In order to study the mechanical properties of cotton-containing hail in the test standard for transparent enclosures of aviation aircrafts (ASTM-F320-2010) and pure ice hail in aero-engine hail suction test

the hail mold was designed and manufactured. Based on natural hail freezing temperature

the hails were made in different temperatures and compressed in a universal testing machine. The quasi-static compressive strength data and the relationship between the freezing temperature and the mechanical properties were obtained. Results showed that the average compressive strength of pure ice hail increased slightly about 2 MPa when the freezing temperature changed from -10 ℃ to -30 ℃; meanwhile the average maximum compressive strength of cotton-containing hail did not show significant change within this temperature range; the temperature dropped to -40 ℃

the average compressive strength of both hail increased significantly

and pure ice hails were more sensitive to temperature

and the rise was more significant. It is proposed that the test hail produced at -40 ℃ can be added to the consideration of the airworthiness test of future commercial aviation engines and large civil aircraft in China.