The FAA has issued a special airworthiness bulletin about windshield failures that have occurred on Gulfstream III, IV/IV-SP/G450, V/G550, and G650/650ER twinjets over the past six years. According to the bulletin, the FAA said it and Gulfstream are aware of at least 20 windshield failures since 2013 that resulted in arcing, cracking, smoke, and/or small fires.
A new windshield with an improved heater terminal block has been designed and is now manufactured by Gulfstream, which in most cases can be used as a replacement because the same windshields are common to multiple models of Gulfstreams, according to the bulletin.
Pilots are advised to assume a structural windshield ply is affected in the event of a windshield cracking event. Further, it recommends that in such an event, pilots follow the appropriate airplane flight manual emergency procedure or abnormal procedure, which includes pulling the associated windshield heat circuit breaker.
Maintenance crews also are advised when replacing the windshield of affected aircraft under normal conditions to replace it with the improved windshield, which has upgraded/redesigned terminal block part numbers.