DCS Mi-8: Doppler Navigation Tutorial

[@stuart-travels]

For some reason I left this system for a while before watching your video assuming it wouldn't be a great nav tool. It's actually really good, so quick to set-up and much less of a pain to use than the Garmin. it is also perfect for the SAR server. Also just want to add that this series is one of the best tutorial series on any module in DCS and I have been through a lot of them. Absolutely excellent work and I really appreciate what you have created.

[@RoamingAdhocrat]

The English cockpit has a couple of bugs here - the three numbers should be labelled "LATERAL DEVIATION KM", "DISTANCE KM", and "COURSE ANGLE" (page 109 of the manual).

[@PizzicatoUK]

Great work. Really clearly demonstrated and concisely explained.

[@peterwassmuth4014]

Awesome as usually!! 100%

[@pierre-michelleblanc7158]

merci beaucoup thank you a lot !! you literaly show where to light on the analogic systeme doppler,, behind the co-pilot seat ,, lol meci ,,,,,i spent so much time to find it,,, ,, so now,, that will be usefull to know .👍👍

[@tedwaetford]

Thanks for your tutorials, they are my go-to for the hip. However you should really re-do this one to include managing magnetic deviation. It really is wrong without it - miss the target on log range flights! Info on finding the appropriate deviation for each map airport (ie ~6 for Caucasus, ~12 for Nevada) and how to apply it would be very useful for your viewers.

[@vsTerminus]

Yea, that's a good point. I'll put it on the list. I have a few of the older tutorials that need to be re-done and I was never totally happy with this one. The magvar thing just solidifies it. Thanks for the feedback!

[@Slipmasina]

Really nice tutorials! Advanced, but easy to understand! I hope you will have energy to make the same for L-39 :)

[@vsTerminus]

I don't actually own the L-39, sorry!

[@vsTerminus]

As an update, I picked up the L-39 during a sale. It's fun, but I still don't have any plans to do a tutorial series on it. I'm struggling to find time for the Mi-8 series as it is :)

[@Ghazibinhafiz]

Thank you very much for this great video. flying all these years and I was wondering what is doppler navigation is?. I really like the video and your presentation. Thanks again

[@jimschlichting3616]

Hi, thanks so much for this and your other tutorials on the Mi8!! Much needed. A follow-up question. I think I understand your explanation of the difference between the "drift angle KM", which gives the distance you're off the vector you input into the Doppler system upfront, and the "drift angle," which I understand shows you how far off in degrees you're actually heading at that moment as compared with the reading in the HSI just above (which reflects where the nose is pointed). But how is the drift angle related to what shows in the slip turn indicators?? Thanks for any clarifications/corrections!!

[@vsTerminus]

Hey Jim, you're correct about the difference between the drift angle indicator and the Doppler drift km readout. But how do those relate to the turn & slip indicators? They don't. Not really. T&S measure instantaneous G forces being applied to the helicopter: Specifically Yaw and Gravity. If you aren't banked or turning, T&S will be centered. However that doesn't mean you aren't drifting. "Inherent Sideslip" from the tail rotor will cause you to drift left even when the slip ball is centered, and because you're not banked and it's not a yaw force, the T&S indicator won't see it. Doppler instruments, however, are comparing your position in the air to the ground below you and they will see and report the drift. They use the ground as an external point of reference. If you correct for said drift (by banking right) and the Doppler instruments report 0, the slip ball will sit slightly right of center. They measure different things in different ways, and even though the information they provide can overlap a bit, they aren't connected and are only loosely related. Does that make sense?

[@jimschlichting3616]

@@vsTerminus Thanks for the explanation. I think I'm showing my ignorance about turn & slip, in particular slip. When I read about forward-slip and slide-slip, I take it that the fuselage is pointed in one direction, but the aircraft is moving in another. That sounds a lot like flying to take account of "drift angle," in that you compensate for an 8 degree left drift angle by pointing the fuselage 8 degrees to the right of the direction you want the aircraft to be heading. If you're on the vector input into the Doppler, the "draft angle " will remain zero. Or if you're 2 km off the vector, you'll remain 2 km off as you're heading in the correct direction and not closing to the vector itself. Is there some overlap here, or am I just confused?? Thanks again.

[@vsTerminus]

@@jimschlichting3616 I think you basically have it. If you draw a line from A to B for your trip, the Doppler Drift KM readout will only tell you how far off that line you are and in which direction. It has nothing to do with the helicopter's orientation or slip or anything, it is your position relative to the intended course line. The Doppler Drift Gauge (The round one to the left of the square Doppler Nav panel) doesn't know about your course, it's just telling you if your nose is pointed the same way as your actual direction of movement. We use the Slip Ball and Turn Indicator to get similar information; When they are centered (in forward level flight) all they are telling us is that they aren't detecting any yaw or bank right now. We take that to mean "I am not slipping/drifting/turning", and in an airplane that holds true. But in a helicopter it fails because those instruments don't see the drift caused by the tail rotor (Where as the Doppler Drift Gauge does see it). So there is overlap between Turn & Slip indicator and the Doppler Drift Gauge, but no overlap with the Doppler Navigation panel. Does that make sense now?

[@jimschlichting3616]

@@vsTerminus Yes, thanks. Your description of how the slip ball is supposed to react got me searching the Internet for further description. Chapter 9 of the FAA handbook had some discussion that I thought very helpful in explaining how to interpret how the slip ball functions. Again, thank you so much for your videos and your tutelage!

[@Tridan24]

Your tutorials are awesome bro I really do enjoy them as I'm a noob with this sort of stuff but these are explained really well. Just a quick question if 02 is the heading then 002.0 is the reading on the dial?... thx again.

[@fh4635]

Hello Terminus, thanks a lot for your tutorials. Shouldn't the magnetic deviation be taken into account when setting the angle for Doppler?

[@vsTerminus]

Yes it should. Good catch, thank you!

[@Dcs-Brasil]

Very good thx!

[@fenny1578]

Am I crazy or is the drift angle indicator the same one used on the Mi-2 for making sure you're in coordinated flight when using the weapons systems?

[@vsTerminus]

I'm not as familiar with the Mi-2's cockpit but it would not surprise me. Soviet doctrine heavily favored reusing existing parts wherever possible. It's why you see so many common elements in the various Russian cockpits in DCS. So it probably is exactly the same.

[@Nomadesband]

Hello comrade, let me ask you something, im doing the "shift metode" where we supose to use ns430, i also duplicate de data to doppler navigation in km and the angle, double checking this one on garmin and on rule via map, switching between land and sea everytime is needed, but somehow always with same result, after reach the plataform doppler show 9km of course to the left, already try 3 times with same result, im glad if you could help me this out, thx

[@RoamingAdhocrat]

hi Iago! When you set the course angle (or "map angle") is it a magnetic or true bearing? It needs to be true.

[@Nomadesband]

@@RoamingAdhocrat thx for replying, i was starting in dcs when made this comment, find out that im drifting everytime, lost doppler precision etc, basically not using corretly the instruments, after fixing that works nice

[@AdmiralQuality]

Thanks for showing me how to use this! I always thought it was some kind of magnetic deviation calculator or something like that. So I tried it for the first time, used it to fly from McCarran to Hoover dam. I almost got there but then a DOPPLER FAIL light came on. Was this due to the steep terrain around the dam? So best to avoid in mountain missions?

[@vsTerminus]

"Doppler Fail" will light up any time you pitch or roll too far. The doppler works by bouncing a signal off the ground and receiving it again. The emitter is the big box looking thing hanging off the tail. If you point it too far away from the ground it can't do its job anymore so Doppler Fail comes on. Try your best to avoid it, especially for long periods of time, because each time it happens it will throw out the accuracy of the readouts by just a little bit, and over time that can accumulate into a significant margin of error.

[@AdmiralQuality]

@@vsTerminus I've had it happen a few more times and it seems to get stuck that way. Even powering cycling the system won't reset it.

[@vsTerminus]

@@AdmiralQuality The doppler system can totally fail / break like most other systems in the helicopter. What happens before the light comes on?

[@AdmiralQuality]

@@vsTerminus Nothing notable. I'm wondering if maybe there's a bug in the failure system or something like that.