Q. I know there are lots of web sites where travelers can post their own reviews of hotels. But where’s the best place to find travelers’ opinions and reviews of airlines?

A. A veteran travel magazine publisher once remarked that “you can’t judge a whole airline by a single flight,” but the collective experiences of many travelers might offer some valid insights as to the level of quality you can expect. One of the best places to find a large number of opinions and reviews is at the U.K.-based site www.airlinequality.com, operated by Skytrax, a leading monitor of all things airline. The database includes thousands of traveler reviews and trip reports on airlines worldwide, searchable by airline from an alphabetical index; participants can rate their individual flight experience on a scale of 1 to 10, and the site assigns star ratings from 1 to 5 for each airline. But that’s not all: You can also find traveler reviews of airports, airline lounges, and airline seating. Skytrax has an affiliated web site at www.flatseats.com where travelers can post their opinions on the premium-class seating options of the world’s carriers; it even includes a photo gallery of front-cabin seats so you can see exactly what you’re buying.

The U.S.-based web site Flyertalk (www.flyertalk.com) also has a section devoted to users’ reports of their flight experiences; to find it, click on Forums>Community>Trip Reports from the home page. But the reports are ordered chronologically by date of posting rather than by company; there is a search function if you want to scour the site for comments on an individual airline, but it’s not as easy as finding them on the Skytrax site.