Estimated reading time 8 minutes, 38 seconds.
On Aug. 19, a U.S. Army pilot sat in the left seat and took control of the S-97 Raider for most of an 80-minute flight, the first time anyone other than a Sikorsky test pilot had flown the compound coaxial helicopter.
Charlie Packard, an Army civilian experimental test pilot assigned to the Redstone Test Center, Army Test and Evaluation Command (ATEC), was the first government pilot to fly a Sikorsky-built operational prototype developed under the Future Vertical Lift program seeking speedier, longer-ranged, more maneuverable military rotorcraft. Packard is designated as the Army’s test director for Sikorsky’s Future Attack Reconnaissance Aircraft (FARA) competitive prototype program.
“This is a huge milestone for the program,” Sikorsky experimental test pilot Christiaan Corry told Vertical in a recent interview. Corry sat in the right seat during Packard’s flight. Because FARA is an ongoing competition, the Army declined to make Packard available for an interview but provided written answers to detailed questions.
“Raider was designed, early on, to prove out a couple of concepts but also to be a technical demonstrator that we would be able to put folks into and take them out and actually show them the technology,” Corry said. “We’ve come a long way in the journey and finally got ourselves in a position where we were able to bring somebody along.”
There were doubts the flight would happen as scheduled because Sikorsky, and parent company Lockheed Martin, locked down most of their facilities because of the Covid-19 viral outbreak. Admission to both its manufacturing and test flight facilities was significantly curtailed, Corry said.
Once given the all clear, Corry and Packard went to Sikorsky’s facility in Stratford, Connecticut, for a couple days of familiarization on the Raider Systems Integration Laboratory. Basically a ground-based, exploded simulator for the Raider, the SIL is both physically and functionally identical to the aircraft, but its components are arranged through several labs so that data can be collected from virtual flights without leaving the ground.
“It doubles as a great familiarization trainer,” Corry said. “There are a couple of things that are unique to flying Raider, like the fact that you have this prop that gives you kind of a third degree of freedom. . . . There’s a bit of pilot technique that one needs to become accustomed to it.”
The pair spent the better part of two days flying the SIL, partly getting Packard used to sitting in the left seat and using the single, centerline collective and outboard fly-by-wire control stick on Raider. After spending a career flying traditional helicopters with a left-hand collective and right-hand stick, getting used to switching sides in the left seat takes some getting used to, Corry said.
“That effectively means that the guy that’s flying in the left seat is for all intents and purposes batting left handed,” Corry said. “I am not confident sitting in the left seat of that machine and letting somebody take it for a spin around the block, so unfortunately it fell to him to sit in the left seat.”
“That was the limitation of the flight,” Corry added. “Certainly in Raider X we’ve addressed that to where it’s going to be common controls on both seats so each pilot will have his own cyclic and collective and it will be natural and nobody has to play left handed.”
The Aug. 19 flight lasted an hour and 20 minutes and included the typical repertoire of the Raider’s public performances to date. On that day, given the weather and other conditions, Raider achieved 187 knots, well in excess of the Army’s threshold speed for FARA.
“He got to investigate whatever he was interested in in the aircraft and he took it through everything from a hover and traditional helicopter stuff to engage the prop and speed up and fly it around like an airplane. . . . Through the course of the flight, I suppose we tried to demonstrate a little bit of everything.”
That included low-speed helicopter-like maneuvering and hover, both with and without the prop, flying around without the prop in traditional helicopter mode, clutching the prop to fly at high speed, rapid ascents and slow descents with the prop engaged to act as a sort of “parachute,” Corry said.
“Charlie was able to do all that up and away,” Corry said.
Raider is an 80 percent representation of Raider X, which Sikorsky is developing for FARA. Its primary opponent in FARA is the Bell 360 Invictus, which has not yet been built. Alongside FARA, which will fill the armed scout mission vacated by retirement of the OH-58D Kiowa Warrior, is the Future Long Range Assault Aircraft (FLRAA) that eventually will replace the UH-60 Black Hawk.
Sikorsky is teamed with Boeing to offer the SB>1 Defiant, essentially a scaled-up Raider, for FLRAA. Bell again is its opponent in that competition and again is offering a radically different design, the V-280 Valor advanced tiltrotor.
An Army pilot flew Valor for the first time in February 2018. Chief Warrant Officer 3 Tom Wiggins of the U.S. Army Special Operations Aviation Command conducted the flight at the Bell Flight Test Facility in Amarillo, Texas, and performed performed hover in ground effect repositioning, pattern flight and roll-on landings.
“This early involvement of the Army [experimental test pilot] and test director initiates the establishment of the combined test team and provides insight to the Army test organization of the technology, test procedures, and aspects of this unique configuration,” said a spokesperson for the Army Combat Capabilities Development Command Aviation & Missile Center. “Having aircraft in flight test provides realistic data of the capabilities that these next-generation rotorcraft can provide as well as provide early indicators of affordability.”
Jay Macklin, Sikorsky’s director of Future Vertical Lift business development, said the flight was important so the Army can get real-world experience with its FVL technology.
“We really keep focusing on helping the Army develop this transformational capability: twice the speed, twice the range, twice the maneuverability and in particular survivability,” Macklin said. “We’ve continued to work very closely with them developing a lot of data, giving a lot of data to the Army, so they can understand and come up with their final requirements for what they’re looking for.”
Every time the S-97 flies, Sikorsky gathers data to inform its final Raider X proposal to the Army. The aircraft is airborne almost weekly these days, testing one configuration or flight characteristic or another prescribed by the Raider X engineering team.
“[We’ve] made a lot of adjustments to our Raider X design based on the knowledge that has come off of the Raider flights. Raider has been incredibly important to our program,” Macklin said. “We believe it has helped us rescue risk on our Raider X design because we’re actually out flying, generating engineering data on every single flight.”