DEPRESSOR 



The depressor design is based on an existing depressor developed by DTNSRDC 

 for airborne minesweeping applications. A sketch of the depressor showing principal 

 dimensions is presented in Figure 4. Physical characteristics are listed in 

 Table 1. 



The depressor consists of a cylindrical fuselage with a disc-ogive nose and 

 squared-off tail, a biplane box wing cell located approximately at the mid-body, and 

 a cruciform stabilizing fin arrangement aft. The wings, stabilizing fins, and aft 

 half of the fuselage are constructed of glass-reinforced plastic. The pressure 

 housing for control and CTD electronics are fabricated from 6061-T6 aluminum alloy. 

 An interior strongback which supports the wings and CTD pressure housing and pro- 

 vides the towing bracket also is constructed of 6061-T6 aluminum alloy. Connecting 

 hardware is stainless steel. 



The pressure housing for the CTD electronics comprises the fuselage forward 

 of the wings. The internal space is 152.4 mm in diameter and 558.7 mm long; how- 

 ever, the forward 20 mm of length is filled with lead ballast leaving a usable length 

 of approximately 538 mm. The housing separates at the aft bulkhead. The forward 

 bulkhead, which also represents the nose of the fuselage, is welded in place. The 

 support for the depressor-attached CTD sensors is mounted to the aft bulkhead. The 

 CTD housing is designed to survive a depth of at least 1.2 km. 



Depressor depth control is achieved by the action of a movable flap on the 

 horizontal stabilizer. The flap is driven by a servo motor through a bell-crank 

 linkage. The pressure housing for the control electronics is located inside the 

 fuselage at the aft end of the body. The control system housing also is designed 

 to survive a depth of 1.2 km. 



In addition to depth control, the depressor incorporates a passive roll-trim 

 device to counteract any built-in lateral asymmetries. The roll-trim device con- 

 sists of a weighted pendulum which actuates a trim tab on the vertical stabilizer 

 to produce a depressor rolling moment in the direction of zero roll. 



TOWCABLE 



The towcable, manufactured by Rochester Corporation as a stock item (without the 

 fairing), is a double-armored cable containing nine electrical conductors. The cable 



has an overall diameter of 8. 8 mm (0.347 in.), a weight in air of 2.87 N/m of length, 



