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A quick follow-up to Why do planes always land on rear wheels instead of the nose wheels?

What airframe designer/manufacturer is credited with the first retractable landing gear system? I ran past the article on retractable gear over in Wikipedia without really finding an answer

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Everyone
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1 Answers1

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It looks like the first plane that actually flew and had at least a partially-retractable undercarriage was a German racing plane, the Wiencziers Renneindecker, from 1911:

enter image description here

You can see the undercarriage designed to collapse to the rear, using a hand crank in the cockpit to lift the gear. Not a great idea by today's standards as the gear would be prone to collapse on landing, but it apparently worked well enough at the time.

There are plans for retractable landing gear dating back to the late 1800s, before powered flight in such a craft was ever achieved, but they didn't become common on planes until just after WWI. Even then, for relatively slow planes (<200mph) it remains common even today to keep the gear fixed and wrap the wheels in a cowl, as for only a ~4% increase in drag over a full retractable setup, you save a lot of weight and mechanical complexity. Notable fixed-gear craft in military service through WWII include the German Ju87 Stuka and the Nakajima Ki-27 "Nate". Though most of the American wartime air fleet had retractable gear as of just after the start of WWII, practically every WWII air corps draftee trained on either a BT-11 or one of the biplane trainers like the PT-13/17/18. Today, plenty of civvie small craft have fixed gear, such as the Cessna 150, 172 and variants, Piper Cubs and Cherokees, some Beechcraft Musketeers, etc etc.

KeithS
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    Nice one! Welcome to Aviation.SE KeithS! – DeltaLima Mar 13 '15 at 18:57
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    It still remains common for slow planes to have fixed landing gear. – raptortech97 Mar 13 '15 at 21:20
  • Very much so; my first flight was in a Cessna 150, which has a nonretractable tricycle config, and a large number of small civvie planes are similar. – KeithS Mar 13 '15 at 21:36
  • Nice! Uh ... the source for the drawing - if you would be so kind? – Everyone Mar 14 '15 at 16:09
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    @Everyone: Try this site and search for "Wiencziers". It doesn't matter if you don't understand German, because the OCR is so horrible that the text is mostly illegible anyways. I seems they didn't train the engine on the old font. Interesting detail: The fuselage was made from steel sheets. – Peter Kämpf Mar 15 '15 at 21:10
  • Plenty of aircraft still feature rearward-retracting landing gear, fwiw! – egid May 05 '15 at 05:25
  • Good point, but every time I hear of gear systems specifically designed for reliability and durability (always a good thing on a plane), "forward-retracting" is in the same paragraph. Not only will the gear strut naturally be pushed further back into the open position by the landing stresses, but in event of a hydraulic failure many such systems allow the pilot to simply release them and let gravity and the airstream open and lock them. Side-retracting gear is the next best especially with single-wheel gear as it folds up nice and compact and you still get that "backstop". – KeithS Jun 30 '15 at 15:35
  • Rearward-retracting gear, OTOH, is totally dependent on the strength of the locking mechanism to prevent the gear collapsing on touchdown, and reinforcing that mechanism (or protecting it using additional shock-absorbing suspension in the gear struts) adds weight. – KeithS Jun 30 '15 at 15:38
  • @KeithS: With the heavy engine and the light structure of that time, there was no space ahead of the center of gravity to stow away the gear. It would had needed a sliding hinge - the rearward retraction was really the only sensible option. – Peter Kämpf Jun 30 '15 at 15:55