The Delta Air Lines pilots who strayed off course over the North Atlantic and came within 30 feet of colliding with another jumbo jet in July were flying without oceanic charts and had made no attempt to verify their location, federal investigators said yesterday.

The National Transportation Safety Board said that the Delta crew had performed only one of six possible navigational procedures available to pilots who make transoceanic flights.

The incident occurred July 8 when the Delta L1011 jet, en route from London to Cincinnati, flew 60 miles off course and almost collided with a Continental Airlines 747 flying from London to Newark. The two jetliners were carrying nearly 600 people.

William Berry, a Delta spokesman, told The Associated Press that Delta procedures were not observed "in certain elements of the flight," but declined to elaborate. Berry said, however, that it was his understanding that Delta flight crews are supplied with plotting charts and also have a "very in-depth, detailed flight plan."

The airline suspended the crew without pay. The captain, who was making his 11th ocean crossing, was suspended for a year, the copilot for three months and the flight engineer for two months.

Immediately after the incident, it was widely reported that the two jetliners missed each other by 100 feet, but the joint U.S.-Canadian investigation revealed that the jets came as close as 30 feet. Canada investigated because the incident occurred off the coast of Newfoundland, which is the first point at which the jets would have been tracked by air traffic controllers as they approached land. While they were over the Atlantic, they were not tracked by radar.

The safety board also expressed concern that deviations from flight paths occur frequently enough to pose "a clear and direct threat to flight safety."

The board urged the Federal Aviation Administration to require pilots flying across oceans to use at least two initial route verification techniques and to verify the path three times en route. The board also recommended that the FAA send to all airlines with oceanic flights a bulletin describing the details of the Delta incident and emphasizing transoceanic rules of operation.

Bob Buckhorn, a spokesman for the FAA, said the agency plans to issue the bulletin promptly. He said the FAA is revising navigational procedures used in oceanic flights.

Currently, the FAA recommends, but does not require, that flight crews verify their location during oceanic crossings when their planes are not covered by radar.

A team of FAA inspectors is investigating Delta's pilot training program, and the Atlanta-based carrier has revised some procedures used in oceanic navigation. The NTSB investigation found that the Delta crew in July did not plot its position or predicted position as the jet crossed way points, nor did the crew perform other verification procedures. The Delta jet was in the third hour of flight when the incident occurred.

It is widely believed that the crew entered a wrong digit into the plane's computerized navigational system before taking off from London. Consequently, the plane strayed 60 miles from its track and flew directly into the path of the Continental jet.

Many airlines routinely use computerized navigational systems to direct jets on oceanic flights.

Crews flying American Airlines and Pan American World Airlines jetliners observed the near-collision of the Delta and Continental jets and took part in a four-way conversation about the incident immediately afterward. Investigators said it was suggested in that conversation that the incident go unreported.

The NTSB said the fact that the near-collision was not immediately reported further "demonstrates the need for airlines to reemphasize to their flight crews instrument flight rule procedures."

The NTSB report said that the board's investigation focused on "errors in navigational procedures," but did not elaborate on how the plane strayed 60 miles off course. The board noted that the Delta crew followed a procedure calling for one crew member to enter the coordinates and another to verify them.