Origins in flight On October 14, 1960, the
United States Navy solicited responses from 25 aircraft manufacturers to a request for proposals (RFP) on behalf of the Army for the Light Observation Helicopter (LOH). Bell entered the competition along with 12 other manufacturers, including
Hiller Aircraft and
Hughes Tool Co., Aircraft Division. Bell submitted the
D-250 design, which would be designated as the
YHO-4. On May 19, 1961, Bell and Hiller were announced as winners of the design competition. Bell developed the D-250 design into the Bell 206, redesignated as YOH-4A in 1962, and produced five prototype aircraft for the Army's test and evaluation phase. The first prototype flew on December 8, 1962. The YOH-4A also came to be known as "The Ugly Duckling" in comparison to the other contenders.
JetRanger When the YOH-4A was eliminated by the Army, Bell went about marketing the aircraft. In addition to the image problem, the helicopter lacked cargo space and only provided cramped seating for three passengers. The solution was a redesigned fuselage, sleeker and aesthetically appealing, adding of cargo space in the process. A Bell executive contributed to the redesign by drawing two lines on a sketch extending the fuselage to where it meets the tail. The redesign was designated Bell 206A, and Bell President Edwin J. Ducayet named it the
JetRanger, denoting an evolution from the popular
Model 47J Ranger. Bell Helicopter ended production of the Bell 206B-3 version in 2010. Bell introduced the
Bell 505 Jet Ranger X to replace the 206 five-seat versions from around 2015 and compete with the
Robinson R66.
LongRanger The 206L LongRanger is a stretched variant with seating for seven. The fuselage, stretched a total of , adds two rear-facing seats between the front and rear seats. Since 1975, Bell has produced more than 1,700 LongRangers across all variants. In 1981, a military version, the 206L TexasRanger was released. The original 206L used an
Allison 250-C20R engine, and a series of model upgrades replaced this engine with more powerful versions; the 206L-1 used a 250-C28, and the 206L-3 and 206L-4 used the 250-C30P. In both applications, the 250-C30P is derated from 650 hp for takeoff and 501 hp continuous. The 206L-3 is transmission-limited to 435 hp for take-off, and the 206L-4 is transmission-limited to 495 hp. The derating of the C30P produces an advantage in hot-day and high-altitude operations, as it can produce the rated horsepower at higher altitudes and temperatures where applications that use the maximum rating of the engine at sea level suffer accelerated performance deterioration with increases in temperature and altitude. The 206L-3 and L-4 have not been offered in a twin configuration under those model designations. In 2007, Bell announced an upgrade program for the 206L-1 and 206L-3 designed to modify the aircraft to the 206L-4 configuration; modified aircraft are designated 206L-1+ and 206L-3+. Modifications include strengthened structural components (including a new tailboom), improved transmission, upgraded engine for the L-1, all of which result in a maximum gross weight increase of 300 pounds and increased performance. Production of the 206L-4 ended in June 2017 with over 3,800 LongRangers built.
Gemini ST and TwinRanger The
TwinRanger name dates from the mid-1980s when Bell developed the
Bell 400 TwinRanger, but it never entered production. In 1989, Tridair Helicopters began developing a twin-engine conversion of the LongRanger, the
Gemini ST. The prototype's first flight was on January 16, 1991, while full FAA certification was awarded in November. Certification covers the conversion of LongRanger 206L-1s, L-3s and L-4s to Gemini ST configuration. In mid-1994 the Gemini ST was certificated as the first Single/Twin aircraft, allowing it to operate either as a single or twin engine aircraft throughout all phases of flight. The
Bell 206LT TwinRanger was a new-build production model equivalent to Tridair's Gemini ST, and was based on the 206L-4. Thirteen 206LTs were built, the first delivered in January 1994, and the last in 1997. The TwinRanger was replaced in Bell's lineup by the mostly-new
Bell 427. ==Operational history==