Those Navy SEALs who killed Osama bin Laden arrived at his hideout in Pakistan by helicopter. While few Americans have seen video of those helos in flight, that is just the most dramatic example of how much the military relies on such machines these days.

No military equipment has been more pivotal for U.S. forces in the wars in Afghanistan, Iraq and elsewhere over the last decade than rotorcraft, but you’d never guess that from the relative pittance the Pentagon annually spends to make them better and safer.

A Defense Science Board study four years ago found that since the Vietnam War, the Pentagon had spent roughly nine times as much developing new and better fixed-wing planes — fighters, bombers and transports — as it had on coming up with faster, safer, more reliable rotorcraft, a category that encompasses helicopters and the V-22 Osprey, the tiltrotor helicopter-airplane hybrid flown by the Marines and Air Force.

The picture hasn’t gotten any brighter since then. In last year’s defense budget, the Pentagon invested more than twice as much of its $808 million aviation science and technology budget on improving turbine engines as it did on all rotorcraft science and technology, and two-and-a-half times as much on fixed-wing aircraft like the troubled F-35.

The result of this skewed spending pattern is ironic. The Air Force’s F-22 and the F-35 Joint Strike Fighter (JSF) are widely regarded as the most modern and potent fighter jets in the world, but neither has ever been used in combat. The many U.S. military helicopters that fly in combat every day – more than three million hours over the past decade — are mostly designs and airframes from the 1960s and 1970s, modernized with some new technologies like GPS but often still airworthy only because of “SLEPs,” or service life extension programs.

“We joke that the money we spend on rotorcraft is coins between the seat cushions in the JSF program,” says Eric Braganca, who recently retired as a lieutenant colonel after a career mainly spent flying MH-53 helicopters for the Air Force Special Operations Command.

Over the past decade, U.S. military rotorcraft have paid a high price for that disparity in investment, according to a recent study done for Congress. Since October 2001, when the war in Afghanistan began, the U.S. military has lost 393 helicopters and one V-22 at a cost of 550 lives – mostly to accidents, not enemy fire. Total fixed-wing military aircraft lost to enemy fire during the same period: three, at a cost of three lives. Total fixed-wing losses to accidents: 51, with 29 fatalities.

“Nobody is shooting down our airplanes, yet we’re very concerned about our fourth- and fifth-generation fighters,” Braganca observes. “Yet the environment that helicopters fly in is so harsh, and that is what’s causing most helicopter crashes, but we don’t have the development going on there.”

Helicopters will always be riskier combat vehicles than fixed-wing aircraft because of where and how they fly. Fixed-wing fighters and bombers soar well out of the range of most ground threats, using precision bombs and missiles to hit their targets. Military air traffic controllers take care to “deconflict” their flight paths.

Helicopters generally fly low to the ground, much closer together, and with no “big brother” air traffic controller watching them. They also often have to land on unprepared terrain, where sand or loose dirt kicked up by their rotors can create pilot-blinding “brownouts.” Landing and hovering as they do on a column of air created by their rotors, they’re also much more likely to get into trouble because of shifting winds and other aerodynamic factors. “The environment we fly in offers so many more dangers than high-altitude airspace,” notes Lt. Col. (ret) Jim Schafer, who flew CH-46 Sea Knight helicopters and the V-22 Osprey in the Marine Corps and now pilots an emergency medical service helicopter. “We’re also inside many more threats than what these tactical aircraft are exposed to, such as small arms. We’ve had helicopters taken out with RPGs (rocket propelled grenades) because sometimes they’ll have to hold them in a hover for 30 or 40 seconds.”

Many of the accidents that have claimed U.S. military helicopters over the past decade, Schafer adds, were caused by “controlled flight into terrain, flying into each other, hard landings” — bad things that can happen to helicopters whose pilots lose “situational awareness” — they can’t tell where they are — or run short of power for some unanticipated reason.

In fact, a hard landing is just what happened to one of the two stealthy Black Hawk helicopters that took the SEALs to Bin Laden’s compound – an incident that, but for the good fortune that no one was hurt when it happened, might have turned the mission into another Desert One. That was the 1980 attempt to rescue U.S. hostages in Iran that ended in death and disaster when a helicopter crashed into a C-130 transport plane because of brownout during a nighttime desert refueling rendezvous.

The Black Hawk at Abbottabad was supposed to hover over the Bin Laden compound courtyard while SEALs fast-roped to the ground. Its rotor apparently lost lift because of unexpectedly hot air temperatures and turbulence set up by the Black Hawk’s downwash hitting the compound’s 18-foot-high walls. The pilot was able to land without casualties, but the aircraft was damaged too badly to fly home and was destroyed in place.

Might that near-disaster in Abbottabad have been avoided if the Pentagon had spent more money on rotorcraft research in recent years? Probably not – but maybe. It’s almost certain, though, that many of the accidents caused by brownouts and similar phenomena might have been avoided with more research into advanced laser, radar and other technologies that can let pilots “see” through clouds of sand, dust or snow. “Technologies do exist,” says Schafer. “It’s a matter of spending the money to put them in there.” More spending on research almost certainly could have brought rotorcraft technology into the 21st Century, too, rather than leaving it mired in the 20th – actually the middle of the 20th.

With the exception of the 1980s-technology V-22, today’s military rotorcraft mostly fly no faster — 140 to 175 miles an hour, usually — and little farther than those that flew in Vietnam.

“Although there have been significant technology advancements over the past 30 years, military helicopters flying today are, for the most part, derivatives of designs from Vietnam or even earlier,” notes Michael Hirschberg, executive director of the American Helicopter Society. “Our military leaders — and the public — should demand the same level of technology in their vertical flight assets as they do in their fighters and bombers.”

One of the rotorcraft industry’s problems, though, according to a 2008 Aerospace Industries Association study, is “an apparent belief that vertical-lift technology is mature.” The Pentagon spent a fair amount of money in the 1970s trying to come up ways to break the less-than-200-mph natural speed limit imposed on helicopters by the aerodynamics of rotors but ended up funding only the V-22 tiltrotor. Today, Sikorsky Aircraft Corp., Eurocopter and the far smaller Piasecki Aircraft Corp. are all working on new “compound” helicopters that aim to match the Osprey’s 250 to 275 mph cruising speed, but the companies are doing it mostly on their own dime. This year’s defense bill contains about $10 billion for rotorcraft, but almost all of that money is to buy or upgrade existing models, not develop new, more advanced ones. The Army’s aviation budget, for example, is $8.26 billion, but only $107 million is for science and technology research to produce more advanced rotorcraft.

Industry officials say another consequence of the Pentagon’s lack of spending on rotorcraft research over the past three decades is that the handful of U.S. helicopter companies that do military work are poorly equipped to do the kind of research necessary to make advances in speed, range and other performance.

Lacking government money for research, most simply haven’t hired the kind of engineers who do that sort of work. That may be one reason that most of the few attempts to develop new rotorcraft for the military in recent years have been cancelled after cost overruns, schedule delays, contract award protests or other problems. Since 2004, DoD has killed Sikorsky’s Comanche attack helicopter, Bell Helicopter Textron Inc.’s ARH-70A armed reconnaissance helicopter, Lockheed Martin/AgustaWestland’s VH-71 presidential helicopter and Boeing Co.’s CSAR-X combat search and rescue helicopter.

That’s why the Bell-Boeing V-22, which went into service in 2007, is the only new U.S. rotorcraft since Boeing’s AH-64 Apache gunship debuted in 1986 — and the Osprey survived its quarter century in development by the skin of its teeth. Moreover, as things stand today, whenever a new rotorcraft program does come along, U.S. manufacturers are either forced to team with foreign helicopter makers who boast new designs or they compete against them with derivatives based on old airframes.

The odd thing about the rut U.S. rotorcraft investment is in is that those who have the power to do something about it are well aware of the situation. The Pentagon and armed services, at times on orders from Congress, have done numerous studies of the military’s rotorcraft needs in recent years, all concluding that more money needs to be invested in rotary wing science and technology, yet the investment ratio between rotorcraft and fixed-wing aircraft remains static. Why? “It’s a question of priorities,” said Maj. Gen. (ret) Carl McNair, a 1955 West Point graduate who was one of the Army’s pioneer combat helicopter pilots, then got degrees in aerospace engineering and served as the first commander of his service’s Aviation Branch after it was created in 1983. “The difficulty within the Army is, we had to compete (for funding) against the tanks,” McNair recalls. “If you’re the infantry commander and you’re given the choice of buying infantry fighting vehicles or helicopters, what are you going to buy?”

Today, says Braganca, “rotorcraft in all the services is the redheaded stepchild, even in the Army,” which flies 66 percent of the military’s helicopters. “I’ve talked to Army aviation battalion commanders who used to catch crap from their bosses because their one battalion in a brigade of four or five battalions ate up 80 percent of the (brigade) budget, because ground-pounders (infantry) don’t need as much money,” Braganca says. “The Air Force doesn’t like rotary wing aviation because it’s not fighters. The Marines love helicopters but they get their funds from the Navy, and the Navy doesn’t like giving money to programs that don’t help Navy sailors. And in the Navy, the helicopters are always shunted off to one side because they’re not the ‘warfighters,’ the pointy-nosed jet guys coming off the catapult on a carrier. Really, rotorcraft in any service doesn’t have a champion.” If it doesn’t get one somewhere soon, the situation may only get worse, especially with Panetta’s Pentagon under orders from the White House to find $400 billion in long-term budget cuts.

Philip Dunford, vice president of Boeing Military Aircraft, told a June 15 conference on Future Rotorcraft in London that the United States has already reached a “tipping point” in vertical lift aircraft and funding needs to be shifted to the aviation platforms doing the fighting. “Let’s balance the funding correctly for the relevance of the product,” Dunford said. “The way we fight wars has changed – it is really the helicopters that are getting in there and doing the dirty work. The balance is wrong in terms of how we fund things going forward.” Or as Braganca puts it, the F-22 and JSF “are great programs with great technology. The question is, are they as needed, both in the wars of the last 10 years and, arguably, the wars of the next 10 as some of these rotorcraft are?”

The answer isn’t rocket science.