From page 19 of the above link:
5.5 Conclusions
A mid-air collision between a commercial airliner and an UAV is most likely to result in the ingestion of the UAV into one of the engines (3 out of 4 events). Reduction or loss of engine thrust with potential debris throw must be assumed. From past experience, engine loss and uncontained engine failure can be regarded as non-catastrophic events.
A mid-air collision at impact velocities above 200kts is predicted to result in airframe skin penetration, independent of the UAV size. The consequences of such penetration will depend on the impact location.
During the landing approach (at or below VFE=160—180kts), a collision with a large UAV is likely to lead to skin and windshield penetration of a commercial airliner.
A general aviation windscreen will be penetrated at cruise velocity. During approach (at or below VFE=87kts), a large UAV will penetrate the windscreen; a small UAV is likely to be deflected without penetration.
No experimental data exist to validate the predictions of windscreen penetration by a solid object. It is recommended to commission an experimental study, impacting actual UAV parts into common windscreen materials. Until then, the results presented in this report should be treated as rough estimates.