A sputtering economy, implosions at financial institutions, or just plain bad management -- on any given day, investors can name a number of reasons to sell a stock. Yet while panic is never beneficial to investors, it's good practice to play devil's advocate with investments from time to time.

In Motley Fool CAPS, more than 125,000 members have weighed in on nearly 5,400 stocks, sharing bullish and bearish opinions alike.

In the case of airline manufacturing giant Boeing (NYSE:BA), a total of 3,610 members have weighed in on its chances of success. I've already plucked out some of the bullish rationale backing Boeing today, so here are three counterpoints to consider, courtesy of CAPS:

Struggling customers: Let's face it, commercial airliners wouldn't exactly be classified as tier-one customers these days. The airline industry continues to struggle as American Airlines (NYSE:AMR), one of Boeing’s big buyers, and UAL’s (NASDAQ:UAUA) United again posted big quarterly losses. Some carriers could have problems obtaining financing, which in turn could cause deferred deliveries of planes.

Union and labor issues: A nearly two-month machinists’ union labor strike halted plane deliveries and led to fourth-quarter revenue and earnings losses. The strike also accounted for $129 million in lost sales at its supplier Precision Castparts (NYSE:PCP), and had effects on many of Boeing’s other suppliers, like Honeywell (NYSE:HON) and United Tech (NYSE:UTX). The company plans to cut 10,000 jobs across its global operations, and it is already shorthanded in some of its production areas.

Delayed projects: New versions of the company’s 747 superjumbo jets have faced delays because of design changes and limited engineering resources. Its new 787 Dreamliner jet has been delayed by nearly two years, causing customers like Continental (NYSE:CAL) to stand by impatiently. It’s already had one big order cancellation for the 787 and expects more throughout this year.

Of course, Boeing has survived and thrived despite dozens of obstacles in the past. But the question about whether the company can continue to grow profitably is why CAPS is such a great resource to augment your own analysis.

To see what the very best CAPS members are saying now about Boeing, just click on over to Motley Fool CAPS and have a look -- it's all free, and open to your opinion.

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