http://www.aviationpros.com/news/118325 ... d-12-f-16s
Bristles Force Guard to Ground 12 F-16s
Feb 5, 2015
Feb. 05--Twelve F-16 fighter jets have been temporarily downed by an unlikely cause -- broom bristles.
The 148th Air National Guard Fighter Wing grounded the aircraft this weekend,
when it came to light that a mechanical sweeper used to clear the tarmac at Duluth International Airport had been losing excessive bristles on the job.
The metal and poly bristles were sucked into the powerful turbine engines of the jets,
prompting the Air National Guard to deem them unfit for service.
"We take FOD -- foreign object damage -- extremely seriously,
whether it be birds in the air or sand on the runway.
There are a lot of things that can cause jet engines to malfunction," said Capt. Jodi Kiminski of the 148th.
Kiminski said mechanics have been working around the clock to return the jets to service for a military exercise scheduled this weekend,
but Duluth's skies have been abnormally quiet as training sorties have been placed on hold in the meantime.
The 148th boasts a total squadron of 22 F-16s,
but at any time some of the jets are out of service for repairs.
The temporary idling of 12 F-16s will effectively keep the unit's pilots on the ground all this week, Kiminski predicted.
None of the aircraft's engines have been irreparably damaged, but Kiminski said: "We have been putting in a ton of hours."
Kiminski said she couldn't attach a dollar value to the repairs.
Yet she doesn't expect the unit will seek to collect any damages from the Duluth Airport Authority,
which is responsible for keeping its runways clear.
"In terms of any financial fallout, that will have to be worked out at another time," said Thomas Werner, executive director of the Duluth Airport Authority.
"I can only tell you that right now we are solely focused on making sure that everybody, including those F-16s, can fly in and out of here reliably, and that's what we're working towards," he said.
Sweepers with larger rotating heads have been used to maintain local runways for more than a decade, according to Werner.
"This particular piece of equipment that had the bristle issue is new to the fleet,
but I don't think that, in and of itself, is cause for concern," he said.
"We've been in contact with both the manufacturer of this particular piece of heavy equipment,
as well as with the manufacturer of the bristle cartridge,
which is separate," Werner said.
"They both have been very good to work with to help us to solve the problem. That investigation is still active and ongoing, in terms of finding the root cause."
Air National Guard staff noticed the bristles late last week, and the extent of the problem became evident upon further inspection of the unit's F-16s during the weekend.
"This airport has an impeccable safety record, and any time that we have something that may pose a problem, we take it offline right away, and this was no different.
As soon as we got word that there may have been an issue with some of the 148th's jets, the equipment was immediately removed," said Werner, noting that the sweeper remains sidelined.
The offending bristles were only a few inches long and were not immediately noticeable on the pavement, Kiminski said.
She explained that flight protocol involves careful inspection, saying: "We have crew members that go out before and after every flight to make sure that there's nothing out there in the way of the jets."
As Werner continues to dig into the issue, he said the leading theory right now is that the airport may have received a defective bristle cartridge.
"But until I have more data, I'm hesitant to say it much stronger," Werner said.
Kiminski referred to the airport authority as a good partner and said: "We are continuing to meet with their professionals to make sure this doesn't happen again."
While the stray bristles caused headaches for fighter jets, Werner said they posed no threat to other airport traffic, both commercial and general aviation.
He noted that the air intake for the F-16 is below the fuselage.
"Because they're so much closer to the ground and because their turbines are so powerful,
they are susceptible to much, much smaller debris than anything else that flies in and out of Duluth," he said.
Werner noted that the runway standards for F-16 operations are significantly more stringent than for other aircraft and asserted that the airport was never out of compliance with safety guidelines for other types of air traffic.
"At no time has the general public that flies in and out of here been at risk," he said.