(CNN) — It's been more than 11 days since Malaysia Airlines Flight 370 went missing from radar screens, and hard facts about its fate remain in short supply.
To fill the vacuum, experts and amateurs have been conjuring and sharing theories on what may have caused the commercial airliner carrying 227 passengers and 12 crew members to seemingly disappear.
As aviation expert Mark Weiss put it: "I don't think you can discount any theory, frankly."
The theories are plentiful.
Speculation: Pilot hero
Pilot Chris Goodfellow, in a posting published by Wired Magazine, suggests a simple scenario in which a wheel of the heavily loaded plane overheated as it lumbered toward takeoff from Kuala Lumpur, Malaysia.
"Yes, this happens with underinflated tires," he wrote, adding that the tire may have burned slowly initially.
Once he became aware of the fire, Pilot Zaharie Ahmad Shah probably turned left toward the closest, safest airport -- Langkawi International Airport, a 13,000-foot airstrip that has an approach over water, he said.
"The captain did not turn back to Kuala Lumpur because he knew he had 8,000-foot ridges to cross," Goodfellow wrote. "He knew the terrain was friendlier toward Langkawi, which was also closer."
The loss of the jet's transponders and communications could be expected in a fire, and a pilot's first response would be to pull the main buses -- conductors carrying a computer system's data and control signals -- "and restore circuits one by one until you have isolated the bad one," he said.
If the buses were pulled, "the plane would go silent. It probably was a serious event and the flight crew was occupied with controlling the plane and trying to fight the fire. Aviate, navigate, and lastly, communicate is the mantra in such situations."
He said radar reports that the plane ascended to 45,000 feet were unreliable. And, even if true, they are not necessarily damning. The pilot might have been seeking to quell the fire by going to an altitude with less oxygen, he said.
A reported rapid descent could have resulted from a stall at such a height, above the plane's limit, followed by a recovery at 25,000 feet. "The pilot may even have been diving to extinguish flames," he said. "But going to 45,000 feet in a hijack scenario doesn't make any good sense to me."
Goodfellow speculated that smoke may have incapacitated the pilots and crew and the plane flew onward on autopilot until it ran out of fuel or the fire caused it to crash. "You will find it along that route -- looking elsewhere is pointless," he concluded.
There is precedent for that. In 1999, a private jet carrying golfer Payne Stewart and five others crashed after apparently losing cabin pressure "for undetermined reasons" after takeoff from Florida, the National Transportation Safety Board found.
Fighter pilots were sent up to intercept Stewart's plane after controllers lost contact with it, and they reported its cockpit and cabin windows were frosted over.
The plane flew more than halfway across the United States, apparently on autopilot, until it crashed in a South Dakota field.
But Jeff Wise, an aviation journalist for slate.com and author of "Extreme Fear," was unpersuaded. He noted that the pilot did not enter the airline code for Langkawi into the jet's navigation system and continued to navigate after Langkawi.
And that way point was entered into the system at least 12 minutes before the co-pilot said good night to air traffic controllers, he told CNN.
In addition, he said, Langkawi lies in neither of the arcs along which investigators believe the plane traveled.
Still, American Airlines pilot John Testrake said events could have played out as Goodfellow described. "It's a possible scenario, but there are a lot of possible scenarios, and that's just one of them," he told CNN.
The plane might also have landed on an island runway that was then covered with trees, he added. "It's anybody's guess. We're speculating; we're just speculating."
Speculation: Pilot suicide
The notion of a crew member bent on annihilation may seem far-fetched, but it's possible.
For example, EgyptAir Flight 990 was flying 217 people from Los Angeles to New York to Cairo in 1999 when it crashed into the Atlantic Ocean. U.S. officials blamed a co-pilot, who was recorded repeating a prayer, for deliberately causing the crash, but Egyptian officials blamed mechanical problems.
The Malaysian Airlines flight, a Boeing 777, could have experienced destruction by pilot or crew, some say.
"It's my belief that there was probably some type of struggle in the cockpit where it was one of the pilots that maybe had a meltdown or did something nefarious to the airplane," said Weiss, a retired American Airlines pilot captain who has flown the Boeing 777 and now works at the Washington consulting firm Spectrum Group.
Or there could have been another crew member or an uninvited or invited guest in the cockpit who "was bent on perhaps committing suicide or doing some destruction on the aircraft," Weiss added.
Though allowing guests to enter the cockpit would be improper and "should be disconcerting to anybody," Weiss said, pilots can do so. He cited a woman's report that co-pilot Fariq Ab Hamid, 27, invited her and her friend into the cockpit, where they sat from takeoff to landing during a 2011 flight from Phuket, Thailand, to Kuala Lumpur.
"That's an enormous breach of security," Weiss said of cockpit guests.
But none of us will know what really happened in the cockpit "until we have the cockpit voice recorder and the flight data recorder," he added.
Commandeering isn't to be confused with hijacking, a political act in which demands are issued by the hijacker, said CNN national security analyst Peter Bergen.
A commandeering is more idiosyncratic, where motives aren't immediately clear, Bergen said.
Some counterterrorism officials say that could be the case with the Malaysian flight, he explained.
"The plane could have been commandeered," Bergen said.
Commandeered flights have a history before the September 11, 2001, attacks on the United States, Bergen said.
For example, in 1994, the cargo plane FedEx Flight 705 was commandeered by an employee with a hammer and spear gun who burst into the cockpit and wanted to crash the plane into FedEx's Memphis, Tennessee, headquarters. The crew thwarted that takeover attempt.
In 2000, a passenger with a suspected history of mental illness commandeered British Airways Flight 2069 between London and Nairobi, Kenya, and put the plane carrying 300 passengers into a nosedive until the crew subdued him.
"So commandeering would fit with the few facts that we do know and certainly a theory that we haven't heard a lot of that isn't a conspiracy," Bergen said.
That the plane terminated transponder data before its disappearance leads some experts to suspect a hijacking.
The political motivation for a hijacking, however, would be as mysterious as the plane's whereabouts.
"If you are dealing with hijackers on board the aircraft, whether it was an organized gang, or whether it was some psychologically disturbed individual that ... managed to gain access to the flight, they can neutralize the crew," said Philip Baum, editor of Aviation Security International.
"But then again, there wouldn't necessarily be any communication at all -- as we witnessed on September 11th," Baum added, referring to the 2001 terrorist attacks in the United States. "If there was an explosive decompression, if a bomb detonated on board the aircraft, then again there would be no communication."
One possible motive could be terrorism. Authorities haven't ruled out that possibility, though experts are divided on this theory, partly because no one has claimed responsibility.
Still, the absence of a claim of responsibility doesn't mean it wasn't terrorism. "There might be another reason for them not coming forward at this point," said Shawn Henry, former executive assistant director of the FBI. "If it was a terrorist incident ... if this was part of a much larger or broader potential act, and for whatever reason, they wouldn't come forward at this point, but at a later time."
Speculation: Mechanical failure
In a less sinister but equally lethal explanation, some experts theorize the plane crashed because of a mechanical malfunction -- or perhaps a total electrical failure.
The latter scenario is improbable, but not impossible, according to Jim Tilmon, an aviation expert and retired American Airlines pilot. It "is very, very hard to imagine" because the Boeing jet has so many generators aboard, he said.
"If all the engine generators fail, they still have what's called the RAT (ram air turbine). That's the generator that literally falls out of the bottom of the airplane, has a propeller on it, and ram-air turns that and gives them generating power enough to go ahead and fly the airplane safely.
"Electrical failure -- it'd have to be total ... absolutely incredible, like we've not heard of before," Tilmon said.
Speculation: The bizarre
Unconstrained by the professional accountability under which the experts labor, some Internet users have offered their own blue-sky theories:
A meteor struck the plane.
Some country's military shot it down.
The plane landed on a remote island.
Aliens abducted the plane.
"Everybody wants to get a handle on something right now," former Federal Aviation Administration investigator David Soucie said of the myriad theories. "No one has an answer, so they're going to try to put one on it. So that creates all kinds of assumptions."