Altitudes

[joojoo]

Hey to all

 

I want to ask what is the difference between barometric and radar alt selection? Why when I try to land in the carrier the altimeter is in minus feet? Maybe I have to change something?

[VaporFlow]

Hi joojoo, the altimeter altitude is measured as pressure altitude, the radar altitude is measured as the altitude of the aircraft to the ground/obstacle beneath it.

 

Here you have an image to "clarify"

 

Edited June 15, 2020 by HC.Coyote
added img

[joojoo]

Thanx! in what way I can change these options in F18?

[randomTOTEN]

Pressure correction is on the Standby Altimeter, below the RDDI

HUD altitude source selection is below the UFC

The radio altimeter is by your right knee. You need to turn it on by moving the triangle to any position other than 0 ft.

[joojoo]

Thank you Random TOTEN, and how can I change the minus indications in feet, what does it mean an indication -300 feet for instance?

[randomTOTEN]

[RaisedByWolves]

Rotate the knob on the altimeter when on the carrier until it shows +70 feet on the HUD. Close enough for government work.

[Harker]

Thank you Random TOTEN, and how can I change the minus indications in feet, what does it mean an indication -300 feet for instance?

The mission lists the QNH and QFE altimeter pressure settings in the briefing. You can find their descriptions here: https://www.skybrary.aero/index.php/Altimeter_Pressure_Settings.

You normally want to use QNH, which corresponds to your local pressure and when you transition above 18,000 ft MSL, you set your altimeter to 29.92, so all aircraft above that altitude have the same setting, to avoid miscommunication and possible collisions.

If your barometric altimeter reads -300 ft, it means that it's set up incorrectly. If you leave it at the default setting of 29.92 and the region you are in has higher local atmospheric pressure, it'll read negative altitude. Pressure increases as you go lower, so if it thinks that 0 altitude corresponds to a 29.92 setting and the local pressure is 30.92, it'll deduce that you're lower than its zero point.

Edited June 15, 2020 by Harker