It doesn’t have to be a single aircraft, and by “aircraft” I mean any vehicle that moves above the ground. Also it can’t be the vehicle itself, so C-5 Galaxies and spacecraft are out.
Guessing without googling, maybe a space shuttle orbiter piggybacked to a 747?
What does one of those weigh?
68500kg dry mass, according to wikipedia.
That works out to about 151016 lbs.
I just now found a claim from Guinness(which I can’t link to for some reason) that says
, but I don’t know how up to date that info is.
Another interesting thing related to the shuttle weight when hauled by the modified 747:
So apparently the modified 747 was not being overly taxed hauling that single object compared to the normal passenger-related load.
This site has some basic information on the weight specs of the shuttle itself:
The last sentence was a surprise to me, not that the fuel would be the bulk of the weight but by how much.
The maximum landing weight of the Shuttle orbiter was around 100 tons. And whenever the Shuttle landed anywhere other than KSC, I believe they transported it to KSC on the 747 without removing the payload. (Obviously if it’s a satellite launch mission, the cargo bay would be empty, but some missions involved retrieving stuff from space, or taking an experiment facility like Spacelab that remained in the cargo bay and brought back.)
Still no match for the An-225 record mentioned above.
Indeed, beat the shuttle weight by way more than double. :eek:
The weight was well within the capability of the 747 (the freight version of the 747 has a max payload around 124 tons), but the orbiter added a huge amount of drag. Which reduced the max altitude to 15,000 ft and range to 1200 miles. This meant it couldn’t fly non-stop from Edwards Air Force Base to Kennedy Space Center.
So far as I know, the A-225 is still the largest plane in the world and it’s specifically a cargo plane. For a thread like this, that’s what I’d look at.
However, just because it could carry the largest single item, doesn’t mean it has. Though I’d expect it’s likely carried the largest payload.
The Stratolaunch, which recently flew for the first time, has the largest wingspan of any plane ever flown and is intended to carry launch-to-orbit rockets. Big ones. Its external payload capacity is listed at 550,000 pounds. It was designed to handle the now-cancelled Pegasus II rocket, which would have had a gross weight of 465,000 pounds. Not sure what they’ll do with it now.
Wow that thing is wild looking. Two cockpits? 2-4 pilots?
Let’s hope they’re in communication, and in agreement! 
There are two fuselages so the payload rocket can be slung between them under the wing, but according to Wikipedia the flight crew is together in the right cockpit, and the left cockpit unoccupied/unpressurized.
They must have some interesting software to coordinate the angles of the front landing gear on each fuselage. When taxiing, they make some turns in which the inboard wheels are much closer to the center of the turn than the outboard wheels, so the two front landing gear have to turn to different angles to get around the corner without skidding. You can approximate this on a car with Ackerman steering geometry, but the two front landing gear steering mechanisms on that thing surely are not linked mechanically.
I imagine a husband and wife team.
“We should turn here.”
“The chart says straight on.”
“I’m sure we turned at that beacon.”
“No dear… I’m going to turn now…”
“OOPS!”
Starting at :45 herewith the inevitable result after a minute.
Why did they continue with the plane after the rocket was cancelled?
Are you familiar with the Sikorsky S-64 Skycrane? They can attach removable cargo pods to it.
The stages of a rocket are independent vehicles. I see no reason why we can’t count the upper stages and payload of a given rocket as the “object”, with the first stage as the “vehicle”. Especially since the upper stages aren’t contributing to the thrust or propellant when the first stage is active.
The first stage of the Saturn V weighed 5,040,000 lb fueled, and we aren’t counting that. But it lifted the second, third, and payload as a joined object. Together, they weighed 1,093,900 + 271,000 + 107,100 = 1,472,000 lbs, or 736 short tons (668 metric tons).