New, 6-12 month delay forecast for 747-8

Buckingham Research forecasts a new delay in first delivery of the Boeing 747-8 of 6-12 months.

Boeing has indicated first delivery was likely to slip into 2011, but hasn’t announced the move yet. Boeing said design issues were the reason; Buckingham said oscillation and flutter issues remain to be resolved, including possibly a need to relocate the inboard engines.

Despite this and the new delay on the 787, Buckingham maintains a Buy rating.

7 Comments on “New, 6-12 month delay forecast for 747-8

  1. What makes Buckingham think the inboard engines need to be reloacted? If they do, that will be a major design change and take more than 12 months to redesign and put into production. Some of the flutter problems can be fixed with installing simple vortex generators. the osceillations can be fixed with changes to the rudder PCU and/or yaw dampner.

    • I’ll have to agree with KC135TopBoom on this one. “Relocating” the inboard engine would not be a mere 12 month undertaking and would require another round of wind tunnel testing just for a starter. You’re looking at 24 months at the absolute minimum.

    • “Some of the flutter problems can be fixed with installing simple vortex generators”

      Hedgehogs don’t fly all that well, do they ;-?

      Thinking of the tanker, flutter seems to develop into Boeings royal illness.

  2. “Some of the flutter problems can be fixed with installing simple vortex generators.”

    I am not aware of any aircraft design where flutter problems were solved with “simple vortex generators”. Flutter is an function of the total dynamic aeroelastic properties, and different flutter modes require different solutions.

    Given they are talking about an engine relocation, it would appear the additional wing span, and different engines, and additional fuselage length has moved the placement of the centre of gravity, centre of elasticity, and the aeroelastic centre over previous 747 models.

    Flutter is a very complex engineering task, and it is not well understood.

  3. Not that I believe it, but if an engine relocation is truly required, I would guess that Boeing would pull the plug before doing such a major redesign.

  4. IIRC, the flutter problem only came up with the outboard MLG doors at the highest flap setting. Couldn’t Boeing just amend the specs to disallow that setting, and modify the MTOW accordingly? Or would that be too much of a hit on the a/c? Moving the inboard engine seems like an extremely drastic change.

  5. I agree with Ninja that they would pull the plug before doing that.
    If its current location is an issue, a modified pylon may be the solution but pretty expensive and at least twelve months by the time it has had the wind tunnel testing done.

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