Captain Steve, a long-tenured commercial pilot and Navy veteran, explains that timing is everything when it comes to handling mechanical issues during a flight. “The most critical phase of a flight is the takeoff,” he starts. “And the most critical phase of the takeoff is right when the aircraft reaches ‘Rotate Speed.’” This is when the pilot pulls back on the yoke and the airplane lifts off the runway. “If I lose an engine then, it’s a big deal.”

Well, this just happened in Denver

In April, United Airlines Flight 2325 took off. Right away, flames shot out of the right engine. The underlying cause of the fire? Of all things, a bunny.

After the cabin confirms with Air Traffic Control that they’ve lost that right engine, the controller offers them time to buzz through a long checklist before executing their emergency landing.

You might think that this “extra time” is unsafe and could lead to a crash, but Captain Steve reassures us. “The airplane flies just fine on one engine.”

The pilot climbs to 9,000 feet…why does that seem high for a single-engined 737?

Captain Steve notes that in Denver, 9,000 feet is still low. The city’s already at 6,000 feet. So the airplane maintaining 9,000 feet as it slowly turns back to the airport is actually quite reasonable.

The pilot must deliver on “Two Out, Two In”

In an emergency, the pilot needs to provide “Two Outs:”

Declare the emergency with Air Traffic Control. Provide the number of souls on board, the fuel status, and the pilot’s intentions.

Contact the company. Reach out to the airline to notify staff of the return so they can provide assistance upon landing.

Next, the flight crew must make “Two In:”

Huddle privately with the flight attendants. The pilot calls the highest-ranking attendant to loop them into the plan. They’ll also provide the remaining flight time.

Speak with the passengers. The pilot needs to inform and reassure the passengers.

Next, the pilot and co-pilot run through their checklists

Captain Steve says they’re likely managing several checklists. For one, the Engine Fire In-Flight workflow. This guides the crew through containing and extinguishing the engine fire.

Another is the Overweight Landing checklist.

Even speaking to the passengers is on the checklist.

After these items are complete, they’ll review the control configurations that acknowledge the single-engine landing.

These steps take time, so the United co-pilot requests a “hold.” This means they’re not rushing the landing and want to maintain their emergency landing status without an exact touchdown time. Holding patterns are usually single-minute legs at the declared elevation, right turns only. In this case, the crew can only make it to 8,000 feet, which is fine.

Why a rabbit in the engine?

Captain Steve explains that airports are actually perfect rabbit habitats. “They’re flat, there’s deep grass…it’s loud and noisy, the normal predators aren’t there.” And while barbed wire fencing is another predator deterrent, rabbits can still fit through.

The Boening 737 engines are sucking in so much air that it’s very possible for a small mammal to get sucked in.

During the checklists, the pilot flags a secondary problem: The landing gear

The co-pilot reports to ATC that the landing gear is now registering as unsafe. They’re still going to need time to address the fault message.

Soon after, the pilot and co-pilot confirm the landing gear came down normally, and everyone clears Flight 2325 for landing.