A Navy Surgeon from East New York was killed in Vietnam when a helicopter in which he was flying blew up, the Defense Department reported yesterday.  His death brings to 815 the number of Long Islanders who have been killed in the war.

Killed was Cmdr. Melvin Lederman of 608 Pennsylvania Ave.  He also leaves two brothers, Martin and Perry, both of East New York.

His family is awaiting further details on the crash, which took place on November 29 while he was attached to Marine Aircraft Group Sixteen.

Meanwhile they arranged military services for Thursday at 1:15 p.m. at Fort Meyers, Va.   Burial will be in Arlington National Cemetery.

The 41-tear-old officer served in the U.S. Army 1946-48.  He was commissioned as a Navy lieutenant commander in August 1968, and was promoted to commander when he went to Vietnam four months later.  He had since received seven Air Medals plus four Purple Hearts and had been nominated by the Marines for other honors for his heroic parachute jumps in the battle areas and for his service with medical, demolition and rescue teams.

On Nov. 18 he wrote home: "I hope I make it though the next week . . . I plan to leave for the states via Japan."

He was graduated from Thomas Jefferson High School in Brooklyn, where he played varsity soccer.  He held a bachelor of science degree and a master of science degree in human genetics from the University of Michigan; a master of science in physics from Yale University and a medical degree from Harvard University.

He interned and held residencies at the Veterans Administration Hospital in Manhattan and Memorial Hospital in Manhattan and other general hospitals.

He was a member of the New Lots Talmud Torah and Jewish Center in Brooklyn.