By the time
your are reading this article the weather should be getting spring-like
and thoughts of getting the helicopter out of mothballs for a great
season of flying begin to take shape. I recently have talked with
a number of builders who are nearing completion of their Rotorway
helicopters and who are scheduling their upcoming helicopter flight
training.
Over the past several years we have had numerous requests for flight
training here at our facility in Missouri. We have had students
bring their helicopters here for training but we have not been able
to provide training for those pilots that want to train in our own
helicopter. We have now purchased a new 2004 Robinson Beta II helicopter
that we will be able to offer training in. We also have a Hughes
300B for those that wish to train in a helicopter with a fully articulated
rotor system.
Remember that professional training is a must. There is no room
for error in a helicopter with a semi-ridged main rotor system,
the type that is found on the Rotorway and Robinson helicopters.
A few moments of inattention or a stupid mistake can have fatal
results.
In my flight instructing I instruct both non-rated pilots, CFI’s
with fixed wing and/or helicopter ratings, and those with many thousands
of hours of fixed wing experience. Typically the helicopter pilots
and CFI’s hire me to provide transition training for them into their
experimental helicopter.
Fixed wing pilots use certain control inputs to get out of trouble
and those same inputs can get you killed in your helicopter. If
the fixed wing airplane that you are piloting approaches a stall,
the proper response is to decrease the wing’s angle of attack by
pushing the elevator control forward. By lowering the nose of the
aircraft the angle of attack of the wing in lessened and the velocity
of the air passing over the wing surface is increased creating more
lift.
During our initial fixed wing training we practice a number of
power on and power off stalls. The reaction to the airplanes pre-stall
warning or the actual stall of the wing is engrained in our automatic
response to that condition.
When flying a helicopter with a semi-ridged rotor system, this
same automatic response can be fatal under certain conditions. If
you are in a climb and initiate a level off by rapidly applying
forward cyclic, the inertia of the helicopter and passengers continues
upward while the rotor system initiates a downward pitch. This can
cause the main rotor of the helicopter to unload. The pilot will
feel light in the seat and the helicopter may begin a roll to the
side and a loss of cyclic control will be experienced.
When the rotor system of the helicopter is unloaded, only SMOOTHLY
applying aft cyclic input will reload the rotor system to allow
cyclic control to be regained. If the pilot does not recognize this
condition and incorrectly applies lateral cyclic input to counteract
the un commanded roll, the unloaded main rotor system will react
violently allowing the teeter stops of the blades to slam into the
main rotor mast with catastrophic results. This condition is known
as Mast Bumping and has caused the in-flight separation of the rotor
system in a large number of helicopters in the past. That is the
main reason for SFAR 73 that requires a minimum of 10 hours of awareness
training in Robinson helicopters prior to any solo flight in a Robinson
helicopter, no matter the number of flight hours in other helicopters
previously logged by the pilot.
The US military lost a number of helicopters with semi-rigid rotor
systems in the early years of the Vietnam War when they were developing
terrain following (nap-of-the-earth) techniques. This is where the
helicopters flew just above the surface following the contours of
the terrain. When they would crest the rise over a ridge and apply
forward cyclic input to follow down the other side, the rotor system
could unload and the mast would depart the helicopter and the ship
and crew would be lost.
Do not allow yourself to get into this situation. I have seen something
similar happen right in front of me and around 30 other witnesses.
We were at a large Rotorway helicopter gathering in California.
A Rotorway pilot friend of mine was flying down wind and apparently
reached down to pick up a water balloon off the floor of his helicopter
to toss at a target on the ground. He was flying solo and was attempting
to do a balloon bomb drop that requires a passenger. The nose of
his helicopter dipped down, the helicopter did a 90 degree roll
to the left, one of the main rotor blades dipped and severed the
tail boom, and the helicopter plummeted to the ground where it erupted
in a ball of flames.
Flying the Rotorway helicopter can be safe and very enjoyable if
certain precautions are taken. Remember that this helicopter is
an Experimental machine that does not meet the rigid design standards
of a certified helicopter.
Last week I visited with Frank Spavale in the St. Louis area. We
were talking helicopters and he pulled out a photo that was the
result of his last flight in an experimental helicopter. He had
been flying over a densely forested area when his engine quit. He
immediately entered an auto-rotation to maintain his rotor RPM.
There were no roads, fence breaks, or openings at all in the forest
canopy so he flared into the tops of the oak trees some 100 feet
above the ground. As the helicopter crashed down through the trees
it inverted. When it came to rest upside down it was impaled on
a 5” diameter tree that had broken off about 10’ above the ground.
The tree went up through the roof of the helicopter, then through
the passenger seat taking a 3” chunk of Frank’s leg with it, and
then on up through the tub. The helicopter looked like a painted
olive on a 5” wide toothpick.
Frank was a very experienced pilot at the time of this crash.
He had built 8 Rotorway helicopters and was well known in the Rotorway
community in those days. What did he do wrong? He did not allow
himself an option for an emergency landing. When you do not allow
yourself an option, you have just that, no options should something
go wrong.
Remember that we are flying experimental helicopters that statistically
will at some point in time experience a failure that will put you
into intimate contact with the ground in a hurry. There are those
that have experienced engine and drive train failures in their experimental
helicopter, and those that will. To date I have had at least 4 instances
that required me to immediately auto-rotate to the ground.
As I have said in a previous article, I did not fly Rotorway helicopters
for about 6 months in 2003 due to my wife’s ailing health. In March
of last year while performing hover training in an Exec 90 the student’s
helicopter experienced another engine failure.
This failure was in part a result of falsified maintenance records
and a lack of required maintenance by the previous owner. The person
that my student had purchased the helicopter from had entered into
the log books that all maintenance was completed including all required
valve lash adjustments. This helicopter had over 300 hours on it
and it sucked a valve during our hover training. Rotorway tore the
engine down and stated that it had been at least 100 hours since
the valves had been adjusted.
A couple of weeks ago I was providing phase two training when the
162F’s engine began severely missing. We were over open ground so
I initiated an immediate auto to the ground. Once we reached the
ground the engine stopped completely. Upon investigating we found
that the upper main engine seal had allowed oil to spay up onto
the flywheel. The flywheel then flung the oil onto the two crank
sensors, which do not like oil. The FADEC computers began swapping
control of the engine systems back and forth rapidly until they
both failed completely. After talking to Rotorway, the engine was
removed from the helicopter, crated, and is on it’s way back to
the factory for tear down and repair- it has a total of around 60
hours on it.
I still fly and instruct in Rotorway helicopters in spite of their
shortcomings. If you fly knowing that the engine or drive train
may quit at any time, you will always keep your landing options
open. Perform the required maintenance as per your helicopter manuals,
preflight your helicopter thoroughly prior to flying it, plan your
route so that you are not over areas that will prevent you from
executing a safe auto-rotation, and don’t take unnecessary risks.
Knowing the limitations of your machine will allow you to have
hundreds of hours of enjoyment while staying safe. Get the proper
initial training, then continue to get refresher training either
at the factory, a flight school, or from a Rotorway-experienced
flight instructor.
Fly safe,
Orv Neisingh R/H CFI
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