F-15 canopies buffed to visual perfection

  • Published
  • By Lanorris Askew
  • Warner-Robins Air Logistics Center Public Affairs
ROBINS AIR FORCE BASE, Ga. (AFPN) --  Even the slightest scratch in an F-15 Eagle windscreen can keep a pilot from seeing the enemy, according to F-15 test pilot Maj. Fritz Heck.

That is why technicians in the F-15 canopy shop here work diligently to overhaul the acrylic bubbles in canopies and give fighter pilots a clear advantage.

Literally starting from scratch, the sheet metal mechanics use a finely-tuned process to save canopies and windscreens from the scrap heap. The process began a little more than a decade ago and saves millions of dollars in new purchases.

"From an operational fighter pilot perspective, seeing the threat is everything," Heck said. "I have flown with damaged canopies and windscreens operationally and have seen the condition of some of the ones that come in here to depot. When the jets come back out for flight test before going home, they are nearly as pristine as the brand new canopies I see when I test jets coming off the production line."

When pilots fly the F-15, their helmets, clipboards, sand and other matter may scratch the glass, according to Peter Wellman, who has been a sheet metal mechanic since 1992.

"As time goes on, the number of scratches becomes an impediment to the pilot's view of targets or where he or she is going," he said. "Our job is to eliminate that damage and maintain the original optics as near new as possible. That is the paramount function of our job."

Members of the shop perform sheet metal write-ups, sealant checks and acrylic overhauls on the canopies and windscreens.

Wellman said that not long ago canopies and windscreens were discarded when they sustained damage.

"Windscreens were once replaced 100 percent of the time and canopies at least 50 percent of the time," he said.

With estimated costs of $160,000 for a two-seat canopy, $85,000 to $90,000 for a single-seater and $40,000 to $50,000 for windscreens, the amount of money spent on the acrylics was astronomical.

In 1990, the technology and industrial support canopy overhaul shop employees came up with a process allowing the acrylic items to be refurbished and returned to the plane as good as new.

Using a polishing and buffing technique, which uses specially textured paper, the process quickly became the wave of the future.

Wellman said the papers, which become finer at each level, remove nicks and scratches from the acrylic "like a dream."

A new windscreen design allows the unit to be easily removed from the aircraft for better access to the inside and outside of the screen.

"We used to do the repairs of the windscreen on the plane and were limited in reach in what could be done to the inside surface," Wellman said. "With our new design it is much better."

The new design came about a year ago and the difference between when the canopies and screens arrive and when they leave is remarkable, according to Cheryl Robinson, a sheet metal mechanic.

"The canopies -- they come in pretty trashed," she said. "But it's such an amazing thing to be able to take pretty deep damage out. That becomes even more amazing when you realize that to get the damage out, they first put more damage in."

When the damaged windscreens and canopies come in, the entire surface is treated using the buffing technique and textured paper. This gives the acrylic surface a completely frosted appearance. The entire unit is then polished until it is perfectly clear.

Heck said pilots are taught from the beginning that an invisible threat is impossible to defeat. With the help of the canopy shop, threats are seen crystal clear.