we ale ee ee ee ee re ee ee ee ABSTRACT This report -<$ a presentation of the deta obtained by Project 5.3 on the blast response of a B~36D aircraft flown in the proximity of the Shot 9 explosion of Operation UPSHOT-KNOTHOLE, The test aircraft was et on the same B-~36D aircraft utilized for similar testing by Project 6.10 during Operation IVY. The instrumentation was modified to include additional measurements on the horizontal tail. Response measurements included: nose, tail, wing tip, and center of -ravity accelerations; wing fuselage, and horizontal stabilizer bending moments; and horizontal stabilizer shear. Peak overpressure at the aircraft was also measured, The purpose of the program was to supplement the blast response é data obtained during the IVY tests particularly to investigate more fully the aft fuselare and horizontal stabilizer response characteristics. The purpose was accomplished even though the peak loads obtained were not @s hich as desired. The creak stabilizer bending moment measured was t. Tete oe than those measured during IVY but were still only a fraction of the t_. 34 per cent of limit load. limit allowable. Peak wing bending moments were somewhat higher The data obtained by Project 5.3, combined with previ- ous data, will allow a complete check of the present blast/load theory in the low and medium load ranges. Theoretical extrapolation to loads approaching design limit should be confirmed by additional experimental data. The position of the aircraft at blast arrival was such that tha reflected shotk wave arrived 4.44 seconds after the direct shock wave; and, because cf fortuitous phasing with low amplitude vibrations initiated by the direct shocx, the peax loads produced by the reflected shock were slishtly higner. However, with proper phasing and shorter time interval between shocks, the reflected shock could induce peax loads considerably higher than those optained from the direct shock. ant, Boe a . i The data obtained by Project 6.10 in IVY are included in this res tne report.