Their maintenance is not done in Dubai unless their aircraft is broken. The APU is a loaner from Berlin and is leaking oil like a seive. I have seen this Challenger operator put a quart of oil in their APU after every couple of sorties. When a Challenger APU is blowing oil which results in the bottom of the fuselage consistantly being covered in oil is not normal for any challenger. If you have ocassion look in their log release sheets you would find this is obviously the finest challenger in the bombardier fleet as nothing ever breaks, for you will not find any writeups. The company needs to return to Berlin and either get another loaner or get theirs repaired and reinstalled. The LVC valve is also on its last legs. The company is too cheap to fly this aircraft to berlin and get it fixed. You ignored the other statement of hail damage on the radome and windshields on their challenger 601, besides the main body of the original statement. By the way i am an A&P with an inspection authorization so i do not take back seats.