Huey Engine Failure?

@ shagrat

Maybe you only fly slick around airport, but I would like to have to proper engine power and fix of the EGT issue - matching real life performance :) This bird went into Vietnam under horrible conditions, a lot of times overloaded during missions etc. And from what I know, the Huey is a very robust and reliable machine. It has to take some serious work to totally shred the engines...

Im very happy that BST got around to implement the overheating. But it needs some additional work and they know it. Huey in DCS is underpowered and the engine fails to easy.

No need to be delicate about this situation as BST has acknowledged the issues and

will solve it sooner or later (probably later as it will take some work)

but I would like to have to proper engine power and fix of the EGT issue - matching real life performance :) This bird went into Vietnam under horrible conditions, a lot of times overloaded during missions etc. And from what I know, the Huey is a very robust and reliable machine. It has to take some serious work to totally shred the engines...

Most frustrating thing for me in current EGT model - DCS Huey still have plenty of power. If you pull enough collective - it will go up as a rocket. But you can't use this power.

Most frustrating thing for me in current EGT model - DCS Huey still have plenty of power. If you pull enough collective - it will go up as a rocket. But you can't use this power.

If anything, that sounds like something it shouldn't be able to do — rotors are not propellers after all. And you can use the power it has; you just have to work your way up to it rather than try to apply it all at once since that leads to mechanical breakage, an engine that has to fight resistance and inertia, and generally over-exert itself.

That's pretty much how all engines work.

Why everyone suggest that I do not know how to fly a helicopter? I do. And by the way, currently you can't "work your way up to it". You will carefully work up to around 70% and then you in the red zone on EGT, where it going to stay forever. Although there are plenty of engine power and lifting power left.

@ shagrat

 

Maybe you only fly slick around airport, but I would like to have to proper engine power and fix of the EGT issue - matching real life performance :) This bird went into Vietnam under horrible conditions, a lot of times overloaded during missions etc. And from what I know, the Huey is a very robust and reliable machine. It has to take some serious work to totally shred the engines...

 

Im very happy that BST got around to implement the overheating. But it needs some additional work and they know it. Huey in DCS is underpowered and the engine fails to easy.

 

No need to be delicate about this situation as BST has acknowledged the issues and

will solve it sooner or later (probably later as it will take some work)

Appendix C Page 1/2.

The numbers for GW, OGE and IGE are pretty close to the chart already. At 2000 ft and 25°C your maximum weight for OGE is 8790 lbs. What the pilots in Vietnam (with their 1-2 years old Hueys) did was to use IGE and translational lift of a running take off when overloaded... And that works in DCS as well.

After flying the Huey for the entirty of its existence in DCS, the most of the last two years in a squadron under a qualified IP I may be far from a perfect Huey pilot, but confident to have understood the limitations of the bird.

There will be a bit more time in some instances after the fix, but ultimately I am pretty sure the torque limits will be modeled accordingly and that will rip your engine apart, if you pull too much collective...

Why everyone suggest that I do not know how to fly a helicopter? I do. And by the way, currently you can't "work your way up to it". You will carefully work up to around 70% and then you in the red zone on EGT, where it going to stay forever. Although there are plenty of engine power and lifting power left.

Because you're expressing problems flying in conditions where the Huey has no problems operating, and because you're suggesting that it should be able to do things it really shouldn't because that's contrary to how aerodynamics and just regular engine mechanics work. Also, 70% of what? Collective travel? I'm asking because, just because you have some travel left in the collective does not mean you have more power available — just more pitch angle. You can definitely work your way up to using pretty much all of the engine power, but this will obviously create massive amounts of heat… so nothing strange if you start to overheat there.

I mean, you could still be right — the Huey does have some strange behaviours when you yank on the collective, like the going up like a rocket you describe — but if anything, that's something that should probably be adjusted in the opposite direction of what you're asking for. This is not a Gazelle, and the Gazelle is already a much stronger case for actually being broken in how it reacts to collective input.

At any rate, none of what you describe really seems to make the Huey “broken.” It just means that you wish it did something else, which is a wholly unrelated (and not necessarily accurate) matter.

Because you're expressing problems flying in conditions where the Huey has no problems operating, and because you're suggesting that it should be able to do things it really shouldn't because that's contrary to how aerodynamics and just regular engine mechanics work.

I'm asking for no such things. All I want is to be able to squeeze from engine what it have. If I use some figures of speech, it dosen't mean that I expect to pull collective like crazy and go for the Moon landing

PS Role model how it should work, for me it DCS Mi-8. You can break it easily if you do not know what you doing, but at the same time, if you do, you can get great performance from this machine.

TBH there may be something in the engine modeling perhaps not 100%, but if I understand my reading of ChickenHawk and Shockwave, in real life the Huey had some very real engine limitations in service. For me the challenge is to fly any of the heli's within their limits. ;)

I'm asking for no such things. All I want is to be able to squeeze from engine what it have. If I use some figures of speech, it dosen't mean that I expect to pull collective like crazy and go for the Moon landing

 

 

PS Role model how it should work, for me it DCS Mi-8. You can break it easily if you do not know what you doing, but at the same time, if you do, you can get great performance from this machine.

TBH there may be something in the engine modeling perhaps not 100%, but if I understand my reading of ChickenHawk and Shockwave, in real life the Huey had some very real engine limitations in service. For me the challenge is to fly any of the heli's within their limits. ;)

The Huey has limits, as outlined in the TM 55-1520-210-10 original manual.

These limits require to manage the engine so not to break it. Like you can't fly the Bf.109, Fw-190, P-51 or Spitfire without addressing its limitations engine wise, or you WILL break it.

Comparing the UH-1H to a Mi-8 is like saying your Toyota Corolla's motor must be damaged as when you try to pull a 5 ton trailer in first gear it cooks the engine after overrevving, while your Mack Truck can easily do it...

But let's wait for BST to fix the EGT and see what happens. :)

Yeah, that is because it has greater performance, as in two far bigger turbines and a 6 blade rotor... :doh:

I'm not comparing Huey and Mi-8, those are very different machines :doh:

But you CAN push DCS Mi-8 to it limits (which are very different from Huey), if you know how. And you CAN'T push DCS Huey to it limits (IT limits, not the limits of Mi-8, what idiot would want to do that?), no matter what. Not even close.

Sorry but you can... at least a couple of DCS pilots I know can, me included. You just need to be careful as you may push her beyond some limits quickly. And Yes, the EGT max limit currently breaks the engine before torque does and that is not 100% realistic, but if it is fixed a you will still have the torque limit. If they model it correct the higher torque levels should also stress the engine over time, so the end result will be pretty much the same.

The situation before modeling engine damage was not "better" but ridiculous. I have tested flying at full collective, 120+ kts with all gauges beyond limits for as long as 2 hours with quick breaks for picking up troops and that is just impossible.

As I said, let's wait for the fix and see what happens to the torque limits.

Current situation in my opinion is every bit as ridiculous, as it was before EGT was implemented. Now you always have plenty of additional power available, it is just a gentle pull of the collective away. But you can't use it, because your engine will die. No other module have this nonsense. You were talking about WWII warbirds? 100% throttle is totally an option with them, you just need to use it wisely. For Huey, it is not a case. It would be much better if they just take out 30% of engine power, but let pilot to use full collective authority when needed.

Current situation in my opinion is every bit as ridiculous, as it was before EGT was implemented. Now you always have plenty of additional power available, it is just a gentle pull of the collective away. But you can't use it, because your engine will die. No other module have this nonsense. You were talking about WWII warbirds? 100% throttle is totally an option with them, you just need to use it wisely. For Huey, it is not a case. It would be much better if they just take out 30% of engine power, but let pilot to use full collective authority when needed.

Batumi airport

0-500 feet pressure altitude (29.92) / free air temperature 20°C.

IGE is 36 psi and

OGE is 47 psi torque

Max GW 9500 lbs actual weight 9504 lbs

200 ft above ground hover at 47-49 psi touching the torque limit, now EGT is in the 690°C range and you are between a rock and a hard place as you can hover for as long as either the engine overheats long enough to start damaging the turbine blades, or the torque to put enough stress on the engine to break it.

The only difference today is, that the EGT is too fiddly and IRL should be somewhere around the upper 30 min limits giving you a more time in the OGE hover, but still you don't have "more" power or performance, only more time.

Current situation in my opinion is every bit as ridiculous, as it was before EGT was implemented. Now you always have plenty of additional power available, it is just a gentle pull of the collective away. But you can't use it, because your engine will die. No other module have this nonsense. You were talking about WWII warbirds? 100% throttle is totally an option with them, you just need to use it wisely. For Huey, it is not a case. It would be much better if they just take out 30% of engine power, but let pilot to use full collective authority when needed.

Yes perhaps, but do read up on actual in service Huey flight parameters there are real limitations. Again there maybe some tweaking to be done however the Huey is not a UH-60. :music_whistling:

And about the collective... For the umptienth time:

throttle = power (controlled by Governor or throttle grip)

Collective = angle of attack (lift) only need to balance torque vs RPM.

You already need the full range of AoA (collective) for emergency procedures, there is no "wasted" travel. It is how helicopter controls work.

To my understanding, in reality, engine performance is not depend on collective position. It is just with the same control inputs, you get less power depending on ambient temperature and/or altitude. And it shouldn't be like you always blown your engine if you dare to pull more collective. With very little regard to any external factors. No sane engineer would design a machine like that.

And about the collective... For the umptienth time:

throttle = power (controlled by Governor or throttle grip)

Collective = angle of attack (lift) only need to balance torque vs RPM.

 

You already need the full range of AoA (collective) for emergency procedures, there is no "wasted" travel. It is how helicopter controls work.

To build on this, I'm still wondering where you (Lehmen) are getting that “70% engine power” or “30% unused” number from. What are you looking at when you come up with that estimate?

And the WWII prop analogy is pretty darn apt, I'd say. There, like with the Huey, pushing full power burns out the engine really quickly. Like them, the Huey can do it, but you really need to have a plan of action of what to do immediately after because unlike them, the Huey doesn't glide that well, which is what you'll most likely end up doing.

To build on this, I'm still wondering where you (Lehmen) are getting that “70% engine power” or “30% unused” number from. What are you looking at when you come up with that estimate?

It just an estimate from muscle memory. Of course it not very accurate, but you always have plenty of additional collective movement on Huey, that you can not use.

And the WWII prop analogy is pretty darn apt, I'd say. There, like with the Huey, pushing full power burns out the engine really quickly. Like them, the Huey can do it

No, current Huey is nothing like DCS WWII props. As I told, with WWII birds 100% throttle is a viable control option. With current Huey, 100% collective is not an option, if you planning to fly home by your own.

To my understanding, in reality, engine performance is not depend on collective position. It is just with the same control inputs, you get less power depending on ambient temperature and/or altitude. And it shouldn't be like you always blown your engine if you dare to pull more collective. With very little regard to any external factors. No sane engineer would design a machine like that.

The collective is setting the angle of attack of the blades, what produces lift. The AoA of the blades induce a counterforce to the engine that is measured as torque (in fact the blades mass and driveshaft friction already induces torque, but it isn't important here).

Now when you pull collective to produce lift the engine Governor feeds more fuel to the turbine to keep the RPM at 324/6600 all the time.

The more fuel is burning, the hotter the turbine gets and the turbine blades start taking damage... Over time this causes severe cracks and parts breaking off, what isn't good for the engine as you can imagine.

Now the collective can be pulled 100%, maximum AoA, so the blades produce the maximum lift possible. Unfortunately if you do this the power(!) of the engine is insufficient to keep the 6600 RPM against the counterforce produced by the blades. The Governor opens full throttle what overheats the engine, in parallel the torque exceeds the limits until the rotor has slowed down enough to lessen the torque.

IRL the torque induced will damage the transmission and engine before the EGT damages the turbine blades, but the engine can't safely produce enough power to support full collective over any meaningful time.

You still use the remaining travel on the collective in auto-rotations or emergencies to produce the maximum lift possible to cushion a descent or flare etc. but accepting that the RPM will drop below healthy limits quickly and you need to pray the torque doesn't shear your rotor off or overstress the engine.

After doing such a stunt, the engine and transmission is likely damaged and need a complete overhaul/replacment. That part luckily is simulated far less realistic in DCS with the couple minutes repair and without getting yelled at by your CO.

No, current Huey is nothing like DCS WWII props. As I told, with WWII birds 100% throttle is a viable control option. With current Huey, 100% collective is not an option, if you planning to fly home by your own.

I'm sorry, but this is just inaccurate. For two reasons.

One is that 100% throttle is not the same thing as 100% collective. You really need to stop equating the two because it can only ever confuse the point you're trying to make, especially if you are trying to depict some part of the simulation as “wrong.”

The other is that 100% collective is an option, but for a very specific purpose that you do not want to use in normal flights — it's an emergency measure. The same goes for pulling 100% throttle — it's an option, but it's really for emergencies only since that kind of power wrecks things in, not just the engine, all along the power train and even in the blades themselves.

The fact that you have to put the governor in EMER mode to be able to plug in 100% throttle should be a pretty obvious hint of where, when, and why (or why not) you use that option. This is no different than ripping the WEP cord in a P-51 — it's called war emergency power for a very good reason.

I know what the relation between collective and governor. But if you are an engineer, and your governor is constantly killing an engine - you go back to the drawing board. And they did! As Huey enthusiast, I had read and watched my share of Huey pilots memuars. And although they mentioned various downsides of Huey, noone ever talked about that you can kill it engine super easily, just pulling up the collective. In fact, they were talking about reliability of the machine. This makes me think, that Bell engineers weren't bunch of guys who had no idea what they are doing.

... I'm still wondering where you (Lehmen) are getting that “70% engine power” or “30% unused” number from. What are you looking at when you come up with that estimate?

I imaging it's from the Max available torque in DCS compared to RL operations.

In DCS at sea level and the default 20°C OAT :

Max Torque is limited to approx 40 psi (917 hp) due to EGT, in RL the limit is 50 psi (1150 hp) due to the gearbox loading limit i.e. the DCS Huey should have an extra 10 psi (220 hp, 25%) available and even then, the limit is due to the gearbox limit, not EGT.

I imaging it's from the Max available torque in DCS compared to RL operations.

 

In DCS at sea level and the default 20°C OAT :

 

Max Torque is limited to approx 40 psi (917 hp) due to EGT, in RL the limit is 50 psi (1150 hp) due to the gearbox loading limit i.e. the DCS Huey should have an extra 10 psi (220 hp, 25%) available and even then, the limit is due to the gearbox limit, not EGT.

I know what the relation between collective and governor. But if you are an engineer, and your governor is constantly killing an engine - you go back to the drawing board. And they did! As Huey enthusiast, I had read and watched my share of Huey pilots memuars. And although they mentioned various downsides of Huey, noone ever talked about that you can kill it engine super easily, just pulling up the collective. In fact, they were talking about reliability of the machine. This makes me think, that Bell engineers weren't bunch of guys who had no idea what they are doing.