Is the AV-8B engine damage/fatigue implemented yet? Having VTOL issues sometimes!

[nickleijenhorst]

I'm asking this question because I had a few occasions where I could not hover in the AV-8B after flying a little mission. For example, I was practicing dogfighting with a friend, after 20 minutes or so, my fuel tank was almost empty, I had no other stores, so I wanted to try and land on a building. I had my water injection set to landing, all settings were correct, but my plane could just not hover, it was exceeding the exhaust temperature constantly, and water injection was not turning on. I had this 2 or 3 times that day, but during some other flights I had no issues with VTOL.

 

My only theory is, is that I damaged my engines during a few minutes of high throttle (because of the dogfighting) and this might be why I was getting such high engine temperatures.

 

Can anyone perhaps enlighten me on this? Do you have similar experiences?

[Revelation]

If you run your engine too hard you will damage it and its performance will be greatly reduced. You want to keep your JPT below 790. You also want to keep RPMs below 90%. The occasional high JPT or RPM for brief moments are usually okay.

[Charly_Owl]

I'm asking this question because I had a few occasions where I could not hover in the AV-8B after flying a little mission. For example, I was practicing dogfighting with a friend, after 20 minutes or so, my fuel tank was almost empty, I had no other stores, so I wanted to try and land on a building. I had my water injection set to landing, all settings were correct, but my plane could just not hover, it was exceeding the exhaust temperature constantly, and water injection was not turning on. I had this 2 or 3 times that day, but during some other flights I had no issues with VTOL.

 

My only theory is, is that I damaged my engines during a few minutes of high throttle (because of the dogfighting) and this might be why I was getting such high engine temperatures.

 

Can anyone perhaps enlighten me on this? Do you have similar experiences?

 

Check this: http://www.mudspike.com/chucks-guides-dcs-av-8b-harrier-ii/

 

Start reading from page 85. Pay special attention to the engine limits page: engine wear and damage by exceeding JPT or RPM is very real. You have to watch your engine settings like a hawk.

 

Page 86 shows you the ENG page, where there is an indication of how much time available you have while exceeding engine JPT limits. Pretty useful if you want to know if you should expect an engine performance degradation or not.

[Eldur]

As soon as you run above 102% RPM and/or 645 JPT for more than 90 seconds, the engine will degrade. And it doesn't matter if you run those 90 seconds at once or if you have breaks (like 30s exceeded, then 10-20 minutes 70%, again and again) in between. Those values mustn't be exceeded at any circumstances if you want to have an intact engine when you'll get back home.

Whether this is realistic or not... well, just think of sitting in one of these things in combat and emergency. Who would employ a weapon system that would practically wreck itself within the given physical limits? The real thing has a life cycle count that's shown on the engine page. The model we have in DCS should have 15,000 cylces IIRC. They degrade at certain rates per second depending of RPM and JPT. As soon as this counter hits 0, the mechanics will remove the engine and do some maintenance to ensure it's functionality, but it should not by any means produce less thrust. In DCS power loss occurs way before that in most cases. Also watch your JPT when sitting on the ground at idle thrust. In standard caucasus summer maps without any special weather settings it's 395. If it shows more, the engine output is reduced already. That's the best way to check if you need to take a new plane after a sortie instead of just R&Ring. Too bad repair doesn't fix the power loss since it doesn't seem to count as damage that enables the repair function.

[Repsol2k]

In the Engine DDI Display u also can check during flight which temperature u had as SORTIE JPT and then u also have a OT TIME which i think should show u how long u overtemped the engine.

 

 

Source: https://info.publicintelligence.net/AV-8B-000.pdf

[nickleijenhorst]

Thanks for the replies guys! This is exactly the information I needed ;)

[Nealius]

I'm starting to think the OT Time is currently unreliable. I had an OT Time of 100sec immediately after starting my taxi, with a Sortie JPT of 450~something.

[Eagle7907]

Is the AV-8B engine damage/fatigue implemented yet? Having VTOL issues sometimes!

 

Yeah, that time from what I understand counts down, not up. I like the aircraft, but the engine trend seems a bit off. I’ve done many missions where I’ve been persistent on keeping JPT below 640. JPT seems to be the most limiting. I’ve noticed there is still a degrade even after staying below 640 at all times barring any other factors like using the water injector switch for TO and LAND. I don’t know.

 

We really need that VREST calculator and other features functional to really know for sure what we are doing wrong or the aircraft is doing wrong. My opinion. Still is fun to fly though!

 

 

Sent from my iPhone using Tapatalk Pro

Edited March 5, 2018 by Eagle7907

[Sarge55]

Just fly it like a rental :joystick: and get a new one for the next mission... :D

[Nealius]

OT Time at spawn seems really random. I've seen 100sec, 132sec, -142sec (yes, negative), and 4sec.