Why does the Boeing 737 sit so low on its wheels compared to the Airbus A320?
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1Related:Is there less vertical space for an engine under the wing of a 737 Max than for an A320neo? – fooot Apr 30 '19 at 21:10
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8I have a feeling „because its landing gears are shorter“ is not quite what you’re after...? – Cpt Reynolds Apr 30 '19 at 21:15
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5Low rider style for cruising the boulevard... – Michael Hall Apr 30 '19 at 23:14
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1Wendover actually just came out with a very relevant and interesting video just on that here: https://www.youtube.com/watch?v=BfNEOfEGe3I. He goes into good detail on the reasons for it and modifications made to evolve it along its lifespan. Check it out for a great overview on the history and future of the 737. – Jihyun May 01 '19 at 05:37
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2For everyone voting to close this question, please see ymb1's post here: https://aviation.meta.stackexchange.com/questions/3802/question-closing-is-too-arbitrary?cb=1 !! – 60levelchange May 01 '19 at 06:46
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@CptReynolds Well, no. That just defers the question to why is the landing gear shorter? – David Richerby May 01 '19 at 15:02
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@DavidRicherby ... to which the rather obvious answer would be „because that was the option selected by the designers“! (in case it wasn’t clear, I was joking...). – Cpt Reynolds May 01 '19 at 18:52
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The 737 was originally designed to be a smaller aircraft serving more regional routes. The original JT8D low-bypass turbofans easily fit under the wings, and allowing the plane to sit lower to the ground made it easier for the plane to operate at smaller airports without support equipment. Passengers could use the built-in air stairs and the cargo bay was low enough that ground workers could climb in to load and unload baggage.
The low height also allowed shorter and lighter landing gear. The 727 had tail-mounted engines which allowed it to sit lower to the ground, so keeping the 737 low helped to keep some commonality there as well. Over time the airplane has grown longer, been fitted with larger diameter engines, and become capable of much longer flights.
The A320 was designed from the start for the larger family of CFM56 high-bypass engines. The main competition was the 737 Classic version, which was powered by similar engines and had grown substantially from the original 737 versions. Both planes ended up in a market where the low height of the 737 didn't have as many advantages.
fooot
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The follow up question "why don't they just make the gear longer?" was covered somewhere else around here, but summarized is: Because longer gear need more storage area & mounting point strength which leads to modifications that make it no longer "just like all the other 737s ever produced" (as well as lots of FAA approvals). This makes it less appealing to airlines who see it as having to train pilots on a new air frame. – FreeMan May 01 '19 at 19:27