: Simulated flight and flight
When flying on the route and terminal area, even if there is no altitude restriction caused by control factors, there are always some restricted altitudes in various intelligence materials. Some of these altitudes can be encountered in domestic flights; some can only be encountered when flying in specific countries; some have the same name, but different countries and regions have special regulations on their meaning and application; some are operated by intelligence service providers based on their own Determined by experience. In short, the "heights" are still more complicated.
Therefore, must first clarify the scope of discussion. This post only discusses various altitudes under IFR conditions, and does not discuss various altitudes under visual flight rules conditions, nor does it discuss various types related to airport operation minimum standards. Height, not to mention the various restricted heights stipulated by various approach and departure procedures and approach procedures. Okay, stop talking nonsense. After reading the following, everyone will understand what "heights" these are.
Various restricted altitudes for flight routes
1. The minimum flight altitude of instrument flight MEA (Minimum Enroute IFR Altitude)
1, defines
The minimum altitude announced between radiolocation points. This height can provide the requirements for the clearance between these positioning points, and ensure navigation signal coverage in many countries. The height is valid within the width of the entire route. MEA is announced through AIP of various countries.
2, purpose
In addition to ensuring the obstacle clearance within the entire width of the route, in many countries, it is also necessary to ensure the integrity of the radio navigation signal during the flight. Usually, the obstacle clearance in mountainous areas is 2000ft (600m). ), 1000ft (300m) in other areas except mountainous areas.
3, usage
MEA is used as a restriction for altitude application and use during normal flight routes. If the aeronautical information does not provide the route's minimum obstacle clearance height MOCA, then MEA can be used as the basis for single-shot, pressure relief and drift restrictions.
2. Minimum Obstruction Clearance Altitude (MOCA)
1, definition
The effective minimum altitude announced between the radiolocation points on the VOR route, deviating route or flight segment. This height meets the requirements of obstacle clearance for the entire flight segment. MOCA is announced through AIP of various countries.
2, purpose
To ensure the obstacle clearance margin within the entire width of the route, in many countries, the obstacle clearance margin is 2000ft (600m) in mountainous areas, and 1000ft (300m) in other areas except mountainous areas. In the United States, the coverage of the navigation signal can only be ensured within 22nm around the VOR (Midi really does it alone).
3, usage
This altitude only provides obstacle clearance requirements. If the aeronautical information does not provide the minimum airway altitude MEA, MOCA can also be used as a restriction for altitude application and use during normal airway flight. In the event of a single shot, decompression drift, etc., the route's minimum obstacle clearance height MOCA is the basis for restriction.
3. Area Minimum Altitude AMA (Area Minimum Altitude)
1, definition
The lowest altitude used under instrument meteorological conditions (IMC), which provides the lowest obstacle clearance margin within a specified area. AMA is announced through AIP of various countries.
2, purpose
Except in high latitude areas, often sets the minimum height of the area in each quadrilateral composed of longitude and latitude to provide the obstacle clearance requirements during the flight in the area, that is, "the minimum safety grid height". In many countries, it is usually stipulated that when the highest obstacle reference point in the area is 5000ft MSL (Mean Sea Level) or below, the AMA value is 1000ft (300m) higher than all reference points in the area; when the highest obstacle reference point in the area is 5001ft At MSL or above, the AMA value is 2000ft (600m) higher than all reference points.
3, usage
If there are weather,If problems such as airborne systems need to deviate from the flight path, if air traffic control monitoring conditions cannot provide obstacle clearance protection, AMA (usually the lowest safe altitude of the grid) can provide obstacle clearance requirements for flying after deviation.
Various restricted altitudes for flying in the terminal zone
1. The minimum sector height MSA (Minimum Sector Altitude)
1, the definition
The radio navigation facility is the center and the radius is 46 kilometers (25 nautical miles) in a circular sector. Provide the lowest available height above all obstacles at least 300m (1000ft) obstacle clearance. MSA is announced through AIP of various countries. MSA chart of
JEPPESEN
2, purpose
Each airport with established instrument approach procedures should specify MSA (or TAA, see below for TAA conditions) to ensure that obstacle clearance is provided during free flight within the specified sector. Obstacle clearance is rounded up to 50m or 100ft. In many countries, it is usually stipulated that the obstacle clearance in mountainous areas should be increased, and the maximum increase can be 300m (1000ft), that is, the obstacle clearance in mountainous areas is 300m-600m (1000ft-2000ft).
3, usage
procedure control conditions, aircraft in the implementation of standard instrument approach, departure or approach, if the flight trajectory is maintained on the trajectory specified by these procedures, there is no need to comply with the MSA restrictions, and the altitude restrictions specified by the procedures are sufficient. ; Z1z In addition to this, when flying freely within the MSA sector, at any time cannot be lower than the MSA limit.
2. Terminal Area/Arrival Altitude TAA (Terminal Area/Arrival Altitude)
1, define
Above all objects in an arc centered on the initial approach positioning point (IAF) and a radius of 46 km (25 NM) Provide minimum 300 m (1000ft) obstacle clearance margin. TAA is announced through AIP of various countries.
2, purpose
Each airport with PBN approach procedures is set with TAA (but not required) , which is used to provide transition between the route structure and PBN approach procedures. Obstacle clearance is rounded up to 50m or 100ft. If there is no initial approach anchor point, the intermediate approach anchor point (IF) is the center of the circle, and the line connecting the end of the arc and the IF is the boundary. The TAA associated with the program must be a 360° area centered on the IF. The TAA boundary is determined by the radial PBN distance from the TAA reference point and the direction of the magnetic path. Generally, the TAA reference point is the corresponding IAF, and in some cases it can also be the intermediate positioning point (IF). If TAA is announced, TAA replaces MSA.
3, usage
TAA is associated with "T" or "Y" type PBN programs. The standard layout of TAA consists of three areas. The extension of the initial approach segment and the middle track divide the TAA into three parts. directly enters the left and right sides of the zone. When the aircraft is maneuvering within the TAA, it should be based on the reference information of the azimuth and distance to the IAF or IF point to ensure that the corresponding altitude limit is provided when the flight path is within the TAA boundary. The aircraft can transition between different TAAs, but The height limit of each part should be met.
3. Minimum radar guidance altitude MVA (Minimum Vectoring Altitude)
1, definition
Minimum radar guidance altitude refers to the minimum radar guidance altitude that should be determined in the radar guidance sector based on terrain, communications and radar signal coverage, and meets the minimum flight altitude and controller The height required for radar guidance. MVA is announced through AIP of various countries.
JEPPESEN's MVA diagram
2, objective
Provides obstacle clearance when flying within the obstacle clearance area of the radar guide sector. The MVA value should be rounded up to 50 meters or 100 ft. In many countries, provides at least 300m (1000ft) obstacle clearance margin, providing up to 600m (2000ft) obstacle clearance margin in the mountainous area. In the United States, the obstacle clearance of MVA is 1000ft in plain areas and 2000ft in mountainous areas.
3. Usage
Used in radar-guided approach and departure, approach and go-around. Different MVA can be set in different radar control sectors. It should be noted that the use of radar to guide the aircraft to a certain anchor point on the published standard instrument approach procedure, so that when the aircraft joins the approach procedure, may not be restricted by the minimum radar guidance altitude, but should comply with the standard instrument approach. Obstacle clearance requirements for close procedures. Several altitudes above
and terminal areas comply with ICAO and most national regulations. There may be differences only in the setting methods. We will call them "regulatory altitudes" for the time being. It should be noted that different countries may have different specific standards for the same height. In addition to the legal altitude,
also has the highest authorized altitude MAA (Maximum Authorized Altitude), the minimum crossing altitude MCA (Minimum Crossing Altitude), the minimum receiving altitude MRA (Minimum Reception Altitude) and the minimum instrument flying altitude MIA (Minimum IFR Alititude). ) Wait for the height, we will not discuss it anymore.
Information service provider-defined limit height
If you are careful, you can find that the various heights discussed above are announced by the AIPs of various countries. That is to say, how each country announces it, and everyone uses it. For companies such as JEPPESEN and Lufthansa Systems (LIDO provider), they are all predators in the field of aeronautical information. Although they all eat with information such as AIP of various countries, their business has grown bigger and they have their own understanding. According to its own understanding, has put forward a lot of "personalized information" different from general intelligence information in intelligence products. There are many examples of in this regard. This post will not discuss others, but only talk about the "personalized information" of JEPPESEN and Lufthansa Systems in restricting height.
1. Enroute Minimum Off Route Altitude Enroute MORA (Enroute Minimum Off Route Altitude)
The lowest yaw altitude of the route is a height proposed by JEPPESEN to define . Enroute MORA provides obstacle clearance within 10nm of the centerline of the route and the positioning point. On the JEPPESEN aeronautical chart, it is indicated by the red altitude number plus the suffix "a".
When the highest obstacle reference point in the obstacle clearance area is 5000ft MSL (mean sea level) or below, the Enroute MORA value is higher than all reference points by at least 1000ft (300m) ; when the highest obstacle reference point in the obstacle clearance area is At 5001ft MSL or above, the Enroute MORA value is at least 2000ft (600m) higher than all reference points . JEPPESEN uses global terrain data to determine the elevation of ground obstacles below the route, thereby calculating the Enroute MORA for each flight segment.
2. Grid Minimum Off Route Altitude (Grid MORA)
Similar to Enroute MORA, the lowest yaw height of the grid is also a height of JEPPESEN proposed to define . Grid MORA is in a grid composed of longitude and latitude lines. Provide obstacle clearance. On the JEPPESEN aeronautical chart, it is represented by the red-brown (above 14000ft) or green (below 14000ft) number of hundred feet in the grid. It should be noted that the JEPPESEN aeronautical chart does not indicate the minimum regional altitude AMA, and all indicate Grid MORA.
Grid MORA in JEPPESEN route map (Figure 14)
When the gridWhen the highest obstacle reference point in the area is 5000ft MSL (Mean Sea Level) or below, the Grid MORA value provides 1000ft clearance for all reference points in the grid; when the highest obstacle reference point in the grid area is 5001ft When MSL or above, the Grid MORA value provides 2000ft of obstacle clearance margin for all reference points in the grid; when it is expressed as "Unsurveyed", it means that the data source is incomplete or insufficient; when the value is accompanied by When the sign "+/-", it means that it is not accurate enough, but it can be considered that it has provided enough obstacle clearance margin for the reference point. JEPPESEN uses global terrain data to determine the elevation of surface obstacles in the grid area to calculate the Grid MORA.
3. Minimum Terrain Clearance Altitude (MTCA)
Minimum Terrain Clearance Altitude is a height defined by Lufthansa Systems' LIDO intelligence product that defines . MTCA provides clearance for obstacles within 10nm of the route centerline and positioning point degree. On LIDO aeronautical charts, it is represented by red altitude numbers.
When the reference point of the highest obstacle in the obstacle clearance zone is below 6000ft (the value rounded up to a hundred feet), the MTCA value is 1000ft (300m) higher than all reference points; when the reference point of the highest obstacle in the obstacle clearance zone When it is above 6000ft (the value rounded up to one hundred feet), the MTCA value is 2000ft (600m) higher than all reference points. Lufthansa Systems uses global terrain data to determine the elevation of ground obstacles below the route, thereby calculating the MTCA for each flight segment.
4. Minimum grid height MGA (Minimum Grid Altitude)
Similar to MTCA, the minimum grid height is also a height defined by Lufthansa Systems' LIDO intelligence product that defines . MGA provides obstacle clearance in a grid composed of latitude and longitude. Redundancy. On LIDO aeronautical charts, it is represented by the red (above 10000ft) or brown (below 10000ft) height numbers of one hundred feet in the grid. It should be noted that LIDO aeronautical charts do not indicate the minimum regional altitude AMA, and all indicate MGA.
When the highest obstacle reference point in the grid is below 6000ft (the value rounded up to a hundred feet), the MGA value is 1000ft (300m) higher than all reference points in the grid; when the highest obstacle in the grid refers to When the point is above 6000ft (the value rounded up to one hundred feet), the MGA value is 2000ft (600m) higher than all reference points in the grid. Lufthansa Systems uses global terrain data to determine the elevation of surface obstacles in the grid to calculate the MGA for each flight segment.
It can be seen that JEPPESEN agrees with the number of 5000ft, while Lufthansa Systems agrees with the number of 6000ft, as the watershed of the two obstacle clearance changes.
Of course, from the perspective of intelligence, if you use their intelligence products, you should follow their methods of processing and disposing of intelligence information, including these "personalized information". This is not optional, but must be observed. Z2z.
said so lively above. Finally, let’s take a look at a question that may be overlooked by everyone. What is the lowest safe altitude for domestic flights? Can it correspond to the heights above?
China’s lowest safe altitude for airways
minimum safe altitude for airways ( please note that I will not use any English or English abbreviations to express this altitude, see below for the reasons: )
1, the definition of
The domestic laws and regulations define the minimum safe altitude for airways. It is the minimum vertical separation between the aircraft and ground obstacles stipulated in the instrument flying aircraft minimum vertical separation standard , that is, the safe altitude for airway, route flight or transition flight, should be higher than the centerline of the airway in plateau and mountainous area , On each side of the route The highest elevation within 25km is 600m; in other areas of , should be higher than the center line of the route and within 25km on both sides of the route . The highest elevation is 400m. The minimum safe altitude of this route is announced by AIP.
2, purpose
Ensure the obstacle clearance within the entire width of the route (note that this width is 25km).
3, usage
This altitude is used as a restriction for altitude application and use during flight routes including normal and various abnormal (single-engine, decompression drift).
So the question is, what is the minimum safe altitude of domestic air routes corresponding to the altitude of the regulations? Is it MEA or MOCA?
If it is an MEA, although the MEA is theoretically different according to the regulations of each country, the domestic obstacle clearance of 600m for plateaus and mountainous areas (note that it is not internationally accepted only for mountainous areas) and 400m for other regions The degree seems to be incompatible with most of the MEA regulations, and there are still many countries that have navigation signal coverage requirements for MEA.
We know that intelligence providers such as JEPPESEN and Lufthansa Systems are producing their own intelligence materials based on the AIP of various countries, so regardless of their own regulations or NAIP and AIP, can actually be marked by intelligence service providers. See what their attitude is towards this matter.
First look at JEPPESEN
. On the JEPPESEN route map, the red number marked on the flight segment is MEA, and the red number plus "T" suffix is MOCA. The first picture is the section from Ejina Banner to Dengkou of W66 route, which is marked with the red number FL197 6000m, shows that FL197 6000m is the MEA; also marked with red number plus "T" 7960T 2425mT, shows 7960T 2425mT is the section Segment MOCA. From JEPPESEN's point of view, which one is the "minimum safe airway altitude" announced by AIP?
After querying the AIP data, we found that the original W66 has a minimum height requirement of 6000m in this section, but this height requirement is a control requirement. JEPPESEN considered this height and designated it as an MEA. At the same time, the section also announced a minimum safe altitude of 2425m. It can be seen from this that JEPPESEN believes that the "minimum safe airway altitude" announced by AIP is MOCA rather than MEA. This point of can be confirmed from other examples of flight segments that do not have a controlled altitude requirement. For example, the section from Dengkou to Baotou of the A596 route is marked with a red number and a "T" 9680T 2950mT, indicating that 9680T 2950mT is the lowest safe altitude of the route.
Let's take a look at LIDO
LIDO route map, the black number marked on the flight segment is MEA, and the red number is MTCA (not MOCA) . Also take the above examples of W66 and A596 routes to confirm. The first picture is the section from Ejina Banner to Dengkou of W66 route, where 8000 is marked with black numbers (that is, the rounding of 2425m and 7960ft in AIP), indicates that 8000 is the MEA of this section; 6900 is also marked with red numbers, indicating 6900 is the MTCA of this segment. In the same way, the section from A596 to Baotou is marked with black numbers 9700 (that is, 2950m and 9680ft in AIP), indicates that 9700 is the MEA of this section; 9600 is also marked with red numbers, indicates that 9600 is the Segment MTCA.
It can be seen that LIDO believes that the "Minimum Airway Safety Altitude" announced by AIP is MEA instead of MCTA (not even MOCA). As for he also marked MCTA, that is the result of LIDO's own calculation based on terrain obstacle data, we can ignore it.
okay, you two for thisViews on things are inconsistent . . .
I don’t know who is right or who is wrong, or everyone has reason. We are not rigorous here. We don’t use emails and ask them what they think, just to guess:
JEPPESEN thinks it is MOCA, guess the main thing The reason is that the minimum safe altitude of domestic air routes only considers obstacle clearance (although the obstacle clearance of 400m and 600m is more Chinese) and does not consider other factors including radio reception, so it does not conform to the general definition of MEA, not to mention domestic Some routes have minimum altitude requirements due to control reasons, so it is appropriate to use MOCA and MEA to distinguish these situations.
LIDO believes that it is MEA. The main reason for guessing is that it believes that the general definition of MEA does not have requirements for obstacle clearance and obstacle clearance areas. They are all stipulated by each country according to the situation, and the minimum safety altitude of domestic routes is obviously not in compliance LIDO's definition of MCTA (the MCTA definition clearly only has a 10nm-wide obstacle clearance zone, which is obviously inconsistent with the 25km route width in the domestic definition of the lowest safe height of the route), which is why the LIDO chart will separate the MEA in addition to the MEA. Reason for calculating MTCA.
and the above are just personal opinions, welcome everyone!
hope this post can be helpful for everyone to understand the various restriction heights.
References:
ICAO Annex 4: Aeronautical Charts
ICAO DOC8168 PANS-OPS/611 VOL1: Air Navigation Service Procedures-Aircraft Operation
CCAR-71 Civil Aviation Use Airspace Measures
CCAR93TM-R4 China Civil Aviation Air Traffic Management Regulations
AC-91-FS-FS -27 Flight Procedures
MH/T4023-2007 Visual and Instrument Flight Procedure Design Specifications
MH/T4019-2012 Civil Aviation Chart Compilation Specifications
MD-TM-2005-002 Minimum Radar Guide Height Regulations
JEPPESEN Airway Manual-General: Jeppesen Airway Manual-General Principles
LIDO-Legends and Tables: LIDO-Legends and Tables
have seen here
