F-16 control surfaces position with no hydraulics.

[sagent54]

Good day ED team. Control surfaces (stabilizers, flaperons) stand still in cold and dark. I didn't find mention of hydraulic system improvement and FLCS roadmap looks like tuning to control in flight but not in other situations. Here is picture of cold and dark F-16C in DCS:

And to compare cold and dark F-16 on parking stand:

I wil try to provide information about timing of hydraulics to depressurize and control surfaces's moving by the gravity to it's lowest positions if I'll find any official documents or video with real aircraft.

[Dawgboy]

If the Viper is fly-by-wire, I would guess the control surfaces are not on the hydraulic systems.  But the question remains, what drives the "cold/dark" control surfaces' positions?  True?

[MROK73]

45 minutes ago, Dawgboy said:

If the Viper is fly-by-wire, I would guess the control surfaces are not on the hydraulic systems.  But the question remains, what drives the "cold/dark" control surfaces' positions?  True?

No!

They are electronically controlled, hydraulically activated...that's why in the second picture the horizontal Tail is down (no hydraulic pressure).

Suggest you to read manuals available on the net, in order to know better the plane. The ED manual doesn't  mention it and Chuck's Guide just a few words.

 

Edited November 9, 2021 by MROK73

[Dawgboy]

20 minutes ago, MROK73 said:

No!

They are electronically controlled, hydraulically activated...that's why in the second picture the horizontal Tail is down (no hydraulic pressure).

Suggest you to read manuals available on the net, in order to know better the plane. The ED manual doesn't  mention it and Chuck's Guide just a few words.

 

 

Thanks, @MROK73...after I figure out what works and doesn't work as intended in Viper EA, i.e., fly it, I'll learn how to work on the jet. 

[MROK73]

 

45 minutes ago, Dawgboy said:

Thanks, @MROK73...after I figure out what works and doesn't work as intended in Viper EA, i.e., fly it, I'll learn how to work on the jet. 

[Creature_1stVFW]

The surfaces don’t always droop when the jet shuts down. 

[mvsgas]

This does not really matter if you guys just want the stabs and flaperons down on a cold jet. But if the questions is whether this is realistic or not? There are to many variables and I highly doubt you can find a good source online. Manuals do not mention this, and photos are not good enough. For example, the photo you posted is of a block 32 that can't even fly.

https://www.f-16.net/aircraft-database/F-16/airframe-profile/2052/

Quote

Special characteristics:

• Unit Markings: USAFWC

By late 2015 was no longer flying due to a twisted airframe. Became an instructional airframe.

About those variables against online sources:

So, whether the flight control surfaces droop down or not depends on several things.

1. One is the Integrated Servo Actuator (ISA). Some will start bleeding down as soon as the engine shuts down, some will take days. The Horizontal stabs are more susceptible to this since they are heavier than the flaperons. How long after the engine shut down was the photo taken? and hour? 3 days?
2. Another is the mechanics. Many of us tent to push the flaperons up after engine shutdown so you are less likely to crack you skull on them. The opposite is true about the stabs. So if you look at photos, are they after the mechanic raise the surfaces by hand or where they down after shutdown?
3. Another variable is if you turn battery off and there is still pressure on the hydraulics, the control surfaces will go to neutral. Because of this, the flaperons could have reset up even tho their natural position after shutdown is down. Someone sees a video of a Demo viper and see thee flaperons reset up, will think that is the normal behavior when is not.

 

 

Edited November 10, 2021 by mvsgas
spelling

[Falconeer]

17 hours ago, mvsgas said:

Another is the mechanics. Many of us tent to push the flaperons up after engine shutdown so you are less likely to crack you skull on them. The opposite is true about the stabs. So if you look at photos, are they after the mechanic raise the surfaces by hand or where they down after shutdown?

I have enough colleague's with a nice scar on their head, if you are not paying attention or didn't push them up 

Edited November 11, 2021 by Falconeer
Typo

[sagent54]

23 часа назад, mvsgas сказал:

This does not really matter if you guys just want the stabs and flaperons down on a cold jet. But if the questions is whether this is realistic or not? There are to many variables and I highly doubt you can find a good source online. Manuals do not mention this, and photos are not good enough. For example, the photo you posted is of a block 32 that can't even fly.

https://www.f-16.net/aircraft-database/F-16/airframe-profile/2052/

About those variables against online sources:

So, whether the flight control surfaces droop down or not depends on several things.

1. One is the Integrated Servo Actuator (ISA). Some will start bleeding down as soon as the engine shuts down, some will take days. The Horizontal stabs are more susceptible to this since they are heavier than the flaperons. How long after the engine shut down was the photo taken? and hour? 3 days?
2. Another is the mechanics. Many of us tent to push the flaperons up after engine shutdown so you are less likely to crack you skull on them. The opposite is true about the stabs. So if you look at photos, are they after the mechanic raise the surfaces by hand or where they down after shutdown?
3. Another variable is if you turn battery off and there is still pressure on the hydraulics, the control surfaces will go to neutral. Because of this, the flaperons could have reset up even tho their natural position after shutdown is down. Someone sees a video of a Demo viper and see thee flaperons reset up, will think that is the normal behavior when is not.

 

 

 

About 2nd. Does 16 have any locks to flaperons stay in place? You're right about that, they are in up position during maintenance as shown in video below

But still, i think that it is strange to keep fluid pressurized by locking isolation valves because it just increases wear of movable parts of valves and e.t.c. 

Thank you for interest to this theme. One day we'll see this machine to be the best simulation of Block 50 M4.1+ in our time(Or maybe not in our...).

Edited November 11, 2021 by sagent54

[mvsgas]

1 hour ago, sagent54 said:

About 2nd. Does 16 have any locks to flaperons stay in place?

 

 

 

No, the same ISA are used on both flaperons and both stabs. The only different ISA is on the rudder.

 

1 hour ago, sagent54 said:

 One day we'll see this machine to be the best simulation of Block 52 M4.1+ in our time(Or maybe not in our...).
 

 

It should never be that since they are not modeling a block 52, they are modeling a USAF block 50 from 2007. I been saying this for over a decade:

On 5/17/2011 at 3:11 AM, mvsgas said:

What block? From what country? What year? are you guys aiming for. This things all matter in term of what avionics and systems you are trying to modeled, the look of the F-16 and so on. F-16C covers a lot of very different aircraft. (block 25 to 52+ and every country will have different capabilities and most will have different equipment, etc)

Edited November 11, 2021 by mvsgas

[sagent54]

6 минут назад, mvsgas сказал:

No, the same ISA are used on both flaperons and both stabs. The only different ISA is on the rudder.

 

It should never be that since they are not modeling a block 52, they are modeling a USAF block 50 from 2007. I been saying this for over a decade:

 

Sorry, my mistake.

[mvsgas]

No need to apologize. Nothing here is that important. Just an internet forum. Hope I help in some way.