Richard "Rick" Crosby Douglas, 56, an ardent advocate of the rights of the disabled who from 1991 to 1995 was executive director of the President's Committee on Employment of People with Disabilities, died of complications from colon cancer June 28 at his home in Washington.

Mr. Douglas, who had multiple sclerosis and who had used a wheelchair since 1980, joined the committee a year after the adoption of the Americans With Disabilities Act, and he became a well-regarded national speaker, meeting with disability rights coalitions and university, government, labor and business organizations.

His message to disabled people was that employment was the key to participation in society and independence. He urged them to be assertive in demanding to be treated fairly and to report businesses that had not complied with the requirements of the ADA. His talks were often grounded in personal experiences.

In 1993, he went to Dulles International Airport to board a United Express commuter flight to Allentown, Pa., where he was to give a speech on the third anniversary of the ADA and on physical barriers still encountered by disabled people. Airline officials first told him he couldn't board the plane because he used a wheelchair but later said he could board if he could get himself inside the aircraft without assistance.

His wife, Nancy Flinn, snapped a picture of Mr. Douglas dragging his body up five stairs into the plane while other passengers and airline personnel watched. Shortly after the incident, an airline official said that the airline followed federal regulations. The official said that the airline's policy stemmed from a safety concern because the plane had no flight attendant and because, in case of an emergency, passengers must be able to leave the plane on their own.

Still, the photograph and story became front-page news and prompted renewed attention to equal access to public transportation for disabled people.

His advocacy efforts extended to those with mental disorders as well as physical impairments, said Justin Dart, former head of the President's Committee on Employment of People with Disabilities.

"He led our organization to the cutting edge of disability rights," said Dart, who asked Mr. Douglas, then director of Vermont's vocational rehabilitation division, to join the committee in 1991.

Since 1995, Mr. Douglas had worked at the Department of Labor as a senior policy adviser. He also headed the department's disability initiative, which helps ensure that individuals with disabilities are included in job training programs.

Mr. Douglas, who was born in Massachusetts, grew up in Connecticut. He graduated from Middlebury College, which gave him its Distinguished Alumni Award in 1997, and he received a master's degree in communications from Fairfield (Conn.) University.

Earlier in his career, he worked for a Vermont-based international marketing firm and served 10 years as director of advertising for British Airways.

His marriage to Barbara Jean Flowers ended in divorce.

Besides his wife, of Washington, survivors include two children from his first marriage, Carrie Douglas of Sacramento and David Douglas of Richfield, Conn.; four stepsons, Christopher Flinn of Burlington, Vt., Jeffrey Flinn of Kirkland, Wash., Jason Flinn of Bascara, Spain, and Aaron Flinn of Charlotte, Vt.; his mother, Francie, and stepfather, Phillip Allen, of Fort Myers, Fla.; two sisters; and three granddaughters.