Thirteen of 20 Hawai'i Air National Guard F-15 fighter jets stationed at Hickam Air Force Base returned to the air yesterday without limitations, the commander of the 154th Wing said.

The wing's remaining F-15 Eagles remain grounded and are awaiting clearance from Air Combat Command on the Mainland.

"Every one of our F-15s went through intense maintenance checks to get back in the air," said Brig. Gen. Peter S. Pawling of the Hawai'i Air National Guard. "All 13 that were cleared were given full-up status, meaning they can perform without limitation. No repairs were needed for any. The other seven we haven't heard back on yet."

F-15s around the world have been grounded since Nov. 3, the day after an Air National Guard F-15C in Missouri experienced catastrophic structural failure and broke apart in flight during basic maneuver training.

Air Force officials in Virginia said yesterday that inspections of all F-15s are 90 percent completed and that 60 percent have been given return to fly orders. The inspections led to discovering nine more F-15s with fatigue cracks along the structure that failed in the Missouri crash.

Hawai'i Air National Guard Tech Sgt. David Heulitt and Master Sgt. Jason Koga were on maintenance crews that inspected Hickam's 20 jets over the past two months.

Heulitt said none of Hickam's planes had cracks, but an ultrasonic test used to check structures for their thickness revealed dimensions differing from the Air Force's blueprint specifications in several spots on the seven grounded planes.

"We here don't know what that exactly means," Heulitt said. "We were given four tests, very in-depth, to perform on each plane and then we sent the information gathered to a team in Georgia. We were not told if the specs we collect pass or fail. They were just different from what we were given. We conducted the tests, collected the data and sent it to them to review. We haven't heard back yet, but that could be because they haven't looked at those planes yet."

Pawling calls the F-15 series the "last of the dogfighting" planes, and said all the ones stationed in Hawai'i were built in the mid-1970s.

Since the fighter jets have been grounded, an F-16 squadron from Duluth, Minn., has been at Hickam covering the wing's F-15 assignments. Pawling estimates the F-15 pilots missed more than 600 sorties the past two months.

"We have 27 F-15 pilots here who've been itching to get out flying again," Pawling said. "They've been training in simulators, but nothing replaces the experience of flying. Skills like taking off and landing don't deteriorate, but we find that what a pilot loses fairly rapidly is combat skills after a month or so. (Yesterday), we got all 13 F-15s into the air and went through some very basic training maneuvers."

Capt. Phillip Malloy has been flying F-15s since 2000 and after two months of using simulators, he said getting back into the air yesterday was "incredible."

"We were all concerned after what happened in Missouri," Malloy said. "It was the best thing for us to get the maintenance checks and make sure we had no cracks ... but nothing replaces flying."

Reach Dave Dondoneau at ddondoneau@honoluluadvertiser.com.