grant977 Posted November 2, 2019 Posted November 2, 2019 Had the Tomcat since day one and have two questions more curiosity than complaint or concern. 1. I’m sitting on the deck of the ship in the caucuses. BRC is 270 I know the boat will cause a 10 degree or so error when on the deck or in close proximity. Why does this happen isn’t the INS immune to this? You get proper heading and speed info from the boat during alingment. 2. Apon alignment jester is supposed to set the amount of magnetic deviation depending on my location ie. caucuses. So as about the boat BRC is 270 and FB of 261 Why do I need to set my localizer to 254 to have the proper heading? Thank you.
Spiceman Posted November 2, 2019 Posted November 2, 2019 (edited) Had the Tomcat since day one and have two questions more curiosity than complaint or concern. 1. I’m sitting on the deck of the ship in the caucuses. BRC is 270 I know the boat will cause a 10 degree or so error when on the deck or in close proximity. Why does this happen isn’t the INS immune to this? You get proper heading and speed info from the boat during alingment. 2. Apon alignment jester is supposed to set the amount of magnetic deviation depending on my location ie. caucuses. So as about the boat BRC is 270 and FB of 261 Why do I need to set my localizer to 254 to have the proper heading? Thank you. 1. The INS is indeed immune. The INS has no concept of magnetic heading. It only sees the world in the grid created by the poles and the equator. The error you see is coming from the AHRS which is seeing the magnetic heading via the mag sensor in the vert stab. All heading information on the HSD, VDI, BDHI and HUD comes solely from the AHRS and the INS plays no part in that. Mag Var is entered so that the AWG-9, taking position info from the INS, can show target mag heading and bearing. You get lat/long, speed and true heading from the boat’s INS during alignment. So again, the mag heading error you’re seeing via AHRS is not related and has no bearing (no pun intended) on that whatsoever. 2. Not sure what’s going on there. If the boat is heading 270, and you’re AHRS is properly slaved, you should hold the needles while showing a mag heading of 261. Edited November 2, 2019 by Spiceman Former USN Avionics Tech VF-41 86-90, 93-95 VF-101 90-93 Heatblur Tomcat SME I9-9900K | Gigabyte Z390 Aorus Ultra | 32GB DDR4 3200 | Samsung 970 EVO Plus NVMe | RTX 2070 Super | TM Throttle | VPC Warbird Base TM F-18 Stick
*Aquila* Posted November 3, 2019 Posted November 3, 2019 2. Apon alignment jester is supposed to set the amount of magnetic deviation depending on my location ie. caucuses. So as about the boat BRC is 270 and FB of 261 Why do I need to set my localizer to 254 to have the proper heading? Thank you. If I have a look at the Kobuleti airport, Georgia, on the DCS editor (or F10 view), its runway 07 reads a nice 70° bearing. If I read the HSD, VDI, BDHI and HUD of an F-14 aligned on that runway, I get 64°. Imagine KBL is the aircraft carrier USS Kobuleti. DCS wise, you'll have a 70° BRC. In your plane (F-14 or anything else, that said), your reference will be a 64° BRC. If that runway was an aircraft carrier with an 9° angled flight deck, the FB would be 55°.
lucky-hendrix Posted November 3, 2019 Posted November 3, 2019 (edited) Normally BRC should be given in magnetic heading, so USS Kobuleti should have BRC64. But a lot of mission designer and scripts make the mistake and give a true bearing. Sent from my VTR-L09 using Tapatalk Edited November 4, 2019 by lucky-hendrix
*Aquila* Posted November 3, 2019 Posted November 3, 2019 But a lot of mission designer and scripts make the mistake and tmgice a true bearing. I agree. That's what I clumsily called 'DCS wise'. They mistakenly just read the bearing on the map and report it in the briefing.
grant977 Posted November 3, 2019 Author Posted November 3, 2019 Spiceman thank you for the clarification now things make more since. Now I see why things are happening.
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