On April 30, 1997, about 0915 eastern daylight time, a Grumman American G-1159, N75CC, registered to Crown Credit Company Ltd. and operated by Crown Equipment Corporation, while on a 14 CFR Part 91 corporate flight, experienced a nose landing gear collapse upon landing at Kendall-Tamiami Airport, Miami, Florida. Visual meteorological conditions prevailed and an instrument flight rules flight plan was filed. The aircraft sustained substantial damage and the airline transport pilot and airline transport-rated copilot reported no injuries. The flight originated from Neil Armstrong Airport, Wapakoneta, Ohio, about 2 hours 15 minutes before the accident. The pilot reported that the nose landing gear collapsed while on the landing roll following thrust reverser application. The nose of the aircraft pitched down and impacted the runway. Both flightcrew members stated to the FAA that they observed landing gear down and locked visual indications following the approach and final checklist completion. Gulfstream Aerospace examination of the landing gear system stated, "Based on the investigation and available evidence it is considered that the incident was primarily precipitated by; 1) an out of rig condition of the 1159H20262 Nose Gear Retract Actuator and/or the 10-321934-1 Micro-switch roller guard, and 2) seal failure within the 1159H20262 Nose Gear Retract Actuator, 3) findings of what was deemed to be excessive friction within 1159LM30667 Downlock "Over-Center" Link assembly would not have been sufficient to cause the event by itself. It is considered that this secondary condition could have provided additional causal effect. Gulfstream Aerospace concluded that the investigation into the cause of the landing incident that occurred on Gulfstream G1159 S/N 117 has not revealed any one specific cause for the incident. (See extract from Report No. 1159SER97-198, Date: 27 July, 1997)