andy151 Posted September 20, 2021 Share Posted September 20, 2021 Have just tried out my new mosquito and was less than surprised at the engine cutting under any negative g. This was a problem with with early merlins and was partially solved with a controlling calibrated orifice and later by bend ix and Rolls Royce pressure carburettors so it simply should not happen Having set up a several simple circuits of Manston in the P47 I was amazed to see constant main bearing failures after throttling back for a few seconds due to a slightly high approach and side slipping the aircraft. I am aware the R-2800 can sustain damage due to the airflow driving the propeller due to the position of the main bearing oil feed , and indeed the airliner crews would handle the throttles to avoid this as the units carried around a 2000 hour life or more . A world war two fighter engine would not get anywhere near this figure and the power unit would almost certainly be removed long before any bearing wear became apparent . As an aircraft propulsion engineer of over 40 years experience it would appears to me that your programmers are taking the manufacturers engine guiding figures as the point of almost immediate failure when they are mostly a guide that the danger of wear may start to lower engine life , If the R-2800 had displayed any where near this level of unreliability would the American military have been able to fit versions in so many of its fighter aircraft which in combat will almost certainly face violent throttle handling and misuse. I feel there is no need to dig too deep into technical details but if anybody is interested I recommend Graham Whites book R-2800 Pratt & Whitney's Dependable Masterpiece which details the development problems and engine versions in minute detail it contains 718 pages however I feel the programmers only need to read one word on the cover Dependable the DCS P47 is a wonderful simulation including the engines starting and handling but it seem to me that it is let down by a massively over simulation of bearing failure. Untitled 1.odt Link to comment Share on other sites More sharing options...
ARM505 Posted September 20, 2021 Share Posted September 20, 2021 This has been a topic that pops up repeatedly - and if I can summarise my understanding of the situation, it's that as sim pilots, we are given a brand new aircraft every time - this would mean that (as you say) rough handling, or prolonged abuse over the published limits would probably not (in reality) kill the engine. BUT, this (in the simulator) would result in everybody thrashing their engines ALL the time, to extract maximum advantage (this is a *combat* simulator after all), resulting in unrealistic performance and fights in general. Since aircraft histories are also not tracked, this is yet more incentive (or disincentive) to not treat the engines carefully in the sim, along with the fact that we don't have any 'skin in the game' as it were, and death (or at least a cold dunking in the English Channel) has no real meaning. Thus, engine limitations are intepreted more strictly than the more generous tolerances real life would probably (probably!) allow. It's a debatable point, and has been many times already. Link to comment Share on other sites More sharing options...
ED Team NineLine Posted September 20, 2021 ED Team Share Posted September 20, 2021 3 hours ago, andy151 said: enginesUntitled 1.odt The negative G cut out is being tweaked but it is not the same as what you are referencing. It is indeed a real thing, and if you are gentle on the controls as you should be, its hardly an issue. The P-47 bearing issue is already reported. Forum Rules • My YouTube • My Discord - NineLine#0440• **How to Report a Bug** Link to comment Share on other sites More sharing options...
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