Question Training Series: Part 3

Hello everyone! This question training series is to help myself, as well as others, better understand the flight procedures that we must follow when in the Expert Server. The rules in the Expert Server are there to help create the most realistic flight environment. So understanding these rules is crucial in order to keep the Expert Server the way it was intended to be. Here is today’s question:

Landing lights are supposed to be turned off when passing 10000 ft and turned on when going below 10000 ft. Altitudes are measured in many different ways, however. So, are we using AGL, MSL, or AAL?

i think it would be MSL.

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why was it dealeted?

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From the FAA Manual:

" The FAA has a voluntary pilot safety program, Operation Lights On, to enhance the see-and-avoid concept. Pilots are encouraged to turn on their landing lights during takeoff; i.e., either after takeoff clearance has been received or when beginning takeoff roll. Pilots are further encouraged to turn on their landing lights when operating below 10,000 feet, day or night, especially when operating within 10 miles of any airport, or in conditions of reduced visibility and in areas where flocks of birds may be expected, i.e., coastal areas, lake areas, around refuse dumps, etc. Although turning on aircraft lights does enhance the see-and-avoid concept, pilots should not become complacent about keeping a sharp lookout for other aircraft. Not all aircraft are equipped with lights and some pilots may not have their lights turned on. Aircraft manufacturer’s recommendations for the operation of landing lights and electrical systems should be observed."

While it doesn’t state what type of altitude is used, I conclude that it is probably AAL, as the reason for the usage of landing lights is to warn other low-flying pilots around the specific airport as well as birds.
It isn’t compulsory though, as some airlines use 5,000ft for example as well!

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Okay, thanks! Do you know what altitude type (AGL or MSL) you would use to add the field elevation to? For example, if you were at an airport that had a field elevation of 100 ft, would you add this to your AGL elevation or to your MSL elevation to find your altitude AAL?

In this example, your AAL would actually be 0ft as you are at the aerodrome. AGL or Altitude Above Ground Level is often similar to AAL, but it varies depending on the surrounding hills and mountains around the aerodrome and always refers to your altitude above the ground beneath you and doesn’t relate to an airport, while AAL only takes the airport elevation. Normally you get the AAL by subtracting the airport elevation from your MSL.
If you are at an airport at 100ft, your AAL would be 0ft as you are at the airport you’re referring to. At the same time, your MSL indicator would show 100ft (because the airport elevation is always in MSL), as you are 100ft above sea level. Your AGL indicator would also show 0ft, as you are on the ground. When you then depart the airport and fly over a mountainous region you could have the following scenario: You climbed till 10000ft MSL. This would mean you are at 9900ft above the aerodrome. However, due to the mountains beneath you, you might only be at 4500ft AGL for example.

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Wouldn’t you subtract from your MSL altitude? Let’s say, for example, you’re at 10000ft MSL above an airport with an elevation of 5000ft MSL. Your AAL altitude would be 5000ft, not 15000ft.

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Yeah, sorry. I meant that, but didn’t use the right word (my English is sadly far from perfect). Corrected it

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Thanks! When you are in the HUD view, is the altitude being shown there in MSL?

Yes, the main altitude on the left is displayed as MSL. You can view your AGL altitude by selecting it as one of your status bar slots.

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I know infinite flight issues violations based on MSL

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I however use AGL if im going into a high altitude airport like Denver.

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Okay, thanks everyone!