They consist of timed races around a course which must be completed using a Mallard in a certain amount of time. This side mission is only available in the Special/Collector's Edition and Enhanced version. The Mallard is extremely difficult to handle, and it's not recommended to try these challenges without a full flying ability gauge. Completing Flight School is the best way to build up this ability, plus it teaches how to do knife and inverted flying, two stunts that are incorporated into the trial.