Coronavirus has kept some of the engineering team away, but the U.S. Army is pressing ahead with ground testing a new, more powerful engine for the Boeing H-47 Chinook.
Boeing, GE Aviation and the U.S. Army Combat Capabilities Development Command Aviation & Missile Center (CCDC AvMC) recently completed a ground test in late March demonstrating the higher-power T408-GE-400 engines on a Chinook.
The current CH-47D/F Chinook is equipped with two Honeywell T55-GA-714A turboshaft engines producing 4,867 shaft horsepower apiece. The 7,500-shp GE38-1B engines, designated T408-GE-400 by the U.S. military, provide the power for the CH-53K King Stallion helicopter.
On March 26 the team successfully progressed to dual-engine flight idle and opened the full rotor-speed envelope while also verifying engine control fault modes and alternate shutdown procedures, according to the Army.
Because of travel restrictions posed by COVID-19 and social distancing measures at Fort Eustis, Virginia, the Army has taken over all on-site testing duties with industry test partners — which includes Parker LORD Corp. — participating by teleconference.
“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,” said Lt. Col. Michael Osmon, chief of flight test for the CCDC AvMC Technology Development Directorate, Aviation Technology, Systems Integration & Demonstration.
The T408 engine is installed on a modified NCH-47D testbed aircraft to evaluate engine integration and performance. A limited set of final ground test events remain to clear the aircraft for flight demonstration testing. The next test event will incrementally open the torque envelope.
A 25-hour flight test program begins this summer at the Fort Eustis Felker Army Airfield and the surrounding area. The program is scheduled to conclude in 2020.
The flight demonstration will “identify and reduce cargo-class engine integration risks in support of potential future capability” — meaning establish whether or not installing the new, more technologically advanced engine on legacy Chinooks is worth the cost.
Testing will characterize structural response, engine governing, thermal compatibility and limited handling qualities within the existing aircraft operating envelope. The demonstration is using modified T408-GE-400 engines, additively manufactured load bearing drive system components and an off-engine torque measurement system provided by Parker LORD.
“Once we have been able to safely demonstrate the entire power range of the aircraft on the ground and know how it reacts, we will be able to bring this test to flight and see how it performs,” said Maj. Zachariah Morford, the Army’s test team lead.
