(e) Stonping Blower  (f) LaDel Electric Blower  (a) Settings  (5) Summary:  Pressure Control System  1. Turn off button on pilot’s  p~nel.  2. Vfuen the airship is in flight with the Homelite  Model HRU-28 auxiliary blower stopped, a  partial vacuum is set up in the exhaust.  This  partial vacuum draws fuel into the crankcase.  In many instances, this has resulted in bursting  the crankcase or cylinders and pistons when  the  pl~nt  was started.  To prevent this, the  fuel line shut-off valve must be tightly closed  whenever the plant is stopped, whether in flight  or at the airship base.  NOTE: Engine can also be stopped by pressing  red stop button, mounted on me.gneto  stator plate until engine stops.  The production schedule calls for a LaDel electric  blower to replace the gasoline powered blower, described  above, on airships K-99 and future.  The only source of  power for this blower is the Lawrance auxiliary generator.  The auxiliary generator must be running at rated speed  before the electric blower may be used.  1. Forward Air Valve: Begins  to  open at 1.50 inches  of water of air pressure in the forward ballonet  as read on car manometer.  2. Aft Air Valve:  Begins to open at 2.00 inches of  water of air pressure in the aft ballonet as  read on car manometer.  3. Gas Valve: Begins to open at 2-1/2-inches of  water as r ead on gas manometer.  (b) Control, Instruments & Auxiliaries Chart  See Fig. XIII  (c) Operation Chart  See Fig. XIV  -45-