Aligned under AFTC, both the organisations used their expertise to test B-52H capability to release GBU-38 with multiple load configurations on heavy stores adapter beam (HSAB) in a 16ft transonic wind tunnel at Arnold AFB.
GBU-38 is a 500lb BLU-111/MK82 unguided free-fall bomb with joint direct attack munition (JDAM) guidance tail kit.
Conducting a ground test in wind tunnel allowed test personnel to control various conditions, including temperature, speed and altitude, crucial for gathering required data for a portion of flight envelope.
Besides, the store separation testing allowed measuring the forces and moments of test article, using strain gauges on a balance, while positioning the store in three ways, including pseudo-freestream, grid and trajectory.
Aerodynamics Test Branch test manager Austin Stewart said: “The test used pseudo-freestream positioning where store was placed far away from parent aircraft and then data at a large range of pitch and yaw angles was taken to determine forces and moments acting on store when it was exposed to tunnel air without interference from parent aircraft.
“Grid data was taken at increments along a line stepping away from release point of store on HSAB.
“This allowed interference of B-52H aircraft on store to be characterised. Trajectory data was taken on a closed-loop system.”
This test, according to AFTC, investigated interference flow fields generated by neighbouring stores, including GBU-31 precision-guided munition, CBU-87 dispenser and MK64 ER air-launched mine.