Yes! TripAdvisor has launched Airline Reviews where you may review your first hand experiences with an airline.
An airline review must be for the operating carrier that you flew. For example, if your flight was marketed as American Airlines AA1234 but it was actually operated by British Airways, write a review on British Airways.
An airline review may include just an individual leg of a flight (e.g. London to Boston) or the review may cover your entire return experience with an airline (e.g. London to Boston to London) if operated by the same airline. If you had multiple stops, your review may also include these legs if it is with the same airline.
To review an airline, get started at www.tripadvisor.com/airlines.