The developer of the 247D disappeared shortly after release of the product. He apparently has gone AWOL for long periods in the past as well so the suspicion is he has serious physical or mental health issues that randomly resurface out of the blue and take him out of action for long period.
On the plus side the release issues with the 247D were mainly minor (RH engine start up sounds missing, temp gauge calibrated incorrectly etc) and because the aircraft pretty much uses entirely custom code the 247D is relatively immune to Asobo update related issues.
It is quite possible to start and fly the aircraft reliably if you take the time to learn the idiosyncrasies, some hints:
- on startup you must pump fuel twice, initially to prime and a second time much later just before engaging starter
- never engage the starter when it first becomes available, keep cranking until you see the crank percentage on the “little ground crew card” reach at least 30% before engaging
- a complete cold engine when OAT has dropped to around freezing will not start in real life or in game. In real life the engine is preheated whereas in game you can either start on a runway and let it warm up before shutting down and moving to your park spot or change weather temporarily to be much warmer for your cold and dark start and then swap back to live weather
- the oil temp is broken, ignore it and use oil pressure readings to keep the engine in safe limits
- watch Ts and Ps like a hawk at all times. In the real aircraft the co-pilot doubled as a flight engineer who continuously monitored the engines for the entire flight
- too cold is as bad as too hot
- the time to correct a problem is when the needle starts to move, NOT after the temps and pressures are already out of range as that is too late, you have already likely lost most of your oil and damaged the engine
- even better, stay ahead of the engine. If you know you are about to level out and throttle back for example adjust cowl flaps etc beforehand
Remember, if all this seems to much just disable the realism and it will fly just like a default aircraft with the same indestructible engine the default planes have. No-one is forcing you to fly with realism enabled at all times. If you are doing a virtual airline mission or flying multiplayer or on vatsim or just want to sight see without obsessing over those big radials for the whole flight, there is nothing wrong with disabling failures for the event at hand.