The one medical condition I know for sure is that if you have ever had a case of Asthma, the medical officer will decline your application. Unless you can get a letter from your doctor saying it was a false diagnosis.
From a different post the limits to a pilot in the AAC are:
The weight limit for a pilot in the AAC is 60.4 - 96.7 kg while the RAF is 56.8 - 94kg. Functional reach is 740mm for AAC and 720 for RAF. Sitting height is 865 - 1005mm for the AAC and 865 - 990mm for the RAF. For both the AAC and RAF buttock - knee range is 560 - 660mm and buttock heel is 1000 - 1200mm.
I was told the application process started with aircrew aptitude tests at RAF Cranwell, if you pass these you do further tests at Middle Wallop. Then upon passing these you do flying grading, then its the pilots course.
The information on the army website is quite useful, http://www.army.mod.uk/aviation/air.aspx
Not really a document as such but a collection of instructions, regulations and bollox produced to keep a load of rubber desk johnny staff officers in a job and ensures the blokes are kept in the dark. Dunno what its classification is but its not exactly 'Harry Potter' material.
Are you a 100% on the ''if you EVER had asthma thing''? I was told I can apply for pilot as long as I had been cleared for 4 or 5 years from it, and the doc felt happy it wouldnt come back again (which he does) its been cleared about 12 years now.
My mucker was half way through training when the MO called him in and said "Bad news Corporal Wheezy-Lung, we've been checking through your civvy medical records which turned up this morning and it seems you were diagnosed with asthma when you were 3 so you're RTU. Fcuk off and close the door behind you"
News to him completely.
Appealed on the grounds that he had actually never had asthma but no use, there it was in black and white, some civvy GP had diagnosed a touch of childhood bronchitis or something as asthma and that was the end of his military flying career.
Probably the fittest guy by far on the course with not the slightest hint of a mild cough even but nothing doing.
So he binned the army and went to fly heavy metal for the airlines instead.
So ask to see your medical records before applying and if the word asthma is in there anywhere, break into your GP's surgery and nick your records or failing that torch the surgery.