Compass ?

[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!

[notimejeff]

Thanks Robo, very helpful post. I have done flight planning with FSX, using a modern aeronautical map of southern England with ruler, protractor, old-fashioned wizz wheel flight computer. I then compared results by planning the same flights again with a computerized flight planner. Very instructive exercise.

[Robo.]

Originally Posted by notimejeff

I have done flight planning with FSX, using a modern aeronautical map of southern England with ruler, protractor, old-fashioned wizz wheel flight computer. I then compared results by planning the same flights again with a computerized flight planner. Very instructive exercise.

That's the way to do it, Sir! Nice one. Thanks for your comment, I didn't realise I made a mistake in there.

[VO101_Tom]

Originally Posted by Robo.

In other words, if you fly straight North as shown on your compass you are actually flying 350° geographic.

Hi. The magnetic declination is 10° West (or -10° with other words). The compass show -10° compared to map direction.
So, if you fly to 360° compass direction, you fly to 10° on the map. Not 350°!

[Robo.]

Originally Posted by VO101_Tom

Hi. The magnetic declination is 10° West (or -10° with other words). The compass show -10° compared to map direction.
So, if you fly to 360° compass direction, you fly to 10° on the map. Not 350°!

Yes, that's what I thought, see post 7. Then I thought I made a mistake when reading jeffs post and 'fixed' it on the mission description without thinking too much (just woke up ) I thought he was saying same thing like me and I did wrong math somehow as I actually added 10 in one leg of my original post. Will edit it back and fix it to avoid confusion, cheers Tom.

[VO101_Tom]

Originally Posted by Robo.

Yes, that's what I thought, see post 7. Then I thought I made a mistake when reading jeffs post and 'fixed' it on the mission description without thinking too much (just woke up ) I thought he was saying same thing like me and I did wrong math somehow as I actually added 10 in one leg of my original post. Will edit it back and fix it to avoid confusion, cheers Tom.

Ok

[MB_Avro_UK]

What about wind direction and speed? 'Still air' navigation is easy.

But wind is not a navigational factor in the game.

Wind Finding anyone?

If a wind takes you one degree off track, after 60 miles you'll miss your target by one mile. After 60 kms you'll miss your target by one km.

Best Regards,
MB_Avro.