Calling, emailing, or tagging airlines on Twitter to vent about your travel experience might help you blow off steam, but it's not guaranteed to get results. There is, however, another way to complain that may have a broader impact.

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Instead of contacting an airline to complain, try giving the Department of Transportation (DOT) a call. The department maintains what it describes as a "computerized aviation industry monitoring system" that's used as part of its annual Airline Quality Rating survey — and customer complaints are an important part of that.

The survey is designed to inform the public and influence travel policy, and incorporates a number of factors, including "on-time arrivals, involuntary denied boardings, mishandled baggage, and customer complaints," according to NPR.

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Overall, customer complaints in the airline industry dipped last year. For every 100,000 passengers, only 1.52 submitted complaints to the DOT in 2016, compared to 1.90 per 100,000 passengers in 2015. But those statistics could be underestimating public sentiment toward airlines, simply due to a lack of awareness about the DOT monitoring system, but also because passengers tend to take their complaints straight to the source.

Here's what happens when you file a complaint with the DOT, according to the official website.

"All complaints are entered in DOT's computerized aviation industry monitoring system, and are charged to the company in question in the monthly Air Travel Consumer Report. This report is distributed to the industry and made available to the news media and the general public so that consumers and air travel companies can compare the complaint records of individual airlines and tour operators.

These complaints are reviewed to determine the extent to which carriers are in compliance with federal aviation consumer protection regulations. This system also serves as a basis for rulemaking, legislation and research. Where appropriate, letters and web form submissions will be forwarded to an official at the airline for further consideration."

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The DOT customer complaint system is an essential tool more travelers need to know about, The Points Guy's Nick Ewen wrote. But it "generally should not be your first line of defense."

When you lose a luggage or get forcibly removed from an oversold flight, bringing the situation to the airline's attention can have more immediate results. If you don't find the airline's response to your complaint satisfactory or suspect they've violated aviation policies, though, drop a line to the DOT, Ewen advised.