In the immediate aftermath of the 737 Max 9 incident on Jan. 5, Alaska Airlines CEO Ben Minicucci proclaimed, "Proudly all Boeing is not just a tagline. It's a commitment."

• He has since altered his tone.

Why it matters: Boeing's manufacturing issues have become PR nightmares for Alaska Airlines as well as its biggest customer, United Airlines, as they scramble to inspect their fleets and ease the minds of concerned fliers and shareholders.

What they're saying: Both airlines are using public communication channels to put pressure on Boeing.

• "I'm angry. I'm more than frustrated and disappointed," Minicucci said in an interview with "NBC Nightly News with Lester Holt," which aired Tuesday.
• "This happened to Alaska Airlines. It happened to our guests and happened to our people," he said.
• Minicucci told NBC that the company had found loose bolts in "many" of its Boeing 737 Max 9s during inspections, and went on to question the quality control at Boeing.

The intrigue: Inviting a camera crew into the Alaska Airlines hangar to inspect the aircraft and point out Boeing's manufacturing flaws is a pretty aggressive public relations tactic — and speaks to the airline's strategy to rebuild reputation and instill trust.

Between the lines: While Alaska Airlines has become the "face" of Boeing's door plug problem — featuring an SNL sketch and all — United is invested from a business perspective because of its large stake.

United Airlines CEO Scott Kirby told CNBC that the latest manufacturing challenges are "the straw that broke the camel's back," and he's reevaluating future orders.

• This comes after United told investors it expects to see a loss of 35 to 85 cents per share due to the Boeing 737 Max 9 grounding, which has impacted roughly 200 flights per day.

Of note: Both airlines are prioritizing customer communications.

• Following the Jan. 5 incident, Minicucci issued a video message to frequent flyers, explaining what happened on Flight 1282, apologizing for the scare and spelling out how the airline will remedy any subsequent flight disruptions since Alaska has grounded about 20% of its fleet.
• United has also kept a steady flow of communications, apologizing to travelers for the cancellations and vowing the 737 Max 9 aircraft "won't fly until they are approved and we are confident they are 100% safe."

The other side: Boeing Commercial Airplanes CEO Stan Deal issued an apology to the airlines on Tuesday, but the reputational damage has been done.

Go deeper... Boeing CEO embarks on "communications task" following Alaska Airlines incident.