One failure was caused by an assembly problem, which led to inspections of all other engines then in service. During the spring and summer of 2013, GE learned of four 747-8F freighters that suffered icing in their engines at altitudes of 40,000 feet and above. The most serious incident involved an AirBridgeCargo freighter; on July 31, while at an altitude of 41,000 feet over China, the flight crew noted two engines surging while a third lost substantial power. The pilots were able to land the plane safely but the engines were found to have sustained damage. Among the possible factors cited was "'unique convective weather systems' such as unusually large thunderstorms reaching high altitudes." Boeing is working with GE on software solutions to the problem. Altitude was restricted until GE changed the software to detect the high-altitude ice crystals and open bleed air valve doors to eject them before they enter the core. In March 2014, a GEnx-powered Boeing 787 had its first in-flight shut down in operation when a JAL flight had to divert to Honolulu after an oil pressure alert, bringing its in-flight shut down rate to 1 per 1/0.0036round0,000 hours. In January 2016 a Japan Airlines 787 had an inflight shutdown after flying through icing conditions, caused by ice formed on fan blades and ingested: the blades moved forward slightly and rubbed on the abradable seal in the casing. In March 2016, the US FAA ordered emergency fixes on the GEnx-1B PIP2. The airworthiness directive affects 43 Boeing 787 Dreamliners in the US. Abradable material in the casing in front of the fan blades was ground to keep them from rubbing when ingesting ice or debris on 330 GEnx PIP-2. In early 2018, of 1277 orders for the B787, 681 selected the GEnx (681/1277*100round1%), 420 the Rolls-Royce Trent 1000 (420/1277*100round1%) and 176 were undecided (176/1277*100round1%). The 2,000th GEnx was delivered by November 2019, 15 years after the engine launch, as it logged 4.5 million flight cycles and 26 million hours among 60 operators. The GEnx is derived from the GE90 with a fan diameter of for the 787 and for the 747-8. To reduce weight, it features 18 composite fan blades, a composite fan case and titanium aluminide stage 6 and 7 low-pressure turbine blades.