"It's the most vulnerable plane that's in service now," said Franklin C. "Chuck" Spinney, who evaluates tactical aircraft for the Pentagon. "You can't hit that thing without hitting something important."
In the last decade, the use of laser-guided ordnance from highflying bombers and unmanned drones has diminished the need for the Harrier's brand of close air support.
Afghanistan provided precisely the kind of austere battlefield where the Marines had maintained the Harrier would make a crucial difference. Yet U.S. commanders held the Harrier out of the first four weeks of combat last year.
As other planes pummeled Taliban and Al Qaeda targets, Harriers based on the Navy's amphibious assault ship Peleliu practiced attack maneuvers over the Arabian Sea, hundreds of miles from the action.
"Other squadrons were going north to the war and we were flying south for more training," recalled Capt. Matthew Parker, a Harrier pilot. "It was very frustrating."
Today, the Marines hope the Harrier will play a more dramatic role in a potential war with Iraq. But given the plane's limitations, many defense officials and military analysts deem that unlikely.
'Answer to a Prayer'
To the Marine Corps' ranking generals, the Harrier has been a major step toward realizing a dream that germinated during World War II in the bloody jungles of Guadalcanal and Tulagi. As Marines battled Japanese forces and malarial mosquitoes on those South Pacific islands, the Navy withdrew and initially left them to fend for themselves without air cover and supplies. The Marines lost more than 1,000 men in the campaign, and their resentment has endured for 60 years.
The precept that Marines in the air should protect Marines on the ground has been central to the corps' ethos ever since. By 1957, Marine leaders had proclaimed the bold vision of creating an entire wing of aircraft with the vertical ability of helicopters and the speed and range of airplanes, a goal they now hope to reach by 2020.
Their breakthrough plane was the Harrier. It was, said one general, "an answer to a prayer."
The Marines are now testing the tilt-rotor V-22 Osprey, designed to speed troops into combat. Its revolutionary technology also has had deadly side-effects, killing 23 Marines in two crashes in 2000 alone.
The Pentagon, meanwhile, is developing the Harrier's replacement, the Marine version of the next-generation Joint Strike Fighter, a plane that will imitate the Harrier's abilities to take off after a short roll and land vertically.
As the military's smallest branch, the Marines have long feared their air wing would be absorbed by the Navy or that the corps itself would be folded into the Army. In waging the political battle to remain a self-sufficient fighting force, they have sought over the years to make their combat role distinctive.
The Marine Corps' generals are painfully aware of the Harrier's shortcomings. Many can rattle off the names of pilots they have buried. But they say that accidents are the price of technological progress, and that the Harrier has proven its value in combat while paving the way for a superior successor. They deny they have needlessly jeopardized Marines in pursuit of their vision of an independent air wing.
"I would resist with all my moral fiber the idea that we would willingly or knowingly try to bring aboard a program -- V-22 or anything else -- and so fall in love with the program that we would put people at risk to ride in those vehicles," Marine Corps Commandant James L. Jones said at a military forum last year.
If the Harrier's problems have lingered, some current and former Marine officials contend, it is because the Navy has once again let them down. As the financial overseer of the corps' aviation program, the Navy hasn't always provided enough money to maintain a plane flown only by the Marines, they say -- a charge Navy officials vigorously dispute.
Undaunted by past failures, the Marines have pressed on. Some survivors of Harrier pilots say that is as it should be, that their husbands and sons knew the risks but believed in the cause. Others are less forgiving, convinced that the corps has been more faithful to its vertical vision than to its pilots. They say the corps has taken unreasonable risks with the lives of their loved ones.
"They deserve the best chance we can give them if we're going to stick them out there to stretch the envelope," said Jim E. Dale, whose brother, 1st Lt. Kerry D. Dale, died in a 1988 Harrier crash after his flaps jammed. "They deserve honesty. They deserve integrity. They deserve the very principles from the corps that we think the corps stands for."
Many of the Harrier's victims left behind adoring wives and children too young to comprehend. Long after their deaths, their parents grasp for memories, adorning their sons' bedrooms with ceremonial swords, plastic airplane models and flags folded neatly into tri-corner boxes.