To jetBlue, his focus on safety was appealing; his take-charge manner and calm under fire were crucial and his corny jokes and upbeat nature were infectious.

JetBlue decided from the beginning that hires didn't have to have airline experience and it wanted to hire locally. When Mr. Spivey showed up, it dawned on recruiters that people who had been through emergencies routinely wouldn't panic onboard airplanes. Fire fighters and police officers come from careers where they dealt with the public and provided customer service, jetBlue officials say. They're used to working holidays. They knew how to handle people in stressful situations and could take command of an aircraft cabin.

"Past experiences are predictive of future behavior,'' Chief Executive David Barger says. "People who don't get too high and don't get too low, you want that in areas where decisions have to be made."

Vicky Stennes, jetBlue's vice president of inflight experience, notes that the airline cabin changed considerably after the 2001 terrorist attacks, putting more pressure on flight attendants. Before hijackers commandeered jets and flew them into buildings, flight attendants could always call the captain to march back to authoritatively end problems. Now flight attendants are on their own because pilots can't leave the cockpit.

"NYPD and FDNY are almost brands themselves and it fits well for us," Ms. Stennes says. "It proved to be such an early success we make a targeted effort to get crew members with emergency response background."

For NY police and fire department veterans, who typically can retire after 20 years of service and receive yearly pensions of half their annual salary, a second career as a flight attendant offers all kinds of benefits, including free or deeply discounted flights. The NYPD and FDNY veterans at jetBlue say the schedule of a flight attendant fits well with what they are used to: a few days on with long hours, then several days off. The pay is less than what they earned working for the city, but the flexibility is better in some cases.

"I came here for the schedule,'' says Laura Romer, 53, a former NYPD detective and hostage negotiation team member who got married, went back to school and found working part-time at jetBlue fit her lifestyle well. "I like that I get off the plane and the job is finished. The beeper doesn't go off at 1 or 2 a.m. with someone saying, 'We got your guy,''' she says.

Police and fire veterans say that like most flight attendants, they try to size up passengers as they board, keeping an eye out for people who need extra help or people who might turn into a problem. The best skill they bring to the airplane cabin, they say, may be the ability to put an end to conflicts before they turn into air rage incidents.

As a police officer, "you learn to de-escalate the situation,'' says Ms. Romer. "It's not what you say to people. It's how you say it to them.''

Once, when two passengers got into an argument because the man in one row reclined his seat and the passenger behind responded by hitting him in the head with a plastic soda bottle, Ms. Romer interceded as a detective might.

"I let him know I witnessed it,'' she says. Then, taking control of the argument, she calmly asked questions to learn more. It turned out that the man with the bottle was ill and agitated. He apologized. The man who had reclined said he understood.

Charles Harris was trained at FDNY in part by Mr. Spivey and spent 25 years in the department when he decided to retire after the Sept. 11, 2001 terrorist attacks. He had been at the World Trade Center as it was destroyed; like so many, he lost friends and colleagues, and attended countless funerals.

Now as a jetBlue flight attendant, Mr. Harris, 56, says he thinks of himself more as a "security chaperone'' than a flight attendant. He says he teaches younger flight attendants a firefighter's tactic—how to vary the tone and volume of their voice to get and keep someone's attention.

"Taking someone down a ladder, they can freeze. You have to vary your voice. If you keep yelling at people the same way, they freeze,'' he says.

On flights, Mr. Spivey makes a point of delivering pre-flight instructions while standing at the front of the cabin making eye contact with passengers. He does it from memory rather than reading a card so that people are more likely to pay attention. He always ends with a folksy story, a parable about not sweating the small stuff, that gets people thinking about what's most important in their lives.

If they clap, and most do, then passengers are rewarded with a corny joke from his extensive repertoire.

The story serves a purpose: When flights run into delays, Mr. Spivey reminds passengers of the lesson of his story and to not get bothered by inconveniences.

After 30 years as a firefighter in Manhattan, Mr. Spivey is most concerned about safety. On a New York to San Diego flight recently, a mother had belted her infant into an empty seat. He asked how old the child was in a friendly, grandfatherly tone and then delivered stern safety instructions about how to position the 21-month-old girl on a parent's lap, belted in for takeoff.

"It sounds like a great idea,'' the child's father, Brian Summers of Chappaqua, N.Y., said, after learning of Mr. Spivey's background.

Mr. Spivey, who is No. 1 on jetBlue's seniority list for flight attendants, lives in Florida and works out of New York, spending nights with his grown children in the New York area when he needs to. He says he misses the camaraderie of the fire department.

He applied to jetBlue because he likes to travel and realized he needed a job after too many unsuccessful visits to horse-racing tracks in retirement.

The everyday duties of a flight attendant—serving coffee and soft drinks, picking up trash in the cabin—weren't a difficult adjustment because fire fighters have to clean the firehouse, make coffee, do dishes, clean tools on trucks, and make beds all the time, he says.

"This is not as stressful as running into a burning building where smoke is down to the floor and you are trying to find people," Mr. Spivey says.