The Maths
In the year 2000 you were allowed to join the armed forces as a homosexual person.
Then given a cut of age for entry to the MOD as a pilot of 24 years for the RAF and 26 years for the RN the oldest age of a serving homosexual serviceman pilot is 35 years for the RAF and 36 for the RN.
So QED if you are homosexual and aged over 35 /36 you cannot be recruited into a service pilot only managed entry scheme into a civilian airline.
Hence indirect discrimination.