EVERETT — Happy Tummy Grill has all the ingredients of a successful restaurant, but Boeing is the secret sauce.

Sun Ho has operated the eatery for 18 years at the corner at West Casino and Airport roads, an epicenter of aviation.

Boeing’s move to relocate 787 Dreamliner production to South Carolina has created turbulence for local businesses like hers, when things were already rough because of the pandemic.

“If Boeing shuts down, I’m shut down too,” Sun Ho said.

Happy Tummy Grill sits back from the street, tucked in an industrial plaza, so it’s easy to miss. Boeing and aerospace contractors make up 90% of the customers. It’s fast and filling, with free delivery and a chicken teriyaki special for $7.99.

The location comes at a price.

“This rent is really high,” Sun Ho said.

She works six days a week, often 12-hour days, always wearing a bright red apron.

The room seats 90 people, but the chairs have been pushed to a corner since the pandemic started. The few scattered tables are mainly used by those awaiting takeout.

“It is very, very slow,” Sun Ho said. “Before it was very busy.”

The departure of the Dreamliner could be the final blow.

“It is difficult and will be more,” she said.

Sun Ho has managed to stay open with pandemic assistance grants, but only scrapes by. She had to lay off three of her five employees. She relies on her sons to pitch in.

“We’d pack this place full during lunchtime when everything was fine,” said her son Sam, 31, lending a hand at the front counter Thursday. “This was the spot.”

Her other son, Harris, 33, was there Wednesday evening filling little cups of sauce for takeout orders.

“I never had to help until recently,” Harris Ho said.

Thursday — payday at Boeing — is still the busy day, but not like before March.

The big takeout orders are gone. So are the lines out the door.

“We used to have tons of deliveries on Thursday and Friday,” Sam Ho said. “Now we just have a couple left. A lot of people we deliver to are older and they’re getting paid out by Boeing for the early retirement.”

Sun Ho said she doubts she will open another place if she has to close this site.

Competition for Boeing dining dollars comes from Mountain View Plaza, a complex of a dozen eateries about two miles away off Hardeson and Sievers Duecy roads.

“A lot of people are going to lose their jobs, those are my customers out there,” said Jae Park owner of Billie On Gourmet Burger & Fish Chips. “We’ll get used to it. We went through COVID so far. It’s going from bad to worse. Everybody here depends on Boeing.”

There are a number of restaurants farther down Casino Road.

“The teriyakis up the street really cover the neighborhood,” Sam Ho said. “We cover the workers.”

Andrea Brown: abrown@heraldnet.com; 425-339-3443. Twitter @reporterbrown.