Forum: aviation.stackexchange.com
Tags: <aircraft-design><runways><aircraft-limitations>
Title: What is the biggest airplane that does not need a paved runway?
Question: Since we  don't need a control tower  for instrument landings I was wondering what else that is thought to be needed could be skipped. I know some small general aviation is done on grass runways and I was wondering what is the biggest airplane that does not need a paved runway? Examples of manufacturer-approved usage or regular (e.g. daily or weekly) usage are preferred.

Answers:
sents: text: Military transports are designed to be operated from unpaved runways- by extension, any of these converted to civilian use can operate from unpaved runways.
text: For example, the Antonov Airlines operates a number of Antonov An-124 'Ruslan' , which can and do operate from unpaved runways regularly.
text: The Volga-Dnepr group specifically states: Multi-leg landing gears equipped with 24 wheels allow to operate the aircraft on unpaved runways ...
answer_details: author: aviation.stackexchange.com/users/9731/aeroalias
score: 43
sents: text: The H-4 Hercules (Spruce Goose) should easily win this contest.
text: That plane was ridiculously huge and, in fact, couldn't use a runway,
text: rather it was a "flying boat" that took off from the the water.
text: So I'd say it's the one...
text: Granted, if you mean a grass or gravel strip aeroalias is probably correct.
text: The only other major planes that I know were designed to land on gravel were the early 737 and the 727 .
text: They both had special landing gear guards that keeps the front gear from kicking gravel into the engines and both
text: have specific instructions for preparing the landing gear for touch down on gravel.
text: Here's the guard, if you were curious, on a 737:
text: Source https://www.flickr.com/photos/capnmikesphotos/14891693505 , Author: Mike Pearson
answer_details: author: aviation.stackexchange.com/users/511/Jay Carr
score: 42
sents: text: It's not quite as big as the Antonov An-124, but honorable mention would have to go to the Lockheed LC-130 .
text: It's designed to resupply scientific and military operations in polar regions, and so it has a dual wheel-and-ski landing gear setup that allows it to take off from and land on snow and ice.
text: (Image source: Wikimedia Commons)
answer_details: author: aviation.stackexchange.com/users/13297/Michael Seifert
score: 21
sents: text: These oldies seem worth mentioning...
text: If you loosen your definition of "airplane" to " the longest class of flying machine and the largest airship by envelope volume " you could think of a Hindenburg-class airship that was in regular commercial service.
text: They landed in fields
text: They're more comparable in size to buildings or very large boats, rather than other airplanes Hindenburg in green compared to Blue: The Pentagon building, Pink: Queen Mary 2,
text: ocean liner
text: Yellow: USS Enterprise, supercarrier Dark blue:
text: Yamato, WWII Japanese warship
text: Grey:
text: Empire State Building
text: Red: Mont, a supertanker Compared to other airplanes (Hindenburg in orange): Or the Spruce Goose (* Not acutal Spruce) .
text: (Just noticed it mentioned in another answer, after posting this) Originally designated HK-1 for the first aircraft built by Hughes-Kaiser, the giant was re-designated H-4
text: when Henry Kaiser withdrew from the project in 1944.
text: Nevertheless, the press insisted on calling it the “Spruce Goose” despite the fact that the plane is made almost entirely of birch.
text: Apparently it is "the largest flying boat ever built and has the largest wingspan of any aircraft in history" at 320 ft 11 in (97.54 m).
text: Not strictly a "regularly used" airplane, but Hughes retained a full crew to maintain the mammoth plane in a climate-controlled hangar up until his death in 1976.
answer_details: author: aviation.stackexchange.com/users/4506/Xen2050
score: 19
sents: text: Going off on another direction if ice counts as "unpaved", a Boeing 757 was landed in Antarctica in November 2015, the first commercial airliner to do that.
text: Source is from the link above.
answer_details: author: aviation.stackexchange.com/users/12220/SMS von der Tann
score: 15
sents: text: Another option might be the Soviet Ekranoplan: these are aircraft that use the ground effect to fly just off a surface of water.
text: For example we might have the Lun-class (73m): or the experimental Caspian Sea Monster (92m): Sadly neither of these are flying any longer.
text: (source:
text: Wikipedia Ground effect vehicle and Lun-class ekranoplan )
answer_details: author: aviation.stackexchange.com/users/14510/user1908704
score: 12

Summary of the answers:
Military transports are designed to be operated from unpaved runways- by extension, any of these converted to civilian use can operate from unpaved runways.  Examples of these would be Antonov An-124, Ekranoplan and the H-4 Hercules. 
Military transport aircraft that can be adjusted for civilian use, like the Antonov An-124 'Ruslan' planes or the Soviet Ekranoplan that can take off a surface  of water, are considered the largest. However, if we broaden the definition of "airplane", then Hindenburg-class airships like the H-4 Hercules (Spruce Goose) would definitely come first.