Block 2 CH-47F To Tackle Payload Shortfalls

By Graham Warwick
Source: Aviation Week & Space Technology
April 22, 2013
Credit: U.S. ARMY

Gaining weight with age is a familiar curse, and after 50 years of service the Boeing CH-47 Chinook can no longer carry the loads it did when the heavy-lift helicopter was first introduced. With weight growth averaging 100 lb. a year, the U.S. Army wants to reset the clock to take the tandem-rotor Chinook well into its second half-century.

Boeing and the Army are working to define a “Block 2” upgrade that would be introduced after 2020, once all of the service's CH-47Ds have been replaced by new-build and remanufactured F models. “We are really after payload improvements,” says Col. Bob Marion, cargo helicopter program manager. The latest CH-47F has boosted international sales of the Chinook, and the Block 2 program could keep the line rolling into the next decade.

“The D to F upgrade introduces a machined airframe and digital cockpit [and flight controls], which are real game changers for the Chinook fleet,” he says. “The new frame improves sustainment and the cockpit enhances controllability and situational awareness. The next thing is payload improvement—we need to take weight out of the aircraft.”

Work to define Block 2 is getting underway as the Army prepares to award Boeing the second and final multiyear procurement contract for the CH-47F. Expected to be signed in May, the five-year contract for 155 helicopters, plus 60 options for export aircraft, will save $810 million, or 19.2%, over year-by-year contracting, says Marion.

Many of the modifications added post-production to Chinooks built under the first multiyear award will be incorporated on the assembly line under the new contract. Additionally, the second multiyear agreement will see the introduction of the first upgrades planned for Block 2, including an advanced rotor blade that will increase lifting capacity by almost 2,000 lb.

“Block 2 would follow Multiyear 2, and we are looking at what [non-recurring development] work we need to start executing now,” says Marion. “The key thing is the JLTV [Joint Light Tactical Vehicle, the planned replacement for the Humvee]. As it goes through development, we have to ensure that the CH-47 can carry a combat-equipped JLTV and crew.”

The Army's goal for Block 2 is to make sure the post-2020 Chinook can carry a 22,000-lb. payload 50 nm., with 4,000-ft./95F high/hot hover performance. “We are still working toward that, and in the future will look to increase that to 6,000-ft./95F,” he says. Today, the CH-47F can carry 16,000 lb. in 4,000-ft./95F conditions, “and we are adding 100 lb. a year [of airframe weight].”

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