1. Introduction

All aircraft do not have the same performance. Weight, weather and winds can make the same airplane have different performance on different flights.
As a controller, you should have knowledge about the performance of aircraft under normal circumstances in order to be able to plan traffic flow and give the pilots relevant instructions.
At the end of this section, you will find a table which lists the performance of the most usual aircrafts. Use this table as reference.

2. Wake Turbulence [S]

All aircraft generate turbulence called vortex wake. Large aircraft flying at slow speeds create the most severe wake turbulence. This turbulence can cause problems for following aircraft, which in severe cases can cause the pilot of the following aircraft to loose control. In addition to separation minimum above, the following spacing minima therefore needs to be taken into account. The wake turbulence categories are based on the certified maximum take-off weight (MTOW) of the aircraft.

Aircraft CategoryMTOW
Light Aircraft (L)7 000 kg
Medium Aircraft (M)7 000 – 136 000 kg
Heavy Aircraft (H)>136 000 kg

2.1 Separation due to vortex [C]

This leads to the following minimum separation that needs to be maintained at all times on Arrival.

Leading AircraftFollowing AircraftSeparation in NM

Vortex separation is required when a lighter aircraft follows a heavier aircraft. 
No vortex separation is required between aircraft of same category, except between heavies.
If parallel runways are being used and they are closer to each other than 760 meters, then they should be considered as one single runway so far as wake turbulence is concerned. 
Any aircraft performing a Touch and Go or a Stop and Go is considered a departing aircraft on the climb out phase.

For departing aircraft, 2 minutes separation (3 minutes if the succeeding aircraft departs from an intersection) is applied when an aircraft in wake turbulence category LIGHT or MEDIUM departs behind an aircraft in wake turbulence category HEAVY, or when a LIGHT category aircraft departs behind a MEDIUM category aircraft.

Any Helicopter under your control must be kept clear of any light aircraft due to the Rotor Down-wash it produces when hovering and the vortices it produces in forward flight.

If you have a heavy and a light aircraft both ready for departure, you should clear the light aircraft for take-off first in order to avoid wake delay. However this only applies if it does not create any undue delay to the heavy aircraft. If this is the case, then the rule applies in that the faster aircraft is released first.

2.2 Waiving wake turbulence Separation [C+]

You may issue a take-off clearance to an aircraft that has waived wake turbulence separation, except, if it is a light or medium aircraft departing as follows:

  • Behind a heavy a/c and takeoff is started from an interception or along the runway in the direction of take-off
  • Behind a heavy a/c that is taking off or making a low or missed approach in the opposite direction on the same runway
  • Behind a heavy a/c that is making a low or missed approach in the same direction of the runway

3. Aircraft Approach Category [C]

A different way to differentiate categories is by their minimum Approach Speed. This is what the different Cat A, B, C, etc refers to on various Approach Charts.

Aircraft CategoryApproach Speed
AUp to 90 kt
BFrom 91 to 120 kt
CFrom 121 to 140 kt
DFrom 141 to 165 kt
EAbove 165 kt

4. Aircraft classification [C]

The pilot of an aircraft must have detailed knowledge about the aircraft's performances.

As ATCO it is hard to know all details about all aircrafts by heart. There are however, situations where you need to know some certain performances in order to issue correct clearance and instructions. Hence you need to know where to find the information.

One way is asking the pilot if (s)he is able to comply with a certain instruction, but that takes extra time and you cannot ask all pilots all the time.

There are several abbreviated listings of different aircraft and their performances on the Web. One of the most comprehensive and up to date is found on ICAOs homepage:

The list over performances should be seen as a guide and it deserves to be stressed that it is the pilot that has the last word when it comes to judging if (s)he is able to comply with a certain instruction.

5. Equipment suffix [C]

These suffixes denote what navigation and transponder equipment is available for the aircraft, as filed in the flight plan by the pilot.

Be alert as to the equipment available on the aircraft and issue vectors accordingly. A list over the most common codes for equipment can be found at the end of this section.

6. Figure 1 - Aircraft performance table [Ref]

LbsLbsNMkiasktasecon ktasMachKiasKiasKiasKias
Antonov 225
Avro RJ-8596.79684.8211.600FL350135412@FL350389@FL350.7312193
BAe ATP50.55049.0501.860FL250115266@FL150236@FL190227120
BAe 146-20093.00084.8201.620FL300135432@FL310383@FL300.741309392
BAe J-3116.20415.212690FL250110261@FL200230@FL25012510085
BAe J-4124.00023.300626FL260115291@FL200260@FL250.65
Cessna 182FL143156@7.500FT1605450
Cessna 2088.0007.8001.275FL27685184@10.000FT175857360
Cessna 3105.2005.2001.000FL250215233
Cessna 414-A6.750FL308105237237938272
Cessna Citation X35.30031.8003.300FL510.88M.92350
DC 8-71355.000258.0004.830FL420164479@FL390352143
DC 9-1590.70081.7001.670FL350467@FL350430@FL350
DC 9-30121.000110.0001.670FL350140490@FL250431@FL350.84325131
DC 9-51121.000110.0002.150FL350145490@FL250440@FL350.84325132
DC 10-30572.000403.0005.970FL334185490@FL300475@FL310.88356153
Do 328-10030.84229.1671.000FL310114335@FL200.5927013512097
Fokker 2864.85659.0001.130FL301455@FL300366@FL300120
Fokker 5043.98042.9902.224FL250287@FL250275@FL250.50918070
Fokker 10091.49088.0001.550FL370140432@FL350404@FL350.82320142160109
Learjet 35-A18.30015.3002.430FL450130486@FL450418@FL450.8335996
L-1329 Jetstar40.9212.200FL330488440
Pilatus PC6A6.1735.864394FL250115@FL10015152
Piper PA-316.5001.295FL273218147227
Saab 340B29.00028.500935FL250115285@FL250252@FL250.5011411588
Saab 200050.26548.5001.265FL310110370@FL250321@FL310.621209880
Shorts 36026.45326.100636FL190102213@10.000FT182@10.000FT1961109781


Table definitions:
MTOWMaximum Takeoff Weight
MLWMaximum Landing Weight
RangeMaximum Operating Distance
CeilingMaximum Operating Altitude
VrTakeoff Rotation Speed at MTOW (KIAS)
VcruiseDesign Cruising Speed at Given Altitude (KTAS)
Vcruise EconomySpeed and Altitude for Bets Fuel Economy and Long Range (KTAS)
MmoMaximum Operating Spped (Redline in Mach)
VmoMaximum Operating Speed (Redline - Jet/Turboprop) (KIAS)
VneNevner Exceed Speed (Redline - Recip-Prop) (KIAS)
VrefFinal Approach Speed at MLW in Landing Configuration (no wind)
VsiStall Speed in MLW in Clean Configuration (Flaps Up) (KIAS)
VsoStall Speed in Knots IAS at MLW in Landing Configuration (KIAS)

7. Figure 2 - Equipment suffix table [Ref]

No DME Equipment on board
/XNo Transponder
/UTransponder with Mode C
DME Equipment Available
/DNo Transponder
/ATransponder with Mode C
TACAN ONLY (usually Military Aircraft)
/MNo Transponder
/NTransponder with no Mode C
/PTransponder with Mode C
/YLORAN, VOR/DME, or INS with no Transponder
/ILORAN, VOR/DME, or INS, Transponder with Mode C
ADVANCED RNAV WITH TRANSPONDER AND MODE C (If an aircraft is unable to operate with a transponder and/or Mode C, it will revert to the appropriate code listed above under Area Navigation)
/EFlight Management System (FMS) with en route, terminal, and approach capability. Equipment requirements are:
  1. Dual FMS
  2. A flight director and autopilot control system capable of following the lateral and vertical FMS flight path
  3. At least dual inertial reference units (IRU's)
  4. A database containing the waypoints and speed/altitude constraints for the route and/or procedure to be flown that is automatically loaded into the FMS flight plan
  5. An Electronic map

/FA single FMS with en route, terminal, and approach capability that meets the requirements of /E 1-4 above
/GGlobal Positioning System (GPS)/Global navigation Satellite System (GNSS) equipped aircraft with en route, terminal, and GPS approach capability
/RRequired Navigational Performance. (Denotes capability to operate in RNP designated airspace and routes)
/WReduced Vertical Separation Minima (RVSM)

8. Automatic Altitude Reporting (MODE C)

  • All transponders are equipped with a MODE C on VATSIM - automatic altitude reporting capability. This system converts aircraft altitude in 100 foot increments to coded digital information which is transmitted together with MODE C framing pulses to the interrogating radar facility.