An aircraft engine system comprising: a turbofan engine ; a lubricating oil system ; a cooling circuit having a bleed air boosted engine oil cooler assembly and heat exchangers connected to provide oil cooling to supplement the bleed air boosted engine oil cooler assembly ; an oil pump connected to pump oil from the lubricating oil system through the cooling circuit to the turbofan engine , wherein the bleed air boosted engine oil cooler assembly comprises: a liquid/air heat exchanger, LAHEX, connected to an oil inlet conduit and receiving fan air from a high bypass fan of the turbofan engine as a cooling working fluid, said LAHEX connected to an oil exit conduit , and an ejector downstream of the LAHEX receiving bleed air from a compressor section of the turbofan engine , said ejector drawing the fan air through the LAHEX ; and wherein the heat exchangers comprise a main fuel/oil liquid/liquid heat exchanger, LLHEX, connected to provide oil cooling employing fuel, pumped from aircraft fuel tanks through feed lines for use by engine combustors , as a liquid cooling working fluid through a first feed line receiving fuel from a fuel pump supplying the fuel to a combustor supply inlet , the main fuel/oil LLHEX connected to the oil exit conduit ; and a servo fuel heater LLHEX connected to bypass fuel from a second stage fuel pump through a servo loop , said servo fuel heater LLHEX connected to the oil inlet conduit . a turbofan engine ; a lubricating oil system ; a cooling circuit having a bleed air boosted engine oil cooler assembly and heat exchangers connected to provide oil cooling to supplement the bleed air boosted engine oil cooler assembly ; an oil pump connected to pump oil from the lubricating oil system through the cooling circuit to the turbofan engine , wherein the bleed air boosted engine oil cooler assembly comprises: a liquid/air heat exchanger, LAHEX, connected to an oil inlet conduit and receiving fan air from a high bypass fan of the turbofan engine as a cooling working fluid, said LAHEX connected to an oil exit conduit , and an ejector downstream of the LAHEX receiving bleed air from a compressor section of the turbofan engine , said ejector drawing the fan air through the LAHEX ; and a liquid/air heat exchanger, LAHEX, connected to an oil inlet conduit and receiving fan air from a high bypass fan of the turbofan engine as a cooling working fluid, said LAHEX connected to an oil exit conduit , and an ejector downstream of the LAHEX receiving bleed air from a compressor section of the turbofan engine , said ejector drawing the fan air through the LAHEX ; and wherein the heat exchangers comprise a main fuel/oil liquid/liquid heat exchanger, LLHEX, connected to provide oil cooling employing fuel, pumped from aircraft fuel tanks through feed lines for use by engine combustors , as a liquid cooling working fluid through a first feed line receiving fuel from a fuel pump supplying the fuel to a combustor supply inlet , the main fuel/oil LLHEX connected to the oil exit conduit ; and a servo fuel heater LLHEX connected to bypass fuel from a second stage fuel pump through a servo loop , said servo fuel heater LLHEX connected to the oil inlet conduit . a main fuel/oil liquid/liquid heat exchanger, LLHEX, connected to provide oil cooling employing fuel, pumped from aircraft fuel tanks through feed lines for use by engine combustors , as a liquid cooling working fluid through a first feed line receiving fuel from a fuel pump supplying the fuel to a combustor supply inlet , the main fuel/oil LLHEX connected to the oil exit conduit ; and a servo fuel heater LLHEX connected to bypass fuel from a second stage fuel pump through a servo loop , said servo fuel heater LLHEX connected to the oil inlet conduit . <EOS>