Civil Engineering Builds Jet Blast Deflector
By Staff Sgt. Jerome White, Public Affairs NCO, 104FW
/ Published October 04, 2008
BARNES AIR NATIONAL GUARD BASE, Massachusetts -- The September drill marked the end of the beautiful views I used to enjoy from the ground floor of the Wing Headquarter building. This is due to the newest addition to our base, a jet blast deflector in front of Building 1, and although I lament the loss of my views of the flight line, I feel a lot safer now that I know why they went away.
A blast deflector takes the exhaust coming out of the back end of a fighter plane, commonly known as jet blast, and deflects it harmlessly up into the air in order to protect things such as buildings, people, and equipment. According to Maj. Brian Murphy, the Deputy Base Engineer, even low power operations can cause dangerous blasts because the wind and heat are focused on a small area. At 35% thrust an F-15 Eagle's blast can produce winds strong enough to knock over people and gives off an incredible amount of heat. At higher levels, such as 85% thrust, these winds can rival a low power tornados and even roll over small vehicles.
I asked Major Murphy if anything went wrong during the construction process and after he stopped laughing his reply was: "Of course...you always have something that goes wrong." In this case the problem involved the design of the deflector's base, which involved both concrete and asphalt. Where these two materials met the installer was having trouble adequately compressing the asphalt enough to keep it from breaking apart without cracking the concrete. The debris from either the asphalt or the concrete had the potential to cause a very serious problem called FOD (foreign object damage). FOD happens when a foreign object, such as a rock, gets sucked up by a jets intake and then rattles around in the engine causing thousands, if not millions, of dollars in damage.
The deflector, which was installed by Blast Deflectors Incorporated, is the culmination of several months of construction and is actually only one of four that will eventually be in place. These deflectors are just one of many projects that Civil Engineering has in the works right now. Others include the new fire department building, an Air Superiority Alert complex, an Explosives Ordinance building, aircraft shelters, and upgrades to the Avionics, munitions, and engine shop buildings, in all more then $40 million of construction will occur between now and 2010.