| GTR-18 | |
|---|---|
Two GTR-18 "Smokey Sams" on LMU-23/E single-bay launchers
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| Type | SAM simulator rocket |
| Place of origin | United States |
| Service history | |
| In service | 1980s-present |
| Used by | United States military |
| Production history | |
| Designer | Naval Air Warfare Center Weapons Division (NAWCWD) |
| Designed | early 1980s |
| Specifications | |
| Mass | 1.430 pounds (649 g)[1] |
| Length | 15.5 inches (394 mm)[2][3] |
| Diameter | 2 inches (51 mm) |
| Wingspan | 6.0 inches (152 mm)[2] |
| Engine | Solid fuel rocket 15 lbf (6.80 kgf) (66.72 N) of thrust[1] |
| Propellant | 499 grams (17.6 oz) X-60[2] |
| Flight ceiling | 1,800 feet (550 m) to 2,000 feet (610 m)[3][1][4] |
| Boost time | 6 seconds at 70° [1] |
| Maximum speed | 165 m/s (540 ft/s)[3] |
Guidance | None |
Steering | None |
Launch | single-bay LMU-23/E or four-bay LMU-24/E[5] |
The GTR-18A, commonly known as the Smokey Sam, is a small unguided rocket developed by Naval Air Warfare Center Weapons Division (NAWCWD) in China Lake, California as a threat simulator for use during military exercises. Widely used in training, the Smokey Sam remains in operational service with the United States military.
The GTR-18 was conceived in the late 1970s by Robert A. McLellan, a Weapons Range Scientist working with Exercise Red FlagatNellis Air Force Base. He first searched for a commercially available system that would perform as he envisioned. It quickly became apparent that no commercial product would perform adequately, so the development of the GTR-18 was undertaken by the Naval Weapons Center (NWC) during the early 1980s, with the intent of developing Mr. McLellan's idea of a simple and inexpensive rocket for visually simulating the launch of surface-to-air missiles (SAMs) during training exercises.[6]
The design of the GTR-18A rocket is very simplistic and intended for minimal cost with the fuselage and nose cone being constructed from phenolic paper while the fins are constructed out of styrofoam.[6][5] The fuselage and fins are joined to the nose cone by the motor tube which contains 499 grams (17.6 oz) of X-60 solid fuel propellant.[2] Because of its very light construction, the Smokey Sam will only cause minimal damage even if it accidentally strikes a low-flying aircraft.[6][2][5]
The complete launch system, known as the Smokey Sam Simulator, includes single-rail LMU-23/E and four-rail LMU-24/E launching pads, an AN/VPQ-1 radar set, the PVU-3A/E Igniter[7] and the GTR-18A rockets themselves, making up the SMU-124/E system as a whole.[6][5]
When launched, the GTR-18's rocket motor produces a distinctive white plume, providing a realistic simulation of the launch of a surface-to-air missile.[8] While the ordinary GTR-18A has a simple, model rocket type motor, an improved "Dual Thrust Smokey Sam" tested in the early 2000s featured a modified rocket motor, providing a 1.5 second boost period, followed by a lower-thrust sustainer burn with burnout occurring at 7.1 seconds after launch.[9]
This motor was altered to use a two-part laminated grain propellant which utilized both the standard zinc based grain and a high thrust aluminium based grain as used by other US rockets. The new propellant allows the "Dual Thrust Smokey Sam" to have a boost and sustain signature to better imitate a surface-to-air missile and while thrust is initially low, the higher thrust for the majority of the motors burn time gives an improved trajectory.[10]
The GTR-18A received the altered designation DGTR-18A in the early 1990s, despite the use of the D ("Dummy") prefix usually being limited to non-flying rockets/missiles used for ground handling training only.[5] The Smokey Sam remains in production and operational service, and is extensively used by the U.S. military.[6]
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1963 United States tri-service rocket designations and post-1963 undesignated rockets
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| Designated (1–) |
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| Undesignated |
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