The Cessna brand is quite popular worldwide. Part of the reason why it is loved so much is its fuel efficiency. But how fuel efficient are they really?
If you have considered buying an airplane, price is something that you will have to take critically into account. Getting caught up in the purchase price alone will not do you justice as several costs come with operating an aircraft. One cost that you’ll have to consider keenly is fuel.
An aircraft’s rate of fuel consumption depends on several factors. These variables include the aircraft’s weight, type of powerplant, altitude, and power setting. The Cessna aircraft family became renowned worldwide partly because of its impeccable fuel economy.
The cost of aircraft fuel might easily exceed 50% of the overall annual operating budget. With the rising fuel prices, lowering these expenses will account for how much you save to own an aircraft. One guaranteed way of doing this, without even considering your flying style, is to choose a fuel-efficient aircraft.
Fuel efficiency determines how much power and flight time you can get out of your aircraft. So, just how efficient is Cessna? Let’s explore the Cessna fuel economy by looking at its design, technical specifications, and factors impacting fuel efficiency.
The Cessna Fuel Economy: How Much Do They Burn?
Owning an aircraft is more or less similar to owning a car. Every time you step into the driver’s seat, you will have to think about one thing, "Do I have enough fuel to get me from point A to B and back?" And depending on how much power your car has and how fast you want to push it, it will determine how much more fuel you’ll need.
Flying is no different, although you won’t have the luxury of stopping at a filling station just because you suddenly ran out of fuel.
When flying, you’ll have to plan for your trip and take into account how much fuel your aircraft burns (we’ll take a deeper look at these factors affecting fuel economy later).
The Cessna is widely preferred for its relatively low fuel burn rate.
But taking it from a general point of view will not give a clear picture as the Cessna aircraft family is spread over different classes.
There are piston engines, turbo-props, and jet engines. We cannot cluster them together.
A jet engine might be very fuel efficient in its class, but you cannot compare it to a piston engine or a turboprop.
Cessna Piston Engines
This is where it all began in December 1911, when Clyde Vernon Cessna (founder of the Cessna aircraft company) made his first flight in a self-made monoplane, piston-engined aircraft.
Over the years, this simple venture has made way for the production of more successful models such as the Skyhawk, Skylane, and Stationair HD.
Walk into any flight school, and there’s a 90% chance that you will find the Cessna Skyhawk, also known as the Cessna 172.
The Skyhawk is the most produced aircraft in any category and is considered the best airplane for training.
Produced in 1955, the Cessna Skyhawk is historically the most successful aircraft, with more than 44,000 units.
It has an average fuel burn rate of 8.5 gallons per hour and a maximum range of 640 nm (1,185 km).
The success of this model meant it had to have several improvements and upgrades.
One interesting variant to the Skyhawk that’s worth mentioning since we are talking about fuel efficiency, is the Turbo Skyhawk JT-A.
Introduced in July 2014, the JT-A has a Continental CD-155 diesel engine with an output of 155 hp (116 kW) and a maximum cruising speed of 131 kn (243 km/h).
This particular variant has an average burn rate of just 5 gallons per hour (3 gallons less than the standard Skyhawk) and has a maximum range of 885 nm (1,639 km), which is 38% more than the standard 172.
Sadly though, in May of 2018, this variant was discontinued due to its low sales brought about by the high buying price.
Powered by a larger six-cylinder piston engine, the Cessna Skylane is a development of the popular Skyhawk, though more powerful.
Also known as the Cessna 182, the Skylane has several variants, some featuring different engine models.
It has an average fuel burn rate of 13 gallons per hour and a maximum range of 915 nm (1,695 km).
The R182 variant (Skylane RG) features retractable landing gear that gives it a more aerodynamic advantage, resulting in 10 - 15% better fuel economy, improved climb rate, and cruising speeds. But this comes at the expense of an increase in its maintenance costs.
Cessna Turbo Skylane
The Cessna Turbo Skylane, also known as the T182T, is an upgraded version of the Cessna 182.
With an addition of a factory-produced turbo-charger, it has an improved performance over the standard Cessna 182. The Turbo Skylane can fly faster, higher, and further.
The 235-horsepower Lycoming engine gives it an average fuel burn rate of 17.5 gallons per hour and an increased range of 971 nm (1,798 km).
Cessna Turbo Stationair HD
Another addition to Cessna’s piston-powered family is the Turbo Stationair. This is a versatile aircraft, fitted with a Lycoming engine producing 310 horsepower that burns 15.4 gallons of fuel per hour on average, and has a range of 703 nm (1,302 km).
Another addition to the Cessna family of aircraft is the turboprop. Compared to piston engines, the turboprop family, which includes the Skycourier and the Caravan, can produce more power, fly faster, operate at higher altitudes, and go farther on less fuel.
Although practically speaking, not all turboprop airplanes are more powerful and efficient than piston engine aircraft.
If we were not considering size, a bigger piston engine would be more powerful than a smaller turboprop. But with the increase in size comes a sacrifice in efficiency for the piston engine.
On the other hand, this is different for turboprop. The bigger the engine, the more efficient it is, which is part of the reason why smaller turboprop engines are not quite as popular with aircraft manufacturers.
Introducing us to the turboprop family is the Cessna Caravan. The Caravan, also known as the C208, was made in 1981.
It is a tough and versatile airplane that’s known for its low operating costs and high performance.
The Caravan is fitted with a single Pratt and Whitney PT6A-114A turboprop engine in a tractor configuration that supplies the aircraft with a total of 675 horsepower, a maximum range of about 1,070 nm (1,982 km), and a fuel burn rate of about 48 gallons per hour.
And because it uses the cheaper and more available Jet-A fuel, the cost per gallon is lower compared to AvGas.
The Caravan was later improved to a more efficient and higher-performing Cessna Grand Caravan EX, also known as the Cessna 208B.
The plane is powered by a more powerful engine made by Pratt and Whitney Canada. It has 867 horsepower, which is 38% more than its predecessor.
Its total payload and cruising speed were also improved. Although the more powerful engine means a higher fuel burn rate of about 58 gallons per hour. The maximum range also went down to 912 nm (1,685 km).
The Cessna Skycourier, also known as the Cessna 408, is a high-wing, twin-turboprop aircraft fitted with two Pratt and Whitney Canada PT6A-65SC engines, each delivering 1,110 hp. This aircraft has an average range of 920 nm (1,704 km).
There is a cargo version of the Skycourier that can reach a maximum range of 940 nm (1,741 km).
Cessna Jet Family
This is Cessna's class of jet engine aircraft known by the "Citation" brand name. The name was given to an American thoroughbred racehorse after it won the American Triple Crown title.
The Citation family has had quite a successful run since it entered the market in 1969, having had over 8,000 units delivered.
The increased power, speeds, and altitudes at which jet engines operate make them preferred over turboprops.
Since they can get to their destination faster, it makes the jet engine aircraft more cost-effective due to reduced flight time. The higher operational altitudes also mean less disturbance from weather and turbulence, factors that result in more fuel consumption during flight.
Cessna Citation M2 Gen2
The Citation M2 is Cessna’s entry-level jet. This aircraft is powered by two FJ44-1AP-21 engines produced by Willams International that provide the aircraft with an output thrust of 1,965 lb (8.74 kN), giving it a maximum cruising speed of 404 ktas (748 km/h) and a maximum range of 1,550 nm (2,871 km).
The engines have an average fuel burn rate of 88 gallons per hour.
Cessna Citation CJ3+
Next in line is the Citation CJ3+. This aircraft is powered by a more powerful Williams FJ44-3A engine that provides it with 2,820 lb (12.54 kN) of thrust, and a maximum cruise speed of 416 ktas (770 km/h), giving out a range of approximately 2,040 nm (3,778 km). Subsequently, the CJ3+ engines have an average fuel burn rate of 165 gallons per hour.
Cessna Citation CJ4
The Citation CJ4, launched in October 2006, came out with a rocky start after experiencing fires caused by its lithium-ion main battery equipment. This caused the FAA to issue an emergency Airworthiness Directive (AD), which called for the main aircraft battery to be replaced with Ni-Cad or lead acid batteries.
Nonetheless, this model has had over 300 units delivered.
It is powered by two FJ44-4A engines manufactured by Williams International, giving this aircraft a thrust force of 3,621 lb (16.11 kN) with a maximum cruising speed of 451 ktas (835 km/h) and a maximum range of 2,165 nm (4,010 km).
The Citation CJ4 engines burn fuel at an average rate of 160 gallons per hour.
Cessna Citation XLS
The XLS is also known as the Cessna Citation Excel. It is powered by two PW545C engines manufactured by Pratt and Whitney Canada that give out a thrust force of 4,119 lb (18.32 kN). This power translates to a maximum cruising speed of 441 ktas (817 km/h) and a maximum range of 2,100 nm (3,889 km).
The Citation Excel has an average fuel burn rate of 215 gallons per hour.
Cessna Citation Latitude
Developed from the Cessna Citation Sovereign, the Latitude is a more recent model that began production in early 2014.
Still using the Sovereign’s twin PW306D1 engines manufactured by Pratt and Whitney Canada, this aircraft has a thrust force of 5,907 lb (26.28 kN), giving it a maximum cruise speed of 446 ktas (826 km/h) and a subsequent range of 2,700 nm (5,000 km).
The engines have an average fuel burn rate of 210 gallons per hour.
Cessna Citation Longitude
The Citation Longitude is designed for the business class and made to be as reliable, comfortable, and efficient as possible, with the manufacturer (Textron Aviation) reporting savings in operating costs of up to 16%.
The Citation Longitude is powered by two HTF7700L engines manufactured by Honeywell, giving the aircraft a combined thrust of 7,665 lb (34.10 kN), resulting in a maximum cruise speed of 483 ktas (895 km/h) and a range of 3,500 nm (6,482 km).
With all this power stacked in its engines, the Longitude has an average fuel burn rate of 270 gallons per hour.
What Determines the Cessna Fuel Economy?
As seen with the different fuel consumption figures, the fuel burn rate is different for each aircraft model and is based on a couple of factors such as airframe design, type of powerplant, aircraft weight, altitude, weather conditions, and operating speeds.
These factors determine how much energy is lost during flight to make up for losses, and how much energy is used to produce the traveling force.
Although an aircraft might consume similar or less fuel than its counterpart, it might not necessarily be more efficient.
Fuel efficiency is measured by the amount of useful energy produced by a unit of fuel.
Take the example of two masses of rock of different sizes being pushed on a flat surface, the smaller one being square, while the larger one is circular. The larger rock would require more energy to push than the smaller one at first, but as momentum builds, the larger rock will be easier to move.
As an aircraft is in flight, it is faced with a couple of aerodynamic forces, namely lift, thrust, drag, and weight.
Weight is countered by the lift produced, and aerodynamic drag is countered by thrust.
The efficiency with which thrust counters aerodynamic drag determines the maximum range a particular aircraft can achieve. This means that any part of the airplane that reduces drag, in the end, makes the airplane more efficient.
Aircraft landing gears are among the most important components, but they limit aircraft efficiency by increasing drag. This problem can be fixed by using retractable landing gear. However, this makes the plane heavier and more expensive to maintain.
Models such as the Cessna 172 Skyhawk have had wheel pants added to provide more aerodynamic surfaces for smoother airflow movement and less drag, which has had a reported increase of 2 knots in airspeed.
Most piston aircraft and turboprops have struts connecting the wings to the fuselage. These connection points cause interference drag behind them. To limit this, fairings are installed to provide smoother airflow.
Wingtip devices such as winglets featured on the Citation Longitude improve aerodynamic efficiency on the wing by reducing wingtip vortices and the resulting lift-induced drag.
These modifications to airframe design reduce overall drag, meaning that the airplane needs less thrust force to counter drag.
Some aircraft propeller systems allow the propeller blades to be put in a feathering position in case of an engine failure. This lets the blades move freely with the wind, which reduces drag by letting air flow past the propellers with as little resistance as possible.
Weight is another very significant factor that affects efficiency and overall aircraft performance.
The heavier an aircraft is, the further the pilot needs to pull up its nose during takeoff (increasing the angle of attack). This leads to an increase in overall drag.
More power is required to overcome the increased drag. Therefore, takeoff performance is reduced with an increase in weight.
If we also consider an aircraft in cruise, its fuel burn rate is higher during the first stages of flight but goes lower and its efficiency increases as time go by. This is brought about by the gradual reduction in fuel weight. As a result, the aircraft needs less power to maintain lift and cruising speeds.
As you go higher, air density reduces, which means less drag. However, this reduces air pressure and temperature, resulting in lower engine power output.
To reduce fuel consumption, an aircraft should therefore cruise close to its maximum possible altitude.
About THE AUTHOR
After spending years watching every video I could find about flying, I finally scratched the itch and got my pilots license. Now I fly every chance I get, and share the information I learn, here.Read More About Joe Haygood