Despite fire, airlines flying Boeing's Dreamliner

Boeing's carbon composite concerns

Here we go again.

Another Dreamliner has caught fire and once again as investigators look for the cause, airlines around the world continue to fly their Boeing 787 planes.

(Read More: Tracking Dreamliners' every move inside the 787 Ops Center)

If this situation reminds you what happened with the Dreamliner and the first battery fire back in January, you are not alone. The situation is very similar.

Boeing and the 13 airlines that fly the 787 are not parking their planes while investigators in Britain search for the cause of the fire onboard an Ethiopian Airways Dreamliner.

Why? The answer is that Boeing and its customers have not seen enough evidence to suggest this type of fire could happen on other Dreamliners.

Plane Fires Are Rare

UBS analyst David Strauss said that by his count there have been 25 ground fire incidents over the last 50 years. So these types of fires on planes are extremely rare.

(Read More: Dreamliner flying again in US after lengthy grounding)

Also, given the increasing use of flame retardant materials in airplanes, it raises questions about what could have sparked the fire in the crown of the plane.

Is it possible something went wrong with the wiring or with one of the components in the Dreamliner's electronics? Sure. But even that possibility isn't enough to spook airlines into parking their 787 fleets.

There's a distinct possibility that the cause of Friday's fire was a faulty component or the incorrect installation of some component in that part of the Ethiopian Airways plane. Either of those possibilities, while certainly not good, would also present Boeing with a problem it could easily check on the 68 Dreamliners flying around the world.

That's the reason Boeing and its customers are taking a cautious wait-and-see approach.

Growing Pains for New Planes

The immediate fallout from the fire on the tarmac at Heathrow Airport swirls around headline risk hitting Boeing shares. Anytime a Dreamliner doesn't take off as scheduled or cuts a flight short there is a predictable flurry of tweets and headlines saying "more problems for Boeing."

(Read More: Boeing's shares reel on Heathrow fire, drag Dow with it)

These are the growing pains that come with a new plane introducing new technology. Following the grounding of the 787 because of problems with the lithium-ion battery systems, investors were just starting to get past the headline risk the Dreamliner poses to shares of BA.

In fact, on Friday morning, Boeing stock had risen to a new all-time high and fewer investors were worried about the Dreamliner. All that changed with this recent fire which knocked $3.8 billion off the company's market cap in the minutes following the first report.

The headline risk of the 787 is once again in play for Boeing investors.—By CNBC's Phil LeBeau. Follow him on Twitter @LeBeauCarNews.

Questions? Comments?

By CNBC's Phil LeBeau; Follow him on Twitter: @Lebeaucarnews