Revolution Mini 500 - is it buildable?

Richard Riley wrote:
An aviation writer friend of mine went to a Robinson training session
a few years ago. He said you had 1.3 seconds to dump the collective
in the R22.

He was thinking of writing an article and calling it "Small Helicopter
Safety: Myth or Fable?"

More recently, Frank Robinson has been reporting it as only 1.1
seconds.
But having said that and having experienced several "throttle chops" in
r-22
helicopters, I can attest that at least my reaction time falls at least
a couple
of tenths below that ! There's nothing like dumping that collective
and feeling
the aircraft pull away from your rear end (no matter how tight those
cheeks
try to hold on to that seat) !

Wayne

Richard Riley wrote:
An aviation writer friend of mine went to a Robinson training session
a few years ago. He said you had 1.3 seconds to dump the collective
in the R22.

He was thinking of writing an article and calling it "Small Helicopter
Safety: Myth or Fable?"

More recently, Frank Robinson has been reporting it as only 1.1
seconds.
But having said that and having experienced several "throttle chops" in
r-22
helicopters, I can attest that at least my reaction time falls at least
a couple
of tenths below that ! There's nothing like dumping that collective
and feeling
the aircraft pull away from your rear end (no matter how tight those
cheeks
try to hold on to that seat) !

Wayne

Dennis,

I see you are back with your same old talking points.

As has been explained, a finding of pilot error does not in any way provide
an endorsement of your design. When your design failed, many pilots found
themselves unable to recover in a manner expected from certified aircraft.
That is the standard. It does not address the design failures that
preceded the pilot errors. It does not address the design's ability to
recover from those failures.

You like to blame the dead, especially low-time dead pilots. You might
have forgotten that you marketed your kit to low-time pilots.

Let's look at the chronology again.


1) Everybody gets excited when they see the Cicare CH-6 prototype fly.
2) You and Cicare dissolve your partnership and you are left without a
helicopter to sell.
3) Without access to Cicare's design or the CH-6 demonstration aircraft, you
attempt to copy the design.
4) While you are still designing your new helicopter, you continue to market
and take orders for an unproven design
5) You delivered kits without adequate testing, claiming TBO's of up to 2000
hours, when your prototype only had a a couple of hundred hours, at most.
6) You marketed your kits to low-time pilots


A classic bait and switch.

Assuming that you make the RIGHT decisioin and don't hesitate or thing
about it.
Richard Riley wrote:
On 7 Jan 2007 14:49:34 -0800, wrote:


More recently, Frank Robinson has been reporting it as only 1.1
seconds.
But having said that and having experienced several "throttle chops" in
r-22
helicopters, I can attest that at least my reaction time falls at least
a couple
of tenths below that !

I've seen medical data that says normal reaction time for an
expected, life critical event (like, someone draws a gun on you, a car
pulls out in front of you) is about 3/4 of a second.

So you got that big, .35 second margin to keep you safe. Nothing to
worry about.

My answer to this post, and below is the last article printed by
KitPlanes Magazine in November 1999 of the flight report wrote by Kin
Armstrong. So if you have already made a negative opinion on the
Mini-500 saga and don't what your opinion to be confused by the facts,
then don't read!!!


anon wrote:
Dennis,

I see you are back with your same old talking points.


There's nothing like the facts to counter unfounded and false
statements. My talking points stay the same, because they are the true
facts. I, unlike people like you, don't have the luxury of changing or
making up stories, or making up or passing on unfounded or untrue
statements. So yes, you will read what I have to say over and over
again, because those are the facts, much to your apparent dissatisfaction.


As has been explained, a finding of pilot error does not in any way provide
an endorsement of your design.


You know, there are people out there that even dispute the fact that
America landed a man on the moon. It just does not matter how much
evidence you put before them, or who provides the evidence, they choose
not to believe it because that is what they want to disbelieve. I give
you Federal accident reports followed up with further company reports,
and still you choose to disbelieve, because that is contrary to what you
want to believe. Even a horse is smart enough to drink water when you
lead him to it enough times, but you will never believe because that is
not what you want to believe, despite the proof or who prints it.


When your design failed, many pilots found
themselves unable to recover in a manner expected from certified aircraft.
That is the standard. It does not address the design failures that
preceded the pilot errors. It does not address the design's ability to
recover from those failures.


Wrong. Many Mini-500 owners say absolutely the opposite. In fact,
attached is a report by the professional test pilot Ken Armstrong,
giving the Mini-500 a brilliant review. The Mini-500 he flew the same
bird that flew from Kansas City to Oshkosh, the same bird that flew at
all the air shows. That Mini-500 was 100% stock all the way, built to
factory specs with all factory mods.


You like to blame the dead, especially low-time dead pilots. You might
have forgotten that you marketed your kit to low-time pilots.


I only tell the facts. I don't even want to talk about it, let alone
blame live or dead people. But you really haven't given be any
alternatives. You put me on the spot, you blame be for killing people
with a bad design, you continually place me in a position demanding
answers, and I can only answer with the facts. If I said it was not
their fault, then I would be lying.


Let's look at the chronology again.
1) Everybody gets excited when they see the Cicare CH-6 prototype fly.
2) You and Cicare dissolve your partnership and you are left without a
helicopter to sell.
3) Without access to Cicare's design or the CH-6 demonstration aircraft, you
attempt to copy the design.
4) While you are still designing your new helicopter, you continue to market
and take orders for an unproven design
5) You delivered kits without adequate testing, claiming TBO's of up to 2000
hours, when your prototype only had a a couple of hundred hours, at most.
6) You marketed your kits to low-time pilots
A classic bait and switch.


You must write fictional books for living!! You have taken history and
twisted it around to your satisfaction.

I'll tell you what, I'll let Ken Armstrong's article in KitPlanes
Magazine do the speaking for awhile. Ken has over 9000 hours flying 40
different types of helicopters. He was a Military helicopter test pilot,
and currently instructs in helicopters.

BUT EVEN WITH A MAN WITH SUCH IMPECCABLE QUALIFICATIONS AND UNTARNISHED
REPUTATION, someone here will find something to discredit him and his
report on the Mini-500. The truth is written below, and yet some of you
will refuse to believe, simply because it is contrary to what you want
to believe.

After all, you read all the bad stuff about the Mini-500 right here on
this newsgroup by credible people, that you have never met or can even
see and some that don't have names... so it must have been true, right????


********Mini Revolution********

Where is Revolution Helicopter’s Mini-500 series heading?

By Ken Armstrong
KitPlanes Magazine
November 1999 Issue

The Revolution Mini 500 possesses an enviable sales record because of
the strong demand for low-cost, kit-built helicopters. However,
marketing success has created problems for the company and its owners.
Revolution has difficulty keeping up with customer expectations, and
some builders unrealistically expect the helicopter to be snag-¬free
during ownership.
In reality, the Mini 500 is no different from any homebuilt helicopter
- or from any commercial helicopter ever produced. They have all
experienced technical/design problems that required modification, and as
a professional helicopter pilot since 1972, I was often the guinea pig
who found out what those problems were. No helicopter design is perfect,
and there is no fling-wing flying that does not have ongoing problems.
What can you do if you own a Mini 500 or plan to buy one? Approach
ownership with an open mind and anticipate some down time while you
install modifications that Revolution considers mandatory for the safe
operation of the helicopter. If you plan to buy a used Mini 500, ensure
all of the mandatory modifications have been completed.

Is the Mini 500 Safe?.....
Any helicopter is only as safe as the pilot in command. There have been
a number of Mini 500 crashes, a number of them resulting in fatalities,
and there is a common thread among them. Accident data from Revolution
and the NTSB, combined with witness reports, indicate there have been
few if any mechanical failures that were not caused by improper
maintenance. In fact, 100% of the crashes had a pilot error component,
with 43% sharing maintenance/pilot error causal factors. Nearly 75% of
the pilots involved in accidents had less than 100 hours rotary wing
experience, and some didn't even have a helicopter rating (more on this
subject in the flight evaluation). Failure to maintain adequate rotor
rpm was a contributing factor in almost half of the accidents. Another
factor was pilots flying with the wrong carburetor jets for the ambient
conditions - an important consideration when operating these
hard-working engines. Operating with a two-stroke engine entails a
higher risk of engine failure than a four-stroke powerplant would, and
pilots must always be prepared to carry out an autorotation.
Another primary factor in the high accident rate for the Mini 500 (44
accidents out of only a few hundred flying) is that there are many being
flown by pilots with relatively little rotary experience, and in a few
of the accidents the pilots weren't even licensed. In the case of an
engine out, proper training and experience is critical.
But other than the higher incidence of engine failures associated with
two-stroke operation and pilot deficiencies, I don't see any particular
safety risk associated with this helicopter, and I wouldn't hesitate to
fly Mini 500s because the autorotative characteristics are quite
reasonable in the event the Rotax takes a time out.

Who Needs Politics?....
I believe the greatest non-technical problem plaguing the Mini 500 is
the polarization between Revolution and a small number of vocal,
dissatisfied owners. Revolution President Dennis Fetters is blessed and
cursed with a strong personality that has bolstered him with the drive
to create the successful Air Command gyro series and now the affordable
Mini helicopter series. But success often breeds problems, and keeping
up with the calls for technical revisions while attempting to provide
really good customer support has been a challenge at Revolution. As a
result, some of the owners have formed the support group known as the
International Helicopter Builders Association Inc. (IHBAI).
Mentioning this group to Fetters is like waving a red flag at a bull.
He feels the organization is trying to undermine his efforts and has
been dishonest about its aims. The group says it simply wants to find
fixes for Mini 500 problems typically agreed to as excessive vibration
creating frame cracks and transmission gears manufactured by a third
party that were not of sufficient hardness. For more details on these
topics, see the May 1999 KITPLANES©.
Having mentioned this builders group, I should add that I met many Mini
500 owners at Sun'n Fun who have experienced no problems with their
helicopters and are having a blast with them. Responses to company
questionnaires indicate that more than 90% of the attendees at company
training programs are completely satisfied with Revolution's efforts. In
the Internet era, it's all too easy for a few unhappy owners to promote
their discontent.

Builders Support Group....
At the 1999 Sun'n Fun meeting, IHBAI members, under President Bill
Phillips, decided they would not hire an engineering team to modify or
fix the Mini 500's problems because they felt Revolution was adequately
tackling the situation. The 14 attendees almost unanimously expressed a
desire to work with the company on problems and fixes. However, Fetters
wanted no association with this group. For the most part, I found these
owners to be levelheaded and simply wanting a solution to their problems
at a reasonable price so they could continue flying.
Stan Robinson, president of U.S. AirPower, talked about the possibility
of installing the three-cylinder, liquid cooled two-stroke engine
currently undergoing flight test in the Revolution two-place Voyager,
but this is unlikely in the near term, especially without Fetters' blessing.

Solutions Are at Hand....
Fetters has always maintained that the company manufactures
modifications quickly and prices them realistically to support his
clients. After many hours of discussion with him, I can appreciate his
point of view and feel the company is striving assiduously to correct
deficiencies and expand the performance and safety envelope.
Solving vibration problems has been a long slow process not because
Revolution wasn't devoting a lot of time to the solution, but because
rotor system dynamics are complex. The late model Talon (the model name
for the improved Mini 500) I flew for this report had the latest
refinements including mast support with rubber isolation, friction
damper on the cyclic system and trimtabs on the rotor system. These
refinements have apparently reduced the overall vibration level from 10
IPS to 0.01 in hover and 0.1 at 95 mph. Revolution asserts that all of
these modifications are recommended because they work together to
significantly reduce vibration. Minimizing the shaking reduces wear and
tear, extends component life and provides greater system reliability.
All new kits include all of the mast support refinements.
An Engine Information System (EIS) is a new option that constantly
monitors cooling, fuel mixture, lubrication and power output for
enhanced reliability. Although I have not evaluated this $675 package,
it comes complete with all probes, wiring and displays to provide a
visual warning in the form in a red light when an engine parameter has
been exceeded. It’s like buying insurance.

Power Enhancement Package....
The factory demonstrator I flew at Sun 'n Fun, 500FD, had the optional
power enhancement package (PEP) installed. The company recommends that
every Mini 500 owner install this system to improve recovery from low
rotor rpm. Faustino Padilla, a 240-pound Guatemalan pilot/owner who
flies his Mini 500 from a base 5000 feet above sea level at very high
temperatures, claims the PEP makes a world of difference to performance.
The PEP system comprises a tuned exhaust system and special carburetion
settings that provide an additional 18% hp and torque equating to an
additional 138 pounds of lift, according to the company. Essentially,
the engine is optimized for the narrow power band necessary for the
helicopter application. Fetters believes that for $950, this is an
inexpensive option that overcomes the need for a more powerful engine,
which would be much more expensive.

Flight Evaluation....
I don't take flights in single-place helicopters lightly, and I've
waited patiently for years for the fleet hours to accumulate
demonstrating the inherent safety of the series (about 28,000 hours to
date, according to Fetters). It was only after a detailed flight
briefing and an impressive demonstration flight by Ricardo Aita, a
company pilot, that I was prepared to place air under the skids. It
turned out I was overly cautious-if that's possible.
Fetters showed me the preferred method for entering the cockpit, and I
found the seat firm but comfortable (firm is best for a number of safety
reasons). The controls came readily to hand for this paunchy pilot of
200 pounds and average height. The control checks with friction off
showed there was no binding or significant friction in the system, and
the friction was then cranked on to meet the company wishes.
I confirmed that the fuel valve was on, skipped the prime with the warm
engine, closed the throttle, neutralized the controls and turned the
master switch on. With the-seatbelt secured, I couldn't reach the
ignition switch, so I had selected both in advance and used the cyclic
mounted starter button to bring the Mini to life. It started easily, and
I idled a short time until the Rotax 582's coolant reached the bottom of
the green. Raising the collective at idle produced a low rotor rpm
warning, the magneto check proved both ignition systems were operating
correctly, and the throttle chop at operating rpm provided a needle
split between the rotor and engine confirming the one-way driven clutch
was operative.
At this point, I wanted to eliminate all friction in the control but
was advised by the company pilot that it was preferable to leave
considerable resistance in the controls. Later I learned that this was
to reduce some of the vibration and stick shake. Although many pilots
prefer to have considerable resistance in the system to minimize pilot
overcontrolling, I prefer no stick trim or friction. I found that the
collective requires some friction in the system or it will rise on its
own during flight-not unusual in some helicopters. Moreover, if a pilot
leaves the cockpit with the engine running, the helicopter could lift
off if the collective is not locked down with a mechanical device or
adequate friction.

Getting Acquainted....
Initially, I had some difficulty mentally adapting to the pedals, which
are shaped like foot rests and move in a slightly different axis
compared to standard pedals. However, after 15 minutes or so of
hovering, I found my body and brain had made the conversion quite
readily. I also found the throttle system friction quite high, and this
resulted in my chasing the engine/rotor rpm somewhat at first-especially
since the correlation system doesn't do it all automatically for the
pilot. However, owners can remove the engine access cover and readily
adjust the throttle friction from no resistance to absolutely locked.
The skill of keeping the rotor rpm at the top of the green can be quite
a challenge for pilots like me who normally fly automatically governed
turbine equipment. My natural fumbling at rotor speed control coupled
with my intentional effort to establish the outside parameters allowed
me to get a really good feeling for the Mini's rotor inertia. It also
allowed me a glimpse into the scenarios that low-time pilots might
encounter and that could lead to the low-rotor-rpm accidents that occur
all too often.
Once I got a handle on the power lever, it was obvious the Mini was a
delight to hover and play with in the ground cushion. It was virtually
free of any noticeable vibration at the recommended rotor speed of
104%-positive proof that the Revolution fixes really work in the hover.
As the rotor speed falls below 96%, some minor vibration creeps in.
However, this is below the normal range and of no real significance
during typical operations.
With the doors off, visibility was excellent in most directions with
minor visual barriers straight down due to the floor and to the sides
due to the doorframes. Nothing unusual there. The Mini had 9 gallons of
fuel on board during the initial takeoff, and the nearly sea level OAT
was 75°F.
Fetters says that most problems on this engine are related to poor fuel
or jetting problems, and after taking a Rotax maintenance course, I know
this to be true in general on two-strokes. As I personally added
high-quality, filtered gas for our operations, I was comfortable with
the anticipated engine reliability and experimented with a broad
spectrum of operating rpms and altitudes. Although the rotor speed's
normal operating range is 96-104%, I conducted operations beyond these
limits and found no unacceptable characteristics.
The combination of relatively high rotor inertia and a sensitive
throttle system results in pilots new to the type chasing the rotor rpm,
but prolonged hovering operations can teach them effective rotor speed
control. While operation in the low yellow rotor rpm band is not
recommended, I found the helicopter had adequate power to recover from
90% or slightly less rotor rpm by milking the collective downward
slightly while fully opening the throttle.
Under the ambient conditions, full throttle produced the following
maximum hover height/rpm combinations: 6 foot hover attainable at 100%,
10 feet at 102% and 15+ feet at 104%. The recommended takeoff power is
104%, so the PEP would obviously produce more than sufficient power for
hovering with the skids approximately 2 feet off the ground at
considerably higher altitudes and/or with much heavier pilots. Unless
you are operating well above 5000-foot density altitude, it would appear
that this engine with the optional PEP is adequate in terms of power
output (assuming that the engine is kept well tuned, with the correct
jets for the ambient con¬ditions, and approved, fresh fuel).

Control Authority....
During a lengthy period of hovering that resulted in improved rotor
speed control as the Mini and I became acquainted, I was able to conduct
numerous hovering autorotations, and I found the Mini had plenty of
rotor inertia to permit gentle touchdowns - even with a slightly drooped
rotor rpm. Over two days, with varying winds, I confirmed that the 20
mph sideways and rearward maximum recommended flight speeds were
conservative and safely flown with no tendency to exceed or even
challenge the tail rotor's capability. There was plenty of control
authority during all maneuvers, and the tail rotor seemed to have as
much power as would ever be necessary at this density altitude. (No
high-altitude testing was conducted during these profiles.) This Hughes
500 lookalike also transitions through translational lift quite
smoothly, and I noted a distinct absence of measurable vibration under
all flight conditions up to 30 mph indicated.
Circuit restrictions, gusty winds and smoke from a forest fire shut
down operations on my second day of flying, so I was unable to conduct a
lot of straight and level flying at normal cruising speeds. Fetters
wasn't keen on my flying in those conditions at all, but my schedule
wouldn't permit a later flight, so I was committed to flying when many
of the other gyroplanes and helicopters chose to sit it out.
Nonetheless, the helicopter flew smoothly up to the maximum speed of 75
mph - an air-traffic induced limit. I wasn't overly comfortable flying
this lightweight under such conditions, but the company pilot who had 60
hours on type subsequently flew the demo in an aggressive and accurate
demonstration program with absolutely no difficulty.
The Mini is not only responsive but also surprisingly stable in
hovering operations, handling like a much larger helicopter. After only
20 minutes in type it was fairly easy to knock over the orange cone
markers with a skid and then stand them up again. This can be
challenging with any helicopter, and it was surprising to be able to
accomplish this intricate task with so little time in type.

Cautious Considerations....
The pilot's operating handbook cautions pilots to apply aft cyclic
while the collective is being lowered after high-speed engine failures
to minimize the helicopter's tendency to nose over. It also advises
avoiding low G maneuvers to avoid chopping off the tail boom. These are
standard cautions with any helicopter. Also, there is a large area of
the height-velocity envelope to be avoided during low-speed and high
hovering operations. I conducted autorotations while within the edges of
the avoid area, and the chart is conservative. However, this is another
way a company can build in additional safety margins for pilots.
The major limitation of the helicopter is that it is hoisted aloft by a
two-stroke engine. Two-strokes can be reasonably reliable if owners
perform the suggested maintenance schedule recommended by Rotax, but
these powerplants do require a lot of fiddling with jetting anytime a
significant temperature or operating altitude is encountered to meet the
carb/mixture/EGT requirements and limitations. Pilot/owners should
follow the recommended procedures to keep their engines in optimum
health. They should also ensure that their autorotational skills are honed.
Now that I have logged a few flights on the updated version of the
Mini-500 series, it's difficult to understand the tempest that has
ensued between the company and a few owners - unless one considers the
personalities involved. The 500 not only looks great, it flies well and
appears to be free of significant vices.
Helicopters are not toys, and they are not easy for low-time pilots to
fly well. But they offer an excellent challenge for pilots who wish to
rise above common pilot skills - vertically. The Mini, especially with
PEP, boasts heaps of power for hot-and-heavy conditions and a blistering
cruising speed for a low-cost helicopter. All this and measly operating
expense, too.
Revolution's current offerings have solved the initial problems common
with the introduction of a new type, and the company is well positioned
to increase customer service and success in the market.

I've never read a negative artical by Ken Armstrong in COPA or
kitplanes. I've never read a negative aircraft review in Kitplanes by
any author. Why would the mini 500 be any different?

My answer to this post, and below is the last article printed by
KitPlanes Magazine in November 1999 of the flight report wrote by Kin
Armstrong. So if you have already made a negative opinion on the
Mini-500 saga and don't what your opinion to be confused by the facts,
then don't read!!!


anon wrote:
Dennis,

I see you are back with your same old talking points.


There's nothing like the facts to counter unfounded and false
statements. My talking points stay the same, because they are the true
facts. I, unlike people like you, don't have the luxury of changing or
making up stories, or making up or passing on unfounded or untrue
statements. So yes, you will read what I have to say over and over
again, because those are the facts, much to your apparent dissatisfaction.


As has been explained, a finding of pilot error does not in any way provide
an endorsement of your design.


You know, there are people out there that even dispute the fact that
America landed a man on the moon. It just does not matter how much
evidence you put before them, or who provides the evidence, they choose
not to believe it because that is what they want to disbelieve. I give
you Federal accident reports followed up with further company reports,
and still you choose to disbelieve, because that is contrary to what you
want to believe. Even a horse is smart enough to drink water when you
lead him to it enough times, but you will never believe because that is
not what you want to believe, despite the proof or who prints it.


When your design failed, many pilots found
themselves unable to recover in a manner expected from certified aircraft.
That is the standard. It does not address the design failures that
preceded the pilot errors. It does not address the design's ability to
recover from those failures.


Wrong. Many Mini-500 owners say absolutely the opposite. In fact,
attached is a report by the professional test pilot Ken Armstrong,
giving the Mini-500 a brilliant review. The Mini-500 he flew the same
bird that flew from Kansas City to Oshkosh, the same bird that flew at
all the air shows. That Mini-500 was 100% stock all the way, built to
factory specs with all factory mods.


You like to blame the dead, especially low-time dead pilots. You might
have forgotten that you marketed your kit to low-time pilots.


I only tell the facts. I don't even want to talk about it, let alone
blame live or dead people. But you really haven't given be any
alternatives. You put me on the spot, you blame be for killing people
with a bad design, you continually place me in a position demanding
answers, and I can only answer with the facts. If I said it was not
their fault, then I would be lying.


Let's look at the chronology again.
1) Everybody gets excited when they see the Cicare CH-6 prototype fly.
2) You and Cicare dissolve your partnership and you are left without a
helicopter to sell.
3) Without access to Cicare's design or the CH-6 demonstration aircraft, you
attempt to copy the design.
4) While you are still designing your new helicopter, you continue to market
and take orders for an unproven design
5) You delivered kits without adequate testing, claiming TBO's of up to 2000
hours, when your prototype only had a a couple of hundred hours, at most.
6) You marketed your kits to low-time pilots
A classic bait and switch.


You must write fictional books for living!! You have taken history and
twisted it around to your satisfaction.

I'll tell you what, I'll let Ken Armstrong's article in KitPlanes
Magazine do the speaking for awhile. Ken has over 9000 hours flying 40
different types of helicopters. He was a Military helicopter test pilot,
and currently instructs in helicopters.

BUT EVEN WITH A MAN WITH SUCH IMPECCABLE QUALIFICATIONS AND UNTARNISHED
REPUTATION, someone here will find something to discredit him and his
report on the Mini-500. The truth is written below, and yet some of you
will refuse to believe, simply because it is contrary to what you want
to believe.

After all, you read all the bad stuff about the Mini-500 right here on
this newsgroup by credible people, that you have never met or can even
see and some that don't have names... so it must have been true, right????


********Mini Revolution********

Where is Revolution Helicopter’s Mini-500 series heading?

By Ken Armstrong
KitPlanes Magazine
November 1999 Issue

The Revolution Mini 500 possesses an enviable sales record because of
the strong demand for low-cost, kit-built helicopters. However,
marketing success has created problems for the company and its owners.
Revolution has difficulty keeping up with customer expectations, and
some builders unrealistically expect the helicopter to be snag-¬free
during ownership.
In reality, the Mini 500 is no different from any homebuilt helicopter
- or from any commercial helicopter ever produced. They have all
experienced technical/design problems that required modification, and as
a professional helicopter pilot since 1972, I was often the guinea pig
who found out what those problems were. No helicopter design is perfect,
and there is no fling-wing flying that does not have ongoing problems.
What can you do if you own a Mini 500 or plan to buy one? Approach
ownership with an open mind and anticipate some down time while you
install modifications that Revolution considers mandatory for the safe
operation of the helicopter. If you plan to buy a used Mini 500, ensure
all of the mandatory modifications have been completed.

Is the Mini 500 Safe?.....
Any helicopter is only as safe as the pilot in command. There have been
a number of Mini 500 crashes, a number of them resulting in fatalities,
and there is a common thread among them. Accident data from Revolution
and the NTSB, combined with witness reports, indicate there have been
few if any mechanical failures that were not caused by improper
maintenance. In fact, 100% of the crashes had a pilot error component,
with 43% sharing maintenance/pilot error causal factors. Nearly 75% of
the pilots involved in accidents had less than 100 hours rotary wing
experience, and some didn't even have a helicopter rating (more on this
subject in the flight evaluation). Failure to maintain adequate rotor
rpm was a contributing factor in almost half of the accidents. Another
factor was pilots flying with the wrong carburetor jets for the ambient
conditions - an important consideration when operating these
hard-working engines. Operating with a two-stroke engine entails a
higher risk of engine failure than a four-stroke powerplant would, and
pilots must always be prepared to carry out an autorotation.
Another primary factor in the high accident rate for the Mini 500 (44
accidents out of only a few hundred flying) is that there are many being
flown by pilots with relatively little rotary experience, and in a few
of the accidents the pilots weren't even licensed. In the case of an
engine out, proper training and experience is critical.
But other than the higher incidence of engine failures associated with
two-stroke operation and pilot deficiencies, I don't see any particular
safety risk associated with this helicopter, and I wouldn't hesitate to
fly Mini 500s because the autorotative characteristics are quite
reasonable in the event the Rotax takes a time out.

Who Needs Politics?....
I believe the greatest non-technical problem plaguing the Mini 500 is
the polarization between Revolution and a small number of vocal,
dissatisfied owners. Revolution President Dennis Fetters is blessed and
cursed with a strong personality that has bolstered him with the drive
to create the successful Air Command gyro series and now the affordable
Mini helicopter series. But success often breeds problems, and keeping
up with the calls for technical revisions while attempting to provide
really good customer support has been a challenge at Revolution. As a
result, some of the owners have formed the support group known as the
International Helicopter Builders Association Inc. (IHBAI).
Mentioning this group to Fetters is like waving a red flag at a bull.
He feels the organization is trying to undermine his efforts and has
been dishonest about its aims. The group says it simply wants to find
fixes for Mini 500 problems typically agreed to as excessive vibration
creating frame cracks and transmission gears manufactured by a third
party that were not of sufficient hardness. For more details on these
topics, see the May 1999 KITPLANES©.
Having mentioned this builders group, I should add that I met many Mini
500 owners at Sun'n Fun who have experienced no problems with their
helicopters and are having a blast with them. Responses to company
questionnaires indicate that more than 90% of the attendees at company
training programs are completely satisfied with Revolution's efforts. In
the Internet era, it's all too easy for a few unhappy owners to promote
their discontent.

Builders Support Group....
At the 1999 Sun'n Fun meeting, IHBAI members, under President Bill
Phillips, decided they would not hire an engineering team to modify or
fix the Mini 500's problems because they felt Revolution was adequately
tackling the situation. The 14 attendees almost unanimously expressed a
desire to work with the company on problems and fixes. However, Fetters
wanted no association with this group. For the most part, I found these
owners to be levelheaded and simply wanting a solution to their problems
at a reasonable price so they could continue flying.
Stan Robinson, president of U.S. AirPower, talked about the possibility
of installing the three-cylinder, liquid cooled two-stroke engine
currently undergoing flight test in the Revolution two-place Voyager,
but this is unlikely in the near term, especially without Fetters' blessing.

Solutions Are at Hand....
Fetters has always maintained that the company manufactures
modifications quickly and prices them realistically to support his
clients. After many hours of discussion with him, I can appreciate his
point of view and feel the company is striving assiduously to correct
deficiencies and expand the performance and safety envelope.
Solving vibration problems has been a long slow process not because
Revolution wasn't devoting a lot of time to the solution, but because
rotor system dynamics are complex. The late model Talon (the model name
for the improved Mini 500) I flew for this report had the latest
refinements including mast support with rubber isolation, friction
damper on the cyclic system and trimtabs on the rotor system. These
refinements have apparently reduced the overall vibration level from 10
IPS to 0.01 in hover and 0.1 at 95 mph. Revolution asserts that all of
these modifications are recommended because they work together to
significantly reduce vibration. Minimizing the shaking reduces wear and
tear, extends component life and provides greater system reliability.
All new kits include all of the mast support refinements.
An Engine Information System (EIS) is a new option that constantly
monitors cooling, fuel mixture, lubrication and power output for
enhanced reliability. Although I have not evaluated this $675 package,
it comes complete with all probes, wiring and displays to provide a
visual warning in the form in a red light when an engine parameter has
been exceeded. It’s like buying insurance.

Power Enhancement Package....
The factory demonstrator I flew at Sun 'n Fun, 500FD, had the optional
power enhancement package (PEP) installed. The company recommends that
every Mini 500 owner install this system to improve recovery from low
rotor rpm. Faustino Padilla, a 240-pound Guatemalan pilot/owner who
flies his Mini 500 from a base 5000 feet above sea level at very high
temperatures, claims the PEP makes a world of difference to performance.
The PEP system comprises a tuned exhaust system and special carburetion
settings that provide an additional 18% hp and torque equating to an
additional 138 pounds of lift, according to the company. Essentially,
the engine is optimized for the narrow power band necessary for the
helicopter application. Fetters believes that for $950, this is an
inexpensive option that overcomes the need for a more powerful engine,
which would be much more expensive.

Flight Evaluation....
I don't take flights in single-place helicopters lightly, and I've
waited patiently for years for the fleet hours to accumulate
demonstrating the inherent safety of the series (about 28,000 hours to
date, according to Fetters). It was only after a detailed flight
briefing and an impressive demonstration flight by Ricardo Aita, a
company pilot, that I was prepared to place air under the skids. It
turned out I was overly cautious-if that's possible.
Fetters showed me the preferred method for entering the cockpit, and I
found the seat firm but comfortable (firm is best for a number of safety
reasons). The controls came readily to hand for this paunchy pilot of
200 pounds and average height. The control checks with friction off
showed there was no binding or significant friction in the system, and
the friction was then cranked on to meet the company wishes.
I confirmed that the fuel valve was on, skipped the prime with the warm
engine, closed the throttle, neutralized the controls and turned the
master switch on. With the-seatbelt secured, I couldn't reach the
ignition switch, so I had selected both in advance and used the cyclic
mounted starter button to bring the Mini to life. It started easily, and
I idled a short time until the Rotax 582's coolant reached the bottom of
the green. Raising the collective at idle produced a low rotor rpm
warning, the magneto check proved both ignition systems were operating
correctly, and the throttle chop at operating rpm provided a needle
split between the rotor and engine confirming the one-way driven clutch
was operative.
At this point, I wanted to eliminate all friction in the control but
was advised by the company pilot that it was preferable to leave
considerable resistance in the controls. Later I learned that this was
to reduce some of the vibration and stick shake. Although many pilots
prefer to have considerable resistance in the system to minimize pilot
overcontrolling, I prefer no stick trim or friction. I found that the
collective requires some friction in the system or it will rise on its
own during flight-not unusual in some helicopters. Moreover, if a pilot
leaves the cockpit with the engine running, the helicopter could lift
off if the collective is not locked down with a mechanical device or
adequate friction.

Getting Acquainted....
Initially, I had some difficulty mentally adapting to the pedals, which
are shaped like foot rests and move in a slightly different axis
compared to standard pedals. However, after 15 minutes or so of
hovering, I found my body and brain had made the conversion quite
readily. I also found the throttle system friction quite high, and this
resulted in my chasing the engine/rotor rpm somewhat at first-especially
since the correlation system doesn't do it all automatically for the
pilot. However, owners can remove the engine access cover and readily
adjust the throttle friction from no resistance to absolutely locked.
The skill of keeping the rotor rpm at the top of the green can be quite
a challenge for pilots like me who normally fly automatically governed
turbine equipment. My natural fumbling at rotor speed control coupled
with my intentional effort to establish the outside parameters allowed
me to get a really good feeling for the Mini's rotor inertia. It also
allowed me a glimpse into the scenarios that low-time pilots might
encounter and that could lead to the low-rotor-rpm accidents that occur
all too often.
Once I got a handle on the power lever, it was obvious the Mini was a
delight to hover and play with in the ground cushion. It was virtually
free of any noticeable vibration at the recommended rotor speed of
104%-positive proof that the Revolution fixes really work in the hover.
As the rotor speed falls below 96%, some minor vibration creeps in.
However, this is below the normal range and of no real significance
during typical operations.
With the doors off, visibility was excellent in most directions with
minor visual barriers straight down due to the floor and to the sides
due to the doorframes. Nothing unusual there. The Mini had 9 gallons of
fuel on board during the initial takeoff, and the nearly sea level OAT
was 75°F.
Fetters says that most problems on this engine are related to poor fuel
or jetting problems, and after taking a Rotax maintenance course, I know
this to be true in general on two-strokes. As I personally added
high-quality, filtered gas for our operations, I was comfortable with
the anticipated engine reliability and experimented with a broad
spectrum of operating rpms and altitudes. Although the rotor speed's
normal operating range is 96-104%, I conducted operations beyond these
limits and found no unacceptable characteristics.
The combination of relatively high rotor inertia and a sensitive
throttle system results in pilots new to the type chasing the rotor rpm,
but prolonged hovering operations can teach them effective rotor speed
control. While operation in the low yellow rotor rpm band is not
recommended, I found the helicopter had adequate power to recover from
90% or slightly less rotor rpm by milking the collective downward
slightly while fully opening the throttle.
Under the ambient conditions, full throttle produced the following
maximum hover height/rpm combinations: 6 foot hover attainable at 100%,
10 feet at 102% and 15+ feet at 104%. The recommended takeoff power is
104%, so the PEP would obviously produce more than sufficient power for
hovering with the skids approximately 2 feet off the ground at
considerably higher altitudes and/or with much heavier pilots. Unless
you are operating well above 5000-foot density altitude, it would appear
that this engine with the optional PEP is adequate in terms of power
output (assuming that the engine is kept well tuned, with the correct
jets for the ambient con¬ditions, and approved, fresh fuel).

Control Authority....
During a lengthy period of hovering that resulted in improved rotor
speed control as the Mini and I became acquainted, I was able to conduct
numerous hovering autorotations, and I found the Mini had plenty of
rotor inertia to permit gentle touchdowns - even with a slightly drooped
rotor rpm. Over two days, with varying winds, I confirmed that the 20
mph sideways and rearward maximum recommended flight speeds were
conservative and safely flown with no tendency to exceed or even
challenge the tail rotor's capability. There was plenty of control
authority during all maneuvers, and the tail rotor seemed to have as
much power as would ever be necessary at this density altitude. (No
high-altitude testing was conducted during these profiles.) This Hughes
500 lookalike also transitions through translational lift quite
smoothly, and I noted a distinct absence of measurable vibration under
all flight conditions up to 30 mph indicated.
Circuit restrictions, gusty winds and smoke from a forest fire shut
down operations on my second day of flying, so I was unable to conduct a
lot of straight and level flying at normal cruising speeds. Fetters
wasn't keen on my flying in those conditions at all, but my schedule
wouldn't permit a later flight, so I was committed to flying when many
of the other gyroplanes and helicopters chose to sit it out.
Nonetheless, the helicopter flew smoothly up to the maximum speed of 75
mph - an air-traffic induced limit. I wasn't overly comfortable flying
this lightweight under such conditions, but the company pilot who had 60
hours on type subsequently flew the demo in an aggressive and accurate
demonstration program with absolutely no difficulty.
The Mini is not only responsive but also surprisingly stable in
hovering operations, handling like a much larger helicopter. After only
20 minutes in type it was fairly easy to knock over the orange cone
markers with a skid and then stand them up again. This can be
challenging with any helicopter, and it was surprising to be able to
accomplish this intricate task with so little time in type.

Cautious Considerations....
The pilot's operating handbook cautions pilots to apply aft cyclic
while the collective is being lowered after high-speed engine failures
to minimize the helicopter's tendency to nose over. It also advises
avoiding low G maneuvers to avoid chopping off the tail boom. These are
standard cautions with any helicopter. Also, there is a large area of
the height-velocity envelope to be avoided during low-speed and high
hovering operations. I conducted autorotations while within the edges of
the avoid area, and the chart is conservative. However, this is another
way a company can build in additional safety margins for pilots.
The major limitation of the helicopter is that it is hoisted aloft by a
two-stroke engine. Two-strokes can be reasonably reliable if owners
perform the suggested maintenance schedule recommended by Rotax, but
these powerplants do require a lot of fiddling with jetting anytime a
significant temperature or operating altitude is encountered to meet the
carb/mixture/EGT requirements and limitations. Pilot/owners should
follow the recommended procedures to keep their engines in optimum
health. They should also ensure that their autorotational skills are honed.
Now that I have logged a few flights on the updated version of the
Mini-500 series, it's difficult to understand the tempest that has
ensued between the company and a few owners - unless one considers the
personalities involved. The 500 not only looks great, it flies well and
appears to be free of significant vices.
Helicopters are not toys, and they are not easy for low-time pilots to
fly well. But they offer an excellent challenge for pilots who wish to
rise above common pilot skills - vertically. The Mini, especially with
PEP, boasts heaps of power for hot-and-heavy conditions and a blistering
cruising speed for a low-cost helicopter. All this and measly operating
expense, too.
Revolution's current offerings have solved the initial problems common
with the introduction of a new type, and the company is well positioned
to increase customer service and success in the market.

BUT...are we talking about the highly trained frequent flying helo
pilot or the weekend hobby pilot who tends to be out of practice and
less tuned into his aircraft? Is the market for these aircraft really
the highly trained pilots or the wannabe's?

Richard Riley wrote:
On 7 Jan 2007 19:26:04 -0800, "BobR" wrote:

Assuming that you make the RIGHT decisioin and don't hesitate or thing
about it.

Well, of course! I mean, a highly trained helo pilot wouldn't ever do
anything but! A third of a second is PLENTY to understand what's
going on and begin corrective action!

BobR wrote:
BUT...are we talking about the highly trained frequent flying helo
pilot or the weekend hobby pilot who tends to be out of practice and
less tuned into his aircraft? Is the market for these aircraft really
the highly trained pilots or the wannabe's?

Richard Riley wrote:
On 7 Jan 2007 19:26:04 -0800, "BobR"
wrote:

Assuming that you make the RIGHT decisioin and don't hesitate or
thing about it.

Well, of course! I mean, a highly trained helo pilot wouldn't ever
do anything but! A third of a second is PLENTY to understand what's
going on and begin corrective action!


When I was getting my PP-R H rating I had an engine failure in an R-22 while
solo. I was in the pattern so locating a landing spot wasn't an issue. Also,
I had been practicing Autos to hover that morning with and instructor.

That said, there was plenty of time to slam the collective down when the
engine failed.

That is the real reason helicopters are so loud. They make them that way so
it really gets your attention when they stop being loud.

What it comes down to is a second is really a pretty long time. Two seconds
is twice as long. back in the 90's I shot pistols in competition. IPSC to be
exact. One of the standard exercises was called El Presidente. 3 targets at
30 feet. The drill was to draw, fire two rounds on each target, reload and
fire two on each target. The going time was around 6 seconds for the drill.
The really fast guys were getting close to 5 and may well have beat 5 by
now.

Drew Dalgleish wrote:
I've never read a negative artical by Ken Armstrong in COPA or
kitplanes. I've never read a negative aircraft review in Kitplanes by
any author. Why would the mini 500 be any different?


BUT EVEN WITH A MAN WITH SUCH IMPECCABLE QUALIFICATIONS AND UNTARNISHED
REPUTATION, someone here will find something to discredit him and his
report on the Mini-500. The truth is written below, and yet some of you
will refuse to believe, simply because it is contrary to what you want
to believe.


There ya go........ I knew there would be someone insult the man!!

As Mr. Armstrong told me, he don't test fly the ones that don't look
safe. Besides, how many kitbuilts were out there at the time?...... five
or so?? I guess he could only write so many flight reviews per kit, with
the very limited numbers to write about. But again, it don't matter if
Chuck Yeager wrote a good report about the Mini-500, some of you have
your minds made up and don't want to confuse the issues with the facts.

Dennis,

I used to read Kitplanes but quit when it became obvious it wasn't much
more than a mouthpiece for its advertisers. Much like Zoom's garbage.

What Drew wrote was simply the FACTS... not opinion, facts.

Two sentences of fact and one sentence with a question. You don't like
reading them... that I can understand given your own interest in the
Mini-500.

John

Dennis Fetters wrote:
Drew Dalgleish wrote:

I've never read a negative artical by Ken Armstrong in COPA or
kitplanes. I've never read a negative aircraft review in Kitplanes by
any author. Why would the mini 500 be any different?



BUT EVEN WITH A MAN WITH SUCH IMPECCABLE QUALIFICATIONS AND
UNTARNISHED REPUTATION, someone here will find something to discredit
him and his report on the Mini-500. The truth is written below, and
yet some of you will refuse to believe, simply because it is contrary
to what you want to believe.



There ya go........ I knew there would be someone insult the man!!

As Mr. Armstrong told me, he don't test fly the ones that don't look
safe. Besides, how many kitbuilts were out there at the time?...... five
or so?? I guess he could only write so many flight reviews per kit, with
the very limited numbers to write about. But again, it don't matter if
Chuck Yeager wrote a good report about the Mini-500, some of you have
your minds made up and don't want to confuse the issues with the facts.