Thin air-roger the restart with normal parameters, and don't forget the failed-engine oil pressure. Each time we start the old Pratt & Whitney JT8D engines, after N2 rotation the next requirement is an increase in oil pressure or we stop the start very soon, and never use the 'low oil press' light as back-up, at least during a start. If we are a long way from a suitable airport, this will motivate us to consider a restart: it gives us, even at idle, a little better pressurization, plus electrical system and hydraulic back-up, but watch the crossfeed and fuel balance, and always use anti-ice systems when in cold clouds (i.e. +10 C down to -20 C etc) with continuous ignition. Will your APU even start if cold-soaked? Just don't switch anything off or on without total crew coordination and when necessary, per checklist and SOPs, especially in abnormal situations. A fairly minor problem can go bad very fast, if you rush onto things.
Two of our crews recently shutdown such engines (we only have two engines) while in cruise flight, and one of the FOs involved, and a mechanic (engineer) both told me that the oil temp. gauges had yellow arcs on the wrong temperatures!! They had both exceeded 15 minutes in the indicated yellow arc, but how could the temp. gauges have been painted wrong?? We have lots of intermixed engine types, -9/-15 etc.
