A couple of interesting things to read in the report about hail.
"Another method to quantify the density of hail encountered is using the GPWS phenomena. It is recognized from the CVR and DFDR that the radio altimeter picks up high density precipitation as false terrain closure and triggers the GPWS to give terrain warning. It is known that GPWS could give false terrain warning when its radio altimeter signal is reflected by heavy precipitation. However, this method could only be used as an indication of the density of the rain/hail."
"It is known that the fuel flow is affected by the amount of hail/water ingested into the engine."
" The presence of water in the core engines will increase the fuel required to keep engine N1 (fan rotation) at certain throttle setting."
"At entering the turbulence, the recording indicates water ingestion by the engines as the fuel flow increased from 600 lbs/h to as high as 770 lbs/h, before it went down to 510 lbs/h at the end of the recording."
"The engine model showed that the estimated 150 lbs/h fuel hike indicates that a 3.5% water/air ratio existed in the core of the engine, which is equivalent to over 5 g/m3 hail content in the atmosphere. The standard for the highest rain could not result in a 3.5% of water/air ratio. Therefore, hail must have been present in the air at the time."
I don't know why fuel flow is affected by water/hail ingestion. Anybody?