The Boeing Co. unveiled a midlife upgrade package for its popular 737 Tuesday that includes a Dreamliner-style interior and aerodynamic and engine improvements that boost fuel efficiency by 2 percent.

The total package of upgrades will be available to airlines by 2011.

The interior improvements will be an extra-cost option; the aerodynamic and engine improvements will become standard on the plane beginning next year.

The biggest visible difference for airline passengers will be the new interior.

That interior will feature blue LED lighting on the plane’s ceiling, larger, redesigned overhead baggage bins and reconfigured vents, speakers and light switches. The new interior will be much like the one Boeing designed for its new 787 Dreamliner.

The “blue sky” interior will give the single-aisle plane a more spacious feeling. The overhead bins will tilt downward for loading and unloading and then swivel up into the sidewall for storage.

The new interior will have individual speakers at each row. And new lighting switches will better distinguish between attendant call buttons and light buttons.

The interior will feature a new sidewall with a single piece air return grille integrated into the sidewall. The present interior has grilles separate from the sidewall for the air return.

Airlines must check behind those grilles to see that nothing has been placed behind them by passengers. The new grilles cannot be pried off.

Boeing’s best customers have been lobbying for a new-generation aircraft to replace the 12-year-old 737 Next Generation design. With the economy on life support, however, Boeing is unlikely to invest the billions needed to develop that plane soon.

The 737s will be built in Renton.

John Gillie: 253-597-8663

john.gillie@thenewstribune.com