Another day, another Boeing (NYSE: BA) delay. Just hours after Bloomberg warned that the Chicago planemaker was mulling another delay in production of its revamped 747 superjumbo jet yesterday, Boeing woke up bright and early this morning and confirmed it.

Seems the company needs to redesign a wobbly "inboard aileron actuator" on the new 747-8, realign the plane's main wheel well, and make literally "dozens" more minor fixes to the plane. Boeing's also testing software to help fix a vibration problem encountered in some early test flights. Together, the fixes and upgrades will postpone delivery on the plane by six months, pushing the monster plane well past the two-years-overdue mark and keeping customers grounded well into mid-2011.

Sitting alongside 'em on the tarmac will be key 747-8 parts suppliers General Electric (NYSE: GE), Spirit AeroSystems (NYSE: SPR) -- which could really use the 747 work, seeing as how GE's "Technology Instrstructure" segment is seeing annual sales declines and Spirit's last quarter was roughly flat year-over year -- and Honeywell (NYSE: HON), less hard up but still struggling with single-digit growth.

Better luck next time
Well, at least it's not the 787 this time. That one's already more than two years overdue. But while we're thanking heaven for small blessings, let's not let Boeing off the hook for announcing yet another delay to a program only slightly lower-profile than its flagship Nightmare-liner.

I mean, I know that building planes is no easy task. Archrival Airbus has certainly had its share of difficulties getting both the A380 airliner and A400M military transport off the ground. Embraer (NYSE: ERJ) encountered turbulence putting its Embraer 190 and Embraer 195 lines in motion. China, Japan, and Russia are all bound to face manifold trials and tribulations as they attempt bring their own planes to market over the next few years. Obviously, Boeing was bound to encounter problems of its own in its effort to bring these groundbreaking new planes to market.

What I cannot for the life of me fathom, is why Boeing continues to persist in promising to deliver these planes on dates certain, and dates certainly overoptimistic -- disappointing its shareholders at every turn.

Remember, Boeing: The idea is to under-promise and over-deliver. Not the other way around.