Boeing continues to make progress toward the expected first flight of the stretched 787-9 later this summer with the start of key systems tests on the first aircraft, and flight tests of the two engine types that will power it in service.

The first aircraft, ZB001, is undergoing systems checks in Building 40-24, the surge line developed on the site of the former 767 assembly line at Everett, Wash., to help ease the pressure on the main 787 production line in Building 40-26. The initial aircraft, which is line number 126, is understood to have had its landing gear “swung” as part of actuation tests early last week.

Further back along the same line, Boeing is also beginning assembly work on the second 787-9 test aircraft, ZB002. This will be followed by the third flight-test airframe, which is designated ZB021.

Like the first four 787-8s, the first three 787-9s will be powered by the Rolls-Royce Trent 1000. The fourth 787-8, ZA004, which was brought out of storage in early June, has been fitted with the first Package C standard engine which will be the standard Rolls powerplant for the 787-9. The aircraft conducted a functional check flight on July 11, and is expected to begin full certification test-flying over the next few days.

Package C is rated at 74,000-lb. thrust, and is designed to have 1% better fuel burn relative to the current Package B engine, which achieved a 2.2% improvement over the first versions of the Trent 1000.

The powerplant is due to be certified later this summer, and will be the baseline engine for the 787-9 when it enters service with Air New Zealand in mid-2014. The Package C version will also power 787-8s from around June 2014. Main changes include modified blades in the intermediate-pressure compressor and a semi-active case cooling system for improved tip clearance control in the low-pressure turbine.

Flight tests are also continuing for General Electric’s (GE’s) second package of upgrades for the GEnx-1B engine, using 787 test aircraft ZA005. The PIP II (performance improvement package) engine package was certified in April and has been under test since ZA005 completed a check flight earlier that month. Until that time the aircraft—which had begun flight tests of the PIP II package late last year—was grounded along with the rest of the fleet following the 787-8 battery failures in early January.

PIP II is designed to bring the performance of the engine up to the original GE-powered 787 fuel-burn specification. Development of a series of upgrades began following the discovery that the baseline version was around 3% adrift. The PIP II package, which also includes a higher rating of 78,000-lb. thrust for the 787-9, includes an effective increase in fan diameter of 0.5 in., optimized outlet guide vanes, a higher-flow low-pressure compressor, improved high-pressure compressor aerodynamics, and durability improvements in the high-pressure turbine and combustor.