SDB: Small Bomb, Big Bang

  • Published
  • By Katherine C. Gandara
  • Headquarters Air Force Operational Test and Evaluation Center Chief of Public Affairs
The Air Force Operational Test and Evaluation Center is a one-of-a-kind organization with a population less than one-quarter a percent of the entire Air Force total force and is charged with testing all new weapon systems that ensure America's warfighters have the right tools to win today's and tomorrow's battles.

Within the ranks of almost 1,200 military, civilian, and contractors at AFOTEC is just over 100 team members at AFOTEC's Detachment 2 at Eglin AFB, Fla., which oversees more than 20 munitions-based test programs including the GBU-39/B Small Diameter Bomb. The specialized seven member SDB test team has a combined 111 years of military and operational testing experience. Test team roles ranged from effectiveness, communications, and armament analysis to logistics and backgrounds such as a weapons system operator in the B-1 brought operational expertise to the team. This is a case where smaller is indeed better, across the board.

The advantage of this smaller weapon is that it can precisely hit a potential stationary target in a crowded environment while minimizing damage to surrounding areas that may contain civilians or commercial areas.

This 250-pound class bomb, though diminutive in size compared to the larger 2,000-pound Joint Direct Attack Munition, allows aircraft to carry more of them, and thus attack more targets per mission. Additionally, the GPS-guided, all-weather bomb can penetrate deeply into a target and has a standoff range of up to 60 nautical miles, which means less risk to aircrews.

While the SDB moved through developmental testing with a 95 percent test success rate, there were some technical challenges during operational testing, according to program managers.

During early operational testing, the SDB program had a significant challenge that affected its ability to use Global Positioning System information. The Eglin test team was able to identify the source of the problem and consequently design and verify a fix as well as modify operational test weapons.

The AFOTEC Det. 2 test team was credited for the program's recovery from what had become known as "GPS-Reset." The SDB uses a GPS navigation system to fly to a target. During the testing process, after the weapon was released it was either unable to acquire the GPS signal used for navigation or it did acquire the signal but lost it during flight and was unable to re-acquire prior to weapon impact. Without the GPS signal the weapon did not guide to the programmed impact point which affected desired weapon effectiveness.

The AFOTEC SDB test team worked in conjunction with other Eglin team members from the Air Armament Center, Boeing, 46th Test Wing, Air Force Research Lab, Air Combat Command, Aeronautical Systems Center and the SDB Program Office. While still maintaining AFOTEC's operational test and evaluation independence, the Det. 2 team was able to adjust schedules, support hardware investigation, and allow weapon modifications that corrected the deficiency and still delivered the SDB to the warfighter ahead of schedule and under cost.

According to the AFOTEC SDB test director, cost savings can be attributed to early involvement in the developmental process and staying on schedule. AFOTEC's biggest contribution comes from staying on schedule even though there were some major issues identified during initial operational test and evaluation, such as the GPS reset and a height of burst lethality limitation. Additionally, a better weapon was provided to the warfighter through AFOTEC's commitment to building operationally realistic scenarios based on current and expected conditions.

The SDB Program Office identified the cause of GPS reset and fixed it in enough time for AFOTEC to verify the fixes prior to the scheduled completion of initial operational test and evaluation. Additionally, the AFOTEC test team provided operational perspective on weaponeering impacts due to the height of burst limitation, which changes the employment guidance given to the warfighter. An additional mission with four more weapons being dropped during the IOT&E timeframe for weapon effectiveness data was generated to validate the new guidance.

AFOTEC has completed involvement with SDB with no further operational testing being anticipated. SDB II, which has a capability to attack moving targets, has begun its acquisition process and AFOTEC is involved from the beginning with operational testing expected to begin in 2013.

The SDB will be integrated on the F-15E first and is being delivered to combat units through the world for use in the Global War on Terror.