Never say never. But the chance of Philadelphia police going onto an airplane to yank a passenger from a seat on a sold-out flight is practically nil.

Police here don't go on aircraft to intervene in airline customer-service disputes, as happened April 9 in Chicago, when aviation security officers violently dragged a United Airlines passenger off a plane when he refused to give up his seat for a crew member.

If a flight is overbooked at Philadelphia International Airport and an airline needs a passenger to give up a seat, in exchange for cash or a travel voucher, the negotiation happens at the aircraft gate – before anyone boards, said Capt. Sekou Kinebrew, a police spokesman.

What happened at O'Hare International when David Dao, 69, was forcibly removed by airport security would not happen at Philadelphia's airport, said Kinebrew, former commander of the 14th Police District in Germantown and Chestnut Hill and currently the head of police public affairs.

 La Salle University
Capt. Sekou Kinebrew said the airlines in Philadelphia don't allow overbooked flights to board, so officers are called to the gate only to ensure that situations don't escalate.

On the rare occasion police are asked to go to a gate area, perhaps because a passenger "is justifiably not thrilled" to be bumped, he said, "we just stand by to make sure the situation doesn't devolve into something criminal, where someone makes a direct threat, or throws a punch."

Police do go on airplanes when alerted that a crime may have been committed, or that a passenger poses a safety risk or has made a threat – "the obvious one: 'I've got a bomb,' " Kinebrew said.  Or if a traveler is deemed too intoxicated to fly, is belligerent, disorderly, or poses a "danger to himself or others," he said.

"Again, it's really uncommon that we have to take that action. I credit the good behavior and the good policies of the airlines and their customers."

After the United episode, three major airlines changed policies regarding bumped passengers.

American Airlines, with a hub and 400 daily flights in Philadelphia, said no passenger who has boarded a plane will be removed to give the seat to someone else. "In light of recent events, American updated its Conditions of Carriage, which states that we will not involuntarily remove a revenue passenger, who has already boarded, in order to give a seat to another passenger," the airline said.

Delta Air Lines said employees can offer customers up to $9,950 in compensation to give up seats on overbooked flights. Gate agents can offer up to $2,000, an increase from a previous maximum of $800, and supervisors can offer up to up to $9,950, an increase from $1,350.

United instituted a new policy requiring airline crews to check in at least 60 minutes before a flight to avoid finding a seat for a crew member after all the passengers have boarded. The airline also said it is reviewing its policies, including incentives for customers, and will announce a plan by April 30.

Philadelphia police who board airplanes follow established "defensive tactics and controls" used for "any type of police-citizen encounter," ranging from an officer just being present, all the way to lethal force. "Hopefully, we would never have to go to this extreme for something on an airplane," Kinebrew said.

One common tactic is "control holds" that Philadelphia police are taught in training "that hopefully would not resemble what we saw in the video in Chicago," he said.  If a passenger is flailing around and police need to temporarily contain a person, "there are control holds that can be used, and then safely escort them off."

"Sometimes, people are in a position by the time we get to them that they can't assist in their own escort. So then maybe we have to pick them up — one officer in the front, one officer in the back.  This could be a medical issue, or a disturbance issue, or a criminal issue."

Unlike in Chicago, where the aviation security officers who removed Dao, a physician, were city employees and not trained police, Philadelphia airport is staffed by City of Philadelphia police.

The Chicago aviation department placed the three officers involved in the episode on leave. The department did not detail its guidelines in regard to using force, or boarding aircraft, but it said the officers were not following guidelines.

After video of the altercation aboard United Flight 3411 went viral, consumers and passenger-advocacy groups called for changes to airline policies.  U.S. airports that are guarded by a mix of municipal staff and police from city departments examined their procedures for patrolling aviation facilities.

"Anytime something like this happens, we reevaluate how we are doing things," Kinebrew said. "Are we doing it correctly?  Can we learn from this to make sure that we don't repeat that episode? We routinely examine our politics, procedures, our tactics. This would be one example of a time to look back."