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 14 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 (and this is why we always suggest
the frames are painted white where 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, sand blast
the frame to remove all of the paint and primer, and then gas weld the
entire frame where cracked and 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 to date built at least 60 of
these helicopters, to travel out from Utah from California and inspect
it for airworthiness. 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 bound for 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. (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. PLACE PHOTOS 1, 2, & 3 here
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 (already a commercially rated helicopter pilot that I was providing
transition training to) 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. Place photo 4 here
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 but the
realization 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 and had decided that he would sell the helicopter after replacing
the tail rotor blades. 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 15 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 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 done to the helicopter
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 rotor 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.
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