[Fixed] [2.9.5.55918 MT] Speed brakes do not close violently without electrical power

[Stickler]

According to the RL flight manual, any interruption in electrical power will cause the auxiliary air doors and the speed brakes (if out) to close violently.

In the game, with speed brakes and auxiliary air doors extended/open on the ground, switching the generators to OFF will only cause the auxiliary air doors to close. The speed brakes will remain extended.

[Zabuzard]

Thanks, looking into it.

[Cat107]

Fixed internally  

[Stickler]

This problem seems to have been only partially fixed in 2.9.7.58923.

Witness the attached track recorded in 2.9.7.59263 MT.

With both engines started but the jet remaining on external power only, having external power disconnected will cause neither the auxiliary air doors nor the speed brakes to close.

Only when moving the generator switches to OFF from EXT ON does this occur.

I suppose that if either the speed brakes or the auxiliary air doors were able to operate on battery power without external (or internal generator) power, there would be no need for the -1 warning. I therefore assume that the two mentioned devices should retract without external (or internal generator) power available; the generator switches being in the OFF position should not be a requirement for retraction.

retraction.trk

Edited September 2, 2024 by Stickler

[Cat107]

Hi, so speed brakes as well as aux air doors are powered via MAIN 28V DC BUS, when you have the battery connected and generator switches set to EXT ON and ground power is removed, then the battery will provide power to the ESSENTIAL 28V DC BUS which will be tied with the MAIN bus as long as the battery voltage is above certain threshold, when the votage drops enough or when you move the generator switches to OFF then the MAIN bus will be disconnected from the ESSENTIAL bus and the speedbrakes as well as aux air doors will close as the MAIN bus will not be powered.

Edited September 18, 2024 by Cat107

[Hiob]

This module really is a marvel.

[Stickler]

Impressive. Working as intended then.

[Stickler]

Did more research on this and found some extracts from the RL manuals which indicate that the system may not be modelled completely correctly after all.

First of all, if the battery could in general power the Main 28V DC Bus, the speed brakes and the aux air doors would be mentioned in the below overview:

The reason why speed brakes and aux air doors are NOT in the list is likely because in case of double generator failure, the main DC line relay is deenergized, thereby disconnecting the Main 28 V DC Bus and the Essential 28 V DC Bus:

Or, described in a more comprehensive way:

Note that "the dc tie control circuit is designed to disconnect the two dc buses during double generator failure so that loads from the main 28 volt dc bus will not discharge the battery".

Since the battery is a 24 V type, the disconnect would occur immediately (24 V is less than 24.5 + 0,5 - 0 V in all cases), regardless of why exactly the RH and LH transformer-rectifiers are no longer powered.

An additional hint is provided by the below emergency procedure:

If the aux air doors could be operated on battery power, the description would most likely not state that the doors are inoperative with double generator failure.

It is noteworthy that a double generator failure should illuminate the DC BUS light, indicating that the buses have disconnected.

Note below that the manual only speaks of the battery powering the essential dc bus "for a period of time", not of the main 28 V dc bus.

If have not been able to generate a DC BUS light in the game. I suppose it should probably illuminate with both engines and/or both generators off. I have not found a definitive source stating where the light itself gets its power. Based on the below extract it may be tied directly to the Battery bus (as the FIRE and OVERHEAT and EJECT lights).

Edited July 5 by Stickler

[Zabuzard]

Ull be able to explore this in more depth once the EFB electric page is available with the next update. You can see the state of each bus with that and more.

Afaik this topic is implemented correct. But yeah, with the EFB you can get more details out of whats going on