Binding

U.S. Air Force Air Mobility Command (AMC) on Monday released the findings of investigations into three mishaps involving the troubled KC-46A Pegasus aerial refueling tanker that cost the service nearly $23 million. The incidents all involved nozzle binding, a situation in which the tanker’s refueling boom nozzle gets stuck or binds with the receiving aircraft’s receptacle. 

Two of the incidents occurred in 2022 and a third in 2024. A fourth mishap took place July 8, 2025 and is still being investigated, AMC stated. There were no fatalities, injuries, or civilian property damage in any of these mishaps.

The first of these nozzle binding mishaps took place on Oct. 15, 2022. A KC-46A Pegasus assigned to the 305th Air Mobility Wing and operated by the 2nd Air Refueling Squadron, Joint Base McGuire-Dix-Lakehurst, New Jersey and an F-15E Strike Eagle assigned to the 4th Fighter Wing and operated by the 335th Fighting Squadron, Seymour Johnson AFB, North Carolina, were conducting routine air refueling operations. 

“During the mishap, a nozzle binding accident occurred during a breakaway which resulted in the air-refueling boom (ARB) striking the tail section of the KC-46A,” AMC said in a statement.

The Accident Investigation Board (AIB) found that a “preponderance of the evidence” showed one cause for the mishap. 

“Due to a limitation of the Air Refueling Boom (ARB) control system,” the KC-46 boom operator “inadvertently placed a radial force on the ARB that caused the nozzle to become bound in the receiver’s receptacle,” according to the AIB. “As a result, the bound forces exceeded the structural limitations of the ARB and caused a rapid upward movement of the ARB when released, striking the tail cone” of the Pegasus.

In addition, two other factors “substantially contributed” to this incident.

The Pegasus pilot failed to notify either the plane’s boom operator or the Strike Eagle’s pilot about an “engine power reduction” on the refueler. 

“This action, combined with the known ARB stiffness limitation and the resulting high engine power setting on [the F-15E], resulted in “a rapid forward movement” of that jet relative to the Pegasus.

In addition, “due to a limitation of the automated boom control system, the ARB entered an uncontrollable state during its upward motion toward the aircraft tail, disabling the boom control laws which could have slowed the rate at which the ARB struck the tail cone, substantially contributing to the mishap,” according to Col. Chad Cisewski, who led this AIB.

The estimated damages to the aircraft were $8,307,257.93, according to AMC.

Less than a month later, on Nov. 7 2022, there was another nozzle binding incident while a KC-46A Pegasus assigned to the 305th Air Mobility Wing and operated by the 2nd Air Refueling Squadron was refueling a F-22A Raptor assigned to the 94th Fighter Squadron, Joint Base Langley-Eustis, Virginia. The flight was in support of a joint-force training exercise from Tyndall Air Force Base, Florida.

“During the second air refueling attempt of the sortie, the KC-46A experienced a nozzle binding event during a breakaway with the F-22A, which resulted in damage to the ARB nozzle,” AMC said in its statement. “The bound forces exceeded the structural limitations of the ARB nozzle, damaging the nozzle beyond repair.”

The AIB determined “by a preponderance of the evidence, one cause for this mishap,” the report stated. The boom operator “made manual control inputs to the ARB which caused a radial force to be applied to the ARB nozzle, causing it to become bound inside the receiver’s air refueling receptacle.”

As a result, “the bound forces exceeded the structural limitations of the ARB nozzle, damaging the nozzle beyond repair.”

Two other factors “substantially contributed to the mishap,” according to the AIB. The first was “the failure” of the Raptor’s pilot “to account for the KC-46A Stiff Boom characteristics, causing a rapid forward movement” of the fighter relative to the refueler. The stiff boom probem is a long-standing issue, which you can read more about here.

In addition, the boom operator was “unable to verify that the ARB nozzle was clear of [the Raptor’s] air refueling receptacle prior to making ARB control inputs, substantially contributing to the mishap.”

The mishap caused an estimated $103,295.12 in damages, AMC noted.

A third nozzle binding incident took place Aug. 21, 2024, when a KC-46A Pegasus assigned to the 22nd Air Refueling Wing and operated by the 931st Air Refueling Wing was refueling an F-15E assigned to the 366th Fighter Wing in support Operation Nobel Eagle, North American Aerospace Defense Command (NORAD) aerospace warning, control, and defense missions in North America. The aircraft were helping to enforce a temporary flight restriction related to a presidential visit. Then-President Joe Biden was reportedly vacationing in Santa Ynez, California at the time. The tanker and one of the fighters were forced to make emergency landings — the F-15E twice having to abort those recoveries before finally touching down at an alternative location. You can read more about that in our initial report here and listen to the audio below.

During the fourth air refueling attempt of the sortie, “the KC-46A experienced nozzle binding of the boom in the F-15E receptacle,” AMC explained. “Upon release, the boom rapidly flew upward, striking the bottom aft portion of the KC-46A, and violently oscillated left and right.”

The boom striking the aircraft and “ensuing forceful oscillations resulted in critical failure of the boom shaft structure, portions of which detached from the KC-46A in flight,” the command continued. “The KC-46A crew declared an in-flight emergency and returned to Travis AFB. Emergency response personnel met the crew upon arrival.”

The boom fell in an open field about 13 miles northeast of Santa Maria, California, with no injuries or fatalities reported, the AIB explained.

The AIB found, “by a preponderance of the evidence, that the cause of the mishap was the [boom operator’s] control inputs to the air refueling flight control system, resulting in an excessive fly-up rate of the boom, which struck the aircraft empennage and caused a critical failure of the boom shaft structure,” according to the report.

There were four other factors that “substantially contributed to the mishap,” the AIB board president ruled. 

• Excessive closure rate and instability of the Strike Eagle.
• The boom operator’s “attempted contact outside the standard [aerial refueling] envelope for the F-15E.
• The F-15E pilot’s “failure to recognize and initiate immediate breakaway procedures, which further delayed positive separation from the KC-46A,” and
• The boom operator’s “lack of knowledge on boom flight control logic and its effects on the boom flight control surfaces prevented the [boom operator] from recognizing the influence of Flight Control Stick (FCS) inputs and programmed boom limit functions during operations, especially during nozzle binding situations.”

The estimated damages to the aircraft were $14,381,303, according to AMC.

The Air Force did not release details about the July 9, 2025 incident. However, at the time, 2nd Lt. Samantha Bostick, Deputy Chief of Public Affairs for the 22nd Air Refueling Wing at McConnell Air Force Base, told us what happened.

“A KC-46A Pegasus from McConnell Air Force Base declared an In-flight Emergency July 8, while operating over the eastern United States, refueling F-22s,” she said. “The crew had to make the decision to land at Seymour Johnson Air Force Base, N.C., and has landed safely there. The aircraft will remain there for the time being.”

You can listen below as the crew of the KC-46, callsign FELL 81 and serial number 17-46033, alerts the U.S. Navy’s Fleet Area Control and Surveillance Facility at Virginia Capes (FACSFAC VACAPES) about losing the boom. FACSFAC VACAPES is better known by its callsign, Giant Killer, and helps monitor for threats and otherwise manage the airspace off the east coast of the United States.

In general, KC-46s are no stranger to issues with their booms. The boom and the control system for it have been a source of serious and persistent technical issues for the Pegasus fleet for years now. A fix for the KC-46’s particularly troublesome remote vision system (RVS), which boom operators in the tanker’s main cabin use to perform their work, is now unlikely to be finished before summer 2027, roughly three years behind schedule, according to Defense News.

The nozzle binding issue is clearly a problem in many respects, not just in terms of the dangers posed by booms breaking away or impacting the receiver or the tanker’s airframe, but it also poses a real danger to those on the ground. Beyond that, the reliability of any type during critical missions is always a concern, as such a mishap could curtail a high-priority mission or the risk of it occurring requires extra increasingly precious tankers being assigned to those operations as a contingency. What we don’t know is how common this is in comparison to the KC-135 or the recently retired KC-10. Hopefully, we can get more clarity in this regard now that the findings of these mishaps are published.

We will update you when we find out more.

Contact the author: [email protected]

Aug. 16 (UPI) — Hours after Air Canada flight attendants went on strike and the airline indefinitely paused all flights, the Canadian government intervenued Saturday and ordered operations to resume.

Jobs Minister Patty Haju ordered the company’s management and the union back to participate in binding arbitration to hash out their differences on wages and compensation. It wasn’t known when flights will resume after opereations were paused early Saturday.

“After eight months of negotiations by the parties, and after meeting with both parties last night and urging them to work hard to reach a deal, it is disappointing to have to conclude today that Air Canada and CUPE flight attendants are at an impasse and remain unable to resolve their dispute,” she said in a statement released Saturday aftetnoon Eastern time.

“The government firmly believes that the best deals are reached by the parties at the bargaining table. It has now become clear that this dispute won’t be resolved at the table. Canadians are increasingly finding themselves in very difficult situations and the strike is rapidly impacting the Canadian economy.”

She invoked Section 107 of the Canadian Labor Code, which directs the Canadian Relations Board to arbitrate the dispute.

“I am exercising this authority because it is critical to maintaining and securing industrial peace, protecting Canadians and promoting conditions to resolve the dispute,” she said. “Despite the parties’ resolution of several key differences, the CIRB is best positioned to help them find a solution on the outstanding items.”

Also, she extended the terms of the existing agreement until a new one is determined by an arbiter.

“This decision will help make sure that hundreds of thousands of Canadians and visitors to our country are not impacted because of cancelled flights,” she said. “Further, the shipments of critical goods such as pharmaceuticals and organ tissue, over 40% of which are moved by Air Canada, should continue to reach their destinations.”

The Air Canada union asked her to direct the parties to enter into binding arbitration.

But on Saturday afternoon, the union blasted the order to end the strike and posted images and video stirkers.

“Now, when we are at the bargaining table with an obstinate employer, the Liberals are violating our Charter rights to take job action and give Air Canada exactly what they want — hours and hours of unpaid labor from underpaid flight attendants, while the company pulls in sky-high profits and extraordinary executive compensation.

“This sets a terrible precedent. Contrary to the Minister’s remarks, this will not ensure labor peae at Air Canada.”

More than 130,000 travelers worldwide fly on the airline daily.

Canada’s largest airline has more than 1,000 flights, including 170 international ones, and from 50 Canadian airports. Between more than 50 U.S. airports and Canada, there are 430 daily flights.

Locked out at 1:30 a.m. EDT were 10,000 flight attendants at Air Canada and Air Canada Rouge represented by the Canadian Union of Public Employees. Air Canada Express, with regional 300 flights and operated by Jazz Aviation and PAl Airlines, is not affected.

The flight attendants went on strike at 12:58 a.m. EDT.

Picket lines had been set up at airports throughout Canada, the CBC reported.

The last negotiations were on Friday night and no new talks were scheduled.

On Wednesday, the airline served the union a statutory 72-hour lockout notice in response to the union’s 72-hour strike notice.

Air Canada was canceling flights ahead of the work stoppage.

“The carriers have since been gradually reducing their schedules of about 700 daily flights to manage the labour disruption created by CUPE’s strike notice,” the airline said. “Some 130,000 customers will be impacted each day that the suspension continues. At this time, Air Canada remains engaged and committed to negotiate a renewal to its collective agreement with CUPE.”

The airline said it “deeply regrets the labor disruption is having on customers.”

Wesley Lesosky, president of the Canadian Union of Public Employees’ Air Canada component, told the CBC it is up to the airline when they would be back on flights. The airline hadn’t responded to the media site.

Air Canada Chief Operating Officer Mark Nasr earlier said after an agreement, it could take up to a week to fully restart operations.

The carrier advised people not to go to the airport if they are booked on the airline.

“Air Canada will notify customers with imminent travel of additional canceled flights and their options,” the airline said. “For those customers due to travel soon whose flights are not yet cancelled, Air Canada has put in place a goodwill policy to allow them to rebook their travel or obtain a credit for future travel.”

Compensation differences

Flight attendants want to be compensated for work before the flights take off and after they land. Typically with most airlines, they get paid only for the hours they are in the air.

The airline, in its latest offer, proposes a 38% increase in total compensation that “would have made our flight attendants the best compensated in Canada.”

The union said a proposed 8% raise in the first year is offset by inflation.

Hajdu told The Canadian Press on Friday that it is “critical” for the two sides to return to the negotiating table.

“It’s very important that we stay focused on the two parties,” Hajdu said. “They have the primary responsibility to solve this. This is a corporation and a union who have all the tools they need, as well as tools from the federal mediation service, to get this deal done.”

On Friday, the minister said she wasn’t ready to intervene in the dispute, and saw a path forward to a deal because most issues have been resolved.

The union accused her of speaking “on behalf” of the company.

“Every party has expressed support for our effort to end unpaid work, except for the governing Liberal Party,” Lesosky said during a news conference Thursday.

Hajdu posted Friday on Facebook that she met with both sides.

“It is unacceptable that such little progress has been made. Canadians are counting on both parties to put forward their best efforts.”

Travel options

The carrier advised people not to go to the airport if they are booked on the airline.

“Air Canada will notify customers with imminent travel of additional cancelled flights and their options. For those customers due to travel soon whose flights are not yet cancelled, Air Canada has put in place a goodwill policy to allow them to rebook their travel or obtain a credit for future travel,” the airline posted.

Air Canada is partnered with Star Alliance, which includes more than 20 airlines, including Lufthansa and United Airlines. Code-sharing flights might be affected.

The New York Times listed ideas for travelers.

Travelers can change flight dates and receive a one-time $50 credit per passenger or opt for an airline credit equal to the value of the ticket for one year.

Travelers are eligible for a full refund requested through the app or website. The airline said it will attempt to rebook travelers on other airlines. Canada’s second-biggest airline is WestJet Airlines, though it has many fewer international destinations.

Because of peak summer travel, options may be limited.

Keelin Pringnitz and her family were returning from a European vacation to Ottawa, but were left stranded at Heathrow Airport in London.

“It was an end of my maternity leave kind of trip,” Pringnitz told CBC. “We went to the Faroe Islands and Norway, travelling through Air Canada to London.”

She said they could fly to the United States, but no assistance once they land there.

“It didn’t go over well with the line,” she said. “Nobody really seemed interested. Everybody seemed a little bit amused almost at the suggestion, or exasperated, because it is a bit ridiculous to offer to take stranded passengers to a different country to strand them there.”

For those with travel insurance, some plans include trip cancellations, including a strike.

The U.S. Department of Transportation, which has jurisdiction over Air Canada flights that depart from the U.S., has a similar policy like the Canadian government. Refunds must be given within 30 days and rebooked if possible. There is no mandatory compensation for delays.

“For U.S. travellers, the key now is to think strategically,” Anton Radchenko, AirAdvisor’s founder, said in a statement to USA Today. “Don’t just look for the fastest alternative route; look for the most stable one. This may mean flying via smaller, less congested hubs like Detroit or Minneapolis, where rerouting is easier, or securing refundable one-stop connections through partner airlines before seats vanish.

“Keep all receipts, track your communications with the airline, and, if possible, pay with a credit card that includes trip interruption coverage. Above all, treat this strike as a high-impact event that demands proactive planning, not reactive scrambling.”