Tuesday, August 17, 2010

World Aviation News- Focus on Flight Test (Updated)

ZA 001, the first Boeing 787, has completed over 620 hours of flight testing and is back at Boeing Field in Seattle after a hectic time at Roswell in New Mexico and Edwards AFB in Southern California for a variety of testing. -Boeing photo

The Boeing 787 flight test program is in full swing and going well. October starts with almost two thousand flight test hours completed, most of them in the first half of this year, and five aircraft now flying. Hot and high trials have been conducted in Arizona. Performance testing was completed at Colorado Springs. Climatic testing (hot/cold and wet) was completed in the climatic Hangar at Eglin AFB in Florida. Crosswind testing was completed in Iceland.
The Southern California good weather has been a powerful inducement for Boeing to send their 787 testing south from cloudy Seattle. I briefly shared airspace in September with Dreamliner 004 (aka Boeing 4)during its visit to Victorville. With testing finished, it moved on to Glasgow Montana for community noise testing before recently heading back to Seattle.
#5, the sole 787 powered with GE engines, continues testing out of Boeing Field

Boeing 1 arrived at Edwards AFB on Monday 16th August for its next phase of testing, including the establishing of minimum unstick speeds at various weights and flap settings. This involved rotating to the maximum possible angle at the lowest possible speed, and letting the rear fuselage scrape the ground, pulling the aircraft off the ground at the minimum unstick speed. To save the rear fuselage from damage, traditionally a low technology skid plate is bolted under the rear fuselage to protect the skin and structure from impact with the runway.

With this task completed, the 787 headed off to Roswell, New Mexico, but suffered an engine surge on the ground which required an engine change.It returned to Edwards last week to complete its maximum energy braking ground tests (rejected takeoff) and then last Monday headed back to Seattle.
The #6 787 is on the point of flying this month.
It's a busy time for the hundreds of flight test people involved in this complexcertification program.

Boeing 747-8 testing is also proceeding at Palmdale and Victorville. The fourth aircraft, RC 503, resplendent in Cargolux red and white colors arrived at Palmdale on 10th August from Paine Field north of Seattle. I happened to be flying out of Palmdale as this neat (and large) aircraft taxied in. Boeing spokesman Tim Bader confirmed that the test fleet would be split between Moses Lake and Palmdale, due to pressure of 787 testing in the Seattle area. It turned out that 503 was only in Palmdale on a brief visit for HIRF testing before heading back north. Cargolux is the launch customer for the freighter version of the 747-8.

The Fourth Test aircraft of the Boeing 747-8 fleet (RC 503) is painted in the colors of launch customer Cargolux. It joined the other test aircraft at Palmdale on 10th August.-Boeing photo

The flight testing has revealed a number of problems which threaten to delay the entry into service of the new freighter. Originally the aircraft was plagued with vibrations of a landing gear door. A series of fixes cured this, however two more problems have now surfaced. The first is a limited cycle oscillation (LCO) of the inboard aileron, attributed to a problem with the Power Control Unit of the control surface. Use of an OAMS (Outboard Aileron Modal Suppression)system may solve this problem. The second is an occurrence of structural flutter at mid weight and near cruise speed. Solution of this problem may take longer to fix and require extra flying.

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