Big ticket Army modernization programs, such as Future Vertical Lift and the Next Generation Combat Vehicle, could delay Block II upgrades to the CH-47 Chinook heavylift chopper.

The Army plans to upgrade 542 Chinooks to Block II configuration, including 473 planned CH-47F and 69 MH-47G Special Operations variants.

Boeing [BA] is “quite concerned” about the effect a production delay could have, including a possible Nunn-McCurdy breach — a significant unit-cost increase that could put the program on life support, Randy Rotte, the Boeing director of cargo helicopters and future vertical lift, said during an Oct. 8 briefing on the upgrades at the Association of the U.S. Army’s 2018 annual conference in Washington, D.C. While Army officials continue deliberations on their upcoming FY 2020 budget submission, the specter of high priority recapitalization efforts crowding out such upgrades has raised alarm bells at Boeing.

Under a $276 million engineering and manufacturing development contract awarded in July last year, Boeing is assembling three CH-47F Block IIs at its Ridley Park, Pa., plant in preparation for flight testing early next year. A new, advanced Chinook rotor blade (ACRB) featuring a swept wingtip design will allow the helicopter to carry more than 1,500 pounds of extra weight, and the CH-47F Block IIs will also have a re-designed, more robust airframe, an upgraded fuel system, and an upgraded transmission providing nine percent added torque.

The new ACRB represented a challenge, but “we burned the majority of the risk off” with 60 hours of dynamic strain survey testing of the new blade on CH-47F Block I rotorcraft in Mesa, Ariz., said Chuck Dabundo, the Boeing vice president of cargo helicopters and the H-47 program manager.

First delivery of a production Block II CH-47F to the Army is expected in 2023. The Army is still in the process of bringing all of its Chinooks to F-model configuration. Estimates are that Boeing could receive more than $14 billion to to bring the Army’s entire fleet to F-model configuration.

Included in the upgrade package are improved avionics, speed enhancements and a heftier drivetrain that will transfer greater power from the 20 percent more powerful Honeywell [HON] T55 engines to the ACRB.

The avionics upgrades on the F models include BAE Systems‘ Digital Automatic Flight Control System, which aids pilots in making safe landings during brownout conditions, and the Active Parallel Actuator Subsystem, which is to inform the pilot of potential performance limitations and help reduce pilot workload.

In July, the Army awarded Boeing a $139.8 million contract to upgrade four MH-47G Block Is to the Block II configuration. Boeing is expecting a contract for another four MH-47G Block IIs by the end of the year. More than a dozen of the upgraded MH-47G Block Is will not have the ACRB at first, as the Army Special Operations Aviation Command indicated a pressing need for the airframe upgrades. Nearly two dozen of the 69 MH-47Gs have their original 1960s airframes, Rotte said.