Author Topic: Flying and Navigation  (Read 7660 times)

Offline EHM-1997 Alexander

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Flying and Navigation
« on: November 20, 2010, 09:41:58 am »
Flying and Navigation

Which flight level should I use?
For short use FL100-FL200 (turboprops) or FL180-FL300 (jets). For longer flights, use FL180-FL260 (turboprops) or FL340-FL420 (jets). Remember to use odd levels when flying east, even levels when flying west (semi-circular system). The flight level for IFR flights are on the 'thousand' levels (e.g. FL80, FL120, FL210). VFR flights are on the 'five-hundred' levels (FL065, FL085, FL095.

In countries like France the semi-circular system is rotated 90 degrees, because it is not very comfortable to change your flight level each time you cross the 180 degrees line.

What's the difference between Altitude and Flight Level?
Altitude is the vertical position of an aircraft above the mean sea level. An altimeter set on the QNH setting indicates an ALTITUDE. When on the ground at the airport giving the QNH, the altimeter shows the airport altitude.
Flight level is the vertical position of an aircraft above the isobaric surface of 1013,25 hPa (standard altimeter setting). An altimeter set on the standard altimeter setting indicates a FLIGHT LEVEL.
Note that you have to use local QNH below transition level (altitude) and standard setting above transition altitude (flight levels). See the Online Flying Manual for more information.

Flight levels illustrated:

Descending: Set QNH to local when passing the transition level.
Climbing: Set QNH to 1013,25 hPa when passing the transition altitude.
The layer between the Transition Altitude and the Transition Level is called Transition Layer.
29,92 inch/Hg is the same as 1013,25 hPa.

The Transition Altitude can be found in the departure chart. The Transition Flightlevel is determined by the meteorological station and is made available via the ATIS message (not simulated in MS Flight Simulator, but IT IS during online flying). Transition altitudes differ per region. At London Heathrow, it is 6000ft, but in the United States, it is usually around 18000ft!

What's the difference between Ground Speed, True Airspeed and Indicated Airspeed?
Ground Speed is the speed of the plane relative to the ground (you can see this on the GPS window)
True Airspeed is the speed of the aircraft relative to the air. It will differ from Ground Speed because of winds (e.g. if TAS is 400 kts and you have a headwind of 25 kts, your GS will be 375 kts).
Indicated Airspeed - In reality, measuring the speed is based on the pressure of incoming air (pitot tube). But the density (thus the pressure) of the air will decrease as you go higher, so you'll get a much lower IAS (e.g. on the ground, 250 KIAS is equal to 250 kts TAS, but at FL320, 250 KIAS is equal to 410 kts TAS). Note that IAS is a true representation of how the aircraft will behave in respect to stall speeds and other known aircraft characteristics.

What's the difference between True and Magnetic heading?

True Heading gives a heading value starting from absolute north (True North Pole). Magnetic Heading gives the value starting from the Earth's Magnetic North Pole, which is different from the True North Pole. The difference between these two is the 'magnetic variation', indicated in the airport charts.

Winds in a weather report, are relative to the True North. Winds you receive from the tower prior to landing are relative to the Magnetic North.

How to make an ILS landing?

Set GPS/NAV to NAV and set the ILS frequency on NAV1 (to get the ILS frequency, click on the airport in Map View and look at the info box that pops up). Intercept the localizer beam in a 20-30 degree angle at an altitude of 2000 - 3000 ft above ground level and click on APR.

Where to find more help?
Check the MSFS manual on flying and navigation issues.
Read through our training academy files
« Last Edit: November 20, 2010, 09:45:28 am by EHM-1997 Alexander »
EHM-1997 Alexander Worton
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