Nice skidmark boost, loud and fast.  Arcin' into t' wind, still nose up at ejection.  Shock cord broke a couple o' feet above t' lip o' t' body tube.  Rcoket body came in flat, nose cone recovered under chute.  One fin cracked almost through, just above t' fillet line.  Nay sure if it's repairable.  Flown with a Jolly Logic Altimeter One for data, can't really explain t' low altitude versus t' sim prediction.  This was t' 19th flight o' this rocket, thar were some frayed spots on t' shock cord, but nothin' that would compromise flat woven kevlar?