correct as-is hung start on latest update is not a real thing

[Simba11]

Dear ED i dont know who told you that you will get a hung start if you don't stable lize a 20% before going to idle but that's actually not a thing. 

[Furiz]

1 hour ago, Simba11 said:

Dear ED i dont know who told you that you will get a hung start if you don't stable lize a 20% before going to idle but that's actually not a thing. 

 

You need to start with who told you it is not a thing, what are yours, his or hers qualifications on the matter etc... then after that, when you introduced the source and made it credible you can say this or that is not a thing.

Otherwise who on earth will believe that what you are saying is true?

[Hulkbust44]

Oh now you're claiming random crap over on the Viper side...

Mobius708

[EagleA25]

Colleague of mine and former F-16 C/D instructor in the Chilean Air Force completely confirmed this is in fact real…

 

He tells me if engine isn’t sufficiently turned by the time Fuel-on is selected, the N2 will not accelerate and it will hung start.

so, yeah, thanks ED for the realism!

[b0bl00i]

I love stuff like this in a module. I want to be able to break stuff and get failures, makes it much more exciting. 

 

Keep it up. 

[Diesel_Thunder]

3 hours ago, EagleA25 said:

Colleague of mine and former F-16 C/D instructor in the Chilean Air Force completely confirmed this is in fact real…

 

He tells me if engine isn’t sufficiently turned by the time Fuel-on is selected, the N2 will not accelerate and it will hung start.

so, yeah, thanks ED for the realism!

Just to add to that, it’s usually not good for N2 turbine (gas generator) to stay in a hung start condition for too long. Usually leads to thermal damage (similar to a hot start, also bad) and at least an engine inspection. 

[nighteyes2017]

from what i understood from an F16 captain i talked to at an airshow: the pratt & whitney engine needs a 20rpm stable, but the general electrics engine is able to just walk from 0 to 100 in one go? anyone with better engine knowledge able to confirm or explain further maybe?

[mvsgas]

For what is worth, I do not know of anyone IRL ( pilot or maintainer) that has ever tried to move the throttle to idle from cutoff on purpose without RPM being at 20% or higher (PW-220E, 220 or GE-100). I know some that have made a mistake (rushing or not paying attention) that have started the JFS with throttle on idle, but corrected immediately and terminated the start because IRL, starting the engine is a critical thing. Everything happens very fast and you are paying attention to RPM, FTIT, oil pressure, main gen and stand by gen lights. Started the JFS with throttle in idle could raise FTIT rapidly, which is signs of a anticipated hot start. Manuals have a very specific terminology for anticipated hot start we all have to memorize to qualify as an engine run person. This also would be sign of autoaccel condition, also cause you to terminated engine start.

 

So, whom ever said is not a thing IRL, has never been run qualified in USAF on any F-16. GE engines can not go from 0 to 100 and I can't think of anyone would try IRL. In the last couple years I work on F-16 with PW engine (Luke AFB in 2009 to 2011) you had to run the JFS for 2 minutes before going to idle, to allow the bleed strap time to close.

 

So IRL, you pay close attention when starting the engine and this is not a problem. In DCS, people just what to flip switch while drinking coffee and start as quickly as possible to airquake and are not paying attention, the only reason this is a problem.

 

Some will say: "Well, we do not have those engine in DCS" your right, I was never run qualified in GE-129. They can also say: "You have never started the JFS with throttle in idle, so you don't know what will happens". Again you are right on that also.

Edited October 4, 2021 by mvsgas
spelling

[b0bl00i]

I'd like to learn more critical tasks when operating the Viper. Hope more procedures and tests are added in to make it more realistic. 

[Frederf]

People with enough engine knowledge will know to high certainty what will happen without actually doing it. There exists someone who knows the GE129 inside and out and can say "oh well yeah you won't get any start because there's a special interlock that inhibits fuel if commanded idle with less than 13.37% RPM" or "I dunno, you'd probably get a fire dumping in fuel at low RPM when ignition hit the pool sitting in the bottom of the chamber."

[Eagle7907]

Correct me if I’m wrong, but also isn’t it proper procedure to make sure the SEC annunciation goes out before going to idle? Not just stable 20%?


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[QuiGon]

2 hours ago, Eagle7907 said:

Correct me if I’m wrong, but also isn’t it proper procedure to make sure the SEC annunciation goes out before going to idle? Not just stable 20%?

 

That's how I do it too.

[Badlego]

Please correct me but i thought so far that throttle Inputs are handed from the Cockpit to a Computer and then to the engine and therefore setting the throttle to idle too early does Nothing as the computer will only start up the engines in the proper conditions. I have No sources for that but i Wonder why the digital Interface has Not been discussed Here yet. Maybe in Startup the Computer System is Not running yet or bypassed for safety reasons?

[mvsgas]

 

[Eagle7907]

Interesting. After viewing the linked thread, since some people labeled some posts on there for scrutiny, I decided to look at a document that can’t be posted that seems to be referenced by many. I will tell you that it doesn’t really mention the words “stabilized”, but it does mention 20% minimum, and also includes maximum rotation speed when ambient temps above 90 degrees F. The SEC is mentioned, but doesn’t specifically say wait until SEC light goes out. It just says the light goes out reaching 20%. So in another way of thinking this, you would wait until it goes out? I think it doesn’t particularly say this because of the conditions that would warrant a later activation from OFF to IDLE.

FYI, this is particularly pertaining to the -129 engine.


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[mvsgas]

On 9/21/2021 at 12:01 AM, Badlego said:

Please correct me but i thought so far that throttle Inputs are handed from the Cockpit to a Computer and then to the engine and therefore setting the throttle to idle too early does Nothing as the computer will only start up the engines in the proper conditions. I have No sources for that but i Wonder why the digital Interface has Not been discussed Here yet. Maybe in Startup the Computer System is Not running yet or bypassed for safety reasons?

There are two input to the engine, Main is throttle position switch that sends Power Lever Angle (PLA) to the Digital Engine Computer (DEC). The second input is physical push/pull wire the connects the throttle control linkage on the Main Engine Control (MEC). This is the only physical connection to any control in the F-16 (any versions). The DEC is like you car engine Electronic Control Module (ECM). The MEC is like very complicated carburetor (not even close in reality, but same concept )

 

The DEC nor the MEC  will prevent you from introducing fuel to early to the combustion chamber AFAIK. Other aircraft the start is very automatic, for example A-10 seem way easier. But in the F-117, F-15 and F-16 you can't just put throttle to idle and hit start.

[Preendog]

Tripped over this first try on F-16.  The throttle defaults to idle if you do a hot or air start, so your first landing and repair will result in this, then video tutorials, then a forum bug search.

On 9/22/2021 at 10:45 AM, mvsgas said:

The DEC nor the MEC  will prevent you from introducing fuel to early to the combustion chamber AFAIK.

If this is the case, what should happen?  In the game, if you move the throttle too early, it gets bricked and you have to respawn or restart the mission.  Nothing actually happens except the aircraft becomes unstartable.  It implies that there's a bug, there was an update that made the video startup tutorial obsolete, or the  plane was junked and needs to be repaired or replaced, but with nothing occurring to indicate that.

If we must have the noob trap at least set the plane on fire or make a alarm light come on or something.  Put an option in the radio menu for a supervisor to come and reset the plane because you were naughty.  The canopy must be open and his model appears at the side, shaking his head as he reaches in to flick the hidden reset switch.  e.  You also have to look away while he flicks the switch.  There should be a text or audio message to the player to look away, otherwise it's just another noob trap.

Edited January 1, 2022 by Preendog

[mvsgas]

3 hours ago, Preendog said:

If this is the case, what should happen? 

In real life? Many things. You can get a No start, hung start, anticipated hot start or a hot start. The question in my mind is: Do we really expect Eagle Dynamics to modeled all of this behaviors when it seem so many do not want to follow a simple thing? The simple thing being no moving the throttle to idle if the engine is not ready.

 

3 hours ago, Preendog said:

There should be a text or audio message to the player to look away, otherwise it's just another noob trap.

How is this a "noob trap"? Try this: Start the JFS, once you have a JFS run light, start the clock (conveniently the cockpit has its own). If you used start one, wait 30 seconds, if you use start two, wait a minute. After the elapse time, check engine gauges. If RPM is above 20% and sec light is out, move the throttle to idle. If you follow that to the tee, do you encounter any problems? If not, why change anything? If yes, record a track and submitted in a separate post as a potential bug.

[unknown]

9 hours ago, Preendog said:

and you have to respawn or restart the mission.

Just ask ground crew to do a repair, wait 3-4 minutes to let them finish, have fun starting up the F-16 again.

[Preendog]

10 hours ago, unknown said:

Just ask ground crew to do a repair, wait 3-4 minutes to let them finish, have fun starting up the F-16 again.

Thx unknown, that works.  If the plane is undamaged the player will have to break something, like jettison the canopy, to repair.

[Dragon1-1]

IRL, it should be possible to attempt another start after aborting the first one. As long as you don't fry the engine with a hot start (which means being quick enough to recognize it and take correct action), you should be able to purge it by running JFS, and then try again. This is similar to a crank start in other aircraft. Just keep in mind JFS isn't unlimited, although it can be recharged by a hand pump IRL. 

[Eagle7907]

Interesting. Is an external air start not possible?


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[mvsgas]

7 minutes ago, Eagle7907 said:

Interesting. Is an external air start not possible?
 

There is no way to start an engine in the F-16 externally. All starts use the JFS ( if the engine is installed obviously)

[Eagle7907]

Oh wow. Huh. Interesting it’s designed that way. So I take it any cart that’s hooked up to it is just ground power? Also interesting to know that if the accumulators gets depleted then you got a delay getting started. I guess that’s why ED just decided to require a repair instead of creating a new scripted ground crew item.

Thanks!


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[mvsgas]

48 minutes ago, Eagle7907 said:

So I take it any cart that’s hooked up to it is just ground power?

You can use several carts. I don't remember their official names and don't feel like researching them but, for electrical power you can use a -60 or -86. For cooling you have C-10 ( C-10 require a -60 hook up to it to provide bleed air) You can also use a -60 to provide bleed air to the aircraft directly, but it uses the aircraft own environmental control system (ECS) to cool the avionics or pressurize the fuel system. This was commonly used for years but someone realize they where putting time on the ECS turbine so its not the prefer choice. To pressurize the fuel system only we used a small air compressor cart (small being relative) and for hydraulics we could used a Mule ( again don't remember the technical names). Non of them could motor or spin the engine. There are other carts for servicing nitrogen and other things.

Edited January 3, 2022 by mvsgas