The certification of Bell’s new 505 light single-engine helicopter makes Bell Helicopter the first OEM to receive a type certificate for a new helicopter equipped with True Blue Power’s TB-17 lithium-ion main-ship battery. The Robinson R44 received approval for the TB-17, under a supplemental type certificate (STC) issued last October, and Robinson Helicopter has also announced plans to equip the R66 with a True Blue lithium-ion battery. The R44 was “the first STC granted by the FAA for lithium-ion battery use as a primary electrical power source, including engine start,” according to True Blue Power, a division of Wichita-based Mid-Continent Instrument (Booth 5717). The Mid-Continent Standby Attitude Module backup instrument display is also standard on the Bell 505, providing attitude, altitude, airspeed, slip, vertical trend and heading information.
In the Bell 505 application, the TB-17 offers a number of advantages over existing sealed lead-acid (SLA) batteries, most significantly weight savings. Compared to an equivalently capable SLA, the 16-pound TB-17 weighs about 45 percent less, according to True Blue. The TB-17, like True Blue’s other lithium-ion-powered battery products such as the TB-44 main-ship battery and backup battery systems, uses nanophosphate lithium-ion chemistry, which has proven to be safe and reliable. “Our TS835 emergency battery has been flying for seven years with no incidents whatsoever and more than 1,000 installations,” said True Blue Power director Rick Slater. The company has also certified its larger TB-44 main-ship lithium-ion battery on the Cessna 208 and 208B Caravan and Bombardier Dash-8 100/200/300 series turboprops. “More are flying with these batteries now,” he said, “and we’re working aggressively to get them on more aircraft.”
Unlike many lead-acid battery installations in helicopters, the TB-17 in the Bell 505 is attached using terminal-style wiring connectors instead of the typical quick-disconnect fitting, which is heavier, costs more and takes up extra space. The TB-17 maintenance cycle is far longer than that of SLAs and nickel-cadmium batteries, with only a capacity check recommended every two years and no routine maintenance required. This increases ship availability and greatly lowers maintenance costs, which average 60 to 90 percent lower than “older lead-acid and nickel-cadmium alternatives,” according to True Blue Power.
Another reason that the TB-17 doesn’t need a quick-disconnect fitting for frequent removal is that the battery is equipped with built-in heaters that pre-warm it for starts in cold weather, eliminating the need to take the battery inside a warm hotel room or FBO on cold overnights. The TB-17 is rated down to -40 deg C, and at that temperature, it can self-warm in 10 minutes.
The battery is also equipped with self-monitoring electronics, which report real-time battery status to the pilot (in the 505 via CAS messages on the Garmin G1000H avionics).
Pilots will also notice the TB-17’s contribution to improving turbine-engine starting, with much faster starting as well as reduced engine temperatures during the start process. “It doesn’t allow the engine to build up as much internal heat during the start,” said Mid-Continent director of engineering Brett Williams, “with the benefit of less wear-and-tear on the engine.”
Over the lifetime of the lithium-ion TB-17 battery, and other True Blue Power batteries, cost of ownership and operation will be lower. No special equipment is required for battery maintenance, nor does the aircraft’s charging system need to be modified for retrofit applications. Normal ground-power units can be used with the True Blue Power batteries as well, and there are no restrictions on their use. Battery lifetime for a typical helicopter application could be as much as eight to 10 years, according to Slater.
True Blue Power is pursuing other applications for its lithium-ion batteries, and eventually as regulators become more comfortable with the safety of the nanophosphate technology, there should come a time when the certification process becomes simpler. Instead of the current requirement to apply special conditions to the certification process, it will eventually be a simple matter of facilitating STCs to the TSOed True Blue lithium-ion batteries.
“We’re seeing a shift in the mood and openness of OEMs and flight departments, [they realize] the need to take a serious look at this technology,” Slater said. “It’s a matter of not if, but when. For ‘more electric’ aircraft, there is no technology beyond lithium-ion that we can talk about. There is nowhere to get this energy and power density, it just has to be managed properly.”
Operators flying with the new batteries are satisfied with the technology. “On the Dash 8, for the first time, pilots don’t have to get a ground cart to start the engines,” said Slater. A Caravan operator in Africa had no access to a battery cart and was happy to be able to start the engine every time on battery power. “These are tangible applications,” he said.
Here at Heli-Expo, True Blue Power is highlighting the Bell 505 battery and the R44 STC and R66 lithium-ion battery application. To illustrate the use of lithium-ion batteries, True Blue Power brought a Tesla electric car, which uses a similar battery technology, to its exhibit.