The often postponed public hearings on National Airport's proposed share-the-airplane noise plan will be held at different locations here on six days from May 14 through May 20.

Under the new flight patterns proposed for consideration of area residents by the Federal Aviation Administration - but not recommended by the FAA - commercial jets now using National would be allowed to approach and leave the airport by different routes instead of following the Potomac River 10 miles north and 5 miles south of the airport.

This would spread low-level-airplane noise over an additional 35,000 Washington-area residents while reducing by 6,000 the number of people who now endure daily high levels of airplane noise, according to a consultant's report prepared for the FAA.

The present flight patterns have not been changed since 1966, when the first large commercial jets began using National. While designed to minimize the impact of jet noise for the majority of area residents, the river route has meant particularly high levels of jet noise for communities near the Potomac, such as Georgetown and Rosslyn north of the airport and Alexandria south of the airport.

However, the consultant Mitre Corporation study concludes the FAA's proposed new flight paths would provide relatively little relief for these or any communities within 5 miles of National. The greatest reductions in noise would occur in Montgomery County north of Cabin John Bridge and in Oxon Hill and areas of Prince George's County south of the Woodrow Wilson Bridge.

The consultant's study and FAA proposals are available at central libraries throughout the Washington area or from the Metropolitan Washington Council of Governments' information center at 1225 Connecticut Avenue NW.

The public meetings will be held:

Saturday, May 14, 2 p.m., at Key Bridge Marriott Hotel, Rosslyn.

Tuesday, May 17, 8 p.m., at Bethesda-Chevy Chase High School auditorium, 4301 East-West Highway, Bethesda.

Wednesday, May 18, 7:30 p.m., Lee High School auditorium, 6540 Franconia Rd., Springfield.

Thursday, May 19, 7:30 p.m., Oxon Hill Junior High School cafeteria, 9570 Fort Foot Rd., Oxon Hill.

Friday, May 20, 7:30 p.m., Minnie Howard Intermediate School, 3801 West Braddock Rd., Alexandria.