EGT governor button and INU heater

[Pegaso69]

Two question (sorry for my english)

 

1 - What's the INU Heater? and when and why we've need to use it?

 

2 - I've try to use the EGT governor button for each engine but i've see only the decraease of th eRPM but the temperature on the strument not decrease.

Maybe i've miss any step?

Anyone can explain me about this Exhaust Gas Temperature check?

 

Thank you so much

 

By

 

PS: Anyone know the correct (not less or more) release date of the english version?

[Mad Dog 7.62]

According to the flight manual, the INU heater should be on at all times. The EGT temp check is done with the buttons by the EGT guage, there is a high end a low end check button.

 

AFAIK no announcement has been made by ED regarding the "correct" release date of the English version.

[Tango]

1 - What's the INU Heater? and when and why we've need to use it?

The INU heater is a heater for warming the oil of the gyroscopes.

 

INU = Inertial Navigation Unit.

 

To sense position, three gyroscopes are aligned perpendicular to each other, adn must rotate as close to each others RPMs as possible. Not everything is perfect however, so to aid in theor rotation (especially during alignment), the oil is warmed up. This permits the gyros to spin faster than they might, and helps reduce the time required to wait for the oil to come up to temperature, and thus for optimum operation of the INU.

 

Once the oil is up to temperature and the INU is aligned (high-precision align is 30 minutes), then I think this heater can be switched off (otherwise why would it be seperately switchable?).

 

I'm not up to speed on INU alignment yet - it's a bit different to what I'm used to, and I'm still learning the finer points of the navigation system.

 

Best regards,

Tango.

[EvilBivol-1]

EEG governor button? One of us is confused.

 

Do you mean the:

- Engine EGT gauge test buttons (front panel, two gray buttons above the EGT gauge)

or the

- Right/Left Electronic Engine Governor (EEG) switches (right panel, silver switches under safety caps)

?

 

In the first case, the buttons are only there to test the gauge. The left button is used to test the gauge when the engines are running (needles drop below 150) and the right button is used to test the gauge when the engines are off (needles climb to over 800).

 

In the second case, the EEG for each engine should always stay on to ensure safe engine operation.

[Mugatu]

30mins!!! does that mean I have to sit on the ground for that time, or can it continue to align in the air (ie moving). Also if it's not aligned what's the impact in the sim?

 

The INU heater is a heater for warming the oil of the gyroscopes.

 

INU = Inertial Navigation Unit.

 

To sense position, three gyroscopes are aligned perpendicular to each other, adn must rotate as close to each others RPMs as possible. Not everything is perfect however, so to aid in theor rotation (especially during alignment), the oil is warmed up. This permits the gyros to spin faster than they might, and helps reduce the time required to wait for the oil to come up to temperature, and thus for optimum operation of the INU.

 

Once the oil is up to temperature and the INU is aligned (high-precision align is 30 minutes), then I think this heater can be switched off (otherwise why would it be seperately switchable?).

 

I'm not up to speed on INU alignment yet - it's a bit different to what I'm used to, and I'm still learning the finer points of the navigation system.

 

Best regards,

Tango.

[EvilBivol-1]

Currently, the simulaiton does not model the various INU spooling procedures beyond simply turning it on. I think it uses a standard 3-5 minute warm-up. Perhaps ED will include additional functionality in a patch/update.

[Pegaso69]

I mean the two silver buttons for check the EGT governor threshold ( right engine and left engine)

on the upper of the rear aux panel, indicatively we have over our right shoulder on the rear side(less or more)

 

not EEG and not EGT Test

 

 

 

Thanx for the INU heater...

Now i understand what is being heated

Edited December 3, 2008 by Pegaso69

[AlphaOneSix]

Those buttons test the PT-12-6 EGT limiting system (temp limiter).

 

In normal operation, this system prevents you from overtemping the engine by pulling in too much power. To put it simply, if the engine gets too hot, the temp limiter system will step in and reduce the power output of that engine automatically so that you don't break it.

 

For the test to work when you push the buttons, two conditions must be met: first, your EGT must be above 850C on the tested engine, and second, your GG (N1) RPM must be at least 87% on the tested engine. The easiest way to meet these conditions is to hover out of ground effect (above 7m). In order to conentrate on the test, it's best to use AUTO HOVER to hold the aircraft in position while you push buttons and/or stare at gauges.

 

What the test is doing is basically lying to the PT-12-6 system and telling it that you have a much lower temperature limit, so that it will think that you are overtemping the engine, and it will respond accordingly by reducing power to the engine you're testing.

 

NOTE: If your aircraft is too heavy, you may not be able to hover out of ground effect (this would normally be considered a bad thing, you should always be able to hover out of ground effect for safety purposes). The numbers I mention below are based on an aircraft with a full fuel load and no wing stores at all.

 

Okay, once a hover has been established, zoom in on your N1 and EGT gauges. It's easier to use the keyboard shortcuts for the test so you can see the gauges without moving your view around. At a normal hover (in my test), the engine N1 readings were matched at 95% and the EGT readings were matched at 870C. Now press the left engine PT-12-6 test button (RALT+RSHIFT+G) and hold it. The N1 of the left engine will drop several percent (to about 91% momentarily, but it should rise back up to about 94%, assuming you started with the N1 readings at 95%), and the right engine will rise several percent (again, in my test, to about 97% before settling back down to 96%). This is because the test is telling your temp limiting system that you're overheating the left engine, so the system reduces the left engine's power. The right engine will make up for the loss of power by generating more power of its own. Thus you end up with a roughly 2 percent split in N1 (94% on the tested engine and 96% on the untested engine, in my case). Along with this split in N1 comes a split in EGT. Since the purpose of the temp limiter is to reduce power so you don't overheat an engine, you will also see a drop in EGT for the tested engine. The drop should be at least 30C. In my test, the drop was 32C (from 870C to 838C), while the untested engine, which had to increase power to make up for the loss, increased 24C (from 870C to 894C). The temps take longer to move, so to see the full move, you may have to hold the test button down for a while (about 30 seconds). After seeing what you want to see, release the button (or let off of the keyboard) and the engines will go back to normal. Repeat the test for the right engine using RCTRL+RSHIFT+G and you should see the same results as before, but with the engines switched.

[Pegaso69]

Thank so much AlphaOne

[Yo-Yo]

EEG governor button? One of us is confused.

 

Do you mean the:

- Engine EGT gauge test buttons (front panel, two gray buttons above the EGT gauge)

or the

- Right/Left Electronic Engine Governor (EEG) switches (right panel, silver switches under safety caps)

?

 

In the first case, the buttons are only there to test the gauge. The left button is used to test the gauge when the engines are running (needles drop below 150) and the right button is used to test the gauge when the engines are off (needles climb to over 800).

 

In the second case, the EEG for each engine should always stay on to ensure safe engine operation.

 

AS far as I remember there are two buttons at right rear panel to check EGT limiter. They just lower the limiter threshold to check how it works without real engine overtemperature.

[Yo-Yo]

 

For the test to work when you push the buttons, two conditions must be met: first, your EGT must be above 850C on the tested engine, and second, your GG (N1) RPM must be at least 87% on the tested engine. The easiest way to meet these conditions is to hover out of ground effect (above 7m). In order to conentrate on the test, it's best to use AUTO HOVER to hold the aircraft in position while you push buttons and/or stare at gauges.

 

 

More safely is to test the engine on the ground when the second one at idle.

If the OAT is low it can be necessary to shut down the second engine.

[AlphaOneSix]

More safely is to test the engine on the ground when the second one at idle.

If the OAT is low it can be necessary to shut down the second engine.

 

Of course you are correct! With one engine at IDLE and the other at AUTO, it is possible to get the AUTO engine up to about 860C EGT by pulling the collective up to about 3 degrees of pitch (at sea level, +20C OAT, no wing stores, fuel internal fuel)

 

Of course, this would be the recommended way to do the test, not while flying. In fact, I will be making a checklist that includes all of these "detailed" checks, and they will all be done from the safety of the ground!