Blaming a “severe and unexpected” reduction in Honeywell TFE731 shop visits, StandardAero announced on 9 January that it will close a business aviation repair station at Los Angeles International airport by the end of March.

The Arizona-based maintenance, repair and overhaul (MRO) company also says the facility’s closure comes after multiple attempts to secure a long-term lease for the Los Angeles repair station failed.

In response to questions from FlightGlobal, StandardAero says it has seen a 40% decline in MRO events for the TFE731 engine over since 2015, which the firm attributes to an aging population of aircraft powered by the engine.

“We believe declining hull values on older aircraft make the maintenance events proportionally infeasible, because of cost,” StandardAero says.

Honeywell has delivered more than 11,000 units in the family of geared TFE731 engines since introducing the type 46 years ago. The type quickly proved popular among second- and third-generation business jets, including with the Dassault Falcon 50 and 900, Gulfstream G100 and Cessna Citation III and Bombardier Learjet 31. It remains in production on several new models, including the Textron Aviation Scorpion and Learjet 75.

Honeywell does not dispute the decline in shop visits for the TFE731, but attributes the trend to product improvements that lengthens the intervals between required maintenance actions.

“Honeywell is committed to continuous interval extension and this is contributing to reduced events worldwide,” Honeywell says.

But owners of older business jets face the prospect of mandatory upgrades, such as installing an ADS-B-equipped navigation system, by 2020. For the oldest TFE731-powered aircraft, declining residual values often don’t justify the cost of investing in such an upgrade at the same time as a scheduled engine overhaul, according to FlightGlobal’s Ascend consultancy.