Here's an example what it might looks like for an aircraft flying through various pressure regions:. Above the transition altitude, altimeter readings are communicated as "flight levels," not as hundreds or thousands of feet. When you set your altimeter to When you're flying in the flight levels with a standard altimeter setting of You'd only come close to reading true altitude from your altimeter under standard atmospheric conditions.
A transition altitude is where you set the altimeter to standard when climbing. ATC determines this altitude usually broadcast over ATIS , and you must revert your STD altimeter setting to the local altimeter setting on descent while passing through the transition level. In the United States, when the surface-based atmospheric pressure in the local area drops below Otherwise, someone flying IFR at 17, feet MSL could be closer than 1, feet to aircraft flying in the lower flight levels.
A transition LAYER is simply the space in-between, and varies in depth from country to country per national regulations. Up to 1, feet of altitude can be marked as a transition layer in many nations. As you climb into the transition layer through the transition altitude , you set a STD altimeter setting. As you descend through the transition level, you revert to the local altimeter setting and thus enter the transition layer.
Vertical separation during enroute flight shall be expressed in terms of flight level at all times. Except when flying in the vicinity of an aerodrome at or below transition altitude.
A QNH altimeter setting is made available in the routine approach and landing instructions. The altimeter setting obtained on radio telephone shall be read back to the ATS unit. Vertical positioning of aircraft during approach is controlled by reference to flight levels until reaching the transition level below which vertical positioning is controlled by reference to altitude.
The relevant portions of 2. The levels at which a flight is to be conducted shall be specified in a flight plan -. All VFR flights above 3, Ft from the ground and water and all IFR flights, when in level cruising flight levels appropriate to their magnetic tracks in accordance with the table set forth hereunder. In controlled airspace, the correlation of levels to track as prescribed in Tables of cruising levels shall not apply whenever otherwise indicated in Air Traffic Control Clearances.
All flights shall be conducted in accordance with Instrument Flight Rules when operated at or above FL A pilot-in-command shall read back level clearance. When required, the pilot-in-command may be instructed to reach an assigned level by a specified time or position and at a specified rate of climb or descend.
The pilot-in-command shall advise ATC immediately if he is doubtful whether the assigned level can be reached as instructed. An aircraft may be required to change level at a time, place or rate specified by ATC.
The pilot-in-command shall effect a level change as soon as possible but not later than 1 minute after the time specified. When leaving or passing through such other levels as may be specified by ATC. From to Name of the aerodrome. Transition altitude in Feet.
The pilot shall report position as soon as possible after the aircraft has passed over each designated reporting point of ATS route defined by designated significant points. Additional reports over other points may be requested by ATC when so required for air traffic management ATM purposes.
On routes not defined by designated significant points, position reports shall be made after the first half hour of flight and at hourly interval thereafter.
The position reports required by 8. Flights may be exempted from making position reports at each designated reporting point or interval, if adequate flight progress data is available from radar. Ten 10 minutes prior to crossing an established ATS route, pilot-in-command shall transmit the following information to the ATC unit serving the airspace-.
Aircraft will join or cross ATS routes at or close to designated reporting points. Aircraft crossing the route shall do so at an angle of 90 Degrees, to the direction of the route and at a level appropriate to the magnetic track. Listening watch shall be maintained on appropriate communication frequency throughout the flight along the ATS routes.
But I would temper that with a little situational awareness. If your scenario were to have taken place in the United States, where the transition level is usually FL, aircraft not under the air traffic controller's purview may fly at 17, under visual flight rules. If the local altimeter setting is below The controller is unlikely to make this mistake but we as pilots should be situationally aware and back up the controller.
We are all in this together, but the pilot has higher stakes in the game. This pilot went ahead and selected on his altimeter. We discussed this at length but the bottom line is that he flies in Europe and he said the "standard" is now to set when you get cleared to a flight level; also that this is the "EASA standard" now.
What say you? Besides, it sounds like a lousy technique. When climbing you always have the possibility of being asked to level off at a lower altitude below the transition altitude, and you will need the QNH to do that. If you are given a intermediate level off above the transition level, one button press on most altimeters gets you back to QNE. There is some debate about what the United Kingdom AIP has to say about this: "The vertical position of aircraft at, or below, any Transition Altitude will normally be expressed in terms of Altitude.
The vertical position at, or above, any Transition Level will normally be expressed in terms of Flight Level. When descending through the Transition Layer the vertical position will be expressed by pilots in terms of Altitude, and when climbing in terms of Flight Level.
They all agreed that you should not change from Altitude to Flight Level until you are reasonably assured you will be climbing above the Transition Level. Just like everyone else does it. It looks like I need to get into the books! Where can I find that published so I can study some more? The altitude at or below which the vertical position of an aircraft is controlled by reference to altitudes. Transition Level. The lowest flight level available for use above the transition altitude.
ICAO, e. In the US and Canada, the transition altitude is fixed at feet and the airspace above is known as the Standard Pressure Region. This restriction ensures that a minimum of ' vertical separation is maintained between the aircraft at ' on QNH and the one at the lowest useable level on Standard Pressure Setting. Descending, even when cleared to an altitude at the time cruising level is vacated, the altimeters will remain on standard pressure until just prior to the transition level.
0コメント