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external start and, depending on the
type of battery, a battery overtemp
warning system. External power
should supply 28 volts, 400 amps.
LongRanger
The starter/generator has a greater
capacity. Voltage regulation and
reverse current protection is done
with a single solid-state unit,
replacing the 206's carbon-pile type.
The generator will not come on-line
with external power is applied.
Another point to note is that the left
boost pump is directly connected to
the battery, regardless of whether the
battery switch is on. This is to
provide constant boost pressure if
the main battery relay fails.
Switching off the fuel shutoff valve
or pulling the appropriate circuit
breaker are the only ways of
146 The Helicopter Pilot’s Handbook
ensuring you don’t flatten the battery
after shutdown.
Oil
The engine oil capacity is 5.5 US
quarts (minimum 4). Oil
consumption is very economical, and
if the oil is up to the mark on take
off, you shouldn't need to top up for
some hours unless you get an oil
leak. The oil grades are MIL L 7808,
or 23699 above –30ºC.
Transmission oil capacity is 5 US
quarts.
In the LongRanger, a single unit
with 2 separate elements (for engine
and transmission) replaces the
individual units on the Jetranger. It is
mounted above the oil cooler blower
Fuel
The JetRanger II and III have the
same fuel tank, which is a singlebladder
type under the aft passenger
seats, holding 76 US gallons (92 in
later models), which can be
increased to 96.7 with a range
extender, giving you an effective 2.5
hours in the air (if a range extender
is used, the minimum pilot weight
needs to be 200 lbs). The tank is
fitted with two boost pumps and
quantity transmitters. The enginedriven
fuel pump and fuel filter are
on the engine casting. The fuel tank
has its own C of G arrangements,
meaning that the moment varies
with the fuel load.
The fuel type is Jet A, A1 or B, JP4,
JP5 or ASTM D 1655. The 206 A, B
and BII are limited to -18 °C with
JET A or JP5, as is the B III, unless
it has a red triangle on the fuel
pressure gauge which allows
operation down to -32 °C.
The TAS for flight planning
purposes is 100 kts, or 110 kts for
the L.
Starting mechanism is either Ceco or
Bendix. The latter uses air pressure
between the governor and fuel
control, while the latter uses fuel
pressure. The Ceco is out of date,
but is still around - the essential
difference between the two is found
when starting - with the Ceco, you
can control the ToT with the
throttle.
The flight manual says that boost
pumps shall be on for all normal
operations, so don't turn them off
until after the engine when shutting
down. However, when starting,
many pilots use only the aft one,
because having both on can mask
problems with the engine driven
pump, which needs help above 6,000
feet, hence the limitation (boost
pumps in turbines are for bleeding
lines and/or fuel draining – they
create a lower than atmospheric
pressure to suck fuel up).
Consumption
Normally, 29 US gals per hour.
Fuel type Jet A-1
Start, taxy and climb to
2000'
3 US gals
Normal cruise consumption 29 US gph (114
lph)
Unuseable fuel 2 US gals
Minimum inflight contents 6 US gals
Maximum contents 76 US gals
Max contents with range
extender
96.7 US gals
Heater consumption 2 US gph
LongRanger
The main concern is that fuel might
get trapped in the two forward tanks.
The Bell 206 147
The system actually has 3, with the
main one is in the usual 206 location,
and 2 smaller ones under each rear
facing seat, interconnected for filling
purposes, but using pressure from
the boost pumps to create a venturi
to suck the fuel from the forward
tanks back into the main tank, from
where it goes directly to the engine.
As fuel to the engine can only come
from the main tank, a problem in the
transfer mechanism (usually from
contamination) can mean fuel being
trapped and unusable.
Cockpit indications are fuel quantity
and pressure gauges, 2 boost pump
warning lights and a fuel low light.
The quantity gauge derives its signal
from 3 transmitters, one being in the
forward tank, so it will always read
total fuel available. As the Fuel Low
probe is only in the main tank, you
can get a fuel low indication with an
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本文链接地址：
The Helicopter Pilot’s Handbook(97)
