12lb boost for more than 5 mins
 

I beg to differ:


https://lh4.googleusercontent.com/-d..._5min%252B.jpg

from:
http://www.wwiiaircraftperformance.o...on-1july40.pdf

In real life pilots would risk all for a kill or to stay alive.

Seadog no matter how many charts you produce the fact remains that there WAS a limit imposed on the use of +12lbs boost. Even the charts you produce sate that use of +12lbs boost MAY shorten engine life. The fact that an engineer was to assess for potential damage after +12lbs boost was used is a bloody good indicator that potential damage could occur. Not definately damaged but MAYBE damaged, after eventual inspection it may be found that engine is perfect but it didn't mean the potential for damage wasn't there. It doesn't matter if an inspection was mandatory or recommended or even to be contemplated, the fact remains that use of +12lbs boost EVEN FOR A FEW SECONDS, DID require the pilot to make a note in the flight log. It was then up to the engineer to determine if the engine needed overhauled based on the fact that +12 boost INCREASED THE RISK OF DAMAGE. He would not be under orders to do this if there was not some good bloody reason for it.

Not one single person replying to your posts is saying a Merlin will break as soon as 5 minutes at +12lbs boost has passed. We are saying the potential for damage was increased the longer it was used. If you don't want to damage your Merlin then turn off CEM. The rest of us will keep it as close to real as possible.

P/O Dutton chose to ignore the 5 min limit. I doubt he was court martialed or penalized in anyway for doing so and his engine may have been a candidate for inspection (as he combined steep dives with overboost), but I doubt he lost any sleep over that.

There is a poster who is claiming that any use of 12lb/3000rpm will result in grounding till a mandatory inspection is done, and I'm glad to see that you disagree with this.

Again, this is exactly what I've been saying. Keep your gauges in the black and 5min+ at 12lb/3000rpm results in increased but still minimal ("low probability") risk, but it is completely ahistorical to claim that pilots did not use 12lb/3000rpm repeatedly or for more than 5 mins as the situation warranted. We know that in the real battle pilots weighed the risks and then "pulled the plug" and some were willing to keep it pulled for more than 5 mins and the game should allow this even with CEM, because that's the way things were. RAFFC went to 100 octane fuel precisely because it allowed the use of 12lb boost and this gave RAFFC a vital edge in performance when it was needed, and some even state that this was the difference between defeat and victory:

Why bother with a game that goes to great lengths to accurately model aircraft performance, but then takes away the winning edge that 100 octane fuel (despite all the sweat and cost that RAFFC went to make sure that they could take advantage of it) provided during the battle?

The way i presented the example caused your confusion. It is not one thing but two seperate issues. The Hartzell bulletin has nothing to do with take off rating of the engine. It just illustrates how seemly minor changes can have catastrophic effects.

A Lycoming O-360 is take off rated and you don't use it except for take off. That is an engine limitation.

The Hartzell bulletin is talking about specific O-360A1A's equipped with a specific hub/blade combination AND using Lightspeed's Engineering electronic ignition.

Your next point, of course I meant inches of mercury. It does not matter though...you don't exceed the 28 on the EFIS!! :)

http://img847.imageshack.us/img847/3766/efis.jpg


have to ask who cares and what is point of this portion of your reply? Are you trying to educate me on TBO determination? It is a fact that sometimes TBO are very arbitrary and not based on any real engineering at all. Why? The company does not spend the money or the time or have enough data.

Many times manufacturer's set them very low at first and then raise them as field experience is gained. Rotax 912 is a modern example.

Everyone is expecting the Centurion Diesels to see a TBO raise too. They did the same thing.

http://www.centurion-engines.com/typ...x.php?id=2&L=1

What is important and seems to get covered up in your reply Viper is the following:

Pilot's fly airplanes IAW the Operating Instructions published by the manufacturer.

End of message.

Anything else is baloney and thinking like a gamer, not a pilot.

I would say this baloney in all my real world experience both in college, PIC, and in maintenance of aircraft. I don't know of any RL pilots who condone exceeding published limits at all. It is not the engineers life on the line.

I certainly don't know any licensed A&P's who think that way or do not follow publications. That is good way to kill somebody, lose your rating, and even go to prison. There are shady folks in aviation. One owner and he FBO are in the process of suing one such individual right now. That is if the sheriff does not get to him first.

In reality, not following published procedures can and will kill you. The FAA statistics show this quite nicely.

The reality is only a tiny fraction of the community knowingly violate procedures. Most understand the importance and the consequences of not following it.

I knew this pilot. He was VERY professional and flew his aircraft by the numbers. Nothing he did in an airplane was unplanned or "seat of your pants".

He died because he did not change his altimeter setting. He made a simple mistake and did not follow procedure to monitor ATIS and adjust the altimeter accordingly. He entered a loop and end up with CFIT.

http://www.youtube.com/watch?v=rLDiPEgysYI

You should know the old axiom, "There are Old Pilots and there are Bold Pilots but there are not any Old and Bold Pilots!"

It got to be a axiom because it spells out the truth.

Your reality is far different from my experiences. I have to take your comments about the 152's and flying outside of CG and everything else with a grain of salt or at least it does not apply to General Aviation in the United States.

Of course there are almost 20,000 airports to land at in the United States. I can find a convenient airport at almost any destination I choose. In the EU, you have just over 2500 airports to land at.....

It is impossible to compare the General Aviation community as GA is a completely different animal in the EU.

Perhaps when the EU GA community matures, it can begin to keep statistics to help make the pilot community safer. Maybe then your civil pilot population will become more educated and not act so recklessly.

http://www.epats.eu/Files/Deliverabl...PADBase-V1.pdf

Continental did that because they did not test or design the engine for any higher rating. When the O-520 first came out, the crankcase was too light even at maximum continuous and there were many failures as a result. Subsequently Conti went to steel on steel for their rings and now very few of them make it to TBO without a top end.

In short, the engine has had too troubles at it's current rating to even think about a manifold pressure increase.

It is also not tolerant at all of improper procedures. Feel free to invest your money in an O-520 and then not follow the book. :p

If the installation has plenty of power, there is no need for a Take Off rating. The Lycoming O-360 has been adopted to so many installation that including many heavy twins. That little 180 hp engine pulls some weighty airplanes around now. The O-360 series is a close to bullet proof as you can get in a light aircraft engine. I wouldn't trade mine for all the tea in china.

I pulled the plug is an expression not a rating. You don't know what throttle setting the pilot used or for how long.

Mate, fly like you want to, i'm not here to tell you how to enjoy the sim. I just don't want to do things the same way you do, so i'm asking for a difficulty/realism option that allows us both to get what we want by deciding if we will toggle it on or off.

Again, this is not a thread about what, it's a thread about how: how do we impose some kind of limit on the gamer-pilot's ability to exceed published limits in a way that's not totally artificial and detracting from immersion, while at the same time giving a realistic amount of inconvenience for those of us who choose to overstep the boundaries.

I'm not asking for an artificial limit the likes of "5 minutes plus 1 second of emergency power, sorry your engine's toast". It's exactly what i disliked most about the IL2 engine management in the previous series, with it's resettable overheat timer of 5 minutes: run around at full power, overheat message comes up and you now have 5 minutes before damage occurs, chop throttle and open rads to rapidly cool the engine, the 5 minute timer is reset without damage to the engine, rinse and repeat.

It's too cut and dry, too artificial, completely unrealistic and since it's 100% predictable behaviour it allows us to game the game.

I'm just saying there needs to be a drawback that attempts to simulate what actually happened: it was perfectly possible to exceed the limits with no consequence for a lot of times, then have it bite the pilot in the behind one time out of many.

A good way to do this is Kurfurst's suggestion, because it provides some sort of "continuity of airframe" between sorties. It won't magically prevent me from running +12lbs all day long, it will just make it easier for my engine to suffer damage in subsequent sorties if i do. Throw in a 5% randomization for the relevant parameters and we got a good solution: i can exceed the limits but there's no cut and dry consequence every time, instead there's uncertainty and this enhances gameplay through a heightened sense of thrill and the need for improved tactics that will mitigate the risk of having to engage WEP.

Roll it into a nice option in the realism settings, let server admins chose an accelerated wear and tear model to give us a condensed snapshot of possible engine issues without having to fly a thousand sorties before something interesting happens and we're good to go. If people don't want to use it they join a different server and everyone's happy again.

So please, can we get back on the topic of how to achieve something like this?

The author might know about petroleum but he certainly does not know about engines or was not aware of the Germans direct fuel injection.

I don't see what the point is other than a book during the war offers a glimpse into the thinking of the time.

I suppose we could take the eugenics theories of the day as fact too??

What? Who the hell mentioned court martials? Is English not your first language?

I don't entirely agree with his stance, nor do I agree with yours that an engineer could just shrug his shoulders and say don't worry about it. ALL engines regardless of what boost was used were inspected at the very least at the end of the days flying and preferably at the end of each flight timing permitted. Using +12lbs boost was by your own admission enough to warrant an inspection at the earliest possible convenience. The earliest possible convenience would be that very evening in the worst case scenario. When doing the routine maintenance at the end of each evening the engineer consults the logbooks of all aircraft flown that day. He sees that this particular aircraft has an entry that the pilot used +12lbs boost. He knows from his orders (Straight from Dowding) that it is SOP to do a more thorough check for wear and tear. Do you now dispute this?

We know it was used, we also know it was used for longer than 5 minutes per flight on occassions. Everyone here actually agrees that it could be used and that there was an increased risk. Why do you keep this up, here it is again in big writing. Sorry for shouting but this point is very important.

WE ALL AGREE THAT USING +12LBS BOOST COULD BE AND WAS USED LONGER THAN 5 MINUTES BUT IT WAS NOT A RISK FREE ACTION.

Ah the bias starts to show. What you want is some "click here = win" button for the RAF? +12lbs boost gave a boost in performance, it was not a massive advantage that guaranteed victory. Even with +12lbs boost the difference in performance between a Spitfire, 109E and even a Hurricane were close enough that surprise, tactics and pilot skill was the determining factor in the outcome of any engagement.

I have a funny picture for Mr. Kacys-whatever, who seems to think 100 octane was only on the British side. Note the funny triangle behind the cocpit, and the numbers written on that. It shows what kind of fuel the plane is to be filled up with.

http://www.kurfurst.org/Engine/DB60x...t1940b_DFC.jpg