Bell 47G Pilot Notes
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B47 Tips
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Preflight checklist
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Startup Procedure - Turbocharged
engine
Emergencies:
For the best outcomes in an emergency situation,
A PILOT MUST CONSTANTLY MENTALLY RUN THROUGH THE EMERGENCY PROCEDURES DURING NORMAL OPERATIONS.
Many emergency actions should not be practiced
unless with a type qualified pilot/instructor and in a helicopter with
dual controls.
CONSIDERATION SHOULD BE GIVEN TO THE PRACTICALITY
OF MAYDAY/PAN CALL OR EVEN, IF TIME PERMITS - AND IT DOES IN SOME
EMERGENCIES - USING THE RADIO TO ASK A MORE EXPERIENCED PILOT FOR
ADVICE.
REMEMBER, IT IS TOO LATE WHEN THE EMERGENCY OCCURS
TO START THINKING WHAT YOU SHOULD BE DOING.
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JAMMED COLLECTIVE
Review:
whenever you are airborne - visualise where you are on the
helicopter's Power Required Curve and the helicopter response
from the Primary and Secondary
effects of the controls
INDICATIONS: THE COLLECTIVE WILL/MAY BE
LOCKED SOLID
AIRMANSHIP: MAYDAY-PAN-ASK FOR
HELP/ADVICE
ACTIONS:
First check that the collective friction is
off and nothing is obviously jamming the collective lever. (Check the
dual collective if fitted).
If there is nothing obvious proceed as follows:
Note the M.A.P. at which the collective is
jammed. Compare this with the power required to hover at your last
takeoff.
If the power indicated is less than hover
power proceed as follows...
Excess height can be overcome by diving the
helicopter (watch your VNE) to about 200-300 feet AGL at a suitable
landing area (about a 100 yard long clearing).
Set yourself on finals with the ambient wind
preferably from the left front, the next best is straight ahead. The
worst is from the right front.
Wash
off your IAS in a tight turn until about 15 Kts is attained as you roll out
on to finals.
An attitude/IAS of less than effective
translational lift will be required next.
NOTE: THIS IS AN ATTITUDE/IAS MANEUVER
- NOT A RATE OF CLOSER MANEUVER.
Hold the attitude/IAS to give
a R.O.D. of not more than 300 ft per minute. (To avoid vortex ring).
If it appears you are
undershooting the
landing area, a small (1/4 inch) change in attitude to increase the IAS will slow the R.O.D. and make the approach angle shallower.
If you are
overshooting a small decrease in IAS
will steepen the angle but this will also increase the R.O.D. which -
with the low IAS and medium power setting - will put you in the area
of Vortex Ring.
In the case of over shooting,
decreasing the RPM with throttle will increase the R.O.D. and steepen the angle
without reducing the IAS.
In practice the RPM can be reduced to as
low as 2900 ERPM. In the real situation it can be reduced lower but
not lower than 2850 ERPM.
It may be safer, if you are overshooting, to
carry out a descending orbit.
At about 20 ft. AGL there will be a strong
instinctive pilot tendency to slow the helicopter to keep the closure
rate constant. THIS IS WRONG!!!! Don't do it!!!
To overcome this tendency, visualize the
helicopter power curve and at 20 ft, push the cyclic in the direction
the helicopter is traveling to make a small acceleration and
therefore increase the IAS.
This makes the helicopter more efficient
and reduces the rate of descent.
At 3 ft AGL, gently reduce the IAS and the
helicopter will slowly sink onto the ground. (Again think of the power
curve to see why this happens).
On the ground reduce the throttle, hold heading
and when the helicopter has stopped switch off the engine.
If the collective has jammed at very high
power which gives you OGE performance the following methods
may be used to get the helicopter to descent...
Reduce ERPM out of the green
operating range down to 2800 ERPM
Carb heat on. This richens the
engine fuel/air mixture and reduces engine power
Turn one magneto off (This is a last resort at below 10 Ft AGL -
as you
don't want an engine failure with a jammed UP lever )
At low power the angle will be flatter with a
higher IAS.
At high power the angle will be steep and IAS
lower.
With a jammed collective the helicopter can be
normally flown to a suitable place.
THERE IS NO NEED TO OVER REACT IMMEDIATELY AND
CRASH A HELICOPTER WHICH IS STILL CAPABLE OF SAFE FLIGHT!!
.........................................................
JAMMED OR LOSS OF THROTTLE CONTROL
Review:
whenever you are airborne - visualise where you are on the
helicopter's Power Required Curve and the helicopter response
from the Primary and Secondary
effects of the controls
INDICATIONS:
THE THROTTLE WILL NOT MOVE
THROTTLE MOTION HAS NO EFFECT ON MAP & RPM
ACTIONS: Very similar to a jammed
collective. The collective can be used to make the helicopter descend.
Lowering the pitch will ensure RPM overspeed
and vice versa, so there is a limit to the amount that the pitch can
be lowered. IAS can be used as in jammed collective.
Again a magneto can be turned off if
NECESSARY to make the machine finally descent.
If necessary the engine can be stopped and an
autorotation carried out. NOTE: first fly to a suitable
area and burn off excess fuel to make the auto easier.
Remember you are more likely to break the
helicopter in auto than using the IAS control procedure.
Sometimes with a throttle control failure the
throttle may wind off requiring lowering of pitch to maintain RPM and
maybe forced into auto or the throttle may wind on requiring a pitch
increase to control RPM.
THIS WILL MAKE IT DIFFICULT to descend using
the IAS control method. At least it will be possible to stay in the
air even if the engine is over boosting.
An auto may be inevitable but at least fly to a
suitable area before entering the auto. Turning off one magneto to
reduce power may allow the use of an IAS control landing but is
unlikely if the helicopter is only moderately loaded!
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FIRE IN THE CABIN
INDICATIONS of this will be obvious.
If it is
electrical turn off battery and generator.
If the cause is not
obvious, i.e. .. if the smoke is coming from a radio, pull the radio
circuit breaker.
If the fire is caused by something else i.e. dropped
cigarette, use the extinguisher and remember to open window and doors
to get rid of smoke and extinguisher fumes.
...............................................................................................
HYDRAULIC FAILURE
INDICATIONS:
The cyclic will become
stiff and suffer from feed back. It will become easy to over control
on the cyclic. The collective, if fitted with hydraulics, will become
stiff to operate.
ACTIONS:
Maintain the I.A.S. to between 35 and
53 Kts using small firm cyclic corrections.
Cycle the Hydraulic switch on the
instrument panel ensure it is on.
If the hydraulics are not restored turn off the
hydraulic switch and leave it off.
On helicopters with electric hydraulic switch
pull the hydraulic circuit breaker to check if an electric
malfunction is not the problem.
If this does not restore the
hydraulics push in the circuit breaker and then turn off the
hydraulics.
Electric power is required to turn OFF the hydraulics.
Land within 20 minutes using a shallow
approach with a short running landing.
The helicopter can be hovered
quite successfully with hydraulics off if required.
The hovering
attitude must be held closely with small early corrections.