The mostly husky, middle-age defendants in blue jeans and T-shirts appearing in front of the federal judge Wednesday weren't the usual drug defendants.

They were workers from the Boeing aircraft plant in Ridley Park, many looking stunned, charged after an investigation into the sale of high-strength painkillers and antianxiety drugs.

Federal agents spent four years probing the illegal trade in oxycodone and similar drugs among workers who manufacture Chinook helicopters and key parts for the V-22 Osprey. Boeing called federal agents into the plant, which has 6,200 employees, in 2007.

On Wednesday morning, the result was a wave of arrests at the Delaware County plant; by afternoon, 36 of 37 people accused were in custody.

Fourteen were charged with misdemeanor attempted possession or sale of typically fewer than 10 pills that were actually placebos provided by a "cooperator."

Twenty-three were charged with felony distribution or attempted distribution of real drugs to their fellow employees in amounts ranging from a few dozen pills to 1,500 doses.

U.S. Attorney Zane David Memeger said the investigation did not turn up a typical top-down drug organization; instead, there were many people operating on their own.

"A number of independent sellers and no shortage of buyers were found by investigators," Memeger said.

The drugs were bought and sold on Boeing property, Memeger said. FBI Special Agent in Charge George Venizelos said the illegal sale of prescription drugs, a major problem across the nation, was an FBI target.

The investigation focused not only on the sellers, but also on the users because of the critical role the employees could play in manufacturing military aircraft.

In court, the Boeing workers were ordered to surrender their passports and forbidden to associate with anyone else charged in the case. They were released pending a future hearing. If they don't show up, they will owe the government $25,000 each. They did not have to put up any cash, and many qualified for federal public defenders. Maximum penalties for the most serious of the charges run to more than 100 years, but any actual sentences will likely be much less.

All but a few of those charged are current Boeing employees; only one had never worked for the defense contractor. Most are in their 40s, 50s, and 60s. One is 23, one of the few women charged. Most are from towns near the plant: Morton, Glendolden, Tinicum, Springfield, Folcroft, Upper Darby, Media, and Boothwyn.

A woman who answered the phone at United Auto Workers Local 1069, which represents about 2,000 employees at the plant, said the union had no comment. Among those arrested was a former union president, Michael Patterson, 53, of Eddystone, charged with attempted possession of oxycodone and fentanyl, also a painkiller. He could not be reached for comment.

Boeing said the employees would be suspended pending an internal investigation. Damien Mills, a Boeing spokesman, declined to say whether the employees were suspended with or without pay. He also said their salaries were proprietary information.

Mills declined to discuss drug-test procedures but said Boeing had a policy of "no tolerance of drugs or alcohol on Boeing property or consumption or sale on premises."

Memeger said no crashes or injuries resulted from work on aircraft by those charged. Mills said, "Boeing took appropriate action to ensure the individuals under suspicion were not in a position to compromise safety, quality, or delivery."

He said workers contacted the company about drug use at the plant in May 2006. Boeing conducted its own investigation and then brought in the federal authorities, who started investigating in August 2007, Mills said.

For a list of those arrested, go to www.philly.com/boeing.

Contact staff writer Nathan Gorenstein at 215-854-2797 or ngorenstein@phillynews.com.