AEROCOMP'S CLIMB TO THE TOP
"New turbine aircraft, new
engines and new directions"
"PIREP NO. 119"
MAGAZINE, FEBRUARY 2001
Pages 44-53 (reprinted with permission)
"The Comp Air 7 Turbine is a high performance aircraft and the most popular of the Aerocomp fleet."
A copy of this article is also available in PDF format
(best for printing) at:
TEXT BY NORM GOYER; PHOTOS BY BILL FEDORKO AND NORM GOYER
IS THE kind of story I love to write. It's about the tremendous success achieved
by Aerocomp, a company in Merritt Island, Florida. It manufactures a wide
variety of excellent kits for experimental aircraft. I'm especially pleased to
be able to bring this to you, our readers, who, like me, were saddened to hear
that, during the past year, quite a number of well-established companies have
gone out of business. Their principals are still trying to find a way to recover
some of the funds they invested before their companies failed.
so with Aerocomp. Sales, which have been booming, show no sign of peaking in the
near future. Some of the reasons for the company's success are the foresight and
marketing strategy by which its owners have designed and are offering an
extensive line of turbine propjet aircraft, one or more of which is sure to suit
the needs and tastes of a wide variety of pilots and business people. In other
words, company owners did their homework because they came up with and are now
offering exactly the kinds of aircraft the customers want to buy, not just the
kind the company thought people would want to build. Also, even if it might not
necessarily be a major factor, because kit manufacturers can be found at diverse
sites, when Aerocomp chose to locate its business in Merritt Island, Florida, it
chose a superb location. The right products, at the right time, at a great
location. It sure works for Aerocomp.
first became acquainted with Aerocomp more than a year ago while covering the
project for CUSTOM PLANES, our sister publication. When my article was
published, it raised a storm of controversy from those who thought the idea of
sticking a 600-hp turbine on the front of a Cessna 206-size aircraft, especially
one molded from fiberglass, was a bit shaky, to say the least. And the
particular type of engine chosen by Aerocomp was the subject of a miniature
range war between factions that has yet to settle down. Some -- but certainly
not all -- of them still believe that much of the criticism aimed at the engine
might've been justified.
"sizzle" in the Aerocomp aircraft was their unique engine/prop
combination. When those aircraft first appeared several years ago, they used a
Walter 601B engine. Aerocomp no longer installs this dash-number engine.).
Walter engines have been installed by some Eastern Bloc countries in their Let
410 19-passenger commuter airlines. Then, after they'd run beyond recommended
flight time, the engines were either overhauled (if warranted) or discarded. It
should be noted that part of the aforementioned controversy came about when some
folks discovered that Walter engines have a TBO of only 1500 hours, but that
number of hours flown by those European commuters weren't done in the same
high-altitude ranges as those of U.S. airlines.
importers were happy to find they were able to obtain quite a number of Walter
engines and all their accessories, as well as the props that went with the
engines, at attractive prices.
of their various origins, the first group of Walter engines sold with early
Aerocomp aircraft had little (if any) accompanying paperwork, but before they
were ever put into service, they were given a great deal of attention. First,
they were removed from their shipping cans, checked carefully and then installed
on a test stand, where they were run for a long period of time. If the gauges
remained in the correct operating range during the extensive bench test runs,
they were installed in aircraft sold to customers.
their very nature, turbine engines can be run in spite of many internal defects
due to age, or any number of factors, without showing any outward signs of
internal problems. (But when one or more parts fail under running conditions,
they can also blow apart in a spectacular fashion.) In the interest of safety,
the engines that were sold were restricted as to power output, and this added to
their margin of safety. That was then. Now, in 2001, it's a completely new
mentioned earlier, Aerocomp is having a most successful sales year. We wondered
how that could be, considering the airplanes are so different from many current
high-performance aircraft. The plane didn't have the sleek lines of a Lancair or
the mystique of the Thunder Mustang, but it was definitely a unique-looking
plane. The first time I saw it, I found it impossible to walk by this aircraft
and not stop and look, because it was so different from most of the
run-of-the-mill experimental aircraft we've been seeing.
found that this aircraft appeals to pilots looking for an airplane with
turbine-powered slam-dunk power that drives you back into the seat when you take
off-power with climb attitudes that rival those of an F-16 and that gives you
the feeling you've finally joined the jet age. But one with affordable turbine
power, and the Comp Air 7 Turbine is certainly that too!
ultimate test is the reaction of those pilots who've gone on a demonstration
flight in Aerocomp's Comp Air 7 Turbine. If they're financially capable of doing
so, when they come back from that demo flight, they're ready to buy! If you've
ever flown in a Cessna 206 or a Centurion, which are great aircraft, you'll be
amazed at the feel and outstanding performance of the Comp Air 7 Turbine.
soon as you have a demo flight in a Comp Air 7 Turbine, you may be inclined to
buy one because of its terrific performance, but as soon as you've become aware
of Aerocomp's excellent affiliated building programs, conducted under the
auspices of Sky Build, Inc. (Skybuild is an independently owned and operated
facility with Steve Darrow as company president), you'll want to close the deal
immediately. It's the clincher! Sky Build, Inc. is located at the Merritt Island
Airport in a complex of several large industrial buildings. (The corporate
offices of Aerocomp are also located in this facility.)
Skybuild's building program, each owner/builder works with company technicians
using company jigs, fixtures and tools. This ensures that every high-
performance Aerocomp aircraft is built correctly. As one segment of the aircraft
is completed by the owner/builder, it's moved to another room, where the next
section is completed. This is not a long-term process, and because in this way,
the builder/owner has met the FAA requirement of building 51 percent of the
aircraft, allowing him to be listed as the manufacturer and also allowing him to
work on the aircraft in the future.
has been in business since 1993, when the company purchased the rights to the
Merlin, a two-place, tube-and-fabric aircraft. The Merlin was one of the
best-flying light aircraft I've ever flown, and whenever I've covered air-
shows, I've often sought it out to use as a camera plane because of its
excellent flight characteristics. At that time, Aerocomp consisted of two
employees: President Steve Young and Vice President Ron Lueck, an experienced
kit builder. (Due to expanded kit sales experienced by Aerocomp, the company now
has more than 20 employees.)
were to build three- and four- place aircraft, using the basic Merlin design.
Before starting, Young and Lueck wisely conducted an informal survey of
potential customers and came away with surprising results: Tube-and-fabric
designs were definitely not being considered by customers for multi-passenger
aircraft; builders preferred composite construction. So Aerocomp had found its
future direction, but there were more surprises to come.
chance meeting with Doug Karlsen, owner of Turbine Design, Inc., of Deland,
Florida, and the owners of Aerocomp family had the missing factor of the
equation: turbine power. The right combination of airplane and engine had been
found, and once their first turbine-powered aircraft was introduced at Sun 'n
Fun in 1999, Aerocomp had nowhere to go but up, up and away!
you build a super-high-performance aircraft like the Comp Air 7 Turbine, with a
propjet in the nose, it's certainly a good idea to train the new owner/pilot in
0 aspects of flying his new aircraft. So Aerocomp organized ground and flight
training for new owners of turbine-powered aircraft. Al Pike is in charge of the
training program (for pilots without turbine experience), which provides at
least seven hours of classroom instruction and a minimum of 11 hours of flight
training. To qualify for this training, a pilot must have a current medical,
flight review and at least 500 hours of total time, including at least 100 hours
in complex, high-performance aircraft. Aerocomp pilots often, but not always,
test-fly newly finished Comp Air 7 Turbines for the owners.
is to be sure that aviation insurance companies will be willing to provide
coverage for the owner/operator of this particular type of aircraft without any
trouble. Once you've graduated from Aerocomp's flight and ground-school course
in turbine operations, this experience will go a long way toward convincing your
insurance underwriter that you can comprehend the complexities of a turboprop
engine and turbo-powered aircraft, and safely fly it. Without this kind of
training, you might be denied insurance coverage, but with it, you'll
undoubtedly qualify for it. In fact, your rates might be lower than average.
a new owner/builder has finished building his Comp Air 7 Turbine at Skybuild's
facility, he may have had all the desired avionics installed by Sebastian
Communications. The aircraft has been painted a striking fire-engine red- in
stark contrast to the mostly white overall paint scheme composite builders
prefer (to prevent ultraviolet damage to the composites). Experts say that the
new epoxies are not as prone to sun damage as earlier formulas. The bright red
color was different and very appealing.
entire cabin was done in gray fabric and leather, so well that its interior
looked more like that of a luxury car than that of a 'plastic' homebuilt. To
gild the lily, a five-blade prop had been installed onto the newly overhauled
Millennium Turbine 601 engine. (See the sidebar for more information.) The new
owner/pilot is told, "No more procrastinating. It's time to go
recently paid a second visit to Aerocomp after being promised a flight in the
red Comp Air 7 Turbine with its overhauled, more powerful Walter 601D engine
fitted with a five-blade prop -- the one I'd seen at AirVenture. The plane was
due back in Florida in the near future for additional radio installations.
Finally we received a call that the plane was indeed back at Merritt Island.
(The plane is normally based in Modesto, California.)
always perform a thorough preflight inspection of the aircraft and the cabin.
You should be aware though that, when it comes to starting a turbine engine,
there are some very different rules to be strictly followed. First, be sure to
turn the plane into the wind (if there's any of a significant velocity) to
prevent the wind from blowing up the plane's huge exhaust stack. Next, to
prevent any possible damage from the prop blast and turbine heat, make a careful
visual check to be sure there's no structure or another aircraft behind your
by checking the position of the fuel tank valve. Move the indicator to both -or
to the correct tank- whichever is indicated for this airplane. Double-check the
fuel tanks are full. This is extremely important, because turbine engines use up
fuel at a high rate. Before you start the engine, apply the parking brake and
stand on the brakes, because when those huge props start rotating, you can
really feel the power, and you don't want the plane to roll until you're ready
to go. To prevent surges, be sure all power switches and navaids are off and the
circuit breakers are in. Check all the controls to be sure they're free and not
binding, because this is your last chance to ensure there will be full movement
of all the control surfaces.
following is the procedure taught by Aerocomp to start the Walter turbine: (The
engine is available with an auto start if desired, but the engine starts just
fine without one.) Check the fuel valve to make sure it's on, that all circuit
breakers are in and that the generator is off. Pull the start lever on the power
quadrant full aft to "fuel cut off." Next, position the propeller
lever in the full feather position. The power lever, located on the power
quadrant, is placed in the idle position. Now you're ready to go.
one hand on the power lever, use the other hand to turn on the master switch.
Check the voltage to make sure there's a reading of at least 24.5 volts. To be
absolutely sure, press the two test lights: one marked beta, the other limiter.
Check the two igniters, 1 and 2, then shut them off again. Now start the fuel
boost pump and check to make sure there's at least 15 pounds per square inch.
Look out and check your immediate area to be sure nobody's wandered into the
danger area of the five-blade prop, then shout out the standard warning:
"Clear prop, or get the mop!"
you engage the starter switch, monitor the gauge for N1. When it's achieved,
move the fuel lever to the start position. Next, turn both igniters on, and
ignite the engine on for two seconds, then off for two seconds. You must also
monitor the ITT heat gauge to make sure it does not exceed 735 degrees, and keep
the starter engaged until the engine reaches an N1 of 45 percent. Also, scan the
oil pressure and temperature readings. When you've made sure the engine has
reached 45 percent NI, you can release the starter.
next step is to check and see if the engine accelerates smoothly to 60 percent
Ni. Check that you haven't exceeded 735 degrees. If the engine does reach 735,
you must pull the start lever to ICO (ignition cut-off) until the ITT drops
below 650 degrees. This is the dreaded "hot start" that must be
avoided to prevent damage to the engine. If the engine is running smoothly, and
all temperatures are in the green, you can switch the generator on, then switch
the 12-volt buss on for the avionics. Now is the time to make sure the radios
and intercom are working correctly.
check the vacuum pump, strobes, beacons and lights as appropriate. It sounds
complex when you see it in print like this, but in actual practice it goes
quickly and smoothly. It's much easier to start a turbine than it is to start a
fuel-injected reciprocating engine. (You almost need three hands for the
the parking brake, and use the prop beta control as the throttle. Avoid using
too much brake or depending on the throttle; you have better and faster control
with the prop lever. You're about to go for the wildest ride you've ever
had-unless you're in the military and have flown some of the latest fighters.
But the Comp Air 7 Turbine will beat them on the takeoff roll. Besides checking
the runway for other aircraft taking off, I suggest you also look up and check
for crosswind traffic. (You'll see why shortly.)
is the same as with any high-performance taildragger, but with just a few more
checks to make before you start the takeoff roll. Place the flaps down 10 to 15,
recheck the fuel quantity and valve position, and make absolutely sure the fuel
boost pump is on. Then, as with any aircraft with a constant-speed prop, cycle
the prop once or twice with the power lever in idle position. Check one more
time to make sure the power lever is in run position.
the power to 30 percent, and slowly move the prop lever to aft position so you
can check that the rpm are decreasing gradually. Now move the prop lever to
full-forward high-rpm position. We were eager to see how this second-generation
Comp Air 7 Turbine aircraft would perform with its newly IRAN'ed (inspect and
replace as necessary) Walter 601 D engine and overhauled Avia Hamilton prop.
wanted to see how this Millennium engine, sporting about 725 horsepower, would
compare to the original 600-hp one. When all systems were go, the pilot brought
the power up to 30 percent torque and released the brakes. Then, as the plane
started to roll, he increased the power lever for smooth and continuous
acceleration. When the engine was up to full takeoff power, he checked the
engine temperatures and made sure the torque limits weren't exceeded. By the
time he'd done that (maybe four seconds), the plane was already off the ground.
We used about 100 feet -maybe less- for our takeoff roll.
best rate of climb (Vy), which was 110 mph with the two people aboard that day.
Now came the fun of flying in a superpowered aircraft. Maintaining a 4000-fpm
climb, we were already about 1000 feet above pattern altitude-- even before we'd
reached the end of the runway! Once the climb rate was established, the pilot
reduced the prop lever to anywhere from 1900 to 1950 rpm for cruise climb, then
checked the pattern again for traffic. Because the Comp Air 7 Turbine was so
powerful, he knew we'd be joining the traffic in a matter of seconds.
for us, our outstanding climb in the Comp Air 7 Turbine was all for naught,
because we had to circle over the Atlantic Ocean for much too long, waiting for
the new Cessna 182 camera plane to catch up to us. When the Cessna arrived on
station, it soon became obvious that Editorial Director Bill Fedorko was ready:
the window of the 182 was up and the long lens of Fedorko's camera was aimed
directly at us. Once we'd established contact, we proceeded according to our
agreed-upon plan, and the Aerocomp and the camera plane flew around together
over Florida's beautiful beaches for about half an hour, while Fedorko
photographed the Comp Air 7 Turbine.
the Comp Air 7 Turbine was so much more powerful than the 182, pilot John Cook (Cook's Diemech firm had overhauled the engine in this
plane) had to throttle
way back to stay in formation with it, but because both planes had a wide range
of comfortable, tight-formation airspeeds, that wasn't a problem. When Fedorko
finished the photo mission, he signaled, then headed "back to the
barn". Now it was my turn to fly the Comp Air 7 Turbine and see what this
new, improved turbine aircraft could really do.
made a note of the recommended power settings for various cruise conditions so I
could see how close the figures in the manual were to reality (which, in
homebuilts, sometimes differs significantly). Because our plane had a five-blade
prop, I held the rpm between 1700 to 1850. 1 then reduced the torque and checked
to make sure the ITT did not exceed 690 degrees. Once I had the right power
setup, I could increase the tension on the knobs on the power quadrant to
COMP AIR 7:
Airframe kit $39,995
[Correction by Aerocomp, Inc.: Note -- PISTON versions of the Comp Air 7 kit are available for only $39,995. The TURBINE version is priced at $49,995].
Wingspan 35 ft.
Wing area 178 sq. ft.
Length 29.5 ft.
Height 8 ft.
Gross weight 3770 lb.
Empty weight 2100 lb.
Useful load 1670 lb.
Engine 660-shp Walter M601D
Cruise at 21,000 ft 275 mph TAS
Never-exceed speed 258 mph
Stall speed, flaps down 50 mph
medium cruise, I checked out the controls by doing steep 360-degree turns in one
direction, then in the other. These maneuvers are quite a test of the airplane's
controls, because you have to use all controls to keep the altitude steady, and
the ailerons and rudder to maintain a well-coordinated bank without skidding or
slipping. I had to use some rudder, but it wasn't a problem. In spite of the
fact that there was such a huge engine in a relatively small plane, the aircraft
first thing I noticed, in addition to the increased performance, was the
quietness and lack of any perceivable vibration (compared to the Comp Air 7
Turbine I flew last year). The cabin had been completely upholstered, and it had
a smooth-running engine and a newly balanced five-blade prop -all of which made
the ride enjoyable and quiet. This was an entirely different experience from a
I reduced power and tried my hand at slow-flying the Comp Air 7 Turbine to see
how it would stall. We were way up at about 5000 feet, so I knew we had plenty
of room. I held back the stick until my arms finally got tired, and I decided
the big bird just wasn't going to stall without a lot more work. I noticed we
were bouncing along at about 45 mph, and the plane was still flying. I had to
use a great deal of rudder to hold the wings level, because the ailerons had
given up several miles per hour before.
Comp Air 7 Turbine finally made a half-baked effort to stall, but as soon as I
relaxed the controls, it quickly recovered from the near-stall. This plane's
inherent stability is a result of that great wing and excellent airfoil, besides
which, the airframe is also very clean. While I'd been slow-cruising along, I'd
made some 360-degree turns in a semi-stall condition and still had no problem
holding it. (Somebody would have to be a real klutz on the controls to
accidentally stall this airplane, but I still can't imagine that he'd be able to
it was time to see how fast the Comp Air 7 Turbine would go. I was able to get
it up to a true airspeed about 235 mph at 5500 feet. The manual states it will
easily deliver 275 mph TAS at 2 1,000 feet. The Comp Air 7 will carry loads up
to 1670 pounds for a gross weight of 3770 pounds. The plane flew much like a
Cessna 206, but without the heavy fore and aft pressures. Of course, these can
be trimmed out, but the Comp Air 7 had an entirely different feel to it.
down at the fuel gauges, I saw it was time to head back to the air- port. As we
entered the pattern, I reduced power and put the prop lever full forward. I then
reduced the power lever to achieve the correct rate of descent, but I didn't
reduce it below idle stop position. I checked the beta light to make sure it was
off. (Funny things happen when the prop starts pushing instead of pulling.)
manual says the pilot shouldn't let the speed drop below 80 mph indicated during
the approach. I pulled about 15 degrees on downwind, then used fun flaps when I
turned final. I didn't want to have to change the tires, so I made sure the
parking brake was off and my feet were off the brakes. The manual said wheel
landings weren't recommended, unless we wanted to redesign the prop tips, so I
set the Comp Air 7 Turbine up for a three-pointer (which is the way I've always
landed taildraggers anyway).
plane did have a five-blade prop with a smaller diameter than the three-blade
one, but the prop still comes awfully close to the ground. As the plane got
closer to the runway, I pulled up the nose just a tad. Then, when we were about
3 feet off, I gradually applied full-aft stick, and the plane squatted and
stayed down. I then flipped up the lockout on the beta prop and made the next
the Comp Air 7 Turbine was practically a no-brainer. It's just a really easy
plane to fly, and you've got to admire its top-notch performance. I was
favorably impressed with the Comp Air 7 Turbine demonstrator I flew a year ago,
but this new version virtually blew me away! I know why these new Comp Air 7
Turbines are selling like hotcakes. When the pilots I know want to buy an
aircraft, they insist on three things: performance, performance, performance!
And Aerocomp's Comp Air 7 Turbine delivers!
For More Information:
Aerocomp Inc. - Dept. PPM
2335 Newfound Harbor Drive Merritt Island, FL 32952 USA
Phone/FAX: 321/453-6641 or 321/452-7168
PRIVATE PILOT MAGAZINE FEB 2001 http://www.privatepilotmag.com
(reprinted with permission)
SIDEBAR: JOHN COOK'S DIEMECH WALTER OVERHAUL FACILITY
"Land and sea mix with power and performance as the Aerocomp Comp 7 flies over Merritt Island, Florida. Photo by Bill Fedorko.
46 PHOTO 1
"The Walter 601 D turboprop engine necessitates a long nose for proper balance."
46 PHOTO 2
"The rugged, forgiving landing gear on this Camp Air 7 Turbine was manufactured by Hammerhead Aviation in El Cajon, California."
46 PHOTO 3
"Turboprop engine controls are slightly different than those for reciprocating engines, but they're easy to learn. The instrument panel is large, allowing room for a wide range of avionics and instruments. The plane is flown with control sticks rather than control columns."
"The Comp Air 7 has performance that makes it ideal for a fast passenger or cargo hauler."
"Double doors make entry and exit easy. Comfortable, adjustable seats make long cross-country trips pleasurable. Seat belts and shoulder harnesses are attached to both the floor and overhead hard points."
"This Comp Air 7 Turbine has an Avia Hamilton five-blade prop swung by a 725-shp Walter 601 D water-injected engine."