment, confirm the strap is secure, throw the strap out, and exit over the sill using the strap as a lowering aid. This is a low tech mechanical solution that works even when the main cabin exits are unusable.

Two operational points matter here. First, the hardware only helps if it is serviceable and readily accessible. Escape straps, their stowage doors, the crank or unlock for the window, and any placards or lighting that identify the escape path must be part of the preflight cockpit safety check. Failure modes include straps cut or unsecured after maintenance, stowage doors that jam, or wear in the attachment points. Second, crews must practise the motions so that under stress they do not fumble. In other words the strap and window are only as good as the checklist and muscle memory backing them up.

There is a second layer that operators flying converted tankers need to remember: modifications. Coulson’s 737s operate with a retardant aerial delivery system installed under an FAA STC. Modifications and mission equipment can change access, the location of panels, and even how fire or impact loads affect structural members near exits. The ATSB record for this occurrence documents the tanker installation and notes operator procedures in the context of the accident. That does not mean modifications caused the buckling, but it does mean modification effects on escape routes must be assessed during the STC and in operator maintenance programs.

What I tell crews in simulation and on type: treat cockpit windows and escape straps like primary emergency equipment. Put them on the preflight walkaround to‑do list. Verify straps are present and attached. Confirm window handles and lock releases are free and that the stowage access is unobstructed by mission kit or loose equipment. Brief egress during the before‑takeoff emergency briefing so both crew know who will go first and how to assist. If one crewmember cannot get their window open, the other must know immediately to attempt their side or to move to the same window without losing situational awareness. The ATSB timeline from the Fitzgerald River accident shows how rapidly events progress after impact. Quick, practiced action saved lives in this case.

For operators and safety managers I would highlight three practical, immediate actions:

  • Hardware inventory and inspection: include escape straps, stowage doors, window lock mechanisms, and attachment fittings in routine maintenance and preflight checks. Confirm torque/attachment integrity during heavy maintenance and after any structural work near the cockpit.
  • Procedural drills: incorporate window egress drills into recurrent training and simulator sessions. Time the task so crews understand the cadence under stress. Train single‑pilot egress from the cockpit window so the assisting pilot knows whether to remain outside helping or to continue to clear passengers and direct rescue resources.
  • Modification impact reviews: whenever mission equipment is installed under an STC, perform a documented egress assessment that looks at how the equipment could interfere with escape routes or alter post‑impact structural deformation patterns. A change control that treats egress implications as safety critical will catch many latent hazards.

The Coulson incident is a reminder that modern aircraft survive surprising abuse when both equipment and people work as intended. Escape straps and opening flight deck windows are not glamorous. They are mechanical, old school, and utterly reliable when kept ready. Operators flying in the fire environment should treat them as mission critical, not optional, and make sure every crewmember leaves the ground confident they can use them if they ever need to.