CH-47 engine integration programme progresses

Boeing, GE Aviation, and the US Army’s Combat Capabilities Development Command Aviation & Missile Center (CCDC AvMC) have further demonstrated the T408-GE-400 turboshaft engine’s performance on the CH-47 Chinook, following another successful ground test.

The team completed the test on March 26 at Fort Eustis, Virginia, after successfully progressing to dual-engine flight idle mode and opening the systems envelope to full rotor speed, whilst verifying the T408’s control fault modes and alternate shutdown procedures. A modified NCH-47D Chinook is being used as the testbed aircraft.

Despite the outbreak of COVID-19 causing travel restrictions and social distancing measures at Fort Eustis, the combined team – along with the Parker LORD Corporation – is continuing the testing phase of the T408 Engine Integration Program. However, due to the pandemic, the US Army has taken over all on-site testing duties and is being assisted by industry partners through telepresence.

NCH-47D T408-GE-400 Engine Integration Testbed [US Army] #1
The US Army's NCH-47D T401-GE-400 turboshaft engine integration testbed. US Army

Lt Col Michael Osmon, chief of test flight for the CCDC AvMC’s Technology Development Directorate – Aviation Technology, Systems Integration and Demonstration, said: “It’s a testament to the hard work and ingenuity of everyone involved that they have been able to develop workarounds to include remote test team members and a socially distanced telemetry setup to continue this testing.”

This recent ground test was one of the few remaining before the aircraft can be cleared to begin the flight demonstration phase. According to the US Army, the next test will incrementally open up the platform’s torque envelope.

As per a US Army press release, the flight test phase will “identify and reduce cargo-class engine integration risks in support of potential future capability.” This will further evaluate the T408’s integration and performance on the NCH-47D when in the air. The service added that “testing will [characterise] structural response, engine governing, thermal compatibility and limited handling qualities within the existing aircraft operating envelope.” The outcome of which will reduce risks and determine the feasibility of reengining the Chinook with a modern, more technologically advanced turboshaft powerplant.

Flight demonstrations of the T408-powered NCH-47D is scheduled to begin this summer and comprises 25 flight-test hours. This will take place at Fort Eustis’ Felker Army Airfield and its local flying area. The testing is scheduled to be completed by the end of this year.