Help! My airplane was fixed with duct tape!

It looks like duct tape, but it's not duct tape, and it's sometimes found on airplanes, where passengers have been known to snap photos of it just prior to flight. And usually, their reactions on social media are outraged: Why would an airline fix a plane with tape? Isn't it dangerous?

Then predictably, an image of its use flies around Twitter or Instagram, like this:

But it's not duct tape. It's called speed tape. And it isn't a danger.

This tape is perfectly acceptable and standard practice in airline maintenance, where it can be used for temporary cosmetic fixes or in a bid to improve aerodynamic efficiency on a damaged part. It's not cheap, either; this super-tape costs around $400 for a four-inch wide roll.

It's called speed tape because, when applied, it will adhere to an airplane wing traveling very fast through the air. It can withstand temperatures ranging from -65°F to 600°F, and has a cloth layer covered by aluminum foil with a super-strong silicone adhesive, making it thicker than duct tape. It's made by a number of manufacturers, such as 3M.

Speed tape was recently deployed, for example, on a brand new Virgin Atlantic A350 aircraft that struck a bird during flight testing. Unsightly, but barely noticeable and inconsequential to the operation of the aircraft.

"The publicity around speed tape is unwarranted," said Chris Brady, an airline captain in Europe and the founder of Boeing 737 Technical Site.

That's why airlines will try to avoid speed tape: because of the negative social media mentions and PR alone.

"The manufacturer's maintenance manual will approve certain uses of speed tape. There's a vetting process," Brady said, noting that any reputable airline will follow these rules or face consequences.

In 2002, United Airlines was fined for improper use of speed tape by a maintenance worker — likely an oversight rather than intentional misuse. At the time, United said it would contest the fine. In another example, a Ryanair flight was forced to turn around mid-flight when speed tape applied to a flight deck window came undone. The speed tape was applied to cover sealant on the window, to allow the sealant, applied just before flight, to cure. The seal and the speed tape did not bear structural loads; each were applied for aerodynamic efficiency. Unfortunately for the airline and the flying public, poor and sensationalized reporting of the incident did not help the reputation of this super tape.

For his part, Brady said he sees speed tape on his aircraft about once every three months, when he conducts the customary preflight walk-around. And if the captain does not worry about it, then neither should passengers.

Mike Arnot is the founder of Boarding Pass NYC, a New York-based travel brand, and a marketing consultant to airlines, none of which appear in this article.