Pentagon’s Tailhook Report Expected to Detail Obstruction, Cover-Up : Scandal: Separate inquiry will deal with specific charges in the sexual abuse of women at an aviators’ convention.

The Pentagon’s inspector general, completing the first phase of the sensitive Tailhook sexual abuse investigation, is expected to issue a report next week detailing officers’ efforts to obstruct the Navy’s inquiry into the incident and disclosing whether the service’s investigators aided the cover-up, Pentagon officials have told The Times.

The report will not address the underlying allegations against Navy and Marine Corps aviators accused of sexually mauling at least 26 women at the September, 1991, convention of the fraternal Tailhook Assn. Those allegations are the subject of a separate investigation and officials said they expect to file “multiple assault” charges after they have completed gathering evidence later this year.

Next week’s report stems from an investigation operating on a separate track. It will address how much the service itself should be blamed for its handling of the scandal and its repercussions. Not until December, officials said, will the Defense Department investigators give a definitive account of the events that have plunged the Navy into a moral and morale crisis over its treatment of women in the service.

In spite of its narrow focus, the report is certain to become a centerpiece of congressional debate, as lawmakers consider legislation designed to strip the military services of their investigative functions in sexual molestation and other cases.

In recent years, lawmakers have sharply criticized the management and investigative methods of the Naval Investigative Service, which looked into the Tailhook incident originally. That investigation identified only six officers suspected of direct involvement, prompting several lawmakers and many alleged victims to charge that Navy investigators had bungled the inquiry and allowed senior officers to shield their subordinates from questioning.

Pentagon officials acknowledged that many suspects, Navy officers and other witnesses had refused to cooperate with the Navy investigation by insisting that they had seen nothing. The officials also conceded that the conduct of the Naval Investigative Service’s review had raised questions about the diligence of some investigators in getting the facts.

On June 18, former Navy Secretary H. Lawrence Garrett III responded to widespread criticism of the Navy investigation and asked Defense Department Inspector General Derek VanderSchaaf to conduct an independent investigation of the Tailhook incident. VanderSchaaf’s office was created by Congress in the mid-1980s as an executive investigative arm independent of the military services.

In an interview with The Times, acting Navy Secretary Sean O’Keefe recently said he believes Navy and Marine Corps officers have cooperated with VanderSchaaf’s investigators. O’Keefe predicted that VanderSchaaf would deliver an “unvarnished” report that will once more plunge the Navy into a storm of controversy.

O’Keefe was named to lead the service on July 7 after Garrett resigned.

In his resignation, Garrett insisted that he neither saw nor heard of misconduct while he was present at the Tailhook convention. But while several witnesses disputed Garrett’s account in interviews with naval investigators, those accounts were excluded from the NIS report that was made public and sent to the Navy’s senior leadership. Knowledgeable officials said that such lapses are among the alleged mismanagement that the Defense Department inspector general has focused on in the first report.

Navy officials had hoped that the inspector general would release all the findings in a single report, allowing the service to present its own responses in one sweeping package and close out the issue. The Navy has been engaged in a far-reaching effort to expunge sexual harassment from its ranks, and service officials have been eager to portray the mistreatment of women as an issue that it has dealt with effectively.

A House Armed Services Committee report released Monday concluded that “public and institutional confidence in the Navy is not likely to be restored until there is a full accounting of Tailhook activities.”

But the House panel also declared that the 1991 Tailhook convention “may prove to be the watershed event” in persuading the military to stamp out sexual harassment. The report cautioned, however, that efforts to eradicate the problem will be ineffective unless senior military leaders insist that it remains important and troops continue to receive training on the issue.

Rep. Les Aspin (D-Wis.), chairman of the House panel, said in a news conference Monday that the fundamental question is whether the military is on track to virtually stamp out sexual harassment in two to five years.

“Our answer in that is yes,” he said. “We believe right now that the services have in place a program which . . . if they continue to carry it out, will result in a successful program against sexual harassment on the scale of the successful program against racial discrimination and against drug use.”