Story ID: 
Gulfstream addresses EVS overhaul concerns
By: Stephen Pope
Caption: Overhauling the cryogenically cooled enhanced-vision system (EVS) installed in many newer Gulfstreams will set an operator back around $30,000–a cost many 
Word Count: 699
Overhauling the cryogenically cooled enhanced-vision system (EVS) installed in many newer Gulfstreams will set an operator back around $30,000–a cost many operators apparently didn’t realize they would be incurring. What’s worse, the overhaul interval for the delicate Kollsman infrared camera system spans just three years/1,500 hours. But this story, it would seem, has a happy ending.
Responding to concerns by operators, Gulfstream and Kollsman have made an important change to the mandatory EVS overhaul language in the maintenance manual by adding an option for on-condition maintenance requiring only a periodic inspection of the camera system. As long as the image quality remains satisfactory, operators can continue flying with the original EVS indefinitely. For buyers of new Gulfstreams carrying the EVS II system the news is even better: Gulfstream has eliminated the overhaul recommendations in favor of periodic inspections of the system’s sealed housing.
Not surprisingly, many Gulfstream operators who were told they had to comply with the mandatory EVS overhaul stipulation to avoid voiding the warranty were happy to learn they can now opt to make it an on-condition inspection item instead. The overhaul required removal and replacement of the EVS detector and cryogenic cooling engine with remanufactured components–which are complicated and expensive–but the original requirement appears to have been borne out of an abundance of caution, Gulfstream now says.

EVS Exceeding Reliability Goal
“We recognized that some customers were seeing the cost of the overhaul as being higher than they’d like to pay,” said Dave Sherrington, avionics entry-into-service program manager for Gulfstream, “so we looked at how EVS was actually performing in service and decided it would be acceptable to leave the camera in the airplane as long as it was performing well.”
A number of operators complained directly to Gulfstream and on online message boards about the overhaul’s steep cost. Despite the fact that this requirement was spelled out quite clearly in the packet of papers that came with every new Gulfstream that rolled out of the factory carrying the original EVS I system, few owners seemed to realize the overhaul would cost tens of thousands of dollars. Based on a review of online discussion threads, the news came as something of a shock to chief pilots and flight department managers responsible for explaining the overhaul bill to corporate bean counters– particularly those who had already paid around $500,000 to add EVS to their airplanes’ options list.   
Gulfstream has since made changes to the maintenance manual that let operators choose whether to overhaul the EVS after three years/1,500 hours and pay the $30,000 or leave it alone. If they choose not to overhaul the camera and it fails after three years but before the end of its six-year warranty period, the camera must go back to Kollsman for the overhaul at the original cost. Choosing this option does not void the original warranty as long as the overhaul is performed at the time the failure occurs, Sherrington said. “This was a significant concession that a lot of operators appreciated,” he said. “Frankly, it is a complicated process, but because of the costs involved with the sensors and other high-tech equipment it was the best that could be done.”
Sherrington said he didn’t have specific figures available about the percentage of Gulfstream operators who have opted to forego EVS overhauls, but said it was a relatively high number. “It’s a pretty well trodden route, and not a small minority,” he said. Fleet data has proved the reliability of EVS and shown that the Kollsman system can last far longer than originally thought. “EVS I is meeting several times its reliability goal,” he said.
Meanwhile, the improved sensor used in the EVS II system includes a sealed nitrogen-inerted housing that has enabled Kollsman to offer a five-year warranty without any overhaul requirement. EVS II and HUD are standard equipment on the G450 and G550 and optional on the G350 and G500. Cost when purchased as an option is around $1 million for the HUD/EVS II combination.