With the announcement that the FAA has awarded a full Type Certificate to the Tecnam P2010 TDI, the U.S. general aviation (GA) aircraft market now has a piston-single that runs on the most widely available fuel at airports – jet fuel. And if Jet A isn’t handy, you can fill it with diesel.
Jet fuels are actually similar to diesel fuel and can be run in diesel engines. But with conventional gasoline engines long having dominated the GA market, few aircraft manufacturers have developed light aircraft with diesel powerplants. Diesel piston engines simply haven’t caught on in the U.S. market, which still runs on 100LL (low-lead) avgas.
Unlike Europe and most of the world, where 100LL is scarce and very expensive, the fuel remains available in America. However along with increasing prices, driven in part by the Biden administration’s agenda, it is facing the prospect of a sundown in production by its main supplier, Innospec
There are new gasoline aviation fuels in development but Tecnam has seen the recent emphasis on diversification in liquid fuels, including synthetic and bio-based Sustainable Aircraft Fuel, as an opportunity to bring a diesel powered light airplane to market.
“It really comes down to what makes our aircraft simple and economical to fly,” says Tecnam’s Director of Sales, David Copeland. “The TDI was born out of that thought, ‘What can we do on a global basis given what’s going on with avgas [aviation gasoline], Mogas [lead-free, ethanol-free automotive gas], diesel and Jet A.”
The Italian firm claims to be the only privately held fixed wing aircraft company in the world. Founded in 1986 by brothers Luigi and Giovanni Pascale, Tecnam produces approximately 300 aircraft per year. In 2020, it ranked 5th among U.S. market GA manufacturers by number of airplanes sold with 154 aircraft delivered.
Tecnam’s line of piston-single and twin engine airplanes includes the P2010, whose clean-sheet, high-wing design reminds most who see it of Cessna’s ubiquitous 172. The composite fuselage/metal wing airplane was initially (and still is) offered with optional 180 hp or 215 hp Lycoming gasoline engines.
FAA certified in 2015, it began selling into the U.S. market in 2016. Certification of the TDI variant with its 170 hp Continental CD-170 turbodiesel engine in the U.S. followed the TDI’s type certification in Europe in 2020. According to Copeland, Tecnam has already delivered 70 P2010 TDIs in Europe and the first U.S. deliveries begin next week with a TDI destined for a customer in the Carolinas.
The new owner likely plunked down about $500,000 for the airplane, a sticker price Copeland says is representative of well optioned TDIs, which feature an avionics package including Garmin’s
Cessna’s 182 Skylane is arguably the closest competitor to the P2010 TDI with similar avionics, passenger/load capacity, range, cruise speed and service ceiling numbers. At 75% cruise power the Lycoming IO-540-powered 182 burns about 13 gallons per hour (GPH).
Tecnam claims a noteworthy advantage with its diesel powerplant burning only 7 GPH of Jet A at 75% cruise power. Given recent prices for avgas and Jet A ($5.34/gal and $4.15/gal respectively at Easton Airport in Maryland), the TDI’s fuel efficiency could add up. Its 63 gallon fuel capacity gives the aircraft range in excess of 1,000 nautical miles and endurance of up to 12 hours.
Tecnam adds that, as with turbocharged gasoline engines, the turbodiesel suffers no loss of performance as altitudes increase up to 8,000 feet. An optional oxygen system is available, allowing flight up to 18,000ft.
The term “diesel” is a touchy one with Tecnam. Despite the fact that the CD-170 is a familiar four-cylinder, in-line, liquid-cooled compression-ignition engine which you can run on fuel from the pump with the green (diesel) handle at your local gas station, the company would much prefer you call it a Jet A engine.
“It’s a Jet A aircraft,” Copeland stresses. “We can say it’s diesel which has an automotive connotation but going forward in 2022, we’re advertising it as a Jet-A aircraft.”
The sensitivity may be aligned with the reputation diesel power acquired with the Volkswagen “dieselgate” scandal of 2015 though Copeland firmly asserts that not one pilot or prospective customer he’s talked to has associated one with the other. The automotive community appears to be conscious of aerodiesels with MotorTrend even covering the subject several years ago. Regardless, the change in marketing lingo suggests the “TDI” designation may be dropped from the P2010’s moniker.
Long term maintenance and cost have been questions for aviation diesels given the relative lack of such powerplants in the American market. The traditional engine re-build so familiar to gasoline-powered airplane owners won’t be part of the extended maintenance routine for P2010 TDI buyers.
“We don’t do an [engine] overhaul. We do a TBR or Time Between Replacements. That’s the biggest difference,” David Copeland affirms. “We’re finding with the diesels in Europe that the engine with the FADEC [Full Authority Digital Control] system [requires] less maintenance up until the point it is replaced though we haven’t experienced any replacements yet.”
Tecnam estimates the mean TBR at 1,800 hours (Continental puts it at 1,200 hours), similar to the standard 2,000 hour time between overhaul (TBO) for the Lycoming IO-360M1A gasoline engine which powers the 180 hp version of the P2010.
On the other hand, overhauling the IO-360 costs about $26,870 as opposed to buying a new CD-170 diesel. Pricing for the CD-170 has not been released by Continental but company spokesman, Andrea Bertagnolli, explained that an overhaul option for CD-170-powered P2010 is a non-starter.
“An overhaul for the diesel combustion cycle engine would be cost-prohibitive to the customer once you factor in the complexity of the engine, overall inspection time, and cost of new parts. The engine replacement option is an easier and more cost-efficient path when all items are factored together.”
A retrofit kit for Continental’s sister 155 hp CD-155 diesel which has been retrofitted to several Cessna 172 models costs $77,980 for the engine and required parts excluding labor. Continental’s Bertagnolli tells me the price for a new CD-155 is approximately $80,000. That suggests the TBR cost for the CD-170-equipped P2010 TDI would likely be in the $90-$100k range. (The used CD-170 would have a core value but it’s not clear whether that would impact the replacement price.)
Therein lies the longstanding challenge that aerodiesels have faced in the American market. Their up-front acquisition cost and replacement cost tend to wipe out savings from fuel efficiency benefits, particularly with engine replacement at one-fifth the cost of a new – not depreciated – airplane.
Cost notwithstanding, Copeland acknowledges that Tecnam figures it’s simply easier to replace the CD-170 than overhaul it, possibly due to the smaller number of U.S. aircraft maintenance shops with diesel engine expertise and Continental’s own desire to gain more lifecycle data.
The FADEC system which manages the CD-170 is attractive because it offers single-lever control, obviating the need for the pilot to manage a fuel-air mixture control, lessening the risk of harm to the engine through inattention or improper operation. “The first thing that you notice is the simplicity and reliability it adds to the aircraft,” Copeland says.
Tecnam has pitched the P2010 as an attractive option for flight school fleet buyers but Copeland acknowledges that it has yet to receive orders for the TDI from flight schools. Given that such schools operate fleets of avgas-fueled airplanes, adding diesels might complicate their operations and balance sheets despite the likelihood that the CD-170 may need fewer periodic maintenance checks than its gas counterparts.
“It’s too early in the program on the [U.S.] domestic side to have a good answer for that,” says Copeland. “In a year or so we’ll have a better feel for the flight school marketplace.”
The P2010 is a more stylish take on the classic high wing single planform. Copeland likens it to a Ferrari and the comparison suggests that customers will largely be owner-operators. The fuel flexibility that the TDI offers gives them options. The rising costs of fuel and a steady-to-increasing gap in Jet A and 100LL prices may one day mean the higher acquisition/replacement cost of turbodiesel powered singles is sufficiently offset by a more obvious perception of the fuel savings they offer.
Jet A is far easier to find on the ramp than diesel. On the other hand, a short drive around the airport premises or just off will almost always bring you right to a diesel pump. There, you could breezily squeeze out a tankful of that less refined dinosaur juice for your Italian airplane.