A couple of quick questions

[funkster]

Hi

I have looked through various posts, manuals but cant seem to get the specific answers for the following:

• When do you use the Fuel Pump (left side panel)? I know you can use it instead of the manual pump in start up but aside from that? I have seen some suggestions that it should be on for the entire flight but then other official start ups not stating its use?  
• What specifically does the Oxygen switch do? Oxygen seems to be provided depending on Altitude (as displayed on dials). Flipping the switch seems to override this? If this is correct when would this be used? 

Thanks in advance. 

[razo+r]

1) When flying high you need the fuel pump. If left off, you will not be able to climb very high (I think somewhere around 15K feet max.)

2) If i remember the oxygen switch puts it to full open? So, for emergency use.

[grafspee]

As it is modelled in dcs right now, fuel pump should be turned on after engine start up. If not you will encounter fuel starvation after certain aerobatics and fuel vapor lock at high alt.

Oxygen valve has 2 positions normal operation and emergency operation. Default position is normal operation. If you flip valve in to emergency you have oxygen just for couple of minutes, it gives chance so pilot can descent to safe alt.

Edited October 21, 2022 by grafspee

[71st_AH Rob]

In fact, the electronic fuel pump should be the only fuel pump, the 'wobble' pump is a legacy of Merlin 61 and 63 production line.  There appears to be an overlap when the Merlin 66 was introduced in March of 43 and it is not required for the start up procedure.  According to the Pilot Notes for a Merlin 66 LF. Mk IX, you turn the pump on until the fuel pressure light goes out, then turn it off and start the engine. Turning it back on as needed only after the cut out switch is in the forward position to prevent flooding. In practice I just turn it on prior to taxiing and forget it.  

[funkster]

Thanks all 

Edited October 21, 2022 by funkster

[Skewgear]

The electric fuel pump toggled from the switch on the left hand panel is a substitute for the wobble pump on the cockpit RHS. Turn it on before engine start until the fuel pressure light goes out; at altitude (~17,000ft+) you need it on otherwise the engine will cough and die from fuel starvation.

Oxygen is not modelled in the DCS Spitfire. Compare and contrast with the Me109K, where failing to use it at high altitudes means your pilot eventually blacks out.

[grafspee]

29 minutes ago, Skewgear said:

Oxygen is not modelled in the DCS Spitfire. Compare and contrast with the Me109K, where failing to use it at high altitudes means your pilot eventually blacks out.

You cant compare it with 109 or 190 system because they are different, spitfire p-47 mosquito and P-51 uses same oxygen mixer which is not equipped with cut off valve but only is equipped with valve which allow to bypass mixer and use pure oxygen in case of emergency, so you can't shut off oxygen in those planes.

In 109 and 190 you can only open or close oxygen supply and you can black out when you fail to open oxygen. Check blinker in spitfire it is working w/o switching anything in cockpit so oxygen supply is armed.

[funkster]

BtW I can confirm that oxygen is modelled on spit as this is why i asked the question. Basically i had switched the oxygen switch to emergency supply thinking it was just off/on switch. i started getting double vision , then worsening vission / grey out when i was at alttitude and noted that the o2 had run out!  I therefore assumed the switch was not just an on / off ...thus one of my questions.

[grafspee]

@funkster Exactly switching in to emergency will drain O2 very fast. If it comes to O2 use, Axis plane require to open valve, Allies planes require nothing, you are good to go.