The Polish air force is set to start flight tests of a bolt-on wing adaptor kit developed as part of a package to convert unguided bombs to precision-guided munitions.
The flight tests, to be conducted using a Sukhoi Su-22M4, are expected to follow a cautious build-up approach after the Polish air force institute of technology found potential danger points in the launch profile. Using a six degree of freedom simulation model based on predicted aircraft and store aerodynamic loads, the institute evaluated the expected behaviour of a "Type A" store throughout a release envelope covering adapter sweep angles from 0° to 30° and aircraft angles of attack (AoA) from 0° to 6°. The institute adopted the simulation model to reduce development time and cost in comparison with similar US adapter kit efforts. These include clearance of the Raytheon AGM-154 JSOW stand-off weapon on the Boeing F/A-18 Hornet to Mach 0.95 which took 20 flights and more than 400h of windtunnel tests.
For the cleanaircraft configuration, tests predict the most hazardous release point will be with wing sweep angle at 30° or more and aircraft AoA at around 3°. "The dangerous mode is a nose-in yawing motion that moves the store wing towards the aircraft's fuselage," says the team.
Source: Flight International
