Simultaneously, a complicated system of shafts, gears and doors activates to reveal the horizontal lift fan installed in the center of the aircraft just behind the cockpit. Together the fan and nozzle produce more than 40,000 pounds of thrust, enough to lift the nearly 20-ton aircraft straight up off the ground like a gargantuan dragonfly.

The lift fan, devised by Lockheed and DARPA in the early 1980s, was the only workable solution that anyone had come up with to give a plane vertical capability plus supersonic speed and radar-evading stealth, the last of which demands an airplane with a smooth outline and nothing hanging or protruding from it.

But this mix of characteristics came at a price to all three F-35 models, even the two that don’t need to take off vertically. “The STOVL requirements have dictated most if not all of the cardinal design elements for all three aircraft,” said Peter Goon, an analyst with the Air Power Australia think tank.

The addition of a lift fan to the baseline F-35 design started a cascade of problems that made it heavier, slower, more complex, more expensive and more vulnerable to enemy attack — problems that were evident in the 2008 war game set over Taiwan.

Of course Lockheed exec O’Bryan rejected that assessment, claiming the JSF’s stealth, sensors and aerodynamics make it superior to other planes. “It’s not rocket science,” he insisted.

But in many ways the JSF did become rocket science as it grew more complex. The original X-35 from 2001 had the advantage of being strictly a test plane with no need to carry weapons. But the frontline F-35 needs weapons. And to maintain the smooth shape that’s best for avoiding detection by radar, the weapons need to be carried inside internal bomb bays. Bomb bays would normally go along an airplane’s centerline, but the F-35's center is reserved for the 50-inch-diameter lift fan. Hence Sprey’s claim that STOVL and stealth are incompatible.

To keep down costs all three JSF variants — the Air Force’s basic F-35A, the Marines’ vertical-takeoff F-35B and the Navy F-35C with a bigger wing for at-sea carrier landings — share essentially the same fuselage. And to fit both the F-35B’s lift fan and the bomb bays present in all three models, the “cross-sectional area” of the fuselage has to be “quite a bit bigger than the airplanes we’re replacing,” conceded Lockheed exec Tom Burbage, who retired this year as head of the company’s F-35 efforts.

The extra width violates an important aerospace design principle called the “area rule,” which encourages narrow, cylindrical fuselages for best aerodynamic results. The absence of area rule on the F-35 — again, a knock-on effect of the Marines’ demand for a lift fan — increases drag and consequently decreases acceleration, fuel efficiency and flying range. Thus critics’ assertion that supersonic speed can’t be combined with STOVL and stealth, the latter of which are already incompatible with each other.

“We’re dealing with the laws of physics,” Burbage said in his company’s defense when word got out about the JSF’s performance downgrades.

But the hits kept coming, chipping away at the F-35's ability to fight. The addition of the lift fan forces the new plane to have just one rearward engine instead of two carried by many other fighters. (Two engines is safer.) The bulky lift fan, fitted into the fuselage just behind the pilot, blocks the rear view from the cockpit — a shortcoming that one F-35 test pilot said would get the new plane “gunned every time.” That is, shot down in any aerial dogfight by enemy fighters you can’t see behind you.

O’Bryan said the JSF’s sensors, including fuselage-mounted video cameras that scan 360 degrees around the plane, more than compensate for the limited rearward view. Critics countered that the video resolution is far worse than the naked eye and completely inadequate for picking up the distant, tiny, minimal contrast dots in the sky that represent deadly fighter threats ready to kill you.

But there are plenty of other problems with the F-35 — some related the airplane’s layout, some stemming from inexperienced subcontractors and still others resulting from poor oversight by a succession of short-tenure government managers whose major contributions were to grow the bureaucracy involved in the F-35's development.

Lockheed’s F-117 stealth fighter was developed in a breakneck 30 months by a close-knit team of 50 engineers led by an experienced fighter designer named Alan Brown and overseen by seven government employees. Brown said he exercised strict control over the design effort, nixing any proposed feature of the plane that might add cost or delay or detract from its main mission.

The F-35, by contrast, is being designed by some 6,000 engineers led by a rotating contingent of short-tenure managers, with no fewer than 2,000 government workers providing oversight. The sprawling JSF staff, partially a product of the design’s complexity, has also added to that complexity like a bureaucratic feedback loop, as every engineer or manager scrambles to add his or her specialty widget, subsystem or specification to the plane’s already complicated blueprints … and inexperienced leaders allow it.

“The F-35 — that whole thing has gotten away from us as a country,” lamented Brown, now retired.

Many of the JSF’s problems converged in 2004, when Lockheed was forced to admit that the Marines’ F-35B variant was greatly overweight, owing in part to the addition of the lift fan. Ironically, the fan and other vertical-launch gear threatened to make the new plane too heavy to take off vertically.

“The short takeoff/vertical landing variant would need to lose as much as 3,000 pounds to meet performance requirements,” Lockheed manager Robert Elrod revealed in an annual report. Panicked, Lockheed poured more people, time and money (billed to the government) into a redesign effort that eventually shaved off much of the extra weight — basically by removing safety gear and making fuselage parts thinner and less tough.

O’Bryan said the weight reduction ultimately benefited all three F-35 variants. But the redesigned JSF, while somewhat lighter and more maneuverable, is also less durable and less safe to fly. In particular, the elimination of 11 pounds’ worth of valves and fuses made the JSF 25-percent more likely to destroyed when struck by enemy fire , according to Pentagon analysis.

Problems multiplied. Originally meant to cost around $200 billion to develop and buy nearly 2,900 planes expected to make their combat debut as early as 2010, the F-35's price steadily rose and its entry into service repeatedly slipped to the right. Today the cost to develop and manufacture 2,500 of the new planes — a 400-jet reduction — has ballooned to nearly $400 billion, plus another trillion dollars to maintain over five decades of use.

To help pay for the overruns, between 2007 and 2012 the Pentagon decommissioned nearly 500 existing A-10s, F-15s, F-16s and F/A-18s — 15 percent of the jet fighter fleet — before any F-35s were ready to replace them. The first, bare-bones F-35s with half-complete software and only a few compatible weapons aren’t scheduled to make their combat debut until late 2015, the same year that Boeing is slated to stop making the 1990s-vintage F/A-18E/F, the only other in-production jet fighter being acquired by the Pentagon. (F-15s and F-16s are still being manufactured for foreign customers by Boeing and Lockheed, respectively.)

At the moment the first operational F-35 finally flies its first real-world sortie two years from now, it may truly represent an aerospace monopoly — that is, unless additional orders from the U.S. or abroad extend the F-15, F-16 or F/A-18 assembly lines. The JSF could be openly acknowledged as the worst fighter in the world and, in the worst case, still be the only new fighter available for purchase by the U.S. military.

Instead of revitalizing the Pentagon’s air arsenal as intended, the JSF is eating it — and putting future war strategy at risk. In 2012 an embarrassed Frank Kendall, the Pentagon’s chief weapons buyer, called the F-35 “acquisitions malpractice.”

But Kendall was referring only to the new plane’s delays and cost increases. He didn’t mention the more deadly flaw that had been revealed in Stillion and Perdue’s 2008 air-war simulation: that regardless of when and at what price the F-35 enters service, owing to its vertical-takeoff equipment the new fighter is the aerodynamic equivalent of a lobbed brick, totally outclassed by the latest Russian- and Chinese-made jets.

To add insult to strategic injury, one of the most modern Chinese prototype warplanes might actually be an illicit near-copy of the F-35 — albeit a more intelligent copy that wisely omits the most compromising aspects of the U.S. plane. It’s possible that in some future war, America’s JSFs could be shot down by faster, deadlier, Chinese-made JSF clones.