Compass ?

[Aussie Pilot]

How do i get the compass to work in the Spitfire and Hurricane? They don't seem to have a magnetic compass.

I see old threads about tutorial video's on this but I can't seem to find them.

[raaaid]

its behind the stick

you can always use the sun

[pstyle]

Dire tional giro is behind stick.
It is not calibrated by default, so you need to set it yourself. There is a twist dial just beneath it.

It topples sometimes.


To be honest, learn the map. Fly by visuals, not by instruments. Keep your eyes outside the cockpit, not inside.

[Robo.]

Originally Posted by Aussie Pilot

How do i get the compass to work in the Spitfire and Hurricane? They don't seem to have a magnetic compass.

I see old threads about tutorial video's on this but I can't seem to find them.

III. Instruments

The most important part is understanding the relevant cockpit instruments and using them correctly. Yes, this is where the navigation gets the bad reputation - the instruments used by the RAF are rather awkward to use in the game and not very straightforward in real life either:

P-8 compass



Originally designed for naval use and therefore not exactly a precise instrument for a fighter aircraft. It is just what it looks like it is - a bowl of spirit with magnetised piece of metal in it. The outside part (the rim with the scale and glass top with yellow lines on it) is movable the pilot could rotate it by hand. You should map 2 keys to control it - Increase / Decrease Course setter.

The needle in the bowl is + shaped. One of the bit of this + looks like a letter 'T'. This bit is always pointing at the magnetic north. If you turn or do some manoeveurs, you will find that the compass will drift a bit and settle down eventually. This is completely normal and expected from a bowl of liquid placed in your aircraft. You will need to fly nice and level with both arrows on your turn-slip gauge vertically to get a precise reading. (Did I mention we fly a fighter aircraft?) The good news is though that you can always tell where your magnetic North is and that will need to be good enough for us to navigate.

How did they use in in real life? A pilot would rotate the rim to get the desired HDG on the 12 o'clock position of the instrument, in our case that would be HDG 245, (the exact value will be displayed on the HUD as you rotate the compass). Then he would flip the small lever on the side to lock the P-8 compass and prevent it from drifting as much as possible. This feature is unfortunately not modelled in game. As he flies he would turn the aircraft until the yellow lines match with the T - needle, almost like shown on the above picture. Mind you that has been taken from my Tiger Moth flight as the compass is not hidden inconveniently behind your control stick like in a Spitfire or Hurricane. Mind you the visibility of the instrument was much much better in real life than it is in game.

You will find that I already added the -10° compensation to fly on course based geographical north (the map).

Directional Gyro

Both Hurricane and Spitfire are equipped with more advanced Directional Gyro instrument. It is always placed on the main panel where your main 6 gauges are for night flying, right there in the middle. The view is also obstructed by control stick, but you can get used to that. Basically, we use the P-8 compass to set up our Gyro and keep cross-checking the correct setting with the compass during the whole flight.

Normally, as a part of your pre-flight routine, you would set-up your P-8 compass (by rotating it untill the N on the rim matches with the T - needle) and by doing that you get your actual HDG (the number on the 12 o'clock of the rim). You would set up your gyro to that value and you're all set. Pretty awkward as you need to fiddle with 2 unprecise instruments that tend to drift away. Also, you need to look around your stick as you try to get a correct reading. If you consider you always 'spawn' with your P-8 compass set to HDG 0, you can keep it like that and get the actual reading by mirroring the reading of where the T- needle points.

This is very easy to do and much less complicated. You will also find it much easier to correct your Gyro once in flight.

Let's say you spawn like this:



North is HDG 50, you would need to rotate the compass 50°to get the correct reading for your Gyro. Or you can simply deduct 50 from 360 giving you the actual HDG of 310. You might prefer a simple and quick visual aid and mirror the value onto the other side of the compass:



50°= 310°



Another examples:

140°= 220°



285°= 75°



You adjust your Gyro based on this reading every now and then. You will get pretty fast at it with some practice and it will become natural after a while.

[Aussie Pilot]

Thanks Guy's.

Great info Robo, thats exactly the answer I was hoping for. Much appreciated.

[Frodo170]

Great info. Just one quick question: Does the mirror system adds the -10º compensation of the magnetic declination or you have to add them after the visual calculation?

PD: Sorry for my bad english.

[Robo.]

Originally Posted by Frodo170

Great info. Just one quick question: Does the mirror system adds the -10º compensation of the magnetic declination or you have to add them after the visual calculation?

No, you need to add that yourself afterwards. If you calculate your desired course from the actual map - let's say you want to fly HDG 180, you need to fly 170° in game and via compass and / or gyro. Your instruments show magnetic North whereby the map is based on geographic North.

Sorry to confuse you with the compass on the pic being out of synch - I simply copied & pasted part of bigger post on RAF navigation. Normally, you would turn the rim to match the T 100%-ly. But with the mirror method you don't have to touch your compass at all...

If you're more serious about navigation, I strongly recommend getting a Cliffs of Dover map made by VO101_Tom and printing it out.

[Robo.]

Also, see below a simple cross-country mission I made for my squadmates from ACG (No.501 and No.64 Squadrons RAF) - http://www.aircombatgroup.co.uk/

Mind you I am not real life pilot and I just compiled what I've learned. I really enjoy virtual flying and navigation, although boring when compared to shooting at 109s, is also an essential skill.

For the ones interested, I prepared a training mission based on real life practice: a aspiring pilot would have to fly a prescribed route, calculate the times and headings for each leg and then follow this path in actual flight, reading certain signs spread in the terrain by the crew en route to prove that he's been where he was supposed to be.



MISSION DOWNLOAD

Unzip into your C:\Users\yourname\Documents\1C SoftClub\il-2 sturmovik cliffs of dover\ and play as a single mission. External views are allowed, you are also allowed to pause your game anch check your gyro settings, time, position vs. the map, especially when you're new to this. Try to fly precisely and focus on the instrument usage (has to be set correctly) and your flying technique - keep constant speed, constant altitude, don't drift off course and look out for the letters and for landmarks to cross-check your position! I deliberately chose an area inland we're not really familiar with, but there are some bigger cities and rivers to help with navigation. There is no wind in this mission. The signs you're supposed to be looking for are almost always placed near some major landmarks, small town on direct route, you won't miss them unless you get lost. There are 6 letters in total, one at each turning point and one somewhere in the middle of the leg.

Preparation:

Your goal is to take off from reading airfield and fly following triangle: Reading (T/O) - Winchester - Swindon - Reading (L).



The whole path is shown on the picture above - we place our compass on the map to calculate our heading for leg 1 - Reading to Winchester. We can see the heading is 215. Then we measure the straight line distance between these two places, see that the red line has got a small blue dot every 10 miles. Distance from Reading to Winchester is 34 miles. Flying at 260 mph IAS at some 3000 feet (I suggest you keep this altitude, for you can see the landscape well enough from here) this will take you 7 minutes 30 seconds.

Note - 260mph IAS at 3000ft. is pretty much what you get when flying with correctly trimmed aircraft at full boost (+6.25lbs.), 2600 rpm and radiator normal (50%).

Important note - don't forget 2 things: IAS to TAS correction and Magnetic Heading correction!

You gauge reads 260 mph at the altitude 3000 feet (that is your Indicated Air Speed, IAS), but you will need to add 1% every 600ft to get your True Air Speed (TAS), e.g. the speed you're actually flying against the ground. At 3000 feet, the difference will make cca 5%, that is 13mph. So when your airspeed indicator reads 260 mph, you are actually flying 273 mph at that given altitude. This does not make much of a difference on this practice flight, but it will considerably add up on longer flight. At 260 mph IAS you will fly the distance of 4,5 miles every minute.

Magnetic heading correction - as stated above, if you obtain your HDG from the map (215 in our case), you will need to add 10 degrees to get a heading as shown by your compass. According to your gyro, you will be flying HDG 205 to get from Reading to Winchester.

Leg 2:



Winchester - Swindon
HDG 332 (322)
42 miles
9 minutes 15 seconds at 260 mph IAS at 3000 ft.

Leg 3:



Swindon - Reading
HDG 112 (102)
40 miles
8 minutes 5 seconds at 260 mph IAS at 3000 ft.

Method:

Take off from Reading, set your instruments, climb to desired altitude, use correct engine settings, trim your pane, fly on course above the airfield, check your gyro and start measuring time as you cross the airfield. You will find that Basingstoke is directly on your route, you can use that as a confirmation of your position and course. Also notice that there is a road leading all the way from Reading to Winchester, you can keep it in sight and use it as a guide and conformation that your HDG is correct. When you reach Winchester, circle slightly to the south, fly directly over the city at the next HDG (322) and start measuring time for the second leg. You don't have to turn directly over the city from 205 to 322. You can use the onboard clock to measure time or stopwatch if you wish.

See how good you are, if you can find at least 5 letters, you're very good. 4 out of 6 is a pass in my book as long as you can rtb within 40 minutes. You can record a track if you wish or you can PM me the letters you found, I can confirm if they're right. I 'might' add some extra letters around the area to confuse you when you get lost.

[notimejeff]

Headings measaured on the in-game map or FMB are in True. To get magnetic heading you add 10: the variation in 1940 was !0 degrees West, so add 10 to true to get magnetic. Have I got that wrong?

[Robo.]

Originally Posted by notimejeff

Headings measaured on the in-game map or FMB are in True. To get magnetic heading you add 10: the variation in 1940 was !0 degrees West, so add 10 to true to get magnetic. Have I got that wrong?

You got it right, if you want to fly geographic north, you need to set your in-game compass to 350.



In other words, if you fly straight North as shown on your compass you are actually flying 10° geographic.

*edit* now I see why you were asking, I wrote 'substract' but I added 10 in one bit.

*edit 2* - oh no, got it wrong here, of course you need to substract 10!