Like the mule or Jeep of former days or the sturdy C-130 transport plane, the Chinook helicopter, made at the Boeing factory in Ridley Township, Delaware County, and tested in the Arizona desert, is now standard Army equipment, having outlasted the careers of the longest-serving officers and enlisted men.

The Chinook, the basic transport and weapons platform for America's wars, has been built and rebuilt at the plant along the Delaware River since the 1960s.

If a pilot upgrade program that starts this month goes well, Chinooks will continue to be made and updated in Delco through at least the 2050s, company and Army officials said at a pep rally and luncheon at the facility Thursday.

Boeing remains the largest industrial employer in the Philadelphia area, but plant headcount has shrunk since a $130 million upgrade that started in 2011 from 6,100, to 4,600, according to Larry Weng, Boeing's director of vertical-lift operations.

The company plans an additional $100 million upgrade to the north end of the plant to accommodate future production of the V-22 Osprey, currently assembled in a former warehouse on the western side of Route 291 next to the engineering center and east of the main production works, added Weng.

The plant completes work on about four Chinooks and one to two Ospreys a month.

The workforce includes around 1,200 members of United Aerospace Workers Local 1069, many of them former military mechanics, who build and update Chinook 47s for the United States and two dozen other nations (including India, Saudi Arabia, and Singapore this year), plus 1,000 nonunion engineers, including those who designed the Chinook's lightweight plastic-composite helicopter rotors, and 1,400 management, administrative, and support staff, including a growing number of data scientists.

Around 80 Aerospace union members are on layoff waiting to be called back to work, down from around 200 a couple of years ago, said local president Mike Tolassi.

"We've been in continuous production since the first Chinook rolled off the production line in 1962. It's a good basic design. The tandem [double] rotor configuration has served our forces well," Chuck Dabundo, Boeing vice president of cargo helicopters and manager of the Chinook program, told plant staff from the dais, next to the stripped body of a Chinook slated for upgrade.

The upgrade program, dubbed Block 2, will boost carrying capacity and range of a few hundred miles by consolidating wiring, lightening, and expanding fuel tanks, and other modifications designed and built at the Ridley site to accommodate Special Forces and Army weapons that have accumulated on the ships in response to war needs in Afghanistan, Iraq, and other countries.

Wearing Army fatigues, leaders of Boeing's military clients sought to boost morale while damping down hints of corporate self-congratulations. "It's not enough to deliver them on time," Col. Greg Fortier, Army project manager for cargo helicopters, told the crowd. "Common men do not win Super Bowls, and common men do not make these ships."

He told of his unit coming under Taliban fire in a two-week, 2002 shooting conflict around Kandahar, in southern Afghanistan, when the Army lacked enough Chinooks to evacuate wounded soldiers on time. The solution: more Chinooks with improved range and defense systems.

The Army used Chinooks to invade Grenada and Panama in the 1980s, Kuwait in the 1990s, and Afghanistan and Iraq in the early 2000s, recalled Col. Scott Beall of the Army's Special Operations Command — the Night Stalkers.

The Special Forces upgraded Model 47G will use 1,400 parts from 500 suppliers and 45,000 person-hours of work per helicopter, and will boost the Chinooks' carrying capacity to 27 tons from 25. The plant will first rebuild or upgrade 69 Model 47G's for the Special Forces and afterward more then 400 Model 47F's for the Army, according to Pat Donnelly, program director for the U.S. military Chinook program.

Heavy use and the need to defend the ships against attack have sped the need for upgrades that will enable the Army to boost its defensive systems and keep up the Army's "heavy-assault capabilities from now through the 2050s," Beall concluded.

This story has been updated with information supplied by Ed Shell of Media, a 39-year Boeing veteran, whose father, a facilities engineer, helped upgrade the dirt-floored former General Steel foundry, adjoining the sprawling old Baldwin Locomotive Works, into the current main Boeing plant in the early 1960s.