How Flash failed JetBlue, and you

— -- Question: Why can't I print a JetBlue boarding pass from my Mac? It keeps showing up without the barcode.

Answer: Customers have been complaining about this boarding-pass problem since at least 2010 (though I had escaped that singular pleasure until May). The New York-based airline says it finally fixed the problem on Friday.

What went wrong? JetBlue Airways picked the wrong tool for this part of its online presence — an exception to a site that is generally cleanly designed and faster than competitors'. But it's not alone in making this mistake.

Specifically, JetBlue elected to use Adobe's Flash plug-in to generate the boarding pass in your browser's window. On a Windows PC, this could work fine, but on a Mac you'd see the complete boarding pass on the screen — then have it print without the barcode that must be scanned at the gate.

JetBlue spokeswoman Allison Steinberg wrote in early June that the problem was due to the Flash player ignoring a default print setting on a Mac. "We're actively investigating a solution and expect to have this resolved this month," she said then. It wound up taking another week beyond that.

While JetBlue's developers were going to all that trouble (I'm afraid to think of all the tests they had to run against different versions of Flash), other airlines have kept on cranking out printable boarding passes by generating Portable Document Format files on their servers. Their passengers need nothing more than a working PDF program: Adobe's Reader, Apple's Preview or outside alternatives like Foxit Reader or Sumatra PDF.

( American, Delta, and United, among others, let you dispense with paper altogether by sending a mobile boarding pass to your phone. In late June, JetBlue tweeted that it was "close to rolling out" a test of a mobile boarding-pass system.)

This airline, however, has plenty of company in giving Flash work that the software isn't cut out for. My favorite example: Personal-finance giant Intuit's ItsDeductible tax-prep application continues to greet users with a login page written entirely in Flash, which of course shuts out iPad users.

Intuit publicist Ashley Kirkendall wrote on Friday that the company was "working on updating the login experience" — as in, junking the Flash requirement — "later this summer."

Even with JetBlue and Intuit's moves to fix or dump Flash, too many other sites persist in using Adobe's software for tasks that you can do in the Web's standard HTML code. For that matter, a lot of sites have yet to drop the habit of using Oracle's sluggish and insecure Java software.

Tip: Taking pictures of your phone's screen

Experienced travelers know to take a screengrab of a mobile boarding pass, just in case they walk into a dead zone right at the TSA checkpoint. But how do you that?

On an iPhone or another one of Apple's iOS devices, you press and hold the Home button and then press the power button at the top of the phone; you'll hear a shutter sound as it takes the photo.

In Google's Android, things are far less consistent — which, among other things, helps explain why photos of iPhone apps vastly outnumber those of Android programs in news stories.