Mobile Tail Enclosure allows 512th, 436th maintenance crews to work during inclement weather

  • Published
  • By Staff Sgt. James Bolinger
  • 512th Airlift Wing Public Affairs
DOVER AIR FORCE BASE, Del. --  A contractor erected a $3 million Mobile Tail Enclosure April 10 at Building 712 here for the 512th and 436th Maintenance Groups.

While the work on the building is not complete, the 99-foot tall, 100-foot wide structure will eventually be a short-term fix for Dover Air Force Base's need for full-in hangars, or hangars which can hold an entire C-5 Galaxy or C-17 Globemaster III, said Col. Alan H. Lerner, the 512th MXG commander.

The massive curved structure, which is visible as visitors enter through the main gate, will ultimately protect Dover's maintenance crews from the elements.

The Mobile Tail Enclosure is a moveable, mini hangar that will allow the Building 712 to mimic a full-in hangar. It will have its own fire suppression and electrical system, which are required for safety purposes, and it will feature a seven-ton crane.

Dover has only two full-in hangars: the wash rack and the isochronal inspection dock. Both of which are often filled with transit aircraft.

"Dover is probably the most active base in (Air Mobility Command) right now, and we have the fewest full-in hangars" said Colonel Lerner.

Because the enclosure only allows Building 712 to mimic a full-in hangar, the new facility must be mobile so aircraft can enter and exit the hangar.

Work began in December on the tracks the mobile building will slide on. Once the structure is complete, it will be pulled by an aircraft towing vehicle along those tracks.
The reason Building 712 and other hangars at Dover require an enclosure to work on the tails of aircraft is because they were designed to house C-141 Starlifters. The last of which, the Air Force retired in 2006.

Right now, Dover maintenance crews pull C-5s and C-17s nose first into these small hangars, said Senior Master Sgt. Matt Sirkis, the 512th Accessories Flight chief. The aircraft are too big to fit inside the hangar, and the tail sticks out between the hangar doors. The doors are designed to close around the tail and create an environment inside the hangar where it is safe for maintenance crews to work.

Problems start when crews need to perform maintenance on the tail of the aircraft, and inclement weather rolls in and makes it unsafe for crews to be on the tail performing maintenance. This creates what maintainers call a work stop.

Work stops at Dover are often caused by high winds and lightning threats, said Colonel Lerner.

Work stops are exactly what they sound like. Maintenance crews here complete all the work on the parts of the aircraft that are inside the hangar and are stuck waiting until the wind dies down to complete their missions.

"We seem to have a wind delay every day," said Sergeant Sirkis. "For example, this week there has been a three-day work stop on a C-5 because of wind delays. It is still sitting in the hangar and crews can't finish the work on it until the wind is below 10 knots."

Work that often gets stopped due to wind is hanging flight controls and working on fore and aft doors. If the wind is blowing faster than 10 knots, crews can't work on the aircraft.
High wind conditions can also stop work for crews inside the hangar. In order for crews to perform landing gear maintenance, they use six fuselage jacks to lift the aircraft off the ground. If wind speed exceeds 25 knots and the aircraft is on the jacks, damage can be caused when the tail of the aircraft shifts in the wind.

Last year, Dover's maintenance crews were afflicted with 440 hours of work stops due to weather.

Other bases with similar facilities include: Robins Air Force Base, Ga.; Hurlburt Field, Fla.; and Altus Air Force Base, Okla.