DCS World 1.5.3 A-10C ADI's Turn and Slip indicator question

[maiochine]

Hi all,

 

I did some research about the A-10C ADI the ARU-2B/A and what I understood is that the turn and slip indicator has marks displaced horizontally on the bottom of it (as you can see in the attached picture)

 

The black line mark correspond to rate 1 turn (360 degree turn in 2 minutes) and the white line mark correspond to rate 2 turn (360 degree turn in 1 minute).

 

I tested that in DCS World 1.5.3 in my A-10C wind calm and coordinated turn at 295 KTAS and the results are the following:

 

_ Black Mark= 360 degrees in 4 minutes

 

_White Mark= 360 degrees in 2 minutes.

 

I tested the (TAS/100)+7 formula witch is around 37 degrees bank and it worked I had a rate 1 turn with no problem.

 

Is this a bug or something I am missing?

 

Thanks guys.

 

Mario

[Dahlbeck]

Hmm... What is supposed to point at that scale?

[maiochine]

Hmm... What is supposed to point at that scale?

 

The white bar at the very bottom witch is now in the center under the ball.

[Puma]

Interesting question. I thought that part of the indicator was the slip part. I.e. Indication of the degrees of difference between planes direction of travel and where the nose points. In ideal conditions it would remained centered, even during a turn. A coordinated turn would have zero slip. Min fuel burn, etc. With wind and other effects, i dont think you can use that for turn timing. Could your refernce have been referring to the bank indicators? 30 degree turn being x minutes? Ive seen thise referenced in a lot more navigation docs.

[paulca]

I think the OP is refering to the turn indicator which is below the "yaw ball". It's the two white bars with the other white bar (shown in the middle) as the pointer.

[maiochine]

I think the OP is refering to the turn indicator which is below the "yaw ball". It's the two white bars with the other white bar (shown in the middle) as the pointer.

 

That's correct.

 

ED is this a bug or is there something I am still missing ? Please reply

 

Thanks

[Puma]

Maybe Im changing the subject, but why do you expect slip in a coordinated turn? I thought zero slip was the definition of a coordinated turn?

[Eddie]

The ADI is working correctly, your research regarding the turn needle is incorrect. The turn rate indicator is driven by the HARS system (even with EGI functioning), the needle displaces one needle width per 1.5 degrees per second of turn rate.

 

In other words, the black marks are a half rate turn (4 mins for 360 degrees) and the white marks a standard rate turn (2 mins for 360 degrees).

[maiochine]

The ADI is working correctly, your research regarding the turn needle is incorrect. The turn rate indicator is driven by the HARS system (even with EGI functioning), the needle displaces one needle width per 1.5 degrees per second of turn rate.

 

In other words, the black marks are a half rate turn (4 mins for 360 degrees) and the white marks a standard rate turn (2 mins for 360 degrees).

 

Thanks Eddie for your answer, I kept looking in the A-10 real manual about it and didn't find any information regarding the turn rate value given by the needle !

 

So with the A-10 seems that they use a rate one turn when they perform holding patterns and standard procedures...

 

Thanks again