The work described in this paper utilizes dust ingestion experimental results obtained using three Pratt/Whitney F-100, two GE F-101, one Pratt/Whitney J-57, and three Pratt/Whitney TF-33 military engines and two different combustor rigs (one utilizing a sector of the Pratt/Whitney F-100 annular combustor and the other utilizing an Allison T-56 can combustor) to scale results so that these previous experiments can be used to approximate the response of more current aircraft engines to foreign particle ingestion. Modern engines experience a combination of compression system erosion and material deposition in the combustor and on the high-pressure turbine (HPT) inlet vanes (and rotor blade complications) whereas the older engines (P/W TF-33 and J-57) experienced primarily an erosion problem as a result of the lower turbine inlet temperatures (TIT). As part of the results presented in this paper, the scaled estimates of material accumulation and component degradation have been compared to documented in-flight ash encounters, specifically KLM Flight 867, British Airways Flight 009, Qantas Flight 370, and an NASA scientific research flight. The results of the study allow one to make estimates of the time to initial issues for the RR RB-211, the GE CF-6, the GE/Snecma CFM-56, and the P/W JT9-D engines encountering dust clouds of specific concentration. Current engine certification procedures do not require any specific test condition that would approach the engine issues described in this paper.