A Delta Air Lines jet that dumped fuel over several Los Angeles schools had not sought approval to do so, according to the US Federal Aviation Administration.

Fire crews treated 60 people Tuesday after Delta Flight 89 dumped fuel over a populated area that includes five elementary schools and a high school while returning to Los Angeles after an engine issue.

Minor injuries were reported among 20 children and 11 adults at one elementary school, although none required hospitalization.

Some people hit by the fuel were decontaminated with soap and water and witnesses reported rain that smelled like gasoline.

READ: Record-breaking Delta flew high in 2019

Pilots generally notify air traffic control of the need to dump fuel and are directed to an area where they can safely do so.

This typically involves designated unpopulated areas and the fuel is dumped at higher altitudes so it atomizes and disperses before it hits the ground.

In this case, according to a transcript from LiveATC.net and obtained by US media, the pilots were apparently asked by air traffic control whether they needed to hold or dump fuel and replied: “Uh, negative”.

The FAA, which is investigating the incident, confirmed in a statement there was no request to dump fuel and noted the procedure was not undertaken at an altitude that would have allowed it to atomize properly.

“A review of yesterday’s air traffic control communications shows the Delta Flight 89 crew did not tell air traffic control that they needed to dump fuel,” it said.

The Boeing 777-200 bound for Shanghai released the fuel to reach a safe landing weight that would avoid bursting tires and damaging the landing gear.

The Aviation Herald website reported the plane was climbing out of Los Angeles airport when it leveled off at 8000ft.

The crew reported a right engine compressor stall and said they needed to return to Los Angeles.

They subsequently reported they had brought the engine under control, the website said, and the plane landed safely about 25 minutes after departure.

Delta said it had contacted Los Angeles World Airports, the LA County Fire Department as well as community leaders “and shares concerns regarding reports of minor injuries to adults and children at schools in the area”.

The airline has sent cleaning crews to help clean outside surfaces at the affected schools.

Iranian authorities have arrested several people in connection with the fatal missile attack on an Ukrainian passenger jet as the investigation headed by Iran gathers momentum.

Media reports say it is not clear how many people have been arrested or with what they have been charged but Iranian President Hassan Rouhani has vowed that those responsible for the tragedy will be punished.

Ukraine International Airlines Flight 752 appears to have been targeted by two ground-to-air missiles shortly after it took off from Tehran.

The Boeing 737-800 was traveling to Kiev and all 176 people on board, including 57 Canadians, died when the plane plunged to the ground and exploded.

Iranians took to the streets after the nation’s military admitted it had downed the jet “unintentionally due to human error” after denying for several days that the accident was due to a missile strike.

READ: Serious flaws on Iran’s claims on Flight PS 752.

It claimed that the Ukrainian jet moved too close to a sensitive military base at a time tensions were high because of the US assassination of General Qassem Soleimani.

In the latest development, CNN quoted Rouhani warning that Iran would push to “detect all aspects of the event and punishing those responsible”.

He said a special court with “a high-ranking judge and dozens of experts” should be established in order to investigate the incident.

“This is not an ordinary case and all of world is looking at us,” he added.

Meanwhile, Iran’s Civil Aviation Organization said that a meeting of investigators from Ukraine, Canada and Iran took place on January 14.

French investigators have been asked to support their Ukrainian counterparts with technical work on the cockpit voice and flight data recorders.

The BEA said on Twitter Tuesday that discussions were still underway between all stakeholders of the safety investigation and it had not at this stage been asked to carry out repair and data download from the recorders.

Canada has also said it will dispatch a team of specialists in aircraft recorder download and analysis once it confirms where the activity will take place.

“As 57 of the passengers who died in this tragedy were Canadian, it is our hope that the TSB will be allowed to bring more of its expertise to a thorough and transparent investigation,” TSB chair Kathy Fox said.

“The TSB is seen as a world leader, and we have participated in foreign investigations for almost 30 years. […] As an independent accident investigation agency, we will also collaborate with the other international investigation authorities with whom we have long-standing and well-developed relationships—including those from France, Sweden, the UK and the US, as well as Ukraine.”

Sweden and the US have also assigned accredited representatives to the investigation.

It may not be the gauze and haute couture of Paris fashion but passengers flying with United Airlines are seeing a new look on the runways of America.

United has rolled out a winter collection of weather-resistant uniforms designed by Carhartt Company Gear (CCG) for its 28,000 technical operations, ramp service and catering operations employees.

The uniforms are the product of a three-year collaboration between CCG and United employees to deliver hard-working uniforms that could stand up to the demands of their jobs.

READ: Record-breaking Delta flew high in 2019.

The project involved about 1000 employees from the airline’s international and domestic operations who participated in focus groups and wear tests.

Their input was used to improve the features and functionality of the work clothes.

The result was a wardrobe of more than 50 pieces designed to address the needs of United’s “below wing” workforce.

This included custom-design pockets to fit wands and other tools, color-blocking on hi-visibility gear to address dirt and grime and fabrics designed to address the wide range of climate conditions across our system.

The airline says the designers paid particular attention to women’s workwear to ensure both the fit and function was correct.

“Every day all over the globe our employees on the ground are facing the coldest colds and the hottest hots,’’ United human resources and labor relations executive vice president Kate Gebo said.

“Through our partnership with Carhartt – the leader in workwear – we’ve confidently created a uniform collection enabling our employees to look good and feel good while continuing to deliver the best service for our customers.”

CCG senior vice president Andi Donovan said that feedback so far from the United front lines was that the new uniforms were “working hard for each and every one of them”.

The new below-wing uniforms are part of a revamp of all United uniforms involving 75,000 employees.

American Airlines has joined competitor United in taking the Boeing 737 MAX out of its schedule until June.

It had previously canceled MAX services to April 6 but now says it does not expect the jet to resume scheduled commercial services until June 4.

The decision affects about 140 flights per day.

It said it was in continuous contact with Boeing and the US Federal Aviation Administration and its decision was based on the latest guidance.

READ: American staff gain $US30 million from 737 MAX deal

“On Jan. 19, American will run a formal schedule change, and customers who were previously booked on a MAX through June 3 will see their reservation updated on aa.com,’’ it said.

“Additional refinements to our schedule through June 3 will also occur in February 2020.”

United made a decision in December to take the MAX out of its schedule until June to give it more certainty by providing customers and its operations “a firmer and more definitive timeline”.

American will initially run flights for staff and invited guests once the plane is recertified and plans to gradually phase in the MAX on commercial services throughout June.

It has not ruled out “additional refinements” to its MAX schedule.

The FAA still has not given a date as to when the MAX will be recertified after the global fleet was grounded in March 2019 after two fatal crashes.

Airlines and Boeing will need to feed into the system not just the planes that were initially grounded but about 400 jets built since.

Boeing decided late last year to suspend MAX production from January 2020.

It cited factors such as uncertainty about the timing and conditions of a return to service and global training approvals as well as the need to prioritize the delivery of stored aircraft.

It recently performed an about-face on training requirements by abandoning its opposition to simulator training for pilots before the jets return to service.

The move came ahead of the release of embarrassing emails showing Boeing staff went to significant lengths to oppose simulator training to keep costs down for airlines.

The bad news kept coming this week with an announcement by credit rating agency Moody’s also announced this week that it was looking at downgrading Boeing’s debt.

These are all issues facing new chief executive David Calhoun as he moved into the hot seat on January 13.

Calhoun, 62, is an industry veteran who is seen as well-equipped to handle the mess after senior leadership roles with GE, Blackstone Group and Nielsen Holdings.

In an email to staff, he said this was a crucial time for Boeing.

“We have work to do to uphold our values and to build on our strengths.’’ He said.

“ I see greatness in this company, but I also see opportunities to be better. Much better,” he said.

“That includes engaging one another and our stakeholders with greater transparency, holding ourselves accountable to the highest standards of safety and quality, and incorporating outside-in perspective on what we do and how we do it.”

Heading the list for Calhoun’s priorities for 2020 was returning the MAX to service and making sure customers and regulators were completely satisfied.

The company also needed to rebuild trust, focus on its values and “operate with excellence”, he said.

“Many of our stakeholders are rightly disappointed in us, and it’s our job to repair these vital relationships,’’ he said.

“We’ll do so through a recommitment to transparency and by meeting and exceeding their expectations. We will listen, seek feedback, and respond — appropriately, urgently and respectfully.”

Other priorities included maintaining production health by taking steps to maintain supply chain and workforce expertise as well as investing in future through programs such as 777X, CST-100 Starliner and the 737 MAX 10.