President Bush's military records, including personal flight logs just released by the Pentagon, paint a picture of a solid, if hardly outstanding, pilot who energetically performed his duties for much of a six-year stint with the Air National Guard. Then, in the spring of 1972, the picture changes.

After initially expressing his intention to make flying "a lifetime pursuit," Bush checked out an F-102 interceptor jet for an 80-minute spin on April 6, 1972, in Texas, and never piloted a military plane again.

Why Bush stopped flying and failed to take an annual physical necessary for him to remain a pilot have become the object of much speculation and reporting that spiked in intensity last week, as it did during the 2000 campaign.

The topic was back in the headlines after CBS News footage included documents -- whose authenticity is now hotly disputed -- asserting that Bush failed to perform to National Guard standards.

Yesterday, another retired Air National Guard officer came forward to attack the network's credibility. Retired Maj. Gen. Bobby W. Hodges, who was cited by a senior CBS official on Thursday as the network's "trump card" in verifying the documents, said in an interview that he was "misled" by CBS and believes the documents to be forgeries.

Hodges said that he was read only excerpts of the documents and never saw the documents. A CBS spokeswoman said the network stands by its report.

A review of the authenticated documentary record for Bush's guard service and interviews with former guard members suggest that the president and his aides have been less than fully candid about unexplained gaps in his military service, and have made misleading and sometimes inaccurate statements that have helped fuel the controversy.

At the same time, Bush's critics have been unable to come up with definitive evidence showing that he failed to meet his minimum obligations to the guard after being suspended from flying for failing to take the physical.

"The records that I have been able to see show a young lieutenant who was very aggressive, a good participant in the program for 31/2 years," said retired Maj. Gen. Paul A. Weaver Jr., who headed the Air National Guard between 1998 and 2002. "Then, near the end, the records show that he was a minimally satisfactory participant."

Weaver said Bush's records suggest a pilot whose interest in flying waned in early 1972 and whose commanders "did everything possible to assist Bush in obtaining the necessary satisfactory time for his remaining obligatory service." In the end, Weaver said, Bush's paperwork was acceptable to personnel officers in Denver, who granted him an honorable discharge at the end of 1974.

The White House now says that Bush left Texas, where he was first assigned when he joined the Air National Guard, for Alabama in the spring of 1972 because his priorities changed and he wanted to work in the political campaign of a family friend, Winton "Red" Blount, who was running for the U.S. Senate.

But in his 1999 autobiography, Bush omits mention of his suspension from flight status. He says only that "I continued flying with my unit for the next several years" after being turned down in 1970 for a program known as "Palace Alert" that might have taken him to Vietnam.

White House spokesmen said there was no point in Bush taking his required pilot's physical in 1972 because he had already decided to move to Alabama, where there were no F-102 planes. To fly another plane, he would have had to undergo extensive retraining.

Whatever Bush's reasons for failing to take the physical, he seems to have put in minimal service at best in Alabama. According to his official personnel records, made public by the White House and the Pentagon, he failed to show for any drills between May and October 1972, even though Air Force regulations required him to attend 90 percent of scheduled drills, barring events "beyond his control."

The records contradict the claims of a former Alabama National Guard officer, John B. "Bill" Calhoun, who came forward earlier this year at the behest of "a Republican close to Bush" to testify to vivid memories of Bush taking part in drills during the period in question. No credible witness has come forward to say Bush was seen performing guard duties in Alabama, despite a $10,000 reward offered by "Doonesbury" cartoonist Garry Trudeau.

White House officials said they have had no dealings with Calhoun and were not responsible for his statements.

The question of whether Bush ever did "substitute service" for the missing drills is controversial, and hinges on technical points in Air National Guard regulations that are almost incomprehensible to outsiders and are much debated by former personnel officers. The bottom line seems to be that Bush did whatever paper-shuffling duties were necessary to satisfy his superiors.

"During the period in Alabama, he did the minimum amount that was required, but he did the minimum amount," said retired Col. Rufus G. Martin, who was Bush's personnel officer in Texas.

Martin said Bush did "a heck of a lot" during his earlier service with the 111th Fighter Interceptor Squadron in Texas but then "changed his mind" and decided "he preferred to be in politics."

By early 1973, Bush was back in Texas, still grounded from flight duties. Records show he crammed in 38 days of office training between May and July 1973, in an apparent attempt to accumulate sufficient "points" to maintain his "satisfactory" standing.

When he entered Harvard Business School in September 1973, his records were transferred to a personnel office in Denver for a final year of service in a unit that existed only on paper.

Whether or not Bush did the minimum necessary to remain in good standing with the guard, it is clear his performance fell well short of the depiction in his 2000 campaign biography, which stated that he flew with the 111th until his release in September 1973.

In a 1999 Washington Post interview, Bush spokesman Dan Bartlett was quoted as saying that Bush's release from the 111th was appropriate because the unit had phased out the F-102s, and that Bush was transferred from Texas to a reserve unit in Boston. Both statements appear to be inaccurate.

Although F-102s were being phased out by 1973, they were still being flown. There is no record of Bush signing up for reserve duty in Boston. Bartlett, now White House communications director, said last week through a representative that he must have either "misspoke" or been "misquoted."

Last week, it seemed as though new documents unearthed by CBS News's "60 Minutes" might shed light on the questions surrounding Bush's substitute service in Alabama.

If the CBS documents are authentic, they would directly contradict the White House claim that Bush's transfer was routine and that no political favoritism was extended to the son of a former Houston congressman. The papers purported to show that Bush's former commander, Lt. Col. Jerry B. Killian, was resisting pressure from his superior, Col. Walter B. "Buck" Staudt, to "sugarcoat" Bush's officer evaluation files.

But document experts began questioning their authenticity almost as soon as they were published on the Internet, citing typographical and formatting issues that suggest they were created by a modern-day word processor rather than a Vietnam War-era typewriter.

CBS officials have declined to say who provided "60 Minutes" with the documents, other than that it was an "unimpeachable source" -- or exactly where they came from, other than the "personal file" of Killian, who died in 1984.

Killian's widow and son have both said that they believe the records are fake. On Friday, CBS News anchor Dan Rather named one of Killian's superiors, Hodges, as a key source in CBS's authentication of the documents. He said that Hodges -- whom he described as "an avid Bush supporter" -- had told CBS that he was "familiar" with the documents.

"It took a lot for him to speak the truth," Rather said.

But in an interview yesterday from his Texas home, Hodges contested Rather's account. He said that he was called on Monday night by a CBS reporter who read him extracts from documents purportedly written by Killian. Hodges said that he may have told CBS that he had conversations with Killian about Bush, but he denied confirming the authenticity of the documents in any way.

"Now that I have had a chance to see them, I think they are fake," Hodges said.

A CBS spokeswoman, Sandy Genelius, said the network "believed General Hodges the first time we talked to him." She said CBS continued to "stand by its story" and a statement it issued on Thursday saying that "60 Minutes" reporters had talked to "individuals who had seen the documents at the time they were written." She declined to name the "individuals," describing them as sources.

Another problem with the CBS documents, cited by Hodges and others, is that Staudt was no longer serving with the Texas Air National Guard when one of the memos was allegedly written.

"Staudt has obviously pressured Hodges more about Bush," the document, dated Aug. 18, 1973, reads. "I'm having trouble running interference and doing my job."

Records show that Staudt retired from the guard in March 1972.

Genelius described Staudt as "a mythic figure" in the guard, who was still "wielding influence" behind the scenes in 1973.

But according to Hodges, Staudt had no influence over guard personnel policy after his retirement. "I met him socially after he retired, but I can't recall having a conversation about Bush," he said.

In 1968, George W. Bush was sworn in to the Texas Air National Guard by Walter B. Staudt. One of the disputed documents was allegedly written after Staudt retired.