Abstract Through application of the Finite Element Analysis method, the damage tolerant capacity of the semi-monocoque fuselage structure of a typical civil aircraft is assessed in this investigation. An analysis of the response of an unflawed variant of the structure identifies bays in the semi-monocoque frame as areas susceptible to crack initiation. The through-thickness and semi- elliptical crack types are considered in the damage tolerant assessment. In order to validate the accuracy of the FEA method in evaluating the state of stress of both crack types in the presence of loading, two benchmark problems are simulated. In both cases, close agreement between computed results and analytical solutions is observed. The effect of both crack types on the structural integrity of the pressurised fuselage structure is then investigated. Under a conservative analysis of results, it is concluded that a safety factor of 4 exists in the avoidance of fracture of a semi-elliptical crack of any dimensions. The growth of the semi-elliptical crack under internal pressure is investigated and it is strongly indicated that a through-thickness crack will form, and the fuselage will meet the Leak-Before-Break criterion. Where a through-thickness crack of length 0.1m exists, this same conservative safety factor against fracture is seen to yield a value of 10. The accurate evaluation of through-thickness cracks of greater lengths is identified as an area of future work, due to the identified reliance of results on the development of a problem specific crack tip refinement.