It looks like a long hot summer for the airline industry -- particularly for flight attendants, the workers who most frequently interact with passengers.

A now well-known incident on April 9 -- when a recalcitrant passenger was dragged off a United (UAL) - Get Report airplane by Chicago Aviation Authority security officers -- has drawn widespread attention to airline customer service shortcomings. It didn't involve flight attendants.

But an April 21st incident, where an American (AAL) - Get Report flight attendant responded badly after he was menaced by a large male passenger, vividly portrays the stress flight attendants can face.

In the video, the large male passenger concluded -- apparently falsely -- that the flight attendant struck a woman or her children. In the video, he declares "Hey bud, you do that to me and I'll knock you flat."

He leaves his seat to menace the flight attendant, who responds by telling him to stay out of it and then taunts him, saying, "Hit me, bring it on." However, no one hit anyone.

"Without a doubt, in recent weeks, we've seen threats against flight attendants, but in fact it's been a growing trend over the last year or more," said Bob Ross, president of the Association of Professional Flight Attendants, which represents 26,000 American flight attendants.

"It seems like the respect flight crew members get on flights is deteriorating at a rapid pace," Ross said in an interview.

On Thursday, Sara Nelson, president of the Association of Flight Attendants, which represents about 50,000 flight attendants at 20 airlines, will appear before the Senate Subcommittee on Aviation Operations, Safety and Security for another hearing on airline customer service.

In a recent message to flight attendants, Nelson said various videos have created challenges for flight attendants.

"The mob mentality response to the video clips, with little correct information about the incidents, has put flight attendants in the crosshairs," Nelson wrote. "We have been focused on trying to do a national de-escalation to keep travelers from coming to the plane with bias against crewmembers."

On Tuesday, at a House Transportation and Infrastructure Committee hearing, Rep. Peter DeFazio, D-Ore., suggested changes may be needed in federal regulations regarding how many flight attendants are required on an aircraft.

Currently, aircraft with seating for between 50 and 101 passengers must have two flight attendants, with one additional flight attendant for each additional set or partial set of 50 passenger seats.

There are "a lot of tensions on planes {and} a question about how many flight attendants there should be on planes," DeFazio said. "They are being asked to referee and all sorts of things. {Staffing} hasn't changed for 20 years." He said flight attendants are overstressed.

Ross said flight attendants' work environment has deteriorated due to "crowded airplanes, a lack of manners, a lack of time between {flight} segments, absolute minimum ground time {and} the whole thing around on-time departures."

As for the April 21st stroller incident, Ross said the flight attendant is unlikely to be disciplined. As for the passenger, Ross said "a stern message needs to be sent" that passengers should not menace flight attendants, but he did not advocate that charges be filed against the passenger for interfering with a flight crew member.

"We don't want to alienate passengers now," Ross said. "We want to educate them. We have to work together."

American CEO Doug Parker took a similar tack on the airline's first-quarter earnings call, after President Robert Isom said no charges would be filed against the passenger.

"We sometimes, because of our policies and procedures, put {flight attendants} in difficult situations," Parker said. "We are going to work to make sure we minimize those, but we are really happy with the job they do.

"We {also} look to provide great service to our customers," Parker said.

A sign of turmoil among American flight attendants is that Ross and three other top APFA leaders face a recall effort. A leader of that effort, who asked not to be named, said backers have gathered about 4,000 signatures on a recall petition for which 7,732 signatures, or 30% of membership, are required.

The flight attendant cited issues including leadership's commitment to change that has not occurred, a failure to communicate and a decision to challenge a U.S. Department of Labor ruling that the 2016 leadership election was invalid because the union failed to provide adequate secrecy for voters.

The recall effort "destabilizes the credibility of the union {and} blames the union for the failure of the company to get to full operating integration," Ross said. "Instead of banding together for strength, they tear the union apart and make themselves weaker.

American said last month that due to technology challenges, it cannot fully implement a joint contract for American and US Airways flight attendants until 2018. The airlines merged in 2013.

This article is commentary by an independent contributor. At the time of publication, the author held no positions in the stocks mentioned.