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Old 12-10-2017, 07:25 PM   #71
3mta3
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Clues to what actually happens when these limits are exceeded are all through the real manual. No warning or cautions of sudden loss of thrust or JPT spikes. Read the real manual. Takeoff - throttle -Full , accelerating transition Throttle - full. Once wingborne reduce power and extinguish 15 sec light turn off water.

Even running out of water with the switch on seems like a benign issue.

Chapter 11 - Flight Charactistics is very good reading. No mention of sudden engine Meltdown.
Even the OT light - Land as soon as practical (not immediate) and use minimum power. Does not warn you won't make thrust and will crash on landing. There are no warning about JPT spikes and sudden loss of thrust.

I like reading manuals and learning new aircraft. It's like learning a new language. I'm passionate about this issue because I love this aircraft and just hope to make a positive contribution to making as realistic as possible. Thanks.
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Old 12-10-2017, 07:34 PM   #72
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Quote:
Originally Posted by 3mta3 View Post
Awesome post and spot on. Does anyone really think the engine is going to destroy itself seconds after reaching one of the limitation tables timed limits?

If so that limit has zero safety margin and why wouldn't the engine start degrading immediately? Why would it be fine at 9:59 and start a catastrophic meltdown at 10:01 that destroys its ability to make rated thrust in mere seconds? What changed in two seconds?

Anyway the same issue is being raised on the Belsimtek threads about the same type of scripted melting of the engine they have coded into the latest Huey update.

I think it strange that certain aircraft can't be made because a certain gov doesn't want them too. Others can't be made as we don't have access to documentation or everything is classified. So it seems they are striving for realism over guessing.

Except when it comes to engine operation. That we will guess about. Lacking any proof the engine melts at the table time limits - we hard code this destruction none the less.

Hell if your going to guess - guess me up a AH64 laser mavericks and a F16!

In this thread you have a Harrier mechanic saying they same thing I am. It will run at max power all day long. It will not damage the engine.

I fly Rolls Royce engines of a similar vintage to the Pegasus hundreds of hours a year. We are trained to use all the thrust if we need it. Yes. Push it to the stops. The engine control will protect the engine.

Anyway it's up to the developers to fix - I'd rather have a realistic Harrier/Pegasus simulation than a arcade level engine model scripted to self destruct. Sorry virtual pilots. You could turn of the JPTL or DECU if you really really want to destroy your engine.

Quote:
Originally Posted by 3mta3 View Post
Clues to what actually happens when these limits are exceeded are all through the real manual. No warning or cautions of sudden loss of thrust or JPT spikes. Read the real manual. Takeoff - throttle -Full , accelerating transition Throttle - full. Once wingborne reduce power and extinguish 15 sec light turn off water.

Even running out of water with the switch on seems like a benign issue.

Chapter 11 - Flight Charactistics is very good reading. No mention of sudden engine Meltdown.
Even the OT light - Land as soon as practical (not immediate) and use minimum power. Does not warn you won't make thrust and will crash on landing. There are no warning about JPT spikes and sudden loss of thrust.

I like reading manuals and learning new aircraft. It's like learning a new language. I'm passionate about this issue because I love this aircraft and just hope to make a positive contribution to making as realistic as possible. Thanks.


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Last edited by bart; 12-10-2017 at 07:36 PM.
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Old 12-12-2017, 11:31 PM   #73
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Quote:
Originally Posted by NeilWillis View Post
Aren't we all jumping the gun here?

To quote the developer's comments on the other forum he mentioned..

"Hi kayreez, I definitely can't rule out a bug since the powerplant modeling is pretty complex. However, keep in mind there are various engine "modes" and the DECU limits JPT and RPM based on those modes. For example with water switch on you get up to 116.8 RPM, however you are only allowed a very short amount of time to use that full RPM limit. Another example is COMBAT mode. You get a higher 111 RPM and associated JPT limit but your are in a regime that is a non-continuous engine limit at full power there. In addition, as you go faster the RPM limit value decreases. Even in non-combat, non-water (normal) engine power mode, you are able to get to 109 RPM above continuous max power of 102. Various RPM limits have different time limits before damage occurs that you can find in the flight manual. There is a safety factor put in above there but best to respect the time limits. So depending on what mode you are in your JPT and RPM limit and governing may differ.
There are a things are not modeled fully...DECU being off, MFS logic, JPT limiter switch off, Logic to disable JPT limiter when throttle pushed, and P3/Fuel Flow limiting behavior.
When you do get engine damage it is and can be subtle. When you go over RPM for too long you start to see an increase in JPT, a reduced capability to limit JPT, higher fuel flow, and less thrust. The longer you stay in the limit the more "damage" you are causing. The worst situation is having no water, but having the water switch on and going into max power at that setting.
Hope this helps and I'll review the code to make sure something else wonky isn't going on. "

Clearly this area is still being investigated, so these diatribes stating that this and that would or wouldn't happen is really beside the point. Until the devs say that they have checked, and the engine degradation model is working as advertised, your comments are frankly irrelevant.

The other side of this is the fact that if you go and cook an engine in real world operations, you'll be held to account for it. In DCS, there is no way to simulate a board of inquiry and grounding of a negligent pilot. How would you suggest we deal with engine damage if not by making it's performance degrade in subsequent flights?

No one is suggesting the current situation is how it will remain, so please try to keep things in perspective. I would also suggest that comparing a module made by a different developer is hardly relevant here either.
In truth, I think it is relevant. This is a bug forum, after all, and if it is not working as intended, then we are here to report it. That’s how this post actually started, with the assumption it is not working as intended.

I’ve never seen a pilot in front of a BOI for exceeding limits, because we don’t ever do it willy-nilly. If it is done, it is done for emergency or combat reasons, and the worst you’ll generally get is a ribbing from your buddies at the mess, especially if the reason you exceeded was due to a screw up elsewhere, like on approach to hover, and the only way to “save it” was to exceed limits.

If someone were to do it intentionally, when not required, it would be different. Still not a BOI, but some kind of disciplinary action or more likely remedial training would occur.
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