The House Post Office-Civil Service Committee, considered a jinx assignment by many policicians, is due for a new chairman -- its fifth in nine years. For most Washington area workers it is the most important committee in Congress.

Chairman James M. Hanley (D-N.Y.) has announced he will not run for reelection. Hanley took over the committee last year.

In line to head the committee, one of the few places in Congress where civilian bureaucrats have more friends than foes, are Reps. Morris K. Udall (D-Ariz.), Charles C. Ford (D-Mich.). Udall is senior, but he declined the chairmanship two years ago and is expected to do so again.

Wilson is under investigation by the House Ethics Committee. It has filed 15 "statements of alleged violations" against the Los Angeles congressman. They include allegations that Wilson diverted campaign funds for his personal use, and then he allegedly accepted financial gifts from persons with a direct interest in legislation. Wilson has denied those allegations and filed a formal statement with the Ethics Comittee.

Wilson is considered an expert on postal matters. His district straddles the area around the Los Angeles International Airport. But for a short break in service on the Post Office-Civil Service Committee, to serve on Veterans Affairs, Wilson today would be chairman. He is also six-ranking majority member of the Armed Service Committee.

Ford, a liberal whose district includes parts of suburban Detroit, has also been a staunch supporter of higher pay for federal workers, and improved benefits for the 2 million white-collar and blue-collar federal civil servants. bHe gets very high marks from unions representing federal and postal workers.

Post Office-Civil Service is the only committee in Congrfess that deals with federal personnel matters on a daily basis. It serves as the channel for legislation to improve -- or cut back -- feferal pay rates and fringe benefits. It has been much more generous with civil servants than other congressional committees.

For various reasons, the committee has been a target of "reformers" anxious to abolish it to streamline House operations. Its counterpart Post Office-Civil Service Committee in the Senate was abolished several years ago. Duties were shifted to the Govermnmental Affairs Committee, which has been less sympathetic to government workers. Federal and postal unions favor retaining the House committee, and they maintain close working relationships with most of its members.

Service on the committee -- except for Washington area legislators -- has often been the equivalent of a taking a hemlock cocktail for many House members. Hanley, the current chairman, succeeded Rep. Robert N. C. Nix (D-Pa.), a long-time Philadelphia congressman who lost a Democratic primary after only one term as committee chairman. Rep. David Henderson (D-N.C.) decided not to run for reelection after one term as committee chairman, and Rep. Thaddeus J. Dulski (D-N.Y.) quit after two terms as chairman.

Committee turnover in recent years has been so high that several one-term legislators were named to head subcommittees, a most rapid and unusual advancement in the congressional seniority system.

If Wilson and Ford decline to take the job, or are defeated, next in line are Reps. William Clay (D-Mo.), a strong advocate of Hatch (no politics) Act changes and Rep. Patricia Schroeder (D-Colo.), whose Denver district includes a large concentration of federal workers. Reps. Gladys N. Spellman (D-Md.) and Herbert Harris (D-Va.) are next in line and both of them -- representing major federal employe voting blocs -- should benefit greatly from moving up the ladder, unlike colleagues from other parts of the country.