Mod 1 - ATM Flashcards
What service does ATC provide?
Aerodrome Control Service
Approach control service
Area control service
Who is provided with an ATC service ?
All IFR flights in ABCDE
All VFR flights in BCD
All SVFR flights
All aerodrome traffic at controlled aerodromes
Define flight information service FIS
A service provided for the purpose of giving advice and information useful for the safe and efficient conduct of flights
FIS shall provide pertinent information on what?
- SIGMET/AIRMET
- volcanic activity
- unmanned free balloons
- release of radioactive materials or toxic chemicals
- changes in the availability of radio navigation services
- changes in condition of aerodromes and associated facilities
What additional information can be provided by a FIS?
- weather conditions at dep/dest/alternate aerodromes
- collision hazards to AC operating in airspace’s CDEFG
- for flights over water any info. Requested by a pilot about surface vessels in the area
What will a FIS provide specifically for VFR flights?
FIS shall include provision of available info concerning traffic and weather conditions along the route of flight that are likely to make operation under VFR impracticable
In order to provide an ATC service what must an ATC unit do?
- be provided with info on each AC and the progress thereof
- determine the relative positions of known AC to each other
- issue clearances to prevent collisions between AC under it’s control
- expedite and maintain an orderly flow of traffic
- coordinate clearances as necessary with other units
What do you understand by the term procedural control?
Term used to indicate that information derived from an ATS surveillance system is not required for the provision of ATC
Who provides an ATC service?
- area control centre (ACC-area control service)
- approach control unit (APP-approach control service)
- aerodrome control tower(TWR-aerodrome control service)
What additional ATS are provided ?
Alerting services, FIS, Air traffic advisory service
Define flight information region (FIR)
An airspace of defined dimensions within with FIS and alerting services are provided
What does the abbreviation DATIS stand for?
Data link automatic terminal information service
Which piece of information will be provided to pilots even when they acknowledge receipt of the ATIS?
Current altimeter setting
What does VOLMET stand for?
Volume meteorological
What is an alerting service?
A service provided to notify appropriate organisations regarding AC in need of search and rescue (SAR) air and assist such organisations as required
To whom shall an ALRS be provided?
- for all AC provided with ATC service
- in so far as practicable to all other AC having filed a flight plan or otherwise known to the ATSs
- to any AC known or believed to be subject of unlawful interference
What do you understand by the phrase ops normal?
- Unless otherwise prescribed AC shall report during the period of 20-40min following the time of last contact to indicate that the flight is progressing according to plan
- the report shall contain the AC identification and the words ‘operations normal’
- the message shall be transmitted to an appropriate ATS unit
What are the three phases of emergency?
INCERFA (uncertainty phase)
ALERFA (alert phase)
DETRESFA (distress phase)
When would you commence the INCERFA?
Unless no doubt exists to the safety of the AC
- when no communication is received within 30min of the time communication should have been received
- AC fails to arrive within 30min if the ETA notified or ETA estimated by ATC unit (whichever is later)
Which phase should be employed when the fuel on board an AC is considered to be exhausted?
DETRESFA (distress phase)
Which phase should be employed when an ACs operating efficiency is impaired but a forced landing is unlikely?
ALERFA (alert phase)
Is a mayday call a distress or an urgency signal?
Distress signal
How is a May Day call transmitted?
- R/T (radio telephony)
- via data link
How is a pan pan call transmitted?
- R/T (radio telephony)
- via data link
What does the code 7500 indicate?
Emergency code indicating that the AC has been hijacked
What does the code 7600 indicate ?
Radio failure
What does code 7700 indicate?
Emergency
What problem would an AC have which would be related to all three phases of an emergency and would start with the INCERFA phase?
Communication issues/radio failure
What is air traffic advisory service?
A service provided within advisory airspace to ensure separation, in so far as practical, between AC which are operating on IFR flight plans
Who is air traffic advisory service provided to?
To AC conducting IFR flights in advisory airspace or in advisory routes (class F) as specified by the state concerned
What shall ATSUs providing ADVS service do?
- advise the AC to depart at the time specified and to cruise at the levels indicated in the flight plan if it does not foresee any conflict with other known traffic
- suggest a course of action by which a potential hazard may be avoided giving priority to an AC already in ADVS airspace over other AC desiring to enter such ADVS airspace
- pass traffic info in the same way as for area control service
What are vertical separation minima below FL290, at and above FL410 and between FL290 and F410?
2000ft FL410 2000ft unless I’m designated airspace such as RVSM 1000ft FL290 1000ft
State conditions under which AC are not cleared to a level previously occupied by another AC after the latter has reported vacating it
When severe turbulence is known to exist
The higher AC is in a cruise climb
The difference in AC performance is such that less than the separation minima May result
The tolerance value used to verify the accuracy of the level information displayed
Shall not be more than +- 200ft
When AC is considered to be maintaining a level vis a vis level information displayed on radar
The level read out indicates it’s within not less than 200ft
When AC is considered to have vacated a level vis a vis level information displayed on radar
The level read out indicates a change of more than 300ft
When AC is considered to have passed a level vis a vis level information displayed on radar
The level information indicates it has passed the level in the required direction by more than 300ft
When AC is considered to have reached a level vis a vis level information displayed on radar
After 3 updates or 15 seconds whichever is greater and the level information indicates it is within not less than 200ft of the assigned level
What is essential traffic information?
Essential traffic information shall be given to controlled flights concerned whenever they constitute essential traffic to each other
Which information shall be included for passing essential traffic information?
- Direction of flight of AC concerned
- Type and WTC of AC concerned
- Cruising level of AC concerned (and estimated time over reporting point nearest to where the level will be crossed OR relative bearing and distance of the AC concerned in terms of the 12h clock)
- actual or est. position of the AC concerned
Under what conditions AC May be cleared to fly maintaining own separation in VMC?
- during daytime and at/below FL100
- during climb/descent
- in VMC airspace classes D&E
- pilot requests this procedure, pilot of the other AC agrees and ATS authority authorises the procedure
- the procedure is limited to a specific time/point/level
- if VMC will not be possible inform ATC and proceed in accordance with alternative instructions given
What is procedural control?
Term used to indicate the information derived from an ATS surveillance system is not required for the provision of ATC service (ie no radar)
What is lateral separation based on geographical location?
Separation by reference to the same or different geographical locations
Position reports positively indicate the the AC are over different geographic locations determined either visually or by reference to a nav aid
What is lateral separation based on VOR, NDB, GNSSGNSS, GNSSVOR in terms of distances and angular differences ?
VOR 15degrees, 15NM or more NDB 30degrees, 15NM or more GNSSGNSS,GNSSVOR 15-135degrees -FL010-190 15NM -FL200-600 23Nm
What is essential traffic?
Controlled traffic to which separation by ATC is applicable, but which is not, or will not be, separated by the appropriate separation minimum
State the longitudinal separation standards and procedures based on time and distance
Time: -AC same level&track 15,10,5,3min -AC crossing tracks 15,10min -AC climbing/descending same track 15,10min -opposite track 10min Distance: -same track&FL 20,10NM -crossing track&same FL 20,10NM -same/opposite traffic climbing/descending 10NM
Describe longitudinal separation
Longitudinal separation shall be applied so that the spacing between the est. position of AC is never less than a prescribed minimum
Explain separation minima based on time
AC same level same track
AC same level and track
-15min
-10min if nav Aids permit frequent determination of position and speed
-5min if 1.AC is +=20kt faster
-3min if 1.AC is +=40kt faster
5&3 only if the AC have dep from same aerodrome OR en route AC have reported over exactly same point OR En route has reported over a fix that ensures 5min separation at the point the dep will join the route
Explain separation minima based on time
AC crossing tracks
- 15min
- 10min is nav Aids permit frequent determination of position and speed
Explain separation minima based on time
AC climbing/descending on same track
- 15min
- 10min if nav aids permit frequent determination of position and speed
Explain separation minima based on time
AC on opposite tracks
10min
Describe direction of traffic
Traffic could either be
- same direction traffic (track of 1 AC is separated to the other track by <45degrees)
- opposite direction traffic(when track of 1AC is separated from reciprocal of the other by <45 degrees)
- crossing traffic(if it’s neither of the others)
AC same direction traffic how many min separation?
What if first AC flies 20kt faster?
15/10 min (depending on nav aids)
5min (only if the specified conditions apply)
Crossing AC how many minutes separation?
15/10min depending on speed
Same-no rule about speed
Explain separation minima based on distance
Same track and FL
- 20NM
- 10NM if 20kt faster
For both if AC utilises
-the same on track DME station OR an on track DME and a collocates waypoint OR the same waypoint AND separation is checked by obtaining simultaneous readings from each AC at frequent intervals
Explain separation minima based on distance
Crossing traffic same FL
- 20NM
- 10NM if 20kt faster
For both provided that
-DME/GNSS readings are obtained from each AC from the facility located at the crossing point or fix point of the tracks AND the relative angle between the ACs tracks is <90degrees
Explain separation minima based on distance
AC same/opposite direction traffic climbing/descending
-10NM
For same direction:
Each AC utilises the same on track DME station or an on track DME and a collocated waypoint or the same waypoint AND one AC maintains level while the other descends/climbs AND separation is checked by obtaining simultaneous DME/GNSS readings from each AC at frequent intervals
Define atc clearance
The authorisation for an AC to proceed under conditions specified by an ATC unit
Explain position reports and the contents thereof (IFR)
When passing a fix,waypoint,intersection
- callsign
- position
- time of crossing (if report is transmitted after passing)
- if assigned:speed
After frequency change:
- callsign
- altitude/FL
- cleared altitude/FL when in climb/descent
- if assigned: speed
Explain position reports and the contents thereof (VFR)
When passing a reporting point
- callsign
- position
- time of crossing (if report is transmitted after passing)
- altitude
In the traffic circuit when requested
- callsign
- position
What is VOLMET and SIGMET?
VOLMET:
-worldwide network of radio stations that use automated voice transmissions to broadcast TAF, SIGMET and METAR reports
SIGMET
-information issued by a met office concerning the occurrence or expected occurrence of specified en route weather phenomena which may affect the safety of AC ops
Describe radio checks and the readability scale
Test signals for adjustments of equipment, or readability test shall not continue for more than 10 seconds and shall be composed of spoken numerals: ONE TWO THREE etc
1=unreadable 2=readable now and then 3=readable but with difficulty 4=readable 5=perfectly readable
[Standard phrases] let me know that you have received and understood this message
Acknowledge
[Standard phrases] yes
Affirm
[Standard phrases] permission for proposed action granted
Approved
[Standard phrases] I hereby indicate the separation between portions of the message
Break
[Standard phrases] I hereby indicate the separation between messages transmitted to different AC in a very busy environment
Break break
[Standard phrases] cancel previously transmitted clearance
Cancel
[Standard phrases] examine a system or a procedure (answer not expected normally)
Check
[Standard phrases] authorized to proceed under the conditions specified
Cleared
[Standard phrases] I request verification of….
Confirm
[Standard phrases] establish communications with..
Contact
[Standard phrases] “true” or “accurate”
Correct
[Standard phrases] an error has been made in this transmission (or message indicated) the correct version is…
Correction
[Standard phrases] ignore
Disregard
[Standard phrases] what is the readability of my transmission?
How do you read
[Standard phrases] I repeat for clarity of emphasis
I say again
[Standard phrases] repeat all, or the following part, of your last transmission
Say again
[Standard phrases] remain at the same level specified
Maintain
[Standard phrases] listen out on (frequency)
Monitor
[Standard phrases] no/permission not granted/that is not correct
Negative
[Standard phrases] my transmission is ended and I expect a response from you
Over
[Standard phrases] this exchange of transmission is ended and no response expected
Out
[Standard phrases] repeat all or the specified part of this message back to me exactly as received
Read back
[Standard phrases] pass me the following Information
Report
[Standard phrases] I have received all of your last transmission (under no circumstances to be used in reply to a question requiring READ BACK or a direct answer AFFIRM or NEGATIVE)
Roger
[Standard phrases] reduce rate of speech
Speak slower
[Standard phrases] switch transponder to the following setting
Squawk
[Standard phrases] wait and I will call you
Standby
[Standard phrases] I cannot comply with your request, instructions or clearance
Unable
[Standard phrases] I understand your message and will comply with it
Wilco
[Standard phrases] as a request: communication is difficult please send every word or group of words twice
Words twice
Describe the contents of an ATC clearance
-AC identification
-clearance limit
-route of flight
-level(s) of flight for the entire route/part thereof and changes if required
-any other necessary information such as
>SSR
>APP/DEP manoeuvres
>Communications
>Time of expiry of the clearance
Explain the purposes of an ATC clearance
ATC clearances shall be based solely on the requirements for providing ATC service
A clearance shall be obtained prior to operating a controlled flight for a portion of flight as a controlled flight by submission of a flight plan.
ATC clearances must be issued early enough to ensure that they are transmitted to the AC in sufficient time to be complied with
Explain the scope of ATC clearances
- The pilot shall inform ATC if a clearance is not satisfactory and ATC will issue an amended clearance if practicable
- In an AC requests a clearance involving propriety, a report explaining the need for priority shall be submitted if requested by the ATC unit
- if, before DEP, it is anticipated that a decision may be taken to proceed to a revised DEST aerodrome, ATC units shall be notified from the flight plan of the revised DEST and route (if known)
- AC on controlled aerodromes shall not taxi on the manoeuvring area with our clearance from TWR and shall comply with any TWR instructions
Describe the contents of a DEP clearance
- AC identification
- clearance limit (normally DEST aerodrome)
- SID designator (if applicable)
- initial level (except when included in SID description)
- SSR code
- any other necessary instructions not contained in the SID (frequency etc)
Describe the contents of an ARR clearance
- AC identification
- STAR designator
- RWY in use (except when part of STAR description)
- initial level (except when in included in STAR description)
- any other necessary instructions not contained in the STAR (frequency etc)
Explain clearance limit
The point to which an AC is granted an ATC clearance
clearance limit shall be: dest aerodrome, point, controlled airspace boundary
Explain route of flight
The route of flight shall be detailed in each clearance when necessary
the phrase ‘via flight planned route’ may be used if it is identical to that filed in the flight plan
An AC should, whenever possible, be offered the most direct routing
Explain Levels
Instructions in clearances relating to levels shall consist of:
- cruising level(s) or a range of levels for cruise climb
- levels at which specified points are to be crossed if necessary
- place/time to start climb/descent if necessary
- ROC/ROD if necessary
- detailed instructions for DEP/APP levels if necessary
Define ATC instruction
Directives issued by ATC for the purpose of requiring a pilot to take a specific action
Describe WHAT and WHEN read-back of clearances and instructions occurs
The safety related parts of ATC clearances and instructions shall always be read back:
- ATC route clearances
- instructions to enter, land on, T/O from, hold short of, cross, taxi and backtrack any RWY
- RWY in use
- altimeter settings
- SSR codes
- newly assigned communication channels
- level, heading and speed instructions
- TRL’s
Describe the controllers responsibilities to listen
The controller shall
- listen to the read-back to ascertain that the clearance or instruction has been correctly acknowledged by the flight crew AND
- take immediate action to correct any discrepancies revealed by the read-back
Explain what a Release is
The transferring unit may offer release conditions or the accepting unit may request release conditions i.e. to turn, climb or descend the AC whilst still in the transferring units airspace
Explain what a revision is
A revision is a coordination method where revision to a previously transmitted flight plan are forwarded (i.e. level changes) and no approval from the accepting ATC unit shall be required
Explain what an estimate is
Estimate phraseology (receiving unit has details on the flight)
- Sending unit: “estimate (significant point) (callsign)”
- Receiving unit:”(AC type) (DEST)”
- Sending unit:”Squawking (code), est (point) (time) AT (level)
Explain transfer of communication
Unless otherwise agreed, transfer of communication of an AC shall be made 5 min before the time at which the AC is est. to reach the common control area boundary. After coordination, transfer of communication of an AC shall be made immediately after the accepting ATC unit has agreed to assume control
The accepting ATC unit shall normally not be required to notify the transferring unit that communications has been established (only if not established)
When basic FPL data has been provided, an est. shall be transmitted when?
An est. shall be transmitted in sufficient time to permit the receiving unit to receive the information at least 20min before the time at which the AC is est. to pass the transfer of control point or boundary
Explain transfer of control
The responsibility for the control of an AC shall be transferred from the ATC unit to the next at the time of crossing the common control area boundary OR at such other point or time as has been agreed between the two units.
The accepting ATC unit shall not alter the clearance of an AC prior to the transfer of control time or point without the approval of the transferring unit. Responsibility for control shall not be assumed until the time of crossing the control area boundary or other transfer of control point agreed
What are the principles and types of coordination?
Coordination shall be between
- the operator and ATS authorities
- military authorities and ATS (if they affect civil AC)
- met authorities and ATS authorities
- aeronautical info. services and ATS authorities
The coordination and transfer of control of a flight between successive ATC units and control sectors shall be effected by a dialogue comprising what stages?
- notification of the flight in order to prepare for coordination, as necessary
- coordination of conditions of transfer of control by the transferring ATC unit
- coordination, if necessary, and acceptance of conditions of transfer of control by the accepting unit
- the transfer of control to the accepting ATC unit or control sector
Differentiate between transfer of control and transfer of communication procedures
TOControl
-at the control are boundary or otherwise agreed > the accepting ATC unit now has control
TOCommunication
-unless otherwise agreed TOCommunication shall be made 5min before the boundary
> > the accepting ATC unit shall not alter the clearance prior to the TOControl time or point without approval of the transferring unit
Describe the means of coordination
ATC units shall establish and apply standardised procedures for the coordination and transfer of control of flights in order to reduce the need for verbal coordination
Such coordination procedures shall conform to procedures and be specified in letters of agreement and local instructions as applicable
Methods of identification for PSR
- Position Report
- Departing AC
- Transfer of Identification
- Manoeuvres
- Direction Finding
Minimum turn needed for identification by turn/manoeuvre method
30 degrees or more
By how many miles from RWY radar identification is needed to identify by departure method?
within 2km (1NM) from the end of the RWY used
what are the methods of identification for SSR?
- recognition of the AC identification in a radar label
- recognition of an assigned discrete code, the setting of which has been verified, in a radar label
- direct recognition of the AC identification of a Mode S equipped AC in a radar label
- transfer of identification
- observation of compliance with an instruction to set a specific code
- observation of compliance with an instruction to squawk IDENT
SSR code for unusual circumstances
series 75 unlawful interference
series 76 radio comm failure
series 77 emergency
Under which of the following circumstances shall position information be given?
- when the pilot requests this info
- upon identification when identification is established based on the turn method
NOT
- before a military jet enters a restricted area
- upon identification when identification is established by dep. method
Explain transfer of identification
Transfer of identification from one controller to another should only be attempted, when it is considered that the AC is within the accepting controllers surveillance coverage
What are the methods of transfer of identification ?
- automated means
- discrete ssr code
- direct designation
- position report
- change ssr code
- IDENT feature
When should position information not be passed?
When the identification is established
- based on the pilots report of the AC position
- within 1NM of the RWY upon DEP and the observation is consistent with the Acs time of DEP
- by use of ADS-B, SSR mode S or assigned discrete SSR codes and the location of the position indication is consistent with the current flight plan of the AC
- by transfer of identification
When should position information be passed?
- when the pilot requests this information
- when a pilots estimate differs significantly from the controllers estimate based on the observed position
- when the pilot is instructed to resume own navigation after vectoring if the current instructions had diverted the AC from a previously assigned route
- immediately before termination of service if the AC is seen to deviate from the intended route
What are the contents of position information?
How can position information be passed to AC?
position information shall be passed to AC in one of the following forms:
- as a well-known geographical position
- magnetic track and distance to a significant point, an en-route nav aid or an APP aid
- direction (using points of the compass) and distance from a known position
- distance to touchdown if the AC is on final approach
- distance and direction from the centre line of an ATS route
What is the minimum information displayed on a situation display ?
- position indications
- map information
- information concerning identity of AC and level of the AC
What are the guidelines for radar vectoring?
- vector along tracks where pilot can monitor the position (in case of ATS surveillance system failure)
- if a vector diverts the AC from an assigned route, the pilot shall be informed of the reason
- no vectoring within 2.5NM (or half prescribed separation minima) from the adjoining airspace boundary
- no vectoring into uncontrolled airspace
- if the pilot reports unreliable directional instruments, agree a turn rate prior to vectoring
What is the minimum information displayed on a situation display ?
- position indications
- map information
- information concerning identity of AC and level of the AC
What are the guidelines for radar vectoring?
- vector along tracks where pilot can monitor the position (in case of ATS surveillance system failure)
- if a vector diverts the AC from an assigned route, the pilot shall be informed of the reason
- no vectoring within 2.5NM (or half prescribed separation minima) from the adjoining airspace boundary
- no vectoring into uncontrolled airspace
- if the pilot reports unreliable directional instruments, agree a turn rate prior to vectoring
What are the uses of ATS surveillance systems?
Vectoring (for separation, for expedition and efficient flow of traffic, to assist in navigation)
Monitoring the flight path of air traffic
Vertical or horizontal separation shall be provided between
All flights in A B IFR in C D E IFR&VFR C IFR&SVFR SVFR flights when prescribed by the appropriate ATS authority
What are radar separation minima?
shall be 5NM
3NM if radar permits (or 2.5NM on final approach)
From where is the separation minima measured?
centre of the position indicators
What are the wake turbulence minima for arriving AC?
NAUTICAL MILES J 6778 HMSL H 4567 HMSL UM 3446 UM LM S L LM 35 SL S 34 SL
What are the wake turbulence minima for departing AC?
MINUTES
Same position J 2333 H 4NM222 M 2 S 2
Intermediate point J 3444 H 4NM333 M 3 S 3
Objectives of Aerodrome Control Service
-prevent collisions between AC and on the manoeuvring area between AC and obstructions and expediting and maintaining an orderly flow of air traffic
What is essential local traffic ?
Essential local traffic shall be considered to consist of any AC, vehicle or personnel on or near the manoeuvring area or traffic operating in the vicinity of the aerodrome, which may constitute a hazard to the AC concerned
When could separation minima be reduced?
in the vicinity of an aerodrome
- when adequate separation can be provided by the aerodrome controller when each AC is continuously visible to this controller
- when each AC is continuously visible to flight crews of the other AC concerned and the pilots thereof report that they can maintain their own separation
- in the case of one AC following another, the flight crew of the succeeding AC reports that the other AC is in sight and separation can be maintained
What are separations on the RWY for arriving AC
If no separation standards are required a landing AC will not normally be permitted to cross the RWY threshold on its final APP until the preceding departing AC has crossed the end of the RWY in use or has started a turn or until all preceding landing AC are clear of the RWY in use
What are the separations on the RWY for departing AC?
If no separation standards are required a departing AC will not normally be permitted to commence TO until the preceding departing AC has crossed the end of the RWY in use or has started a turn or until all preceding landing AC are clear of the RWY in use
What are the separation minima between two successive departures?
<1min when AC are using parallel RWYs which do not cross
1min AC on tracks diverging by at least 45 degrees immediately after take off
2min between TOs when the preceding AC is 40kt or more faster
5min if a departing AC will be flown through the level of a preceding departing AC and both AC propose to follow the same track
What is Traffic Advisories (TAs) ?
in relation to TCAS
It is an indication given to the flight crew that the proximity of another AC is a potential threat
What is Resolution Advisories (RAs) ?
in relation to TCAS
It is an indication given to the flight crew recommending a manoeuvre intended to provide separation from all threats OR a manoeuvre restriction intended to maintain existing separation
What Actions shall be taken by the pilot in case of a TA?
TCAS
Pilot shall not manoeuvre the AC in response to TAs
On receipt of a TA pilot shall use all available information to prepare for appropriate action if an RA occurs
What Actions shall/shall not be taken by the pilot in case of a RA?
(TCAS)
Pilot shall:
-respond immediately by following the RA (unless doing so would jeopardize the safety of the aeroplane).
-follow the RA even if there is a conflict between the RA and an ATC instruction.
-not manoeuvre in the opposite sense to an RA.
-as soon as possible, notify ATC of any RA which requires a deviation from the current ATC instruction or clearance.
-promptly comply with any modified RAs and limit any alterations of the flight path to the minimum necessary to comply with RAs.
-promptly return to the terms of the ATC instruction or clearance with
the conflict is resolved and notify ATC as such
What happens in the case of an RA from a controllers perspective?
-Pilot shall follow an RA and report “TCAS RA”
-Controller is no longer responsible for separation and acknowledges “Roger”
-Controller shall not attempt to modify the aircraft flight path until the pilot reports “clear of conflict”
-Controller provides traffic information if deemed necessary
-Controller resumes responsibility for separation when:
>pilot reports resuming current clearance or
>pilot reports resuming current clearance and/or controller issues a
new clearance.
What are the limitations of ACAS/TCAS?
-ACAS will not detect any non-transponding aircraft.
-ACAS will not issue RAs for traffic without an altitude reporting
transponder.
-RAs/TAs are not issued against threats with a closure speed of over 1200 kt or vertical rates over 10,000 fpm.
-ACAS will not display a maintain rate RA requiring a vertical rate greater than 4,400 fpm.
-ACAS will fail if the input from the altimeter is lost.
-Certain RAs are inhibited below certain altitudes (varies, but below 1450 ft).
-ACAS may not display all aircraft in areas of high-density traffic.
-Horizontal manoeuvres are prohibited.
-Any active ground/terrain warning system inhibits ACAS to issuing TAs only.
-RAs can be generated before ATC separation minima is violated, even when the minima will not be violated.
What is GPWS?
Ground Proximity Warning System
Automatic warning to the flight crew when the aeroplane is in potentially hazardous proximity to the earth’s surface.
What is TAWS?
Terrain Awareness and warning system
TAWS is an advanced GPWS.
GPWS has no forward-looking ability.
TAWS provides a Forward Looking Terrain Avoidance (FLTA) function which looks ahead of the aircraft along and below its lateral and vertical flight path.
What is MSAW?
Minimum Safe Altitude Warning
-function of an ATC radar data processing system.
-intended to help prevent controlled flight into terrain (CFIT) by generating an alert to ATCOs of potential or actual infringement of
minimum safe altitude.
What is APW?
Area Proximity Warning
-uses surveillance data and flight path prediction to warn the controller when an aircraft is, or is predicted to be, flying into
airspace such as controlled airspace, danger areas, prohibited and restricted areas.
What is STCA?
Short Term Conflict Alert
The generation of STCAs is a function based on surveillance data, integrated into an ATC system.
The objective of the STCA function is to assist the controller in preventing collision between aircraft by generating an alert of a potential
or actual infringement of separation minima.
Which collision avoidance tool uses surveillance data?
APW - Area Proximity Warning
Which ground based safety nets are available to controllers?
MSAW - Minimum Safe Altitude Warning
APW - Area Proximity Warning
STCA - Short Term Conflict Alert
Which ground based safety net tool deals with altitude?
MSAW
What shall be implemented when traffic demands exceed the defined ATC capacity?
ATFM
What is the slot tolerance available to ATC?
-5 to +10 mins
With regards to slot tolerance, what is ATC responsible for?
CTOT compliance monitoring at departure ADs
