These two tech glitches grounded planes nationwide. How worried should we be?

Technology and commercial air travel have come under heightened scrutiny in the wake of two tragic Boeing 737 Max crashes. So, when a pair of software glitches grounded airplanes nationwide recently, travelers might understandably begin to wonder about the vulnerability of the various computer systems that keep their planes running.

But separate outages affecting reservations and preflight check systems highlight how dependent airlines have become on the vendors behind hundreds of software applications, experts say. Because the nation's air travel system is highly specialized and somewhat insular, a problem in one part of the ecosystem can have an outsized ripple effect, turning into delays, cancellations and riled passengers.

An outage Monday with Aerodata systems, which track a jet's weight and balance, created slowdowns for Southwest, Delta and Jet Blue flights across the country. Last week, Sabre's reservation system seized up, delaying passenger check-ins from New York to San Francisco.

Aerodata did not respond to a request for comment. A Sabre representative declined to comment.

Airlines for decades have relied on specialized providers for a host of tools, including reservation systems, flight planning and catering, said Henry Harteveldt, a travel industry analyst with Atmosphere Research Group. But owing to the industry's lack of growth, and niche requirements, the selection of software providers is more limited than in other sectors. What's more, small and midsize airlines tend to mimic the leading carriers, flocking to the same vendors they adopt.

So when an outage occurs, he said, "it brings multiple carriers to their knees."

For air travelers trying to get home or make it to a friend's wedding, even short-lived technical difficulties can ruin a trip.

"When you have so much tied up in the system, when the system doesn't work, you are pretty much out of luck," said George Hamlin, president of Hamlin Transportation Consulting.

The airlines' highly specialized technology sets them apart from industries like retail or banking, which can more readily purchase "off the shelf" software for their operations. Carriers themselves are multiple businesses rolled into one - from travel booking to food service to commercial flight - each with its own software needs.

A single airline could be operating several hundred applications from dozens of vendors, which makes redundant systems and backup plans crucial, Harteveldt said. Though Monday's outage was relatively small scale, no such contingency system appeared to be in place. "Unfortunately we do see these technology problems far too often."

Mike Boyd, an aerospace analyst with Boyd Group International, said computer systems are bound to trip up on occasion, but that the benefits far exceed the drawbacks. The weight and balance measurement system that malfunctioned Monday used to be preformed by hand, with pencil and paper, he noted. But computers are far more accurate and far more reliable in terms of data.

"The difference is computers crash and pencils don't," he said.

The airline industry used to have internal systems for many other routines and processes, he said, but vendors offer tools that are far more cost-effective, reliable and accurate. U.S. air travel is safer and more efficient than it's ever been: There's been one fatality among 7 billion passengers on 90 million flights in the past decade, according to the FAA. And on-time arrivals have climbed from 76 to 80 percent, on average, over the same the time frame, U.S. Department of Transportation statistics show.

The safety data stand in stark contrast to a pair of devastating 737 MAX 8 crashes that killed 346 people in Indonesia and Ethiopia. Regulators and airlines around the world grounded the Boeing jets last month. Although authorities are yet to formally assign a cause to either crash, investigators have already concluded that the anti-stalling feature, known as MCAS, was activated in the final minutes of the Ethiopian flight.

Boeing, meanwhile, is still working on a software fix for the plane's flight-control systems.

Though Monday's outage was a hassle for those it stranded, it posed no safety risk. In the end, Boyd said, the disruption had the effect of a "big snowstorm, except it hit a bunch of airports."

But widely publicized computer outages could attract another kind of unwanted attention: hackers in search of targets.

"When these types of outages occur, they do reveal a weakness in the system. And if there are attackers that are looking for paths to negatively impact airlines in general, they would see these as opportunities," said Tim Erlin, vice president of product management and strategy at Tripwire.

When glitches strike multiple airlines, an attacker could infer how vital a system is to the operations of multiple carriers, how reliant an airline is on a system through its response to a glitch, and the financial impact of a particular weakness, he said. The industry's reliance on third-party contractors expands the opportunities for attackers too, since businesses have less control over their vendors' security practices.

Target's infamous data breach, Erlin pointed out, apparently began through a refrigeration contractor.