[NO BUG] L/R HYD fail: Observations

[Moafuleum]

Pretty much what the title says. After i took some damage in battle and lost hydraulic pressure, I activated the emergency hydraulic system (which had been activated automatically anyway) and a was able to return home. I saved the track file but i restarted the mission quite often (bc i was shot down quite a few times) by using Ctrl+R and somehow the track file is messed up and is unusable. However I tried to replicate it and was successful by creating a mission in the ME and set both HYD pumps to fail right from the beginning. The following i observed:

 

• The system did not pressurize the FLT and COMB HYD system. According to the manual the EMER HYD pressurizes the FLT HYD system
  
• I was able to deploy the flaps without any issues. Strange since according to the manual, secondary systems like flaps and gear need comb HYD pressure
  
  
• I was not able to deploy the landing gear. I needed to twist the landing gear lever to extend the gear in "emergency mode". Correct according to manual: needs comb HYD
  
  
• I was also not able to activate the DLC. Pressing this button still drops flares. I am not sure why this was the case. According to the manual for the DLC to engage, the flaps and gear must be deployed. Maybe because I was not able to sweep the wings fully forward (but they were almost completely forward) due to hydraulic pressure loss.
  
  
• I was able to roll also with the spoilers. Lateral stick movement with both main hydraulic pumps failed should only cause the tail surfaces to move but not the spoilers on the wing. BUG?
  
• After landing, the spoilers deployed to assist braking. Now I am confused. The DLC did not deploy, however spoiler brake and roll with spoilers work?
  
  
• Wheel brakes did work. I did a quick search through the manual and I figured that they are operated by a hydraulic system but I couldn't find from which one.
  
  

I append a track file. However don't expect too much from it. I reviewed one of them and it is messed up. In the first one i landed on the runway but in the trk I landed on the desert sand and crashed after rolling over some sand dune :D Thus, they frankly don't show exactly what was going on...

 

 

Thanks for having a look (or just correct me if I was not able to study the manual correctly)

f14hydraulicfail.trk

f14hydraulicfail1.trk

Edited April 14, 2019 by IronMike

[sLYFa]

According to the manual the EMER HYD pressurizes the FLT HYD system

The backup flight module only pressurize the part of the COMBINED hydraulic system that drives the the rudder and the horizontal stabs. It does not pressurize the entire combined hydraulic system, hence the gauge will still read zero.

I was able to deploy the flaps without any issues. Strange since according to the manual, secondary systems like flaps and gear need comb HYD pressure[/b]

Flaps have a backup mode that uses the outboard spoiler module (which is electrically driven) to operate flaps. This will only extend the main flaps and slats, not the axiliary flaps.

I was also not able to activate the DLC. Pressing this button still drops flares. I am not sure why this was the case. According to the manual for the DLC to engage, the flaps and gear must be deployed. Maybe because I was not able to sweep the wings fully forward (but they were almost completely forward) due to hydraulic pressure loss.

Without hydraulic pressure in the combined system, inboard spoilers (i.e DLC) won't deploy

 

I was able to roll also with the spoilers. Lateral stick movement with both main hydraulic pumps failed should only cause the tail surfaces to move but not the spoilers on the wing. BUG?

Outboard spoilers should still work as they are operated by a seperate electrically driven hydraulic pump. Inboard spoilers should not work though.

After landing, the spoilers deployed to assist braking. Now I am confused. The DLC did not deploy, however spoiler brake and roll with spoilers work?

Again, only outboard spoilers should work

Wheel brakes did work. I did a quick search through the manual and I figured that they are operated by a hydraulic system but I couldn't find from which one.

The brakes are normally operated by the combined system. For emergency operation, there are two brake pressure accumulators installed on the aircraft (IIRC in the front wheel bay). Whenever combined hydraulic pressure drops below approx 1500psi, the system automatically transfers to draw pressure from one of these accumulators as follows:

Applying toe brakes will draw pressure from the auxiliary pressure accumulator, pulling the parking brake will draw pressure from the parking brake pressure accumulator. The pressure in both accumulators can be seen on the pressure gauge below the HSD.

Edited April 3, 2019 by sLYFa

[Victory205]

"sLYFa" knows his systems. Well done.

[Moafuleum]

Ah I see...

Did I miss it in the manual or is a read in the NATOPS nacessary?

 

However thanks for the answer! One issue less in the bug forum section!

[Airhunter]

The brake and accu pressure gauges are not simuated right now though. They are in the red zone at all times.

[QuiGon]

The brake and accu pressure gauges are not simuated right now though. They are in the red zone at all times.

They are documented in the DCS manual though:

- http://www.heatblur.se/F-14Manual/cockpit.html#emergency-brake-pressure-indicator

- http://www.heatblur.se/F-14Manual/general.html#wheelbrakes

- http://www.heatblur.se/F-14Manual/general.html#id1

Edited April 3, 2019 by QuiGon

[sLYFa]

Ah I see...

Did I miss it in the manual or is a read in the NATOPS nacessary?

I didn't read much of HB's manual but it might be in there. All the info I posted is from the NATOPS flight manual. But assuming HB simulates thing thoroughly, it should also apply to DCS.

I generally highly recommend reading NAVAIR 01-F14AAA-1. I know there are a lot of pages but most systems and procedures descriptions are short (sometimes even lacking though) and on point from a pilot perspective. And it is a well structured document so you can quickly look up something in case you forgot it. The foldouts are also gold IMHO.

 

"sLYFa" knows his systems. Well done.

Thank you sir!

[Moafuleum]

I have the NATOPS here i must admit but didn't find the strength to go through comprehensively.

 

Anyway thanks for clarification! It turns out a module is much more fun when one is forced to apply emergency procedures and not only fly with an invincible UFO