Solar radiation and temperature cycling can have an effect on rotor blades relative to bonding agents and sealants. It is possible that solar radiation can raise the temperature of metallic structure well in excess of 160-degrees F. One manufacturer of elastomeric elements used in rotor systems indicated that the total exposure to temperatures in excess of 160-degrees F is limited to one hour over the design life of the elastomeric element. Exceeding this limit will cut the life expectancy (MTBF) by 50%.
In Iran we experienced air temperatures of 113-degrees F. The ground temperature was 168-degrees F and the temperature inside the cabins was 180-degrees which was the limit of our thermometer. It got so hot inside that it cooked the black boxes and some of the instruments.
