The Jets’ slogan for this season is “Take Flight.” On Sunday, they failed to leave the runway.

Gang Green blew a 16-point second-half lead and lost 17-16 to the Bills to open the season 0-1. New coach Adam Gase lost his debut as he watched his offense sputter for most of the day, his defense collapse late and his kicker stink like last week’s leftovers.

The Jets forced four takeaways in the first half from Bills quarterback Josh Allen, but still led only 6-0 at halftime. Buffalo then crept back into the game and stole one from its AFC East rivals.

“It is demoralizing when you can play that well and still lose a game,” defensive end Leonard Williams said. “It was just a bad start to the season when we had this game in the bag.”

It was a familiar refrain in the Jets locker room, where they talked about closing out games. It was the same song they sang in 2018, when they blew four fourth-quarter leads, and in 2017, when they blew three.

New coaches. New uniforms. Lots of new pricey free agents. Same old Jets.

“When you take a loss like this, it kind of defines you,” running back Le’Veon Bell said. “We’re going to see how guys respond. When you have that many turnovers and we still don’t win the game, we didn’t deserve to win that game.”

Bell was one of the bright spots for the Jets. Playing in his first game in 20 months, Bell played every snap, rushed for 60 yards on 17 carries and caught six passes for 32 yards and a touchdown. He also caught a two-point conversion.

The Jets’ two other big free-agent signees from March also had good days. Wide receiver Jamison Crowder had 14 catches for 99 yards, a constant third-down option. Linebacker C.J. Mosley was all over the field, scoring a touchdown on an interception in the first quarter, recovering a fumble and breaking up two passes.

The game changed when Mosley exited at the start of the fourth quarter with a groin injury. The Jets led 16-3, but fell apart without Mosley on the field. Allen, who had struggled mightily early, marched the Bills down the field for two easy scoring drives. He ran for a 3-yard touchdown to cut the lead to 16-10 with 10:21 left in the game and then found wide receiver John Brown, who beat cornerback Darryl Roberts, for a 38-yard score with three minutes left. Stephen Hauschka’s extra point gave the Bills their first lead at 17-16.

“We didn’t do a good job of finishing what we started,” Gase said. “When the defense was rolling like that, we’ve got to be able to do something on offense. In the second half, they probably had too many plays because we weren’t doing enough on offense. That’s where we’ve got to play complementary football.”

The Jets also were doomed by kicker Kaare Vedvik, whom the team claimed off waivers last Sunday from the Vikings. He is the third kicker the Jets have had in a month and each one feels worse than the last. Vedvik missed a 45-yard field goal and an extra point, four crucial points in a one-point loss.

“We’ve just got to get better,” Gase said. “We have to make extra points. We have to make field goals. We can’t be losing points in those areas of the field.”

After the Bills took the late lead, the Jets got the ball back at their own 25 with three minutes left, but quarterback Sam Darnold missed Robby Anderson twice on deep passes — one underthrown and one overthrown — and then failed to connect with Crowder on fourth down, ending any hope of a last-minute win.

Darnold did not have a good day. He completed 28-of-41 passing for 175 yards with one touchdown. The offensive line struggled to protect him, allowing four sacks and nine quarterback hits. The Bills also tipped at least five passes at the line.

“Whenever you have the lead going into the fourth quarter, that’s never the result you want,” Darnold said. “We need to continue to fight and finish throughout the fourth. Our offense, myself, we need to do a better job of finishing drives, too. When our defense forces four turnovers and we don’t have any as an offense, we need to win the ballgame.”

The Jets were left searching for answers.

“I felt like our energy died, man, and we wasn’t playing team ball,” safety Jamal Adams said. “So any time you do that, a team is going to take advantage of it.”

A home loss to a division opponent is never a good way to open a season. The Jets now are staring at games against the Browns, Patriots, Eagles, Cowboys and the Patriots again — a brutal five-game stretch.

“We can’t let one game define our season,” Gase said.

It may not define them, but a loss like this will linger for a while.