A lot of this is down to the relationship between the operator and the local regulatory authority. If the local office is happy with the crews experience on type and that the company is well established then they are more likely to permit the operator to develop AFM procedures to allow the crews to perform a minor structural inspections, provided that the impact point/s can be positively identified, there is no visible structural damage and the bird remains are relatively intact. The impact points also have to be accessible. Crew inspections on impact points on the empennage, engines and upper fuselage would not be allowed for obvious reasons
If there are any doubts as to the impact regions then i'm afraid that engineering certification is required.