Course Correction Magnetic Declination KA-50 Black Shark

[MortalMando]

Hello Shark pilots! 
I have a question about the INU alignment. With the "accelerated alignment (AA)" and "Normal alignment (NA)" modes of the INU, a course correction must be carried out afterwards. The manual says that you have to enter the true heading into the magnetic declination encoder and then set the navigation mode from Gyro to Manual. If you then go back to gyro, you should compare it with the magnetic compass.

Unfortunately, I do hardly notice any change in the orientation of the HSI. On the contrary, subjectively I sometimes even have the impression that the HSI is no longer correctly aligned in the park position, which tempts me to set a value other than the true heading in the magnetic declination encoder. In addition, the manual does not mention any of the settings on the Latitude selection rotary.

So my question is, how do I align the helicopter correctly? What exactly should I pay attention to when comparing HSI and compass? Do I need to use the Latitude selection indicator?

This might go a little in depth into the systems. I am thankful for clarification.

Image from the Manual attached.

[primus_TR]

If you (or anyone else) still need this information: 

 

Using the Magnetic Heading for alignment is more practical than using Manual alignment.

For alignment by Magnetic Heading (you can use this both when landed or in the air):

1. Check the magnetic variation for your location in F10 map with the compass rose. 

2. Dial in the magnetic variation (for example, for Minvody, it is 6.7).

3. Set the Man/Gyro/MH switch to MH

4. Wait for the HSI to align, and then switch it back to Gyro. 

That's it for MH.

For Manual (you can use this only when landed): 

1. Check the magnetic variation for your location in F10 map with the compass rose. 

2. Note the compass indication. Your true heading will be compass heading plus magnetic variation. (e.g. if compass shows 210, than your true heading will be 216.7 if at Minvody). 

3. Set the Man/Gyro/MH switch to Man.

4. Dial in the true heading.

5. Wait for the HSI to align, and then switch Man/Gyro/MH back to Gyro. 

 

[zerO_crash]

What is practical is highly dependant on the situation. On the ground, you should use the manual method, rather than the magnetic one, as different metal objects nearby as well as visual obstructions will indeed alter the magnetic reading as seen from your position. It is therefore something that you have to chose on a case-by-case basis. Manual can only be performed on the ground, however it gives you a correct readout. Magnetic, can both be performed on the ground as well as in the air, though on the ground, as stated before, it will be subject to interference from primarily metal objects around, resulting in erroneous readout.

[primus_TR]

6 hours ago, zerO_crash said:

What is practical is highly dependant on the situation. On the ground, you should use the manual method, rather than the magnetic one, as different metal objects nearby as well as visual obstructions will indeed alter the magnetic reading as seen from your position. It is therefore something that you have to chose on a case-by-case basis. Manual can only be performed on the ground, however it gives you a correct readout. Magnetic, can both be performed on the ground as well as in the air, though on the ground, as stated before, it will be subject to interference from primarily metal objects around, resulting in erroneous readout. 

Unless power lines or very large metal objects are close by, metal objects within the aircraft are more relevant for magnetic compass correction. There is no downside to using magnetic inu adjustment when on the ground as long as you've not landed on a big metal ship or sitting under power lines. In any case, magnetic interference from metal objects is not modeled in the sim, hence a non-issue 

Edited June 15, 2023 by primus_TR

[zerO_crash]

4 hours ago, primus_TR said:

Unless power lines or very large metal objects are close by, metal objects within the aircraft are more relevant for magnetic compass correction. There is no downside to using magnetic inu adjustment when on the ground as long as you've not landed on a big metal ship or sitting under power lines. In any case, magnetic interference from metal objects is not modeled in the sim, hence a non-issue 

 

There don´t have to be any large metal objects, in fact, objects of any size that are metal will cause interference. Whether it is an APU-cart, a truck or a car for that matter, they all will potentially affect your readout. Manual section 9-20, read the "NOTE", hence, it IS an issue. Apparently, magnetic interference is indeed coded in and will indeed interfer with the compass/alignment. That´s why it´s important to get correct info out there.

Edited June 15, 2023 by zerO_crash

[primus_TR]

10 hours ago, zerO_crash said:

There don´t have to be any large metal objects, in fact, objects of any size that are metal will cause interference. Whether it is an APU-cart, a truck or a car for that matter, they all will potentially affect your readout. Manual section 9-20, read the "NOTE", hence, it IS an issue. Apparently, magnetic interference is indeed coded in and will indeed interfer with the compass/alignment. That´s why it´s important to get correct info out there.

 

Not to be argumentative, but the manual also contains general information about the systems for information only, and not all of them are modelled in the sim. Believe me, I've been around since Flanker 2.0 times (way before LoMac), and had Black Shark since version 1, and I can assure you that magnetic interference from metal objects is not modeled in this sim. You can easily verify this: bring your mobile phone closer to the compass and see if it causes interference  (joke). Seriously though, to test this, you can set your chopper close to another chopper (a huge metal object that should normally cause magnetic interference) and see if the magnetic compass moves or is disrupted in any way.  

[zerO_crash]

On 6/16/2023 at 10:02 AM, primus_TR said:

Not to be argumentative, but the manual also contains general information about the systems for information only, and not all of them are modelled in the sim. Believe me, I've been around since Flanker 2.0 times (way before LoMac), and had Black Shark since version 1, and I can assure you that magnetic interference from metal objects is not modeled in this sim. You can easily verify this: bring your mobile phone closer to the compass and see if it causes interference  (joke). Seriously though, to test this, you can set your chopper close to another chopper (a huge metal object that should normally cause magnetic interference) and see if the magnetic compass moves or is disrupted in any way.  

Well I´ve been on since LOMAC, so don´t worry. As to the manuals containing mistakes and poor wording (in certain places), there still is a logic to certain aspects of them. Typically, if a feature is not implemented, they state so. They also don´t typically mention effects, which are not implemented. Rather, I've seen the opposite - lack of description regarding dynamics/systems/features that have been implemented. I have personally seen compass go off at times in certain modules (MiG-21Bis, Mi-8MTV2/Mi-24P) (not due to heavy maneuvering). I´ll have to check it once I get my new PC, but I don´t see anywhere in the manual that this feature is not implemented. Again, notice, it states "can", not necessarily "will". That´s the simulator-side of things.

 

As to IRL, depending on how you treat the simulator (makes little sense to treat it as a "game", but do yourself good...), it´s mostly logical to actually adhere to specific habits/norms/rules with regards to authenticity and actually learn what is proper. You could abuse current bugs/issues in DCS to your advantage, but then it makes very little sense then to run a simulated environment. Just because e.g. MiG-21Bis had an issue with the radar where flying upside-down made it not present any ground clutter, didn´t mean you should fly it like that either. 

[primus_TR]

This exchange has become irrevelant to the topic at hand, but just to indulge you one last time: I never said anything about mistakes or poor wording in the manual. Those are your words. On the contrary, KA50 has a particularly well-written manual. But sometimes the reader may need a little more familiarity with ED's style to tell what exactly is modelled, and what is not from the information provided in manuals.

The fluctiations you'd see in compass during flight, not only in mig21, mi8, but in all the other modules (assuming that you are actually referring to the compass, and not the HSI), will be due to bank or pitch angle, and will settle down after coming back to level flight. Since we were talking about INU alignment on the ground, I don't see how it is relevant In any case, magnetic deviation due to interference from metal objects is not modelled in the game. but believe how you wish, false as it may be. I explained you a method to very easily verify it, but obviously you have no interest in such verification. And as regards your other irrelevant (to the topic at hand) comments, I'll let you believe what you want, facts notwithstanding. I'm not interested in further exchange with you. Have a great day. 

[zerO_crash]

This exchange is irrelevant becuase your recommendation is completely off. It was "ME" who stated that the manuals do contain errors and poor wording, never claimed it came from you. If you´ve ever seen a real aircraft manual, you´d notice how much essential info is missing. Furthermore, in certain cases (subjects), the wording leaves a room for interpretation, which is not too good. One example here being simply the fact that a whole section on trimming alone is missing, which is a must in pretty much any aircraft. The topic is simply too important to convey it in simplified 2-3 page text.

 

Read again what I wrote, those are not fluctuations due to maneuvering. I made it pretty clear! We derail, becuase you, recommend something against the manual and logic. You are "helping" by introducing a faulty recommendation. I´ll double check magnetic variance (due to nearby objects), however magnetic variance due to the helicopter itself has been, and is modelled. It has been there ever since BS2 - manual 6-52. By default, the helicopter has magnetic variance which will introduce fault into the INU-alignment. Case closed!

Edited June 18, 2023 by zerO_crash

[zerO_crash]

A somewhat late update for anyone reading the topic. Here, Chizh explains precisely why correcting heading by the magnetic method is only recommended in the case of necessity (i.e. if you need to reset the INU in flight due to a failiure/damage/loss of power), in essence expanding on what I mentioned:

 

"Вопрос:  Какая разница между магнитной коррекцией (МК) и коррекцией по заданному курсу (ЗК)?
Ответ: Коррекция по магнитному курсу не даст требуемой точности, такая коррекция дает ошибки от половины градуса до единиц градусов, что будет заметно при работе с запомненными точками на больших удалениях. Это происходит потому, что сам магнитный компас имеет погрешность в несколько десятых долей градуса, а при вибрациях и тем более в полете показания компаса считываются с точностью вплоть до 3-5 градусов.

Коррекция по заданному курсу позволяет получить точность вплоть до 0.1 градуса при достаточно кропотливых измерениях истинного курса вертолета с использованием карты и линейки."

 

In any other case than failiure/damage/loss of power, you wish to perform the manual method - for increased accuracy.

 

Because of people who have no idea of a given subject, expressing their "quick solutions", it furthers misunderstanding and inability by other systems to work properly. In this specific case, correcting heading with MG, makes "precision" alignment useless with datalink, as it introduces too much inaccuracy.

 

If you want to have to most accurate INS, and usable datalink, then perform a "precision" alignment on ground power (if not possible, do it on batteries), engines running are a no-go. Furthermore, perform a manual heading correction. That will allow as low drift as 1% - 2% of the total flight route. Also important, is how you fly. Remember, that above 12* pitch/roll, the doppler won't provide accurate input, as such, it will perform off "memory" mode. That will intoduce more drift. If you fly for 60 minutes in memory mode (higher altitude and/or above 12* pitch/roll), the output from PrPNK will turn to readings off TsVM-N - reckoning mode (air speed) as it considers that more accurate at this point. That's the least accurate measurement of patch, but also least probable (you'd have to perform a flight at high altitude most of the route).

 

In layman's terms; for most accuracy of the PVI-800, after performing "precise" alignment (ground power/batteries), make sure to fly relatively stable without prolonged changes in pitch/roll. Occasional input from "memory"-mode is not too noticeable, but heavy maneuvering will require a INS FIX before moving in on AO. The accuracy will primarily be noticed with datalink and "TGT PNT" usage.

 

Enjoy!

Edited May 3, 2024 by zerO_crash