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A.L.1                      PART IV - EMERGENCY HANDLING
Page 84
            (d)  Carry out forced landing procedure (see para.94) or abandon.

           90.  Electrical system failures
           (a)  Single generator failure
                If either generator fails, the output of the other is sufficient for non-
                combat flying provided that all non-essential electrical services are off.
                When the follow-up tailplane is in use an additional heavy electrical
                load is imposed; use of the interconnection should therefore be
                limited to flight above 0.9M.
           (b)  Double generator failure
                If both generators fail, all electrical services will be supplied by the
                batteries.  These, if fully charged, will maintain the following output
                before they fail (i.e., battery voltage below 16 volts).

Output-Amps .. 150 125 100 75 50 38 25
Time-mins.  .. 2 3 5 10 18 40
NOTE.-When 2 24-volt batteries are fitted these times should be doubled. To assist the pilot in deciding which loads should be shed, if generator failure occurs, the following table lists the major services and the current they require.
Service Load
Service Load
Booster pumps            .. 35 Pressure head heater   .. 6
Radar ranging              .. 30 Starter control
(relighting)            ..          ..

A.C. inverters                .. 15 Fuel contents gauge      ..    4.5
Tailplane actuator       .. 12 G.G.S.            ..      ..          .. 4
Hood control                .. 10 G.G.S. retraction              ..    3.5
VHF sets            ..         ..       7.5 All other electrics            .. 10   
IFF set                ..         ..      6.5   ____
D.M.E.                 ..         ..   6 Maximum flight load 156    
NOTE.-The average flight load is 105 amps. (c) Double generator and battery failure Once the batteries are discharged, no electrical services can be operated, e.g., trim tab actuators, tailplane motors, electro-hydraulic selectors, etc.  If the flying controls are in Power, Manual selection will not be possible unless Mod. 502 is embodied, in which case Manual may be selected by pressing the emergency selector buttons. In addition the fuel gauges and electrically-operated flight instru- ments will become unserviceable. The fuel booster pumps will cease operation which may entail reduction in altitude and engine r.p.m. (See para. 57(e).) No relight facilities will be available. (d) Action in the event of double generator failure (i) If complete generator failure occurs, switch off all non-essential electrical services to conserve the battery for as long as possible. (ii) Switch OFF the tailplane interconnection (when fitted) and set the tailplane angle to ½° nose-up.


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