User Guide

225
Flight Instruction
224
Flight Instruction
CROSS-START
If you have an unusually strong battery, or if you’re running
on external power, you can go ahead and start the other engine
the same way. In the real world, however, most batteries only
have enough energy for one nice, cool start; we’ll give both our
battery and the second engine a little help.
Begin by moving the condition lever on the engine you’ve
just started (the right engine) to the HI IDLE position. Now, on the
left subpanel, hold the R GEN switch in the RESET position for at
least one second, then move it to ON. You’ll see the R GEN FAIL
light on the annunciator panel extinguish, and the right ammeter,
above the windshield, will show a hefty charge rate. In about six
seconds, you’ll also see the BATTERY CHARGE annunciator. Go
ahead and charge the battery until the loadmeter has dropped
back to about the 50% mark.
Now, turn the right generator back OFF. This seems para-
doxical, but there’s a reason: the starter draws the most current
during the first few seconds after you turn it on, when it’s accel-
erating the engine from a standstill; then its current requirements
drop off quite steeply. If you suddenly hit the operating generator
with a huge load like that (up to 1000 amps!), you’re asking for
trouble. At best, you’ll probably blow a current limiter - a big, very
expensive fuse - down under the floor; you can’t fly until it’s been
replaced. At worst, you’ll blow a “mechanical fuse”: in order to
protect the unbelievably expensive gears in the engine, there’s an
intentional weak point in the only hideously expensive starter-
generator driveshaft, which will shear if hit with a sudden load.
Either way, you’re not going flying until you’ve called a mechan-
ic...and maybe the bank...
Now move the left ignition/start switch to the ON position,
and watch the left NG start to wind up. When it hits 10%, you
know you’re past the big amperage load, so now go ahead and
hold the R GEN switch to RESET for one second, then move it to
ON. You’ll notice that the left NG will now wind up a lot faster,
and stabilize at a higher level, since it has the right generator help-
ing the battery - and as you continue the start, the ITT will peak at
a much lower level. Once the left engine is stable, move its igni-
tion/starter switch to OFF, reset and turn ON its generator, and
finally bring the right engine’s condition lever back to LO IDLE.
Conventional King Air wisdom suggests starting the right
engine first, since the battery is in the right wing root and the cable
run to the right starter/generator is shorter. Actually, on most later
King Airs, the big junction box with the start switching relays is in
the middle of the airplane anyway, so it doesn’t make much dif-
ference, but tradition dies hard. Move the right ignition/engine
start switch up to the ignition/engine start position. The R FUEL
PRESS annunciator should extinguish right away, and the right NG
tach will start to wind up. The green R IGNITION annunciator
should also be on at this time.
Now take a quick glance to see if the right oil pressure is at
least beginning to stir off its peg. Wait for NG to stabilize above
12% - the higher, the better - but don’t waste any time once it
does.
Now is when things are going to start happening faster. Move
the right condition lever to the LO IDLE position, and keep your
hand on it in case you have to abort the start. You’ll see a momen-
tary “kick” of the right fuel flow gauge, indicating that jet fuel is
being sprayed into the combustion chamber. Within no more than
10 seconds (generally a lot less), you should hear the “Whoompf!”
of lightoff, and the ITT gauge should come to life.
Watch it like a hawk! It’ll rise rapidly at first, then hesitate,
then start rising again as the secondary fuel flow nozzles kick in.
By the time it gets to about 700 degrees, the rate of rise should be
slowing perceptibly. If it’s still zipping on up, I’d suggest aborting
the start by pulling the condition lever back to idle. Don’t de-ener-
gize the starter - even after the fire has gone out, you still need to
keep plenty of air moving through the engine to cool it back down.
In a normal start, of course, that won’t be necessary; just
keep an eye on ITT as the NG continues to accelerate. At 50% NG
RPM, you can move the ignition/engine start switch back to the
center OFF position. At this point, you can relax: the engine is self-
sustaining, and the start is complete.