Airbus A380 planes

Once it enters service, the A380 will become the world's largest airliner and at least the second largest plane. Additional stretched models are also planned, and one of these will almost surely supersede the An-225 to take the official title as world's largest plane.

Your question also mentions two other classic aircraft that were certainly enormous by any measure. Unfortunately, both proved to be disastrous follies that were great embarrassments to their proponents. The Spruce Goose, officially known as the Hughes H-4 Hercules, was the brainchild of flamboyant billionaire Howard Hughes.

The aircraft had originally been ordered by the US government during World War II as a giant cargo plane ferrying up to 750 armed troops or two 30-ton tanks. As the war concluded, Hughes believed he could adapt the massive plane to revolutionize long-distance transportation in the fledgling airline and air cargo industires.

His creation was the world's largest plane at the time and is still the largest flying boat ever built with a maximum takeoff weight of 400,000 lb (180,000 kg). The enormous craft also holds records for the largest wingspan at 319 ft 11 in (97.5 m), tallest airplane at 79 ft 3 3/8 in (24.2 m), and the largest aircraft ever made from wood.

DC-3 planes

The Transportation Security Administration is writing some rules (.pdf) it says will increase the security of general aviation, a category so broad it covers everything that isn't a military or scheduled commercial flight. The edict, if adopted, would hold the operators of small planes to a rash of new regulations, some of which mirror those now in place for commercial aircraft.

The TSA puts a forward spin on the regs, which would, among other things, require fingerprinting and background-checking of flight crews, cross-referencing pasenger manifests with no-fly lists and conducting "safety threat assessments" on passengers and crew members. "General aviation operators are excellent security partners and this will give them a strong common framework for security," TSA Administrator Kip Hawley said in announcing the proposed rules. "This will reduce risk while supporting the open nature of the general aviation industry."

The people who will have to follow the new rules don't see it that way.

The new guidelines would apply to all general aviation aircraft over 12,500 pounds, a category that by some estimates includes more than 10,000 aircraft nationwide. The feds would tap an unspecified third party to establish and run a "compliance assurance program." In other words, aircraft operators would face annual inspections.

The general aviation community bristles at many of the proposed rules because not only will they be time consuming and annoying, but some of them will incur financial costs. For example, nearly 300 general aviation airports will be required to adopt potentially expensive security programs and they'll almost certainly pass those costs on to those who use those airports.

The Experimental Aircraft Association, which represents private pilots and aircraft enthusiasts, has had a look at the TSA proposal and isn't happy with it. “These new regulations would compel many operators of large vintage aircraft, warbirds, turboprops and others over 12,500 pounds to comply with new, costly, and burdensome requirements which, frankly, do not appear to equate with their risk assessment profiles,” says Douglas Macnair, vice president of government relations. “General aviation aircraft are not carrying the public and are in all instances pilots are personally acquainted with their passengers."

The EAA also plays the patriotism card, saying the proposed rules would bring restrictive requirements to range of aircraft "flown in tribute to those who fought to secure the very freedoms now being threatened." Take that, TSA.

The EAA has compiled a fairly comprehensive list of aircraft that would fall under the new rules. It includes the DC-2 and DC-3, the Sikorsky S-61 helicopter and the Convair CV-240, the last of which was manufactured in 1956. The TSA will seek 60 days of public comment before moving forward.

It's likely to get an earful.