TECH. SGT. SHANE A. CUOMO / U.S. AIR FORCE Thirteen of Hawaii's 20 F-15s resumed flights yesterday. The F-15s, from the Hawaii Air National Guard's 154th Wing, had not flown since the Air Force grounded the F-15 fleet after a training exercise crash Nov. 2. Here, an F-15A Eagle took off yesterday from Hickam Air Force Base.

Isle Guard’s F-15s back in the air

As thirteen of the jets head back into the skies, seven receive additional analysis

Thirteen F-15 fighter jets belonging to the Hawaii Air National Guard returned to service yesterday, but seven others remain grounded for additional analysis.

No structural defects were discovered during the mandatory inspections, the Air Guard said.

"We're on cloud nine," said Brig. Gen. Pete Pawling, commander of the Hawaii Air National Guard's 154th Wing, following a 1 p.m. launch.

Pawling's unit launched 23 flights yesterday with some of the jets getting into the air twice.

The Air Force's fleet of 676 F-15 jets was grounded because of "airworthiness concerns" after a plane based in St. Louis crashed Nov. 2 during a training exercise.

Pawling said structural problems at the back end of the canopy were discovered in the jet -- a C model -- belonging to the Missouri Air National Guard.

"The plane separated at that part," Pawling added.

Tech. Sgt. David Heulitt, an aircraft inspector with the 154th Maintenance Squadron, said it took a month, beginning at the end of November, to check out all the aircraft belonging to the 199th Fighter Squadron.

"It was a very in-depth inspection," Heulitt said. "We looked for cracks or signs of fatigue. We didn't find any defects in any of the jets."

Pawling said the remaining seven grounded jets are A- and C-model F-15s. They are among 35 percent of the Pacific Air Forces' F-15 inventory still undergoing analysis by engineers.

The Hawaii Air Guard's 20 F-15 jets, built between 1974 and 1978, were acquired in 1987.

"It was the first time they have been grounded since we got them," said Pawling.

In Hawaii the F-15 Eagles are responsible for the air defense of the islands, including any airborne terrorism threats. They are scheduled to be replaced in 2010 with F-22 Raptors.

In June an F-15 jet from the Oregon Air National Guard went down in the Pacific Ocean during a training mission. And in a separate incident in June, an F-15 crashed near Eielson Air Force Base in Alaska.