|

The CH-47D was the result of June
1976 contract for a modernized Chinook. The Army recognized that that
the Chinook fleet was rapidly reaching the end of its useful life and
signed a contract with Boeing to significantly improve and update the
CH-47. Three airframes, CH-47A, CH-47B, and a CH-47C, were stripped down
to their basic airframes and then rebuilt with improved systems to
provide three CH-47D prototypes. The first CH-47D was rolled out in
March of 1979 and the aircraft became operational with the 101st
Airborne Division in 1984. A total of 472 CH-47A, B, and C model
Chinooks were converted to CH-47D's.
Improvements included upgraded power plants, rotor transmissions,
integral lubrication and cooling for the transmission systems, and
fiberglass rotor blades. Other improvements included a redesigned
cockpit to reduce pilot workload, redundant and improved electrical
systems, modularized hydraulic systems, an advanced flight control
system, and improved avionics. The Chinook has two tandem three-bladed
counter-rotating fiberglass rotors. The CH-47D is powered by two Allied
Signal Engines T55-L-712 3750 shp turboshaft engines and has a maximun
speed of 163 mph (142 knots). The CH-47D carrys twice the load of a
CH-47A and has improved performance. The CH-47D can operate at night and
in nearly all weather conditions. The CH-47D is equipped with an
air-to-air refueling probe. The Chinook can accommodate a wide variety
of internal payloads, including vehicles, artillery pieces, 33 to 44
troops, or 24 litters plus two medical attendants. The Chinook can be
equipped with two door mounting M60D 7.62mm machine guns on the M24
armament subsystem and a ramp mounting M60D using the M41 armament
subsystem. The "D" model can carry up to 26,000 pounds externally. The
CH-47D has three cargo hooks: a center (main) hook and two additional
hooks fore and aft of the main hook.
In the Cockpit, the Pilots seat in the CH-47 is on the right, and the
Copilots is on the left. The Pilot in Command generally sits in the left
seat (There is more room over there). The minimum crew required to fly
this helicopter is two t pilots (excluding staff aviators wherein a
senior instructor pilot shall be seated in a seat in such a way that
there is continuous and full access to the flight controls), and a
flight engineer.
The maximum gross weight of the CH-47D is 50,000 pounds. Typical weight
of the Chinook helicopter is 32,000 pounds with a full load of fuel. The
typical range of the Chinook flying at 120 Knots Indicated Airspeed (KIAS),
or 136 Miles Per Hour (MPH), is 300 nautical miles. A typical mission
profile would include a gross weight of 45,000 pounds, fuel consumption
of 2,400 pounds per hour (roughly 358 gallons), and 6,000 pounds
(roughly 895 gallons) of fuel available at takeoff. Gross weight is the
empty aircraft weight, plus fuel weight, plus cargo (internal or
external). The duration of a typical Chinook mission is approximately 2
hours and 30 minutes.
At engine start, for a typical Chinook mission, the aircraft has
approximately 1,068 gallons (6,600 pounds) of fuel on board. On the
mission, the helicopter will consume approximately 940 gallons, or 6,300
pounds of fuel. At 2 bucks a gallon for jet juice, that's $1,880.00 a
flight just for the fuel.
|