What happened

Shares of Boeing (BA -1.75%) fell more than 5% on Friday after reports surfaced suggesting company employees misled the Federal Aviation Administration (FAA) about the safety system that eventually led to the grounding of the company's 737 MAX aircraft. The new disclosures are sure to raise more questions about Boeing's handling of efforts to win certification for the MAX, which was involved in two fatal crashes before its grounding.

So what

According to Reuters, Boeing has turned over instant-message exchanges from 2016 between two employees discussing 737 MAX safety systems, with one employee saying "I basically lied to the regulators (unknowingly)" about issues with the plane's flight control systems.

Rendering of the 737 MAX midflight.

Boeing's troubled 737 MAX. Image source: Boeing.

The FAA on Friday confirmed Boeing has only recently disclosed internal messages discovered months ago, with the regulator calling the messages "concerning" and demanding an explanation for the delay in turning over the documents.

The report seems likely to increase regulatory scrutiny of Boeing, which has already taken a lot of heat from lawmakers and the press over its internal processes. Customers including American Airlines Group, Southwest Airlines, and United Airlines Holdings have removed the plane from their schedules until 2020, and are growing increasingly impatient with the company.

Now what

For all of the company's issues in 2019, shares of Boeing are still up nearly 10% year to date, an indication that investors remain confident that it will eventually resolve the 737 MAX concerns and return the hot-selling plane to service, resuming business as usual. Some confidence is likely well founded, given that Boeing's duopoly with Airbus leaves airlines with few other choices when shopping for airplanes.

Still, these latest headlines are a reminder of how poorly Boeing management has handled the 737 MAX crisis, and the company has made a series of other missteps in recent years in other parts of the business. Boeing, for me, is in "show me" mode, and until the company can prove it has its act together, I would avoid investing in the shares.

Boeing shares are down Friday, but there are better choices for investors looking to buy aerospace and defense stocks right now.