On 15 March 2007, the pilot and co-pilot operated inbound flight SA6583 from O.R. Tambo International Airport (FAJS) to Durban International Airport (FADN) and arrived at FADN at 1915Z. According to the pilot, they used the aircraft’s weather radar to help them avoid adverse weather during the descent to FADN. The radar operated satisfactorily during the descent and approach for landing. After landing at FADN, the aircraft was turned around in 45 minutes for the return flight SA6582 to FAJS. The crew taxied to runway 06, the active runway at the time, but just prior to take-off, ATC advised the pilot that a Boeing B737-800 had had to execute a go-round due to a tailwind component with the surface wind at 240/15kt. The pilot and co-pilot repositioned the aircraft and prepared to take off from runway 24. The fire crew reported that there was no standing water on the runway, although it was raining quite heavily. From their position at the threshold of runway 24, the pilot carefully scanned the area with the weather radar but this showed no returns. The Boeing B737-800 which approached from that direction supported the radar information that it was safe for take-off. After the co-pilot (pilot-flying) concurred with the pilot (pilot non-flying) that it was safe for take-off, they obtained take-off clearance from the ATC. Maximum thrust on both engines was selected and the aircraft climbed away steeply. As there were no radar returns indicated ahead or to the right of the aircraft, the co-pilot commenced the right-hand turn towards the Greytown VOR (GYV) at an IAS of 280 kts. The pilot and co-pilot individually checked that the weather radar settings were correct and adjusted the tilt, gain, range and stab settings but no green, yellow or red returns appeared on the radar. At 9 000ft AMSL, light hail was encountered and the crew selected the ‘Engine Anti-Ice’? as well as the ‘Low Ignition’? switches to the ON position. The hail seemed to lessen but shortly thereafter, it became much worse with the radar screen still remaining completely clear. The co-pilot then made a 30 degree turn to the right and the captain asked ATC if they had any weather returns on their radar, but due to the noise of the hail on the fuselage, ATC was unable to hear the transmission clearly. Some moderate turbulence was experienced which became severe in short bursts. At this stage, the captain and co-pilot had to communicate using hand signals. The captain scanned the radar in an attempt to find a clear path through the clouds and also monitored the co-pilot’s flying. All engine parameters remained normal. The aircraft continued climbing in a north-easterly direction and at 15 000 ft AMSL, cleared the clouds and continued to its destination without further incident. Probable Cause The aircraft encountered severe hail during climb-out after taking off from Durban International Airport. The aircraft’s weather radar did not show any hail on the radar screen.