With its 747-8 Intercontinental first flight complete, Boeing has now begun the just-over 600 flight hour process of certifying the new 467-passenger jet, the largest in the company's history.

The 20 March 4h 25min flight over Washington state pushed the aircraft, RC001, harder than first anticipated to 6,100m (20,000ft) and 250kts (463km/h), a direct result of the new jumbo benefitting from the more than 2,000h already accumulated on its freighter test programme since February 2010.

"It's one of the cleanest first flight airplanes of a new design that I've seen and it just went perfectly," says 747 chief pilot Capt. Mark Feuerstein, who was at the controls with Capt. Paul Stemer.

Feuerstein says the aircraft experienced roughly a half dozen maintenance squawks and none that would prevent any 747-400 crew from dispatching the aircraft again: "The airplane is actually ready to go fly right now."

The aircraft departed runway 34L at Paine Field in Everett, Washington at 9:59 local time with an approximate rotation speed of 160kts at flaps 20, beginning its maiden sortie with a slow turn to the west along the Olympic Peninsula "keeping the airspeed fairly slow below 230kts, looking at the handling qualities of the airplane with the gear and flaps down, that's a very typical start to the flight," says Feuerstein.

When the aircraft neared the Pacific coast, it turned eastbound, followed by the first raise of the landing gear and flap retraction, and "took a little detour" for air-to-air photography in front of nearby Mt. Baker, he adds.

Following its photo work, RC001 moved toward central Washington "where we do a lot of our stability and control work. From about [20,000ft] to 10,000ft we did simple approaches to stalls, a couple of directional stability conditions that looked at how the airplane turns and how straight it flies, then we continued some basic functional checks of the systems of the airplane to make sure that it all works properly," says Feuerstein.

Feuerstein and Stemer took advantage of the aircraft's maturity allowing them to "pull some tests forward", such as steady heading side-slips and turning approaches to stalls down to 105kts. Additionally, the stability augmentation was deactivated on the aircraft "to see what the bare airframe behaved like and it was absolutely phenomenal. It was kind of fun actually to do that so early in the programme," says Feuerstein.

The maturity of the aircraft's systems comes from the work already done on the 747-8F, adds Feuerstein: "It was the first opportunity for Paul and I to get a look at all of those changes rolled together into the one airplane. Because on the freighter fleet, each airplane is a little bit different. Today, we actually got an early look at what the freighter is going to look like when it's finished and it looks great."

The aircraft landed on runway 31L at Boeing Field in Seattle at 14:24 local time, where it will be based for the flight test campaign.

RC001 will focus its time in flight test conducting flutter clearance, flight controls, ride quality, and stability and control evaluations, building on the work it began on first flight. Flutter clearance is among the most important tasks for the aircraft as it is structurally different from the freighter, with an elongated upper deck and horizontal stabilizer fuel tanks.

The aircraft is expected to fly again late this week as it continues its initial airworthiness trials, while Boeing anticipates RC021, the second test aircraft, which is now out at the fuel dock in Everett, to join the flight test programme in April. Its purpose will be to certify aircraft's interior, including the galleys, lavatories, smoke penetration and environmental control system.

747 vice president and general manager, Elizabeth Lund, says Boeing will wrap up the flight test campaign "early in the fourth quarter" followed by a final analysis of its data and final submission to the US FAA for certification and delivery at the end of the year.

Lund says the freighter is due for delivery mid-year to Cargolux, while first 747-8I is expected to be delivered to a completion centre for finishing as a business aircraft for the Kuwaiti Government before the end of 2011.

At 76.3m (250ft), the -8F and -8I are the longest full production commercial aircraft in history, while the 5.6m (18.3ft) stretch over the 747-400 means the passenger model will be certified to accommodate up to 605 passengers in single-class configuration.

Boeing holds orders for 108 747-8s including 76 freighters and 33 Intercontinental passenger aircraft. Pending the approval of the Chinese government, Boeing will add the additional 5 747-8Is from Air China to its backlog.

Source: Air Transport Intelligence news