The General Electric Honda HF120 engine for the HA-420 HondaJet light business aircraft has received FAA Part 33 engine certification, clearing the way for the start of full-scale production.

The engine development proved far more arduous than GE or Honda expected. Certification comes nine years after the formation of the joint venture between the engine makers and four years later than originally planned when the program was launched in 2006. Certification for the HF120 production engine was first targeted for 2009, but several issues were encountered during development, one of the most serious being the failure of ice ingestion tests in 2011 that led to a redesign of the HF120’s blisked fan and changes to manufacturing processes.

The engine’s thrust rating also grew marginally to 2,095 lb. from 2,050 lb.-thrust when first launched, and followed the decision to baseline the engine for higher power following initial work on Honda’s original HF118 development engine. GE Honda says certification follows a ground and flight-test program that involved 13 engines and more than 14,000 cycles and 9,000 hr. of testing. As well as the unusual blisked fan, the HF120 design also incorporates composite outlet guide vanes, a high-temperature titanium impeller in the compressor, a reverse-flow configuration combustor and single-stage air-blast fuel nozzles. The engine also features a two-stage, low-pressure turbine and a counter-rotating, high- and low-spool shaft system.

The HF120 is now entering limited production in GE’s Lynn, Mass. facility. Full-rate production is expected to transfer to Honda Aero’s Burlington, N.C. facility in the second half of 2014 following the granting of the site’s production certificate.

Honda Aircraft is hoping to secure certification of the HondaJet in late 2014.