Winged Chinook — Boeing Vertol Model BV-347 walkaround

Winged Chinook — Boeing Vertol Model BV-347 walkaround

31º 19′ 25″ N / 85º 42′ 49″ W

The Boeing Vertol Model BV-347 made for a rare Chinook. Flight testing began in May 1970 to research helicopter design for the U.S. Army’s Heavy Lift Helicopter Program.

These modifications include:

• Four rotor blades in each hub, an increase from three, with each blade also having a 30” (76.2cm) increase in length.
• Stronger engines
• Fuselage lengthened by 100” (279.4cm)
• Aft mast height increased by 30” (76.2cm)
• Retractable main gear
• Fly-by-wire system
• Installation of a gondola which could be lowered from the cockpit where a pilot (facing to the rear) could fly the Chinook
• Detachable wing which was controlled hydraulically to vary incidence (rotating upward 90º while in hovering)

These images of this rare Chinook were taken April 2011 at the U.S. Army Aviation Museum* but for more photos, as well of images of the interior showing the retracted gondola, please go to this Chinook Helicopter web site**. The gondola must have been a good piece of engineering since a pilot was lowered with a set of flying controls but it must have been a risky proposition for that pilot. The gondola pilot would be hovering under a load while maneuvering a load of cargo and should the helicopter lose power the Chinook would be settling to the ground quicker than the gondola could be retracted — the gondola pilot would be landing an instant before the Chinook, sandwiched between the ground and helicopter.

The modified Boeing CH-47A Chinook, four rotor blade hubs, longer fuselage and wing evident — photo by Joseph May

The left wing, note the flaps that would deploy with relation to airspeed and load also the bay the retracted gear was stowed within — photo by Joseph May

The taller rear mast and view of the wing which could alter its incidence through 90 degrees of rotation from the horizontal to the vertical — photo by Joseph May

The wing showing the jack screw housings which controlled the flaps — photo by Joseph May

The longer rotor blades can clearly be viewed in this image — photo by Joseph May

The wings were an investigation into increasing the range and payload of the Chinook. They could be detached and stowed within the Chinook, as well.

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* A post of my visit to the U.S. Army Aviation Museum, as well as many of its aircraft as well as excellent full scale dioramas, can be viewed by pasting the museum’s name into the search window and selecting ENTER.

** The Chinook Helicopter web site is also the source of information used to write this post