The fastgrowing Unmanned Aircraft scene accounts for an increasing number of new users who should have access to the airspace as any other full-fledged airspace user. Simultaneously, in order to maintain the currently achieved levels of performance in ATM, Unmanned Vehicles ought to be compliant with existingaviation regulations as well as with specially tailored requirements and standards. A subset of those requirements should address flight performance, which can be very diverse among Unmanned Aircraft. At the present time, there is a lack of research on this particular aspect of Unmanned Aircraft Systems integration in ATM, as solutions to other type of technological and regulatory issues are being pursued. By means of fasttime simulations of non-segregated RPAS operations in a given airspace, this project studies how Unmanned Operations impact ATM system performance in terms of Safety, Efficiency and Capacity and makes a suggestion on where the line could be drawn regarding admissible RPAS Flight Performance for TMA.