Purchasing a
Kit-Built Helicopter
As I travel around the country providing helicopter flight instruction,
airworthiness inspections, and maintenance training to builders
and new owners of different models of helicopters, I see an increasing
trend in purchases of previously-built kits that have changed ownership
once, if not several times. Often there are no maintenance or service
records accompanying the helicopter, and sometimes the records that
do come with it are inaccurate at best. The owner/repairman has
the liberty to put anything on those records that he sees fit without
anyone looking over those records to insure accuracy of the entries.
I have found on more than one occasion that the records in no way
match the actual service and maintenance history of the helicopter
but seem to be concocted to provide a spotless history to aid in
the sale of the helicopter. The buyer needs to spend some time investigating
the actual history of the helicopter prior to laying down his/her
hard-earned cash and finalizing the deal. I have learned this the
hard way.
In this article I will provide several true stories that I am familiar
with from personal experience. There are many more that are less
dramatic that I could share but these that I am including should
cause the reader to ask themselves whether or not they have taken
the time to properly investigate the helicopter’s history prior
to committing to it’s purchase.
Over the past 20 years I have built three helicopters, 2 Rotorways,
an UltraSport 496 2 place and assisted in the completion and overhaul
of many others. The first kit helicopter that I purchased was a
previously built Rotorway Exec 152. I fell in love with this helicopter
at first glance, purchased it and hauled it home. It was the most
beautiful flying machine that I had ever seen (I had succumbed to
a major case of got-to-have-it-itis). I knew nothing about helicopters
so when I performed the pre-purchase inspection I went through the
motions of checking everything out, although I did not have a clue
as to what most of the components were and less of a clue about
how to determine each components airworthy condition. It looked
good to me so I wrote the check and proudly transported it to it’s
new home while entertaining visions of soon soaring around the neighborhood
in my new flying machine.
When the helicopter was unloaded from the trailer and snug in it’s
new hangar I took the time to take an in-depth look at my new dream
machine. I was surprised to see that the frame (which was at that
time painted black) had several cracks at or near the welds where
the tubular frame members were joined. Due to the black paint, the
cracks were very hard to see unless the light was just right. This
is why we always suggest the frames are painted white so that any
cracks will show up as dark lines against a white background. These
early kits were sent out with the frames just tack welded together
and it was up to the builder to finish the welding process.
I called the factory to find out what to do about the cracks and
Tom Smith advised me that the frame was most likely welded with
an electric welder instead of with a gas torch. He explained that
the gas torch heated the frame components evenly and as they cooled
slowly the stresses were relieved evenly. If the frame was welded
with an electric arc, the heating was less even and often the resultant
stresses in the frame would, in time, lead to cracks forming in
the frame.
I elected to take the helicopter apart down to the frame and then
sand blast the frame to remove all of the paint and primer. Next
I gas welded the entire frame where it was cracked. I used the torch
to heat all of the remaining welds to anneal them, relieving any
remaining stresses.
During the rebuild process I noticed a lot of items that were not
up to aircraft standards. As I went through these items and fixed
the deficiencies one by one, I realized that although the seller had
told me that the ship was “ready to fly”, it was actually un-airworthy
and required months of effort before it was indeed safe to fly. When
I thought it was ready, I hired Darrold Crawford (who has built at
least 60 of these helicopters) to travel out from Utah to California
to inspect it.. This inspection took 7 days due to the myriad of items
that did not meet his critical eye. Those items were fixed one by
one and on day seven we hovered the helicopter.
In those days we did not have the internet and the extensive networking
of builders and flyers of Rotorway helicopters that we have now.
It was up to each builder to figure out most of the building process
on their own. The manuals provided by the factory were poor at best
and contained many of the errors that we still find in the present
162F manual. Today any builder who wishes can take advantage of
the great store of experience and knowledge that is out there with
a click of the mouse, a few minutes on the phone, or a visit from
one of the industries professionals to check out his/her progress.
I am often called on to assess the condition of a helicopter prior
to it’s purchase and more often called upon to inspect and help
repair one after the new owner has it home. As I am writing this
article, I am on an airliner over Oklahoma returning to California
to finish rebuilding a recently purchased kit helicopter that had
a dubious past and nearly got my student and I killed 3 weeks ago.
We had to wait for a few parts from the factory before we could
complete the rebuild.(I share this so that others will learn by
reading what I learned the hard way).
The new owner called me to tell me he had purchased an Exec 90
with all original components and 269 hours logged. The maintenance
records were all there and “appeared to be complete”. After looking
at all of the available information I gave the new builder a shopping
list of parts to order so that we could replace those that had exceeded
their calendar lives or had known problems. At the scheduled time
I arrived in California to assist the new owner in replacing the
secondary drive, all belts and hoses, installing new elastomeric
main rotor bearings, new coolant, etc. During the airworthiness
inspection I noticed that the upper engine mount was broken in 2
places and the engine adjustment screw was fractured, and several
of the heat shields were cracked at their mounting brackets.
Once all of the apparent deficiencies were fixed and maintenance
items were completed, we rolled the helicopter out to the ramp and
fired the engine. It ran smoothly as we began the belt break-in
procedure. After the belts were adjusted several times, and the
blades were tracked and balanced we began hover testing the helicopter.
We logged 4 hours of hover testing/inspection/belt adjustments and
everything was running like a top. It was time to take it around
the pattern for in-flight testing so hour five was spent completing
several flights in the pattern with shut-down and inspection between
each flight.
Hour six was the doosy! I had meticulously inspected every component
of the helicopter that I knew to inspect and my confidence in the
ship was growing with each flight. The belts had stretched to the
point that we could fly an hour between adjustments. The southern
California airport that we were flying from was totally surrounded
by commercial and residential structures with very few emergency
landing sites. I elected to head for the Pacific Ocean coast some
3 miles to the west were we would not be flying over the congested
areas longer than we absolutely had to. This area offered us many
emergency landing spots where beaches and bluffs overlooking the
Pacific were plentiful.
We flew over the coastline for about 15 minutes when I decided
to return to the airport to once again check the helicopter systems
and belt tensions. We entered the traffic pattern as directed by
the control tower, Turned down-wind over homes and factories, and
while on our final approach to taxiway Alpha at about 30 feet agl,
the entire helicopter began to buzz. I had never felt this in any
of the hundreds of helicopters that I have flown and instructed
in. I could feel the cyclic, collective, antitorque pedals, and
even my seat vibrating at a high frequency that felt like the entire
helicopter had been set to receive incoming cell phone calls and
the switch was set on “vibrate”.
I have always taught my students, “When in doubt, auto out”. Since
we were at approximately 30 feet in the air I just lowered the collective,
headed for the ground, flared, and set the helicopter down. I told
my student (he was already a commercially rated helicopter pilot
and I was providingh him transition training) that I was going to
exit the ship to look for the source of the BUZZ while he held the
controls. I immediately heard a ticking sound coming from the area
of the tail rotor as the ship idled. As I looked back at the tail
rotor it suddenly stopped and fell downward at around a 30 degree
angle. My heart nearly stopped as abruptly as the tail rotor had.
We shut the helicopter down and upon inspection found that the
tail rotor shaft had fractured and broken where the drive pulley
is bolted through it. I had never heard of this shaft failing before
this event. We realized that had we been at altitude when the buzz
first occurred, I would not be sitting here writing this article.
The tail rotor would have departed the helicopter and the resultant
lack of weight at the rear of the tail boom would most likely have
put us into such a forward CG(center of gravity) that aft cyclic
would not be able to keep us from becoming a lawn dart. It caused
me to shudder to think of how close my student and I had come to
becoming only memories.
What had I missed? I am considered to be one those who are knowledgeable
when it comes to the Rotorway line of helicopters. I fly them, I
build them, I inspect them, I instruct in them, I fix them, what
had I missed that had caused this near disaster?
A call to the previous owner revealed that the reason that he had
sold the helicopter was that he had suffered a tail rotor strike
during a practice autorotation. He had decided that he would sell
the helicopter after replacing the tail rotor blades that had been
destroyed. If I had known about the tail rotor strike I would have
given the tail rotor shaft a much closer look for damage, although
the fracture was hidden under the drive pulley flange and would
not have been visible without removing the pulley. Since there is
no known history of this shaft breaking, I would most likely not
have thought to replace the shaft even if I had known of the strike.
In the future I will be keenly aware of this area and will replace
that shaft if there is any suspicion of damage to the tail rotor
blades.
I called the factory and talked to Tom Smith regarding the failure.
He told me that the helicopter serial number had quite a history
of replaced parts and that it had suffered several tail rotor strikes
without any record of the tail rotor shaft being replaced. The factory
keeps track of parts that are purchased for each serial number kit
and that information could mean the difference between life and
death for the new owner and his or her flight instructor.
Over the past 20 years I have learned an incredible amount about
kit helicopters, much of it from personal experience. I make it
a priority in life to pass this information on to other owners and
builders, many of whom are my students, in order to keep others
from experiencing the same problems and failures that I have encountered.
I encourage everyone involved in this industry to share their experiences
so that we can all live to enjoy these marvelous flying machines
while respecting their limitations.
Part 2.
Several years back I was relaxing at home after returning from
a 10 day instructional trip. That afternoon I received a call from
a new owner of an Rotorway Exec 90 who needed flight training. He
was only a 2 hour drive from my home and wanted to know if I could
start his training the following morning. I agreed since I was not
scheduled for anything for the following week.
When I arrived at his hangar I performed an extensive airworthiness
inspection and we spent nearly 6 hours fixing and adjusting a number
or components that needed attention. I inspected the log books that
came with the helicopter and saw that over the 296 hours that the
helicopter had flown, the required maintenance had been performed
exactly as called for in the helicopter’s maintenance manual. I
was actually impressed by the thoroughness with which the previous
owner had logged everything that was done to the helicopte,r including
every valve adjustment and bolt torque performed over it’s life.
It had been given an annual inspection just prior to my student
purchasing it so everything appeared to be good to go.
After determining that the helicopter was ready for flight, we
fired up the engine and began our hover testing. The engine was
a bit weak but that is not abnormal for one having nearly 300 hours
on the meter. It seemed to run well so after several short hover
flights I determined that it was safe to begin my student’s hover
training. About 30 minutes into the hover training the engine made
a loud bang and then quit. I set it on the ground, and we hiked
back to the hangar at the other end of the airport to get my student’s
truck, a tow rope, and the helicopters ground handling wheels.
We put the wheels on the helicopter, attached the rope to the bumper
of the pickup and the front landing gear legs of the helicopter.
I agreed to walk along holding the tail boom of the helicopter down
to lift the front of the skids as he would SLOWLY drive the truck
to pull the helicopter back to the hangar. All was going well until
about half way down the runway he received a cell phone call and
forgot that he was pulling the helicopter behind him. The truck
started going faster and faster and my walk became a trot and then
finally long striding jumps as I attempted to keep the helicopter
tracking behind the now accelerating truck and my oblivious student.
Just as I was about to loose control of the helicopter (I could
envision myself sprawled on the runway as the helicopter careened
off into the ditch that ran along it’s length) my student glanced
back and slowed down.
We finally got the helicopter back to the hangar and removed the
valve covers to inspect the valves. We found one of the exhaust
valves had stuck in the open position and a piston had hammered
into it causing the top of the piston to disintegrate. We decided
to remove the engine and send it back to the factory for overhaul.
They determined that the valves had not been adjusted in over 100
hours and this lack of maintenance had led to the valve failure.
Remember that the maintenance manuals were complete and showed that
all valves had been adjusted as per the manual.
The new owner called the builder who had made the log book entries
and who had given the helicopter a fresh annual inspection including
logging the recent valve adjustments. The previous owner told the
new owner that the ship was impeccably maintained and that it was
not his problem, and don’t call him anymore as he was not interested
in hearing about any problems with the helicopter. Obviously this
previous owner had doctored the maintenance records to show complete
compliance with the helicopter maintenance schedule while neglecting
to actually perform the maintenance itself. We need to be very careful
in looking at the history of any helicopter that we purchase. The
paperwork will only show what the previous owners wish them to show.
If that person does not possess the degree of integrity that we
assume he should have, the logs may show a much brighter picture
of the machine than what we are actually getting when we hand over
the purchase money.
If you are considering the purchase of a used kit helicopter, do
some investigation into it’s history. Inspect it thoroughly, and
ask the seller the reason that components have been recently replaced.
These machines can be a lot of fun but can also bite hard if something
goes wrong at the wrong time. |