What happened

Shares of Boeing (NYSE:BA) lost altitude on Monday following an analyst downgrade. The stock traded down as much as 4.6% as investors digest the long recovery ahead for the aerospace giant.

So what

Boeing and its investors will be glad to see 2020 gone. The stock lost 34% for the year, and at one point traded down nearly 75%, on the one-two punch of continued issues with the 737 MAX and the pandemic's impact on commercial airlines.

The year seemingly ended on an upbeat swing, with the 737 MAX recertified to fly again after 20 months on the ground and a COVID-19 vaccine providing hope that the worst is over for aviation. But Boeing faces a multi-year recovery, and has no quick fix.

A Boeing 787 in flight.

Image source: Boeing.

Bernstein analyst Douglas Harned on Monday downgraded Boeing to underperform from market perform, noting that a hoped-for surge in 787 Dreamliner sales in the fourth quarter never materialized. Boeing delivered just one 787 in December, and none in November, and the plane continues to be haunted by questions about production quality.

The 787 kept Boeing airborne through the early days of the 737 MAX grounding, but Boeing will find it difficult to rely on revenue from that plane to fuel a rebound elsewhere. Boeing took on $25 billion in new debt in 2020 in response to the dual crises, and needs a rebound in plane sales to pay down that debt.

Now what

Boeing is at a crossroads. The worst is likely behind it, and with the stock still well below where it traded prior to the 737 MAX issues and pandemic, it is tempting for investors to climb on board and hope to ride the wave upwards.

But Boeing faces a tremendous challenge in delivering planes in this environment, and is unlikely to see production at levels assumed when the stock was flying high any time soon. And Boeing's current price to sales is actually much higher than it has been over most of the past three decades, raising questions about how affordable the company is.

I'm bullish on an eventual aviation recovery, but there are much better alternatives to Boeing for those looking to invest based on that recovery. Investors should be leery of Boeing right now.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.