The BLR FastFin is a major part of Bell’s recently announced enhancements for the 412EP medium-twin. FastFin will be standard on all new 412s and available via retrofit on existing aircraft. More than 600 already are in service on the UH-1, 205/206 and 212/412, according to Dave Marone, BLR vice president. Those aircraft have logged more than one million flight hours with the system.
The $75,000 system (uninstalled) consists of a new re-sculpted carbon-fiber vertical fin and a pair of parallel five-pound aluminum tailboom strakes that dramatically enhance aircraft performance. Marone said FastFin gives the aircraft an additional 1,250 pounds of IGE hover capability. “That translates into up to 90 percent of the useful load of the aircraft,” he said. “You have anywhere from 7.5- percent increase at sea level or 1,000 msl on a warm day to over 90 percent at the 6,000- to 8,000-foot range. Even a guy operating at sea level in the Gulf of Mexico is going to get additional utility from that,” Marone said. “In the Gulf you can get up to 2,000 feet density altitude on a hot summer day. With the system, you are going to get 300 pounds of additional IGE hover capability in that scenario plus 10 to 15 knots of critical wind azimuth tolerance, so operational flexibility and safety is enhanced quite a bit.”
BLR estimates that the system will pay for itself in one to two years for operators flying 400 hours annually.
The strakes work by taking the accelerated main rotorwash airflow around the tailboom and stalling it on the left side, creating low pressure on the right and higher pressure on the left so the boom naturally moves in the direction of the applied tailrotor thrust. The fin relocates approximately one third of the vertical surface area to the aft tailcone, which is below the thrust arc of the tailrotor.
“You still have the surface area for weathercock stability, but you’ve removed the impediment to lateral thrusting,” Marone explained. “The trailing edge of the vertical fin has a rounded radius cut similar to the leading edge of the vertical fin. Having that large radius cut makes operations from critical wind azimuths far less likely to create a significant decrease in efficiency when that airflow is trapped by the sharp leading edge.”
BLR (Booth No. 1814) is accepting orders to retrofit the system on Bell 412s for operators of nine or fewer aircraft, while Bell’s Aeronautical Accessories affiliate is accepting orders from operators of 10 or more aircraft. Marone estimates it would require six business days for experienced shops to complete the retrofit.
FastFin is part of a new upgrade package announced by Bell for all 412EPs. It includes more powerful Pratt & Whitney Canada PT6T-9 engines, which yield a 15-percent power increase, and glass-panel avionics akin to those onboard Bell’s new 429 light twin, better onboard communications and a new tailrotor. The 2,143-shp PT6T-9 will replace the current 1,800-shp PT6T-3D, yielding a 15-percent shp increase, improved OEI and high/hot performance, and electronic engine control.
The upgrade will yield a 10- to 12-percent increase in Cat A/PC1 and PC2 performance and a future path to increased payload and range. The new onboard communications system will be compatible with civil standard headsets, eliminating the need for military-style, low-impedance microphones and earpieces.
STC approval for the package is expected later this year, with customer installations beginning in 2012. Bell vice president Larry Roberts said the upgrade was prompted by customer requests, primarily from the oil and gas market. A price for the entire package has not been set.