BEECHCRAFT KING AIR C90
Introduction This is the Beechcraft King Air C90,
if everything that define utilitarian can be put into a picture, here is it.
Six different King Air models have been produced by Beechcraft, the first of which,
the King Air 90, debuted in 1964 following three years of design and test flights.
The 90 is the smallest boat in the fleet as well. The plane has always been associated with traits
like dependability, versatility, and a chic appearance. Beechcraft, never one to rest on
their laurels, kept their noses to the grindstone and kept developing their King Air 90 aircraft.
The aircraft has undergone improvements with cutting-edge design throughout the years,
making it a popular choice for business travel.
When the King Air C90 first rolled off the manufacturing line in 1971,
it was a new and improved King Air 90 as a result of the improvements made over the years.
The weight and wingspan of the aircraft were both enhanced, and the cabin pressure
was also raised. The engines have been modified numerous times to increase performance numbers,
and the rear fuselage was streamlined with more efficiency for better flying speeds.
But that isn’t all. What say we learn more about this incredible airplane?
Design/Exterior If first impressions are
anything to go by, the Beechcraft C90 "King Air" will undoubtedly leave you in awe. This aircraft
looks amazing even while it is merely "cold and dark" on the ramp. A cantilever low-wing
monoplane with a traditional tail, the King Air C90 is a pressurized, twin-engine turboprop
commercial aircraft. It includes retractable tricycle landing gear with one wheel on each
unit that is hydraulically operated, as well as an airstair door on the port side of the wing.
For pressurization and cabin heating, it uses dual bleed air. The reversible, three-bladed propellers
have full feathering. The C90 "King Air" maintains the timeless design of prior production models
in the lineup. The swept-blade propellers and winglets, though, make the distinctions clear
right away. The C90 'King Air' is distinguished by these attributes alone. The winglets and the
swept blade propellers give the C90GTx 'King Air' a rapid, sporty look. Previously optional
on the Queen Air, de-icing boots on the leading edges of the wings, fin, and tailplane were now
standard equipment on the King Air to increase its utility and safety in varying flight conditions.
Interior
The King Air C90GTx has one of the best interiors in its class.
The interior is decorated in a professional manner, as is typical of commercial airplanes.
Up to 7 people can be accommodated in the airplane, which can be flown by a single pilot.
The Beechcraft King Air C90 has 6 seats in total, 4 of which are bucket-style in
the front. A belted toilet seat that can be utilized as an extra seat is located in the
back cabin. Another normal padded seat is located at the far back of the turboprop.
When compared to other airplanes in its class,
the King Air C90 has a roomy interior. 4.75 feet is a respectable height for the category
of interior height. The cabin is 4.5 feet in width and 12 feet 7 inches in length overall.
The C90 is available in 5 different color or style variations from Beechcraft and Textron.
Beechwood, Greige, Mocha, Parchment, and Silver are the available selections.
An area is available to store equipment and baggage at the back of the aircraft. The
Beechcraft King Air C90GTx can carry a maximum of 350 pounds of luggage. Because it is simple
to reach during the flight, the interior baggage space is convenient for both passengers and the
crew. Since the baggage space is a part of the cabin as a whole, there are no doors to open.
Engine Two 550 shaft
horse power Pratt and Whitney PT6A-135 engines provide the King Air C90 with
its power. They are three-stage, axial-flow engines with a single-stage reaction turbine
and compressor. The fuel flow is scheduled by a pneumatic fuel control. For each given position
of the propeller control lever, the propeller speed is constant within the governing range.
One tank system is used for each engine in the airplane's fuel system, which is made up of two
independent tank systems. The main system and an auxiliary system are further separated into a tank
system. A nacelle tank and two wing leading-edge tanks make up each main system, and they all
gravity feed into the nacelle tanks. There are 194 total usable gallons in each primary system.
The 41-gallon usable fuel tank for the auxiliary fuel system is situated in the wing, in front
of the engine nacelle. To feed fuel to the main system, it uses an automatic fuel transfer system.
Both a high-pressure fuel pump and a low-pressure boost pump are powered by each engine.
Additionally, each nacelle tank has a low-pressure standby boost pump that is electrically powered.
A 24-volt, 34-ampere-hour nicad battery, two 250-ampere starter generators, or an
external power outlet provide power to the 28-VDC electrical system of the airplane. There is a hot
battery bus available to power various convenience lighting, emergency gear, and other things.
No matter where the BATT switch is set, these devices always have power.
Performance This plane has a range of 840 nautical miles.
Similar to the Dash 21 engines they replace, the PT6A-135A engines of the GT version are rated at
550 shaft horsepower. The new Pratts, however, are actually 750-shp engines that have been limited
to the lower takeoff maximum power. This implies that the new engines can continue to produce their
full-rated horsepower at a considerably higher altitude as the C90 climbs. The C90 reaches its
stride at 25,000 feet or higher as opposed to the earlier King Air 90s, which reached their
top speeds at 16,000 feet. The C90 is rated to 30,000 feet and can cruise at about 260
knots with the new engines, but we don't believe many pilots will frequently use that altitude.
One explanation is that, when flying at 30,000 feet, the cabin altitude is almost
12,500 feet with a maximum cabin pressure of five PSI. Although that is legal, not
every pilot finds it pleasant. Reduced vertical separation minimum standards for flying beyond
28,000 feet are another issue. The King Air can comply, but it involves extra work for
little gain in fuel efficiency. Because the C90's props turn at a maximum speed of 1900
rpm rather than the previous 2100 rpm, the cockpit is substantially quieter. The 90
series King Airs' cabins have always been exceptionally quiet and cozy,
but the cockpit is very near the prop tips and is thus not as peaceful.
However, if Beech had not made key operational improvements, the lower maximum propeller rpm
would have increased the need for a longer takeoff runway. Despite the fact that the new propellers
and operating rpm are quite effective during climb and cruise, they are unable to match the
high rpm props' static thrust during takeoff. Therefore, a C90 King Air uses flaps during
takeoff for the first time. The new C90GT by comparison utilizes the same length of the
runway for a sea-level takeoff as the C90B with the first notch of the flaps down. Due to the
new derated engines' capacity to maintain full power in hot or high takeoff conditions, the
GT uses many hundreds of feet less for takeoff at higher elevation airports, especially on hot days.
The C90 King Airs have had automatic propeller feathering, although it was an option rather
than standard equipment, as it is on the larger King Airs. Autofeather and rudder bias are now
standard for the C90GT. In the event of an engine failure during or soon after takeoff,
the autofeather system automatically feathers the propeller of the dead engine,
and the rudder bias steps on the opposing rudder to maintain the plane's course. The working
engine's bleed air pressure is used by the rudder bias mechanism to push the rudder in the right
direction. It has no electronics or intricate components and is a very straightforward device.
Avionics The King Air C90GT is outfitted
with Rockwell Collins' Pro Line 21 avionics suite, which includes digital radio and audio systems,
multi-sensor flight management systems (FMS) that use multiple aircraft position inputs,
solid-state weather radars, Rockwell Collins' automated chart-selection system to lessen the
workload of the pilot, monitoring of onboard systems and XM satellite weather, universal
graphic weather for international operations, and a Rockwell Collins flight data recorder.
Other avionics include a global positioning system (GPS), traffic collision avoidance systems (TCAS),
terrain awareness and warning systems (TAWS), a high-speed USB database loader,
and integrated flight information systems (IFIS), which give pilots
access to a variety of capabilities. To improve safety and situational awareness,
the features include map overlays and computerized Jeppesen charts.
Systems Because the C90 King Air still
has toggle switches, gauges for various systems, and only basic electronic flight instruments,
you won't mistake it for any brand-new design turbine aircraft. However, the C90 definitely
has a huge airplane feel to it. Instead of using engine bleed air to heat the windscreens, wipers
are used to clear the rain. The power levers and control wheels are hefty in a way that inspires
confidence. And from where you're sitting, you can see many jets and other smaller aircraft below.
Variants After testing the "proof-of-concept"
King Air 87 for ten months—an aircraft that was never sold—Beechcraft launched the Model 65-90 in
January 1964. In October of that same year, the first 65-90 produced was delivered. The 65-A90,
65-A90-1, 65-A90-2, 65-A90-3, and 65-A90-4 are all variations of the 65-90. After producing the 65-90
for two years, Beechcraft switched to the 65-A90 in 1966. The A90's TOGW was raised from 9,000 to
9,300 pounds, and its PT6A-6 engines from the original 65-90 were replaced with more potent
PT6A-20 engines. It also had a new engine de-icing system, and its flight deck had been updated.
The 65-A90 was the most extensively produced of the variants. The A90-1 was an unpressurized
version with square windows built for the US Army, which was known as the U-21A. The U-21B
was a specialized military variant of the A90-2 with a changed cabin configuration. The A90-3 was
another military variant manufactured for the US Army that was given the RU-21C designation due to
enhanced electronic equipment. The A90-4, which was also manufactured for the US Army, received
stronger airframes and higher gross weight. Between 1967 and 1971, a total of 162 military
variants were constructed, several of which were outfitted with electronic surveillance equipment.
Beechcraft produced 206 A90s between 1966 and 1968 before switching to the King Air B90. The
B90 features superior ailerons and a larger wingspan than the A90, which somewhat enhances
its performance. Additionally, it received larger cabin windows, increased pressurization,
and better instrumentation. Additionally, its TOGW was raised from 9,300 to 9,650 lbs.
Beechcraft switched from the B90 to the King Air C90 in 1971. There are several
variations of the C90, including the C90-1, C90A, C90B, C90SE, C90GT, C90GTi, and C90GTx,
which is still manufactured today. Based on the B90, the original C90 has been updated
with a better pressurization system, a changed cabin, and PT6A-21 engines.
The C90-1 version features the E90's tail, better power output, and a higher maximum cabin pressure
differential. Improved electrical, pressurization, and heating systems, as well as improved landing
gear retraction, are all features of the C90A. The C90B has a higher MTOW and noisier
Hartzell props, whilst the C90SE is a more affordable, simplified version of the C90B.
Beechcraft replaced the four-blade Hartzell propellers on the C90B with three-blade
propellers on the C90SE and did away with the high-end Collins avionics system. For the C90SE,
Beechcraft also substituted a lightweight curtain for the fixed wall separating the
cockpit from the cabin. The C90GT has PT6A-135A engines that are more potent.
A GT derivative with improved Collins ProLine 21 avionics is the C90GTi. The
C90GTx's MTOW was raised to 10,485 lbs and it comes standard with winglets.
The C90GT, powered by more potent PT6A-135A engines,
can by comparison travel 1,068 nautical miles at a standard cruise speed of 247
knots and needs 4,406 feet of runway for takeoff and 3,060 feet for landing.
Market The first thing
you'll notice about a King Air C90 or a Cessna 421C is their enormous size. Seats in both cabins
are roomy and suitable for individuals of all shapes and sizes, including the tall and wide.
The pilot must make a long, hunched-over climb up the aisle between the seats, but once there,
they are greeted by a spacious cockpit with plenty of panel space for the newest technology, plenty
of legroom, and big, comfortable chairs. The pilot is seated high off the ground in both aircraft,
enjoying a "grand appearance" view that is clearly different from any piston single.
Both offer strong all-engine operating performance numbers, with the C90 slightly outperforming the
others in terms of climbing and cruising. The C90 will average approximately 220 KTAS,
while the 421C will average approximately 205 KTAS. The C90 will exceed 1,000 fpm early in the
climb and maintain that value for the majority of the climb into the flight levels. The 421C
will maintain 1,000 fpm early in the climb, but engine temperatures will necessitate a cruising
climb airspeed of around 600 fpm while leveling off in the flight levels. What are the genuine
differences for the picky customer when cabin size and performance are so similar?
A C90 or a 421C will both successfully get you from point A to point B,
and both will cost far more to run than any single-engine piston. Which do you choose,
though? According to our verdict, it ultimately depends on your needs.
Your trip requirements may be perfectly satisfied by the big-piston Cessna 421C, and if you have
between $350,000 and $450,000 to spend, you can get one of the nicest Cessna 421Cs ever
built. You should be able to purchase a 421C with really beautiful paint and upholstery, a fully
equipped avionics panel, low engine and airframe times, and an instance with no history of damage.
That $450,000 will also get you a C90, but it will be an earlier 1970s model with outdated
avionics, worn paint and interior, and engines in their prime. However,
it will be a turbine, which can be frightening to the inexperienced.
However, if you can afford to fly behind a PT6, you should. Ultimately, the engines are crucial,
and this is where the C90 excels. Tired paint and mediocre interiors will only be an irritation for
a short time. If you have a competent GPS unit and an autopilot, you might not mind having
steam gauges. So, if you can find a "good bones" C90 with good engines, you've got a contender.
Pros
The King Air C90 has a functional bathroom system that provides comfort for passengers.
A smart passenger might even choose the belted restroom for the lengthy trip rather than the
main cabin seats if all the seats are taken. There is ample space for legs and solitude.
The C90 has plenty of room for luggage as well. You can actually transport six people,
and their luggage, and still have room for a lot of gasoline. It is a sturdy,
reliable Beechcraft King Air that is also a comfortable cross-country cruiser.
The C90's biggest feature, though, is its PT6 engines. There are literally
thousands of PT6-21 engines flying around the world, so locating an experienced maintenance
source is simple. It is not the "sexy" huge engine found on some other planes,
but it is a sturdy and smooth engine that hums along without a murmur, like the C90. Unless
you run the fuel tank dry, it should not fail unexpectedly once started. That's pretty awesome!
Cons There is a weak point
in every King Air 90 model: the pressurization air travels from the cabin to the nose, then via the
air conditioner evaporator, a crossover duct, and the heater on the other side, before returning to
the cabin. These ducts get old and brittle after 9,000 hours, split, and leaks start to appear.
Although it is plumbed differently, this crossover duct is present in other King Air variants.
When troubleshooting pressurization,
prioritize your 90 if you have one because it has the most issues with this duct.
Conclusion The C90 won't travel
the furthest, nor is it the fastest or most powerful, but you get a lot of airplane and
performance for your money. The C90 is mocked by professional pilots for being a sluggish turbine,
but those who truly know best will attest that it arrives on most trips just a little bit later than
some other sleek aircraft, and its owner doesn't have to empty their bank account to buy or fly it.
Of course, there are E90s and F90s, as well as other modifications to make the C90 seem
like the newer and faster model, but the C90 is the most common King Air 90 model.
Why? The C90 lives the unofficial design philosophy of the whole King Air fleet:
"In no single aspect of consideration is it the best, but in every category, it is really good.”