Sikorsky has lifted the veil on a series of technological enhancements that could help keep its Black Hawk utility helicopter relevant until the 2070s.

Some of the technology insertions, detailed to Latin American air force leaders on April 4 at the FIDAE Airshow in Santiago, Chile, have already been well-documented by the manufacturer. These include the development of the Improved Turbine Engine Program (ITEP) to boost the rotorcraft’s hot-and-high performance and the plan to turn the Black Hawk into an optionally piloted vehicle that could be flown with two pilots, one pilot or no pilot at all.

Others, including an advanced tail rotor and new main rotor blade tip as well as a more capable main gearbox, are being matured more quietly as improvements to the aircraft that could be made available over the next five years, says Chris van Buiten, vice president of Sikorsky’s Innovations group.

Many of the technologies being studied are currently at technology readiness levels of 5-6, and if implemented will be targeted at the U.S. government customer first, but it is unclear whether they will form part of a new Black Hawk variant or merely cut into the existing production runs as incremental upgrades.

Among them is a new advanced main rotor blade tip, designed to replace the swept-tapered anhedral (downward-pointed) currently used on the UH-60M.

“That swept-tapered anhedral is the best we could design and build 15 years ago,” says van Buiten. New computer technologies have been able to develop different-shaped blade tips, he notes, which could allow several hundred pounds of additional payload. Other changes include adjustments to the tail rotor’s blade chord and rotor hub, again to improve payload and reduce maintenance costs.

The company is also exploring changes to the main gearbox that would allow it to take “greater advantage of the ITEP engine at lower-density altitudes,” says van Buiten. “Today’s gearbox can support 3,400 shp. . . . We want to fit more power into the same space,” he adds.

A larger main fuel cell at the rear of the fuselage could be introduced as well, as could conformal auxiliary fuel tanks to increase range.

One technology that holds particular promise is a hub-mounted vibration suppressor to replace the Black Hawk’s current bifilar vibration absorber. The suppressor, developed by Lord Corp., has been flight-tested by Sikorsky as part of the U.S. Army Aviation Applied Technology Directorate’s Active Rotor Component Demonstration and proved it could produce near jet-smooth flight, says van Buiten.

suppressor

The computer-controlled vibration suppressor reads the vibrations in the rotor hub and then spins a number of masses and generates moments that cancel out different vibrations, rather than the handful that can be cancelled out by the bifilar.

“It’s an early application of active rotor technology,” says van Buiten, “It is a tricky environment, but it is easier trying to do it on the blade . . . attacking the vibration at source,” he says.

But Army aviators do not need a jet-smooth ride, van Buiten points out. The real benefit would come from extending the life of components on the helicopter.

“A more benign environment will improve reliability, improve availability and reduce maintenance,” he says. Perhaps more crucially, the suppressor could find use in Sikorsky’s commercial products, the S-76 medium helicopter and the S-92 heavy helicopter, both of which use a bifilar. The S-92 could be an early beneficiary, as it shares much of its dynamic system with the Black Hawk. The S-76 and S-92 are widely used as VIP helicopters, where the benefits of a smoother flight would be widely appreciated. Air ambulances and military medevacs also could benefit, as patients could receive better medical care in flight thanks to lower vibration.

Next on the agenda is to further prove the adaptability of the company’s Matrix autonomous flight technology. So far, this has been tested on its S-76 Sikorsky Autonomy Research Aircraft testbed, but now the company is installing the technology on an early-model UH-60A that is due to fly toward the end of the year.

helicopter parts

“We want to show the retrofitability; if you can do it on an A-model, then it is easy to do it to an M-model . . . and that holds tremendous promise,” says van Buiten. Once operational, the demonstrator will prove the ability of the Matrix system to assist with two-pilot, one-pilot and then later autonomous operations.

“It will demonstrate how it can be a partner in a complex mission and help eliminate controlled flight into terrain,” says van Buiten. “The same sensors that fly when no one is onboard would be vigilant while there are two pilots onboard, augmenting their decision-making.”

The Matrix UH-60A will be a simpler helicopter than the UH-60MU that has already conducted trials using the Matrix system, as the UH-60MU required significant modifications to its hydraulic electrical system and servos.

The system being fitted to the UH-60A will be “far more retrofittable,” adds Van Buiten.