Airplane Doors

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A hilarious meme a few years back was an airport sign board that read, “When one door closes, another one opens. Other than that, it’s a pretty good Cessna.” It’s funny because it’s true. Airplane doors were not there at the inception. The first planes didn’t need no stinking pilot enclosures and, hence, didn’t need no stinking doors, either. Pilots flew out in the open, which was fine when your top speed was no faster than a trotting horse. And even for a time after, pilots made do with flying goggles and small windscreens.

But as planes got faster, it became clear that aircraft needed some kind of enclosure to protect the pilot from the airstream. So, planes were given enclosures, and those enclosures were by necessity given doors. There are a few unspoken rules about doors. One, they don’t work very well in general, and two, airplane makers are all for putting as few of them on their planes as possible. It seems crazy, but the practice of shortchanging owners on the number of doors is rooted in a few commonsense concerns. Doors are heavy, hard to get to work well, and for low-wing planes, they require additional structure on the part of the wing that gets walked on, for obvious reasons.

Finally, doors aren’t as structurally integral to the fuselage as having no door is, so planes are automatically at least a bit stronger the fewer doors they have. So, putting just one door in a plane, as you see on many Piper, Beechcraft and Mooney single-engine models, is done to save weight, cost and complexity and to maximize the structural integrity. And while doors have gotten better, thanks to better manufacturing methods that yield closer tolerances and a better fit, the struggle is real, both for manufacturers, which need to figure out how to make a good-fitting, light and durable door, and for pilots and their passengers, who get to fight to make do with the few doors they’ve got.

First airplane doors: Perhaps the Avro Model 12, which was the first plane with an interior
Doors grow in popularity: Mid-1920s
Cheat code: On several models, pilots were in the open and passengers inside an enclosure
Door-making challenge: No suitable materials to make windows
Window/door breakthrough: The invention of acrylic glass in the early 1930s
Popular enclosure type: The bubble canopy
Door on bubble canopies? The canopy itself either hinges open or slides rearward
Potential safety risk? Canopies can open in flight, sometimes leading to a fatal crash
Doors become popular: 1930s, popularized on cabin-class biplanes and monoplanes
Material used for the doors: Usually the same materials as the rest of the plane
Early cabin biplane: Beechcraft D-17 Staggerwing
Max occupants: 5
Number of doors: 1
1930s innovation that complicated doors: Pressurization
1930s airliner: Douglas DC-3
Number of passengers: Up to 32
Number of doors: One
J-3 Cub of mid-1930s: One Dutch door for both occupants
Advantage: You can fly with it open
Ercoupe of 1930s: First popular slide-back canopy
Advantage: Roll it back in flight
First modern piston single: 1947 Beechcraft Bonanza
Number of seats: 4
Number of doors: 1
Ultimate Bonanza expression: Current G-36 Bonanza
Number of seats: 6
Number of doors: 2 (progress!)
Most popular plane: Cessna 172
Doors? 2
Other popular ’60s planes: Piper PA-28
Doors? 1
Position of door: On the passengers’ side
Reason: Unknown
1970s innovation: Beechcraft Model 23 Sundowner
Doors? 2! One on each side
Safety concern: Door popping open in flight
Level of risk: From the door being open, almost none
Reason for increased risk: Pilot panic over the open door, loss of control
Airliners number of doors: Often up to three
Used for boarding and deplaning: Just one
Reason: Jetways are set up for one-door operations
Exception: Airbus A380 jumbo jet
Boarding doors: Three
Reason: Saves a lot of time when boarding as many as 500 passengers
Time to board full A380 flight: As little as 20 minutes
Early Cessna 172 issue, circa 1956: Poor door functionality
Early Cirrus SR22 issue, circa 2001:Poor door functionality
Number of doors on six-passenger TBM introduced in 1990: One
First year pilot-side door offered as an option: 2002
Cost: Around $50,000
Added weight: Around 75 pounds