Environmental chambers as follows, usable for the systems specified in 1.A. or 19.A. or the subsystems specified in 2.A. or 20.A.: a. Environmental chambers capable of simulating all the following flight conditions: 1. Having any of the following: a. Altitude equal to or greater than 15 km; or b. Temperature range from below -50ºC to above 125ºC; and 2. Incorporating, or designed or modified to incorporate, a shaker unit or other vibration test equipment to produce vibration environments equal to or greater than 10 g rms, measured ‘bare table’, between 20 Hz and 2 kHz imparting forces equal to or greater than 5 kN; b. Environmental chambers capable of simulating all of the following flight conditions: 1. Acoustic environments at an overall sound pressure level of 140 dB or greater (referenced to 2 x 10 -5 N/m 2 ) or with a total rated acoustic power output of 4 kW or greater; and 2. Any of the following: a. Altitude equal to or greater than 15 km; or b. Temperature range from below -50 o C to above 125 o C.