Bell Eagle Eye (Model 918)

History of the Hawkeye (Type 918)

The Bell Hawkeye (Corporate Model 918) is/was an Unmanned Aerial System (UAS) developed for participation in the U.S. Navy's Vertical Takeoff - Unmanned Aerial Vehicle Program (VT-UAV). Like most other contemporary UAVs, the Hawkeye is known as a system capable of operating in severe weather conditions and providing its operators with a real-time battlefield assessment report. The program claims that less manpower and maintenance time will be required than conventional manned aircraft currently in service.

Using a UAV/UAS system also eliminates the possibility of the pilot being shot down, killed or captured by the enemy because the UAV/UAS operator can be stationed in the United States without being directly exposed to the enemy.

There are inherent advantages to rotorcraft systems and their ability to land and take off from solid surfaces. Such a platform would not need to operate a runway or launch a catapult/return net system. The tilt-rotor system can take off and land like a traditional helicopter, but thanks to its adjustable engine nacelles, it can fly like a traditional fixed-wing aircraft. Hanging around rotorcraft is an advantageous proposition compared to first- and second-generation fixed-wing direct-flying drones (like the Predator series) -- those "birds" that need to fly around a specific target area.

The Hawkeye can use its dual-rotor capability to remain "housed" in designated airspace for as long as its internal fuel supply allows. Of course, given its hovering nature and size, this would expose the Hawkeye to more precise ground fire, which could lead to larger stationary targets. Hawkeye has also completed land and sea tests to further demonstrate its capabilities.

The latter environment is notable because it exposes the UAS to a variety of oceanic conditions, including unstable launch/recovery platforms and expected corrosive oceanic elements that typically have effects on internal and external systems.

Bell started working on the Hawkeye in 1993 and built its first scale model prototype, called the "TR911X". Two demonstration prototypes were eventually produced under the brand, and the first flight was recorded on March 6, 1998. Each of these prototypes was equipped with an Allison 250-C20 series turboshaft engine. Soon after, the Hawkeye was included in the required flight test program, which included two phases - one on land and the other at sea. While the first prototype was lost in an accident during subsequent testing, the second prototype was able to complete the test without any major accident.

While both the U.S. Navy and the U.S. Marine Corps showed early interest in UAS, Hawkeye went unnoticed for a while, and neither party ordered further evaluation models.

In 2002, a full version was built under the name "TR918". This new version is equipped with a Pratt & Whitney Canada PW207D turboshaft engine. The U.S. Coast Guard became interested in the tiltrotor system and worked with Bell to develop a larger version of the original technology demonstrator. In theory, Hawkeye could be a good complement to the Coast Guard focused on Search and Rescue (SAR), able to use their good times prowling the seas looking for survivors or tracking down perishables trying to "cargo" smuggled into the U.S. land.

The resulting Bell/USCG design became the "HV-911". Once again, however, Hawkeye waited for its "day in the sun" until the Coast Guard shelved dedicated production tools indefinitely.

The design of the Bell Eagle Eye is no different from that of the larger Bell-Boeing V-22 Osprey manned tiltrotor transport helicopter. Eagle Eye features a centralized airframe containing key electronic and digital components that bring the system to life and manage the main powerplant. The straight wings are attached to the fuselage, and each straight wing maintains a single rotor system by coupling the drive shafts of the transmission system. A prominent air intake was mounted on top of the fuselage, which itself gradually retracted into the tail. The fins are flanked by horizontal stabilizer planes, each with a sloping vertical fin.

The landing gear consists of two twin-tired main landing gear legs, one as the front leg and the other as the fuselage leg. A pair of smaller outboard landing gear legs are attached to the rear of each rotor nacelle, which come into play when the nacelle is at a fixed upward angle during landing/takeoff.

The Hawkeye has a payload capacity of 200 pounds and can be used for reconnaissance, surveillance, electronic warfare (EW) and weapons loading as needed.

If the development type HV-911 is used as the final mass-produced type, it can be equipped with the above-mentioned Pratt & Whitney Canada PW207D series turboshaft engine. The powerplant provides up to 641 hp to a pair of tiltrotor outboard assemblies mounted on each wingtip. Each rotor assembly rotates a three-blade rotor system. According to evaluation test results, the Eagle Eye can reach a top speed of 225 mph and has a service ceiling of about 20,000 feet.

Single-engine life is about 6 hours an excellent advantage considering the loitering nature of the drone on the battlefield or the airborne element of Search and Rescue (SAR).

While U.S. purchases of Eagle Eyes have stagnated, interest from overseas powers has increased. Bell has teamed up with German firm Rheinmetall Defense Electronics and French firm Sagem to potentially bring Hawkeye into European stockpiles.

This arrangement allows the European offices - assuming they flourish - to be able to assign whatever payload they need to their specific Hawkeye airframe. Bell will only be responsible for the construction and delivery of the engine unit, engine and avionics.

This is the flexibility inherent in Hawkeye's design.

According to Bell, Eagle Eye is "the most versatile drone system on the market".

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