Boeing CH-47A Chinook helicopter 65-07992.

65-07992

Boeing Vertol's BV-347

The Boeing Vertol BV-347 in flight with the landing gear retracted.

An original, one of kind winged helicopter on its first flight - 27 May 1970.

   65-07992, Boeing build number B-164, was a CH-47A helicopter. The U.S. Army acceptance date was 24 February 1966. The administrative strike date was 11 April 1975. 65-07992 accumulated 734.0 aircraft hours.

   During January 1969, Vertol began a cooperative program with the Army to develop the Model 347 advanced technology helicopter. Boeing Vertol converted CH-47A 65-07992 into the experimental BV-347 to test various concepts and components for use in the future Heavy Lift Helicopter (HLH) Program, and on such future helicopters as the conceived, but cancelled, XCH-62.

   The aircraft was extensively modified and featured a 110 inch stretch in the main cabin, retractable landing gear, a four blade rotor system in which the blades were longer than the standard CH-47D blades by 30 inches, and an aft pylon extended upwards by 30 inches.

   An unusual modification was the provision for a hydraulically actuated wing with normal acceleration load-sensitive flaps, permitting incidence control throughout the aircraft's flight envelope. The removable wing could be mounted on the top center fuselage to augment the lift from the rotors.

   Another unusual incorporation was a gondola installed in the main cabin area that could be lowered in flight. The gondola was fitted with a set of flight controls that allowed an aft facing pilot to control the aircraft.

   The prototype was fitted with an advanced fly-by-wire control system and was powered by updated Lycoming T55-L-11 engines giving it a maximum speed exceeding 180 knots.

   The prototype Model 347 made its first flight on 27 May 1970 at Vertol Division's Center 3 Flight Test Facility, near Eddystone, Pennsylvania and was extensively flight tested.

   Performance, handling qualities, vibration and noise characteristics were evaluated to determine the improvements provided by incorporation of advanced technology systems in a large tandem-rotor transport helicopter.

   Compliance with the provisions of the contract statement of work and with military specifications MIL-H-8501A and MIL-A-8806A was determined.

   Several shortcomings identified during the testing were corrected by the contractor after the testing was completed. The effects of these corrections were evaluated during additional testing conducted on 11 and 12 August 1971.

   Level flight performance and out-of-ground effect hover performance were significantly improved over that of the CH-47C helicopter. The excellent static longitudinal stability characteristics enhanced the mission capability of the aircraft. The steering and glide-path modes of the automatic flight path control system worked satisfactorily and reduced the pilot workload in instrument flight conditions. Cockpit noise and vibration characteristics were noticeably improved over those of the CH-47C.

   The US Army Aviation Systems Test Activity conducted the Phase II technical evaluation of the Boeing-Vertol Model 347 winged helicopter during the period 3 through 11 April 1972.

   The Model 347 winged helicopter was tested at the contractor's facility near Philadelphia, Pennsylvania. The evaluation was conducted to determine the improvements provided by addition of a wing system to a transport helicopter. Compliance with the provisions of military specification MIL-H-8501A was determined. Evaluations of the variable incidence wing system and the retractable landing gear system were also made.

   With the wing in the hover position (rotated vertically), out-of-ground effect hover performance of the Model 347 winged helicopter was similar to the non-winged aircraft.

   Both the winged and non-winged Model 347 helicopter could hover out of ground effect using less power than could the CH-47C.

   Level flight performance at a heavy gross weight (54,000 pounds) was improved over both the non-winged helicopter and the production CH-47C.

   Addition of the wing to the Model 347 helicopter did not significantly change the generally excellent handling qualities reported for the non-winged version of the aircraft.

   The strong longitudinal stability exhibited by the aircraft reduced pilot workload in maintaining trim airspeed and pitch attitude. Only minimal trim changes in all control axes were required when transitioning between climbs or descents and level flight.

   After the prototype completed the test program during the early 1970s, it was retired.

   At some point, 65-07992 was transferred to the Army Aviation Museum located at Fort Rucker, Alabama.



   As of 6 August 2011, the last known location of 65-07992 was at Fort Rucker, Alabama.

   Aircraft status: Museum exhibit.

Early 1970s Photographs

The Boeing Vertol BV-347 under construction at the Boeing facilities.

The Boeing Vertol BV-347 in flight with the gondola extended.

The Boeing Vertol BV-347 with the wing rotated vertically.

The Boeing Vertol BV-347 undergoing flight testing.

2004 Photographs

The following photographs show 65-07992, as of 2 April 2004, configured as the Boeing BV-347 and resting at the U.S. Army Aviation Museum next to the XCH-62 Heavy Lift Helicopter (HLH). The museum is at Fort Rucker, Alabama, near the Daleville gate.

The Boeing 347 resting at Fort Rucker, 4 July 2001.

CH-47 Chinook 65-07992, a.k.a. the Boeing 347, at Fort Rucker, Alabama, 2 April 2004.

2008 Photographs

The following photographs show BV-347 65-07992 as of 25 June 2008. In the mid 2000s, 65-07992 received a new paint job and was moved out of the fenced area to it's new location in the grassy area behind the Army Aviation Museum located on Fort Rucker, Alabama, near the Daleville Gate.

Having received a fresh coat of paint, CH-47A Chinook helicopter 65-07992, converted to the Boeing BV-347, sits outside the Army Aviation Museum at Fort Rucker, 25 June 2008. Click-N-Go Here to view a larger image.

2009 Interior Shots

The following photographs show the interior of BV-347 65-07992 as of 16 April 2009. The aircraft is parked outside the Army Aviation Museum located on Fort Rucker, Alabama, near the Daleville Gate.

The interior of 65-07992 as of 16 April 2009.

The cockpit of 65-07992. Click-N-Go Here to view a larger image.

The cabin area of 65-07992. Click-N-Go Here to view a larger image.

The forward section of the main cabin area of 65-07992. The large square item is the retractable gondola that contained another set of flight controls used to operate the helicopter when it was lowered for in-flight testing. Click-N-Go Here to view a larger image.

An auxiliary circuit breaker panel mounted in the main cabin amidship. Click-N-Go Here to view a larger image.

Click-N-Go Here to listen to a sound recording of the comparison between an A, C and the Model 347 Chinook helicopter of the noise generated by the rotor system. This effort was accomplished in conjunction with a joint Army-Boeing noise reduction program. Unfortunately, the project was not funded to a level to produce significant changes in the CH-47 noise level. File is in Real Audio format [2.1 Mb].

Click-N-Go Here to read a Technical Test Report concerning Design, Fabrication and Flight Test of the Active Arm External Load Stabilization System for Cargo Handling Helicopters utilizing th BV-347 aircraft [170 pages, 2.1 Mb, .pdf format].

This aircraft was piloted by:

CIV Frank H. Duke, Model 347 Project Test Pilot

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This aircraft was crewed by:

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