EVERETT ? Boeing plans to put a small, but important set of 777X engineering work in Philadelphia rather than metro Puget Sound, where similar work is done on the 787.

The work will move but not the people doing the work, according to an official with the union representing Boeing engineers, the Society of Professional Engineering Employees in Aerospace (SPEEA).

The move is expected to happen in January. The group is called the 777X Environmental Control Systems ? Thermal Analysis Engineering Work.

Engineers in the group work on the airplane cabin’s feel, which includes factors such as humidity, air pressure and noise, said Bill Dugovich, SPEEA’s spokesman.

The plane’s passenger experience is a selling point of the 777X. Boeing executives have said that the company aims to recreate the 787 experience, which has higher humidity and more comfortable air pressure than most airplanes.

?We’re taking as much of that as we can, because we want to recreate that experience,? said Jim Haas, Boeing Commercial Airplanes’ product marketing director, in April.

Some of the high-level engineering on achieving that goal will be done in Philadelphia, according to SPEEA.

Boeing declined to comment on the move.

But a spokesman noted that the Chicago-based company has previously said that it plans to take advantage of “the engineering skills from across the Boeing enterprise.” That includes using engineers in Charleston, South Carolina; Long Beach, California; Huntsville, Alabama; St. Louis, Missouri; and Philadelphia, Pennsylvania.

Last spring, the company announced plans to move about 1,000 engineering jobs out of metro Puget Sound. The move was part of a series that have seen roughly 4,300 jobs shipped out of state.

SPEEA is pushing the Legislature to add engineering job requirements to aerospace tax breaks extended for Boeing last year.

Dan Catchpole: 425-339-3454; dcatchpole@heraldnet.com; Twitter: @dcatchpole.