PART III - HANDLING

            tial, the test should be carried out as often as possible
            as a check of serviceability and to ensure against the
            system becoming sluggish.
       (ii) With the parking brakes on, open up to 80 per cent.
            r.p.m. and move the emergency fuel system switch to
            ON.  Open the throttle slowly and carefully to fully open
            and check that the r.p.m. do not exceed 100 per cent. to
            101 per cent.  If the r.p.m. reach 101 per cent. before
            the throttle is fully open the emergency fuel system is
            unserviceable and the aircraft should not be flown.
       (iii)While still at full throttle move the emergency fuel system
            switch to TEST.  The r.p.m. will fall to about 96 per
            cent. r.p.m. on a normal day, about 91 per cent. on a
            cold day and to 99 per cent. on a hot day. The initial
            drop may be rather more than these figures but the
            recovery time from the moment of selecting TEST to
            stabilizing must not exceed 3-4 seconds.  If it does, the
            emergency fuel system is unserviceable.  Repeated tests
            of a serviceable emergency fuel system during the same
            run-up should not differ by more than 1 per cent.
       (iv) Finally, move the emergency fuel system switch to ON.
            The r.p.m. should then return to the original full throttle
            figure.  If it is intended to use the emergency system
            during take-off as a safeguard, leave the switch on, release
            the brakes and commence the take-off.  Otherwise the
            switch should be returned to OFF before releasing the
            brakes.
            NOTE:-(a)   If it is necessary to throttle back to less than
                        80 per cent. (either before or after take-off)
                        switch the emergency fuel system OFF
                        before opening up again.  This is to ensure
                        that the emergency system does not over-
                        ride the main system during the early part
                        of the acceleration period causing com-
                        pressor stall and possible flame extinction.
                  (b)   If an unserviceable emergency fuel system
                        results in overspeeding, the throttle must be
                        closed to prevent possible damage.  If the
                        r.p.m. exceeds 104 per cent. irrespective of
                        j.p.t. the engine must be stopped, and will
                        have to be removed for overhaul.

       56.  Take-off

       (i)  Align the aircraft on the runway and where possible
            test the emergency fuel system.

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