Report: United Airlines, Alaska Airlines Find 'Loose Bolts' on Plane Doors Following Inspections Preliminary inspections on grounded Boeing 797 Max 9 aircraft began after a door flew off an Alaska Airlines plane mid-flight on Friday.

By Emily Rella

Opinions expressed by Entrepreneur contributors are their own.

United Airlines and Alaska Airlines said that preliminary investigations of Boeing 737 Max 9 aircraft in their respective fleets have found loose hardware and bolts on some door plugs.

"Since we began preliminary inspections on Saturday, we have found instances that appear to relate to installation issues in the door plug -- for example, bolts that needed additional tightening," United Airlines explained in a statement, per ABC News. "These findings will be remedied by our Tech Ops team to safely return the aircraft to service."

Related: 'Grateful to be Alive': Passengers Recall Harrowing Moment Airplane Door Flew Off Alaska Airlines Flight

The news comes after a plane door panel blew out mid-flight on an Alaska Airlines aircraft on Friday. The Federal Aviation Agency grounded over 170 Boeing 737 Max 9 planes for emergency inspections following the incident, causing hundreds of cancelations across both airlines.

United did not specify how many of its 737 Max 9 aircraft were found to have loose hardware. The airline currently operates 79 of the models.

Alaska Airlines made a similar statement, noting that none of the aircraft would fly again until formal inspections and investigations were completed.

"No aircraft will be returned to service until all of these steps are complete," Alaska Airlines wrote in a release regarding its 65 Boeing 737 Max 9 aircraft. "The safety of these aircraft is our priority and we will take the time and steps necessary to ensure their airworthiness, in close partnership with the FAA. "

Boeing, whose valuation is down over 9% in the past five days following the news of Friday's accident, released a public statement late Monday: "As operators conduct the required inspections, we are staying in close contact with them and will help address any and all findings. We are committed to ensuring every Boeing airplane meets design specifications and the highest safety and quality standards. We regret the impact this has had on our customers and their passengers."

Related: Alaska Airlines Brewing Coffee That Tastes Better In the Air

No passengers were injured during Friday's incident, and no one was seated in the two passenger seats next to the door.

As of late Tuesday morning, United had canceled another 203 flights and Alaska Airlines had canceled 108.

Emily Rella

Senior News Writer

Emily Rella is a Senior News Writer at Entrepreneur.com. Previously, she was an editor at Verizon Media. Her coverage spans features, business, lifestyle, tech, entertainment, and lifestyle. She is a 2015 graduate of Boston College and a Ridgefield, CT native. Find her on Twitter at @EmilyKRella.

Want to be an Entrepreneur Leadership Network contributor? Apply now to join.

Editor's Pick

Business News

JPMorgan Shuts Down Internal Message Board Comments After Employees React to Return-to-Office Mandate

Employees were given the option to leave comments about the RTO mandate with their first and last names on display — and they did not hold back.

Growing a Business

Entrepreneurs Should Invest in Service, Not Just Sales — Here's How to Build a Customer-First Business

A customer-first business strategy that prioritizes exceptional service, empowers employees and leverages feedback can transform satisfied customers into loyal advocates, driving sustainable, long-term growth.

Business Ideas

70 Small Business Ideas to Start in 2025

We put together a list of the best, most profitable small business ideas for entrepreneurs to pursue in 2025.

Business News

'More Soul-Crushing Than Ever': Popular Hiring Platform Finds Around 20% of Its Postings Were 'Ghost Jobs'

Is that job listing too good to be true? There's a one-in-five chance that it might be.

Business News

'Masculine Energy Is Good': Mark Zuckerberg Tells Joe Rogan He Thinks Companies Need More Aggression

On the most recent episode of "The Joe Rogan Experience," Meta CEO Mark Zuckerberg said corporate culture has become "neutered."

Growing a Business

5 Risk-Taking Lessons From Founders Who Bet Big and Won

Discover the bold moves and strategic risks that catapulted these entrepreneurs to success. Learn how their fearless decisions can inspire your own path to growth.