Budget Airline Flight Checker inaccurate

mahler

I've just looked up the Flight Checker for a flight from Gatwick to Mahon on September 4th. According to the Flight Checker there isn't a flight available for that date. However when I go into Monarch airlines website I see that there is a flight from Gatwick on the 4 September leaving at 17.45 for £21.49! Why isn't this flight shown on MSE.com Flight Checker?

dmg24

Are any Monarch flights shown on there?

fifeken

Just below where you enter your price there is:

Airlines Included: AerLingus, AirBerlin, BMI Baby, Easyjet, Flybe, FlyMonarch, Norwegian Air, Ryanair, Thomson Airways, WizzAir.

So Monarch flights are covered but I think they only sell packages to Mahon from Gatwick, not flights only, so that could be why it doesn't come up