November 1, 2000
Conversions:
The Soloy
Allstar: Helicopter in
Do engine conversions make a real difference in performance and operating
costs? Rotor & Wing found an old STC that breathes new life into a
well-established helicopter.
by Ron Bower, Reporting from the island
of
SOMETIMES YOU HIT THE JACKPOT and get a writing assignment that takes you to
tropical paradises like Kahalui, on the Hawaiian
Nevertheless, the helicopter tour industry is an unrelenting taskmaster,
requiring a sustained day-in, day-out effort and attention to detail. It’s not
the kind of business that runs itself.
Once you get past the glamorous veneer of living and working in the
helicopter business in
The Hawaiian air tour market is highly price competitive, and the rates are
market driven. Consequently, profit margins are thin. There have been many
start-up operators who learned this axiom the hard way, then faded into the
beautiful sunset empty handed.
However, the operator who can manage maintenance expenses and DOCs better than the competition can win in the long haul.
A typical tour ship can fly 80 to 100 hours per month; the DOC multiplier adds
up quickly if you can find a way to get a savings edge.
For operators of Eurocopter AStars,
one of those edges can be found in the Soloy
Corporation’s resurrection of a 1986 Supplemental Type Certificate (STC). This
STC (#SH3324NM) originally was intended only for a re-engining
of the AS-350D using the Rolls-Royce Model 250-C30.
The latest update to this STC now includes the AS-350B and AS-350BA models.
Called the "Soloy Allstar,"
this conversion permits operators of -B and -BA models to replace their
factory-installed Turbomeca Arriel
1Bs with the alternative engine without sacrificing performance.
There are about 1,700 civil-registered AS-350 series helicopters in the world,
about 1,200 of which are AS-350B, BA, and D models. The remaining 500 AS-350s
are the -B1, -B2 and -B3 models. These have more powerful Arriel
engines to which this Soloy STC does not apply.
From a reliability and performance viewpoint, most operators of AS-350B and
AS-350BA helicopters powered by the Arriel 1B have
been well satisfied with their engine. Why, then, would the Soloy
Allstar even be a consideration?
Close comparison
The best way to answer that question would be to make a side-by-side comparison
of two helicopters of the same type, one equipped with the old Turbomeca engine and the other with the Soloy
Allstar conversion. Alex Air Helicopters at the
airport on
Steve Alexander, owner of Alex Air Helicopters, graciously agreed to allow
me to fly the Allstar so that I could see the
difference for myself. However, my first flight aboard Alex Air’s immaculately
painted Soloy Allstar
(N90Q) was not as a pilot but as a passenger.
The pilot, Herbert Marcher, was smooth as silk lifting the max gross weight Allstar off the ramp and positioning it for takeoff. I’m
sure Herb has given the tour guide spiel hundreds of times, but I nonetheless
found him to be affable, knowledgeable and interesting. All of the passengers—a
family of five plus myself—were relaxed from beginning to end.
Shortly after takeoff, Herb turned south and put the Allstar
at max continuous power for the climb to 10,000 feet. Our destination was
During the perfectly timed climb, Marcher pointed out landmarks and facts
about
After the flight, Steve Alexander told me he bought the AS-350BA Soloy Allstar to evaluate ways to
improve uptime and reduce engine maintenance and overhaul costs. This
helicopter was originally an AS-350D and had been previously converted to an
AS-350B with the Soloy STC. Subsequent upgrades to
the airframe—swapping the rotor system for additional performance and increased
gross weight—converted the helicopter into an AS-350BA.
Alexander well understands the make-or-break key to success of managing DOCs. According to him, the Allstar
has performed exceedingly well, and he is looking forward to substantial
savings at engine overhaul time—perhaps in the 40% range.
As a result, he’s considering converting his other AS-350BA from Turbomeca power to a Rolls-Royce Model 250 engine under the
Soloy Allstar STC at the
next overhaul interval.
Another important benefit of the Rolls-Royce engine, according to Alexander,
is wider availability of replacement parts and overhaul sources at lower prices
than the Turbomeca. Other factors include quicker
turnarounds and lower overhaul and repair costs on engine accessory items such
as fuel controls, governors and bleed valves.
At Alex Air, having high uptime availability of aircraft is crucial. If one
of their two primary AS-350BA breadwinners is down for maintenance, they lose
half their revenue potential. That’s why Alex Air’s hangar is busy at night
performing routine and scheduled maintenance and preparing the aircraft for the
following day’s scheduled flights under the guidance of Tim Cole, Alex Air’s
director of maintenance.
A look under the hood
I spent an evening at the hangar watching and visiting with the maintenance
crew as they diligently worked to prepare for the next day’s busy schedule.
Cole is high on the Soloy Allstar
-C30M conversion. He says that, in more than 700 hours of operation, there has
not been a single hour of lost revenue due to engine-related maintenance on
N90Q. With AOG parts shipments often taking a day to come from the mainland,
more sources of parts is an important benefit, he adds.
With the cowling removed, it was obvious that the Rolls-Royce engine
installation is clean and easily accessible for maintenance on the AS-350.
There are no changes in the transmission or other drive train components. The
STC provides a replacement engine cowling, allowing for the differences in air
intakes and exhaust stacks.
Integral, easy-to-use preflight access doors make preflighting
the engine area easy. Sitting side-by-side on the ramp, the helicopters look
virtually identical. One difference is in the exhaust stack. For the
Rolls-Royce engine, the stack is above the engine, while it is in the rear on
the Turbomeca.
Taking a second run
The next day, I took my second flight in Alex Air’s Allstar—this
time at the controls, with Herbert Marcher beside me. According to Marcher, the
Rolls-Royce powered AS-350 performed every bit as well as the comparably
configured Turbomeca sister ship. From a max gross
weight standpoint, anything the Turbomeca could do,
the Rolls-Royce could do.
This reported performance is in keeping with Rolls-Royce’s published
specifications comparing an AS-350BA with the C30M and with the Turbomeca Arriel 1B. This
comparison shows slightly better performance for the Rolls-Royce engine than
for the Turbomeca Arriel 1B
for OGE hover altitude. Soloy’s product brief states
that, at maximum cruise power (MCP), the -C30M burns four gallons per hour less
fuel than the Turbomeca Arriel
1B.
The STC includes replacement engine instrument gauges for TOT, torque, dual
rotor tach, and N1 (compressor) readings. The
existing engine controls are unchanged in the cockpit. Marcher mentioned that
the Rolls-Royce throttle is slightly more sensitive than the Turbomeca during start modulation.
My perception is that the -C30M started exactly like any L-3 or L-4 LongRanger; just use small modulation adjustments, and it’s
a piece of cake. Since there are no aerodynamic differences with the STC, the
flight was quite typical for an AS-350.
The Rolls-Royce Model 250-C30M is almost identical to the -C30s used in
thousands of other helicopters. Only minor accessory changes have been made to
a Model 250-C30P and 250-C30S found on
According to Chris Ankrom, director of aftermarket
development at Rolls-Royce, the Rolls-Royce Model 250 family, which includes
the -C30 series, now boasts about 140 million total flight hours in more than
28,000 engines. Rolls-Royce is supportive of the Soloy
STC, since the OEM would supply engines and parts to operators and overhaul
shops for any conversions.
Historically, there are two major lingering questions for potential
customers in most engine-mod products. First is the concern over having a
one-of-a-kind aircraft for which you can’t find service, parts or maintenance
support. Second is not wanting to go through a
"teething" period to determine if the mod will perform as advertised
without unanticipated problems.
The Soloy Allstar
conversion (backed by Rolls-Royce’s broad support of the C30M) answers both of
these lingering questions. For operators that want a choice, this is one to
consider.
AStars Survived Engine Difficulties in
the American Market
The infamous AS-350D was a quasi-Americanized version of the Aerospatiale
AS-350B that had become popular in
Because "squirrel" has negative connotations in the American
vernacular, Aerospatiale apparently felt that the AS-350D needed to have an
Americanized name. For marketing reasons, the company also decided the
helicopter should have an American powerplant.
Although the new name, "AStar" seemed to
work for the American market, Aerospatiale’s choice of the Lycoming LTS-101 for
the engine was less fortunate.
Aerospatiale spent several years trying to overcome the stigma of their
engine choice for the AS-350D. Eventually, the company withdrew the
Lycoming-powered D model from their product line.
Ultimately,
At its high-water mark, there were about 260 AS-350Ds registered in the
The STC was later sold to Rocky Mountain Helicopters, Inc., which used it to
replace the company’s Lycoming-powered fleet of AS-350Ds with the well-known
Rolls-Royce 250-C30. At about the same time, Aerospatiale offered a
manufacturer-supported conversion plan for AS-350Ds to become AS-350Bs by
installing the original Turbomeca Arriel
1B engine, thus allowing the helicopter to be redesignated
as a bona fide AS-350B.
Today, there are only 107 AS-350D AStars
registered in the world, and I suspect that many of those have had Turbomeca or Rolls-Royce Model 250 engine conversions. It’s
entirely possible that the government registration documents were never
corrected.
Nonetheless, there are still some AS-350D owners who haven’t experienced
engine problems with their Lycomings. Lycoming
undertook a modification program that in time fixed many of the problems, but
not before user confidence was lost in general.
The AS-350B has since had incremental performance enhancements that include:
the AS-350BA (same engine as the AS-350B, but with improved rotor system); the
AS-350B-1, which was a short-lived, interim step toward the AS-350B-2; and now
the current production model, the powerful AS-350B-3.
Choice: An Emerging Philosophy Shift for Operators
To the pleasure of many, alternative engine choices recently have come into
vogue for new helicopters.
At least part of the answer might be the cultural change in globalization,
as reflected by international trade agreements like NAFTA and those of the
European Commission and now greatly exacerbated by the
"buy-it-anywhere" capability of the Internet.
With buyers now able to exercise more personal options in buying products
worldwide, the idea of being limited to one source of supply can prove
distasteful.
In reaction to this new buying style, helicopter manufacturers are starting
to consider or announce customer "choices" for engines in new models.
Some don’t get beyond the announcing stage—the original MD 900 and the Agusta A119 Koala are two examples.
Some are driven by competition, market opportunity, or customer demand, such
as the recently announced addition of the Pratt & Whitney PW206B2 as a
choice for the EC-135. These Pratt engines will allow a higher Category A takeoff weight for the EC-135 than the original Turbomeca Arrius 2B1 engines.
Engine-mating decisions are some of the most crucial choices that airframe
manufacturers must make. This decision can greatly influence the ultimate
success of the sales volumes of their product. No manufacturer takes these
decisions lightly. Many business factors come into play, not the least of which
is cost, since the airframe manufacturer must buy the engines from the engine
vendor. Since engines are typically the most expensive component in a
helicopter, if the engines cost too much, they may force the total aircraft to
be priced too high to be competitive in a price-sensitive market.
There are other important success factors beyond just purchase price that
affect the manufacturer if end-user customers aren’t satisfied: reliability,
service availability, technical support, speedy overhaul and repair, and a
responsive replacement parts distribution system. Even engine accessory
components like fuel controls, governors, and now FADECs,
are important to customers. From a customer viewpoint, if the helicopter is AOG
it usually stops their revenue (or intended benefit) and simultaneously
increases their expenses—not a happy situation.
With turbine engines rotating internally in the 40,000 to 60,000 RPM range,
periodic overhauls are required. If overhaul prices are deemed overly expensive
or if overhaul downtimes are too long, customer satisfaction can wane.
When an engine manufacturer stumbles in service, costs or performance, the
market will go elsewhere. In new helicopters, the manufacturer will change OEM
vendors. Pratt & Whitney has beaten out the incumbent Rolls-Royce Model 250
series with their newer PW206 for the MD 902 and PW207 for the
The venerable Pratt & Whitney Canada PT6 won for the Agusta
A119 Koala, beating out both Rolls-Royce and Turbomeca.
Strangely enough, Turbomeca beat out Pratt &
Whitney for the Sikorsky S-76C and C+ (United Technology Corp. owns both
Sikorsky and Pratt). Pratt PT6s were in the S-76B model.
The market that the turbine engine manufacturers must sell to is narrow and
highly competitive. The "big three" engine providers in most western
commercial light and medium helicopters are Rolls-Royce, Turbomeca,
and Pratt & Whitney. Others, like GE and Lycoming, historically concentrate
on military markets and larger helicopters.
With each new airframe manufacturer’s design, there usually comes a
mating-dance line at their door from the engine manufacturers. The process is
designed to get the best price and performance package. Airframe manufacturers’
only hope for success is sustained sales volumes, so they can recover the high
development costs and then still turn a profit. This is a tough trick in a
small, highly competitive market.
However, in the used helicopter market, it is a different situation.
Customers usually must look to STC mod shops for engine solutions if they want
choices. The Soloy Corporation has sold more than 400
modified engine gearbox units, including Bell 47s, Hiller UH-12s, even the Bell
206LT (light twin). About 10 AS-350Ds that were converted from Lycoming LTS-101
to the Rolls-Royce Model 250-C30 are still flying today.