Section 2

Question 1

What type of service can an Aerodrome Controller provide?

Answer 1

Aerodrome Control Service

Basic service

Alerting service

Question 2

Who does an Aerodrome Control Unit provide service for?

Answer 2

An Aerodrome Control Unit provides services principally to aircraft flying with visual reference to the surface in, and in the vicinity of, the ATZ and operating on the manoeuvring area.

Question 3

What is an Aerodrome Controllers responsibility?

Answer 3

Aerodrome control shall issue information and instruction to aircraft under its control to achieve a safe, orderly and expeditious flow of air traffic with the objective to-

Prevent collisions between-

1- Aircraft flying in, and in the vicinity of the ATZ

2- Aircraft taking off and landing

3- Aircraft and vehicles, obstructions and other aircraft on the manoeuvring area

4- And assist in preventing collisions between aircraft on the apron

Question 4

Is an Aerodrome controllers solely responsible for the prevention of collisions?

Answer 4

No, pilots and vehicle drivers must fulfil their own responsibility in accordance with rules of the air

Question 5

Aerodrome control can be divided into 2 roles, what are there?

Answer 5

Air control and Ground movement control

Air control does 1 and 2 of the responsibilities and ground control does 3 and 4

Question 6

In addition to the aerodrome controllers responsibilities, what are the specific responsibilities?

Answer 6

1- Notify emergency services as per local instructions

2- Inform aircraft under their control of any depletion of the aerodrome emergency services

3- Provide an Approach Control Service when carrying out functions delegated by Approach Control

4- Supply the following information to Approach Control and according to unit instructions, Approach Radar Control-

4a- pertinent data on IFR, SVFR and VFR traffic including departures, missed approaches and overdue aircraft

4b- appropriate items of essential aerodrome information

5- Inform the aerodrome operator when it becomes apparent that there is deterioration in the state of the aerodrome or associated facilities for which the aerodrome operator is responsible

6- Initiating overdue action at aerodromes when no Approach Control unit is established

Question 7

What shall aerodrome control co-ordinate with approach control?

Answer 7

Departing IFR flights

Arriving aircraft which have made their first call on the tower frequency (unless they are transferred to approach control)

Question 8

What shall approach control co-ordinate with aerodrome control?

Answer 8

Aircraft approaching to land, if necessary requesting landing clearance

Arriving aircraft which are to be cleared to visual holding points

Aircraft routeing through the traffic circuit

Question 9

When shall the responsibility of a departing aircraft be transferred from aerodrome control to approach control ?

Answer 9

1- in VMC, prior to the aircraft leaving the vicinity of the aerodrome, or prior to the aircraft entering IMC

2- in IMC, immediately after the aircraft is airborne

Question 10

When the reported met visibility consists of two values which value shall be used?

Answer 10

The lowest one

Question 11

What is the VFR minima criteria in class D airspace ? Who is exempt from this ?

Answer 11

Ground visibility of 5km and/or a cloud ceiling of 1500ft, by day and night.

If the weather is below this then request the intentions off the pilot

Helicopters operating under police, helimed, rescue, power line, grid, pipeline callsigns or SAR training flight

Question 12

When does the VFR minima in class D apply ?

Answer 12

If an aircraft is wanting to operate in accordance with VFR to or from the aerodrome, or enter the aerodrome traffic zone, or aerodrome traffic circuit, of an aerodrome within class D airspace when the ground vis is less than 5km and/or cloud ceiling 1500ft by day or night

Question 13

What is the VFR minima for aircraft transiting and remaining outside the ATZ of class D airspace ?

Answer 13

FLIGHT visibility and/or cloud ceiling 1500ft except power line, etc

Question 14

When shall traffic information be passed to an aircraft?

Answer 14

On any occasion that a controller considers it necessary in the interests of safety, or when requested by a pilot.

Question 15

What type of traffic information and instructions should be passed by an aerodrome controller?

Answer 15

1- generic traffic information to enable VFR pilot to safely integrate their flight with other aircraft

2- specific traffic information appropriate to the stage of flight and risk of collision

3- timely instructions as necessary to prevent collisions and enable safe, orderly and expeditious flight within and in the vicinity of the ATZ

Question 16

What information should ATC pass to aircraft under their control of any subsequent changes?

Answer 16

1- significant changes in meteorological and runway conditions

2- changes in essential aerodrome information

3- changes in the notified operational status of approach and landing aids

Question 17

What is essential aerodrome information?

Answer 17

Essential aerodrome information is that concerning the state of the manoeuvring area and it’s associated facilities that may constitute a hazard to a particular aircraft

Question 18

List the 11 essential aerodrome aspects

Answer 18

1- construction work or maintenance on the manoeuvring area

2- rough portions of the manoeuvring area and whether marked or not

3- failure or irregular functioning of the aerodrome light system. Defects must be passed to pilots in the form they have reported to the controller. ATCO should not make any assumptions that a particular defect renders an associated aid unserviceable or not available. The pilot is responsible for his course of action

4- failure or irregular functioning of approach aids

5- aircraft parked close to the runways or taxiways and aircraft engaged in ground runway of engines.

6- depth of snow layers on runways and taxiways, snow piled or drifted on the manoeuvring area, melting snow and slush, rutted ice and snow

7- in snow and ice conditions- information concerning sweeping and/or sanding of runways and taxiways

8- reports on the estimated braking action determined either by the equipment, or reports by pilots which have already landed. Including a description of the prevailing conditions (standing water, snow settling)

9- bird formations or individual large birds reported or observed on or above the manoeuvring area or in the immediate vicinity of the aerodrome. Also any bird dispersal action being carried out.

10- warnings of the presence of water on runways

11- information on the location and operational status of any arrester gear installation

Question 19

What is the aerodrome controller responsibility regarding the apron?

Answer 19

To provide advice and instructions to assist the prevention of collisions between moving aircraft

Question 20

What 3 aspects of control of surface traffic can a controller use?

Answer 20

1- an aircraft is cleared to taxi. A second aircraft may be given taxi clearance plus information on the first aircraft and their intentions with a clear ‘follow’ or ‘give way’ to it

2- an aircraft is cleared to taxi and all further requests for aircraft movements are refused the first aircraft comes into sight of the controller.

3- an aircraft is cleared to taxi and asked to report when clear of the apron or passing an easily identifiable reference point

Question 21

Should vehicles give way to aircraft at all times?

Answer 21

Yes other those in an emergency

Question 22

Can you use the phrase ‘give way’ to vehicles to resolve conflictions between vehicles and aircraft ?

Answer 22

No

Question 23

When issuing a crossing instruction of a runway in use to a taxiing aircraft, controllers shall ensure that the crossing instruction is issued on the same frequency, True or False?

Answer 23

True

Question 24

What is a runway incursion?

Answer 24

A runway incursion is any occurrence at an aerodrome involving the incorrect presence of an aircraft, vehicle or person on the protected area of surface designated for aircraft taking off and landing

Question 25

What should a vehicle or aircraft do if lost on the aerodrome?

Answer 25

Should stop, notify ATC on their last known position. If the vehicle or pilot recognises that they’re on the runway, they should vacate ASAP unless stated by ATC otherwise

Question 26

What information should be passed to an aircraft requesting start up or taxi clearance ?

Answer 26

Runway in use Surface wind/ direction and speed including any significant variations Aerodrome QNH Outside air temp (turbine engine aircraft only) Significant metrological conditions (RVR)

Question 27

When can red illuminated red stop bars be deselected ?

Answer 27

Only to be de-selected when clearance has been given for an aircraft or vehicle to enter the runway

Question 28

If a conditional clearance has been issued when should the stop bars be de-selected ?

Answer 28

Until the landing aircraft has gone passed the holding point, can the red stop bars be de-selected

Question 29

If the stop bars are un-serviceable and it is not possible to de-select etc, when may an aircraft be instructed to cross such a illuminated stop bar?

Answer 29

The affected runway or intermediate holding point and the aircraft are visible to the controller. (This can be used for SMR) and risk assessed The phraseology used is to leave the pilot or driver in no doubt that the crossing instruction only applies to the particular inoperable stop bar. Conditional clearance shall not be used! Additional MATS 2 procedures may be required where local risk assessments have identified that further mitigation measures may be necessary

Question 30

What is a clearance limit?

Answer 30

In addition to providing instructions about the route to be followed, all taxi clearances are to contain a specific clearance limit. This clearance limit should be a location on the manoeuvring area or apron

Question 31

Why should controllers be cautious with the phrase ‘follow the....’ when giving taxi instructions ?

Answer 31

As it could lead the following aircraft into the active runway or passed a holding point

Question 32

If an aircraft is at a holding point or taxiing to a holding point, and departure instructions need to be passed what should the controller empathise?

Answer 32

Hold at A1, D2 etc then go on with the departure instructions

Question 33

Should conditional clearances be used for movements affecting the active runway? Yes or no? If so except when?

Answer 33

No Except, when the aircraft or vehicles concerned can be seen by both controller and pilot or driver

Question 34

What is the criteria for multi line up clearances?

Answer 34

1- During daylight hours 2- all aircraft are continuously visible to the aerodrome controller 3- all aircraft on the same frequency 4- pilots are advised of the number of aircraft ahead in the departure sequence, and the position/runway from which these aircraft will depart 5- the physical characteristics of the runway do not render preceding aircraft in the departing sequence invisible to succeeding aircraft on the same runway

Question 35

What information should be passed to the aircraft when passing a line up clearance regarding multiple line ups?

Answer 35

The intermediate holding position designator shall be included in the line up instruction

Question 36

Who is responsible for issuing take off clearances and advising pilots of any variations to the surface wind?

Answer 36

Aerodrome controller

Question 37

When the pilot requests instantaneous surface wind, what word is to be inserted at the start?

Answer 37

‘Instant’ wind 250 degrees 5 knots

Question 38

When passing pilots wind checks what time scale is this?

Answer 38

Two minute average

Question 39

When can a take off clearance be issued?

Answer 39

Should be passed separately from any other message. Aircraft is at or approaching the holding position for the runway in use or when an aircraft is lined up on or entering the runway in use

Question 40

A departing aircraft shall not be given instructions which would require it to make a turn before it has reached what height?

Answer 40

500ft This does not apply to light aircraft

Question 41

When passing departure instructions to an aircraft what words can be put before the clearance to prevent the aircraft taking off or to be confused with a ground movement ?

Answer 41

‘ After departure ‘

Question 42

IFR aircraft is not to be given take off clearance until what?

Answer 42

1- ATC clearance from area control (if required) has been passed and acknowledged 2- approach control have authorised its departure and any septic instructions have been passed to the aircraft eg- turn after take off, track to make good before turning onto desired heading Level(s) to maintain

Question 43

When given the instruction ‘cleared for immediate take off’ it is expected that the pilot will what?

Answer 43

1- at the holding position, taxi immediately onto the runway and commence take off without stopping the aircraft (NO TO HEAVY AIRCRAFT) 2- if already lined up on the runway, take off without delay 3- if an immediate take off is not possible the pilot should advise the controller

Question 44

Regarding immediate take off clearances, aerodrome controller may after college-ordination with approach control do what?

Answer 44

1- expedite departing aircraft by suggesting a take off direction which is not into wind 2- reduce the overall delay to traffic by altering the order in which he clears aircraft to take off 3- when the ATS surveillance systems are not avail either, clear departing IFR flights to climb VMC and maintain their own separation until a specified time, location or level

Question 45

When should cancelling a take off clearance after an aircraft has commenced its take off roll be necessary ?

Answer 45

Only if the aircraft will be in serious and imminent danger if it was to continue

Question 46

What are the designated positions in the traffic circuit?

Answer 46

1- downwind leg 2- late downwind 3- base leg 4- final (clearance to land) 5- long final (between 8 and 4 miles) aircraft is on a straight in approach

Question 47

What is the standard over head join?

Answer 47

Report in the overhead at 2,000ft above the aerodrome elevation (remain in VMC) and when cleared descend and route dead side of the circuit and descend to circuit height 1,300ft. The aircraft will then cross the upwind end of the runway in use at circuit height then position accordingly into the existing circuit direction

Question 48

When shall the runway designator be use?

Answer 48

Landing, low approach and when an aircraft is on a touch and go, unless MATS 2 states otherwise

Question 49

When aircraft are using the same runway, a landing aircraft may be permitted to touch down before the preceding landing aircraft which has landed is clear of the runway provided what?

Answer 49

1- runway is long enough to allow safe separation between the two aircraft and there is no evidence to indicate braking may be adversely affected 2- during daylight hours 3- the preceding landing aircraft is not required to back track in order to vacate the runway 4-the controller is satisfied that the landing aircraft will be able to see the preceding aircraft which has landed, clearly and continuously, until it has vacated the runway 5- the pilot of the following aircraft is warned. Responsibility for ensuring adequate separation rests with the pilot of the following aircraft

Question 50

What as an aerodrome controller would you do if you thought an aircraft was positioning themselves dangerously on final approach ?

Answer 50

Instruct them to carry out a missed approach

Question 51

Who is exempt from separation minima in the traffic circuit?

Answer 51

1- aircraft information with respect to other aircraft in the same formation 2- aircraft operating in different areas or lanes on aerodrome equipped with runways suitable for simultaneous landings or take offs 3- aircraft operating under military necessity as determined by the appropriate authority

Question 52

What is the main purpose of the ATM?

Answer 52

To assist in achieving maximum runway utilisation and aerodrome capacity

Question 53

What may the ATM be used for?

Answer 53

1- determine the landing order, spacing and distance from touchdown of arriving aircraft 2- assist in applying longitudinal separation for departing aircraft 3- enable the controller to confirm that the initial track of a departing aircraft conforms with the clearance issued 4- provide information to aircraft on the position of other aircraft in the circuit or carrying out an instrument approach

Question 54

Once approved by the CAA, what other uses are there to the ATM?

Answer 54

1- following identification, validate SSR codes of departing aircraft and verify associated Mode C read outs 2- monitor the progress of overflying aircraft identified by approach radar control to ensure that they do not conflict with the tracks of arriving or departing aircraft 3- establish separation between departing aircraft 4- pass traffic information 5- establish separation in the event of a missed approach 6- assist in taking initial corrective action when the separation between arriving aircraft becomes less than the prescribed minima PROVIDED THAT- A- the controller had undertaken specified training B- the controller is only providing an Air Control Service and a separate Ground Control Service is being provided by another controller on a separate frequency C- the procedures are detailed in MATS 2 If approved by the CAA units where air control and ground control are combined they can be exempt

Question 55

If an aircraft was to go around/low approach if they were on QNH and QFE regarding TIA what would it be?

Answer 55

QFE 400ft QNH 520ft but rounded up to nearest 50ft

Question 56

What does the term runway in use mean?

Answer 56

Is used to indicate the particular runway or landing direction selected by the aerodrome control as the most suitable at any particular time.

Question 57

What is to take into consideration regarding choosing the runway in use?

Answer 57

Surface wind direction most closely aligned When light and variable - 2,000ft (MATS1) Or 1000-3000 for MATS 2 Traffic pattern Length of runway or landing runs Approach aids available Meteorological conditions

Question 58

Shall a runway be selected for noise abatement purposed for landing operations?

Answer 58

No, unless visual or instrument glide path guidance is available to that runway

Question 59

What are the limitations of crosswind/tailwind components regarding noise abatement ?

Answer 59

Crosswind component Gusts exceeds 15kts or tailwind component including gusts exceeds 5 kts

Question 60

What additional parameters when noise abatement is not to be used as a determining factor in runway selection?

Answer 60

1- the degree and type of runway surface contamination 2- minimum visibility and cloud ceiling 3- other weather conditions such as wind shear or thunderstorms 4- if the pilot, prompted by safety concerns considers that a runway offered, including those for noise abatement a purposes, is not suitable, he may refuse that runway and request permission to use another. If so the ATCO should inform the pilot of a possible delay

Question 61

Who should be informed of a runway change, once agreed by aerodrome and approach?

Answer 61

1- aircraft under their control 2- aerodrome fire service 3- contractors working on the aerodrome who will be affected by the change 4- other agencies according to local instructions

Question 62

What information such be passed regarding WIP on the manoeuvring area?

Answer 62

1- methods of access to working area 2- the area in which vehicles may operate 3- the runway in use and the effects of any changes 4- method thy LDA of obtaining permission to cross the runway in use 5- signals or methods of indicating that vehicles and personnel must leave the manoeuvring area

Question 63

When should the runway be inspected?

Answer 63

Following any incident, or suspected incident on a runway involving tyre failure, aircraft structural failure, or in the case of turbine engines aircraft, engine malfunction, the runway is to be inspected before any other aircraft are allowed to use it.

Question 64

If there is a downgraded of RFFS, what should the ATCO do?

Answer 64

Advise aircraft over ATIS or RT that are landing or taking off. The flight crew decide whether if they’ll continue or divert

Question 65

When should ATC be notified about the release of racing pigeons ?

Answer 65

If within 13km of the aerodrome should be notified at least 14 days prior to the date of release. ATC should receive a phone call 30mins before release to confirm location and number of birds. ATC can chose to delay the release up to 30 mins

Question 66

The requirements for lighting at aerodromes in the UK appears in what CAP?

Answer 66

CAP 168

Question 67

When RVR readings are taking place (human method) the centre line lights will be switched off, when shall this not take place?

Answer 67

1- While an aircraft is taking off 2- After an aircraft has reported completing a final approach turn 3- after an aircraft has reached 5 miles from touchdown on a radar approach

Question 68

When should aerodrome lighting be displayed both at day and night?

Answer 68

Day- high intensity systems, where installed on the runway to be used, whenever the visibility is less than 5km and/or the cloud base is less than 700ft Night- irrespective of the weather conditions When the met consists of 2 values the lowest one will be used

Question 69

When should hazard beacons be displayed?

Answer 69

By day whenever the visibility is less than 3500m

Question 70

What cap can you find information about lasers, search lights and fireworks?

Answer 70

CAP 736

Question 71

What are the limitations for light displays at an airfield ?

Answer 71

Within 500m either side of the extended centreline, within 10miles of an aerodrome Can be within 3miles of an aerodrome but not on the extended centre line (no light should stray towards the aerodrome or extended centre line)

Question 72

What are the guideline for firework displays regarding at an aerodrome ?

Answer 72

Limited to a height of 1500ft above ground level and should not take place within 500meters either side of the extended centreline within 5miles of an aerodrome or within a 2mile radius of an aerodrome

Question 73

What should you do when there is a laser attack against an aircraft?

Answer 73

1- acknowledge the report from the pilot 2- seek as much information regarding the incident as possible from the pilot including - Time of attack Altitude and position at the time of attack Description of the laser light, colour, continuous etc Any avoiding action taken Any impact upon vision / concentration 3- anticipate the need for the pilot to adopt manoeuvres techniques to minimise impact on the aircraft 4- dial 999, pass all relevant information to local police 5- warn pilots of the other aircraft in the vicinity that laser activity has been reported. 6- record the details in the ATC watch log and complete an ATC Occurrence report

Question 74

What would you do if there was a laser attack on ATC?

Answer 74

1- Look away from the laser beam if possible. Do not attempt to find the light source by staring at the laser 2- shield eyes and consider the feasibility of lowering/raising sun blinds to reduce the effects of the laser 3- advise aircraft under your control that a laser is illuminating you 4- avoid rubbing eyes 5- consider the feasibility of increasing ambient light levels to minima any further illumination effects 6- consider handing over the control position to a colleague in a position not exposed to the laser 7- where local agreements have not established inform supervisor who can decide wether to restrict traffic in and out of the aerodrome, inform aerodrome operator manger and dial 999 and pass all relevant information 8- ensure the event is recorded in the ATC log and reported further by ATC occurrence report

Question 75

What is wind shear?

Answer 75

Wind shear is a sustained change in the wind velocity along the aircraft flight path, which occurs significantly faster than the aircraft can accelerate or decelerate

Question 76

Can wind shear occur at any level?

Answer 76

Yes, but it is low level wind shear, occurring from the surface to a height of approx 1500ft which can cause problems of sufficient magnitude to affect the control of aircraft in departure or final approach phases of flight

Question 77

How should controllers alert the possibility of wind shear?

Answer 77

1- the presence of frontal/squall/thunderstorm activity in the vicinity of the aerodrome 2- the presence of low level inversions where the surface wind will be significantly different from that at only a few hundred feet above ground level 3- local terrain or buildings considered in relation to wind speed and direction, such a large obstructions can cause wind shear as well as the more usual turbulence and gusts

Question 78

What 3 things could happen to an aircraft relating to wind shear at low level?

Answer 78

Aircraft is taking off and climbing and hits wind shear could lead to a sudden fall in airspeed, which results in reduced lift until the inertia of the aircraft has been overcome and the original speed regained. Aircraft on final approach passes through wind shear which causes sudden loss of airspeed and a consequent increase in the rate of descent. A rapid applicant of power will be required so the aircraft doesn’t sink to a low height If aircraft passes through a wind shear line from a tailwind to a headwind component the inertia of the aircraft results initially in a increased airspeed and a deviation above the glide path. A rapid applicant of power will be required so the aircraft doesn’t sink to a low height

Question 79

Does onboard wind shear warnings over ride TCAS warnings in the cock pit?

Answer 79

Yes

Question 80

What should controllers be aware of if an aircraft was to complete a missed approach due to wind shear?

Answer 80

For the aircraft to exceed the missed approach altitude.

Question 81

Reports from a pilot should contain what information, regarding windshear?

Answer 81

1- a warning of the presence of wind shear 2- the height or height band where the shear was encountered 3- the time at which it was encountered 4- details of the effect of the wind shear on the aircraft, eg speed gain or loss, vertical speed tendency, change in drift

Question 82

How can wind shear be reported?

Answer 82

ATIS or RT to individual aircraft

Question 83

What is prevailing visibility?

Answer 83

Is defined as the visibility value that is reached or exceed within at least half the horizon circle or within at least half of the surface of the aerodrome

Question 84

When shall prevailing visibility be reported?

Answer 84

Where the visibility in any direction is less than the prevailing visibility and less than 1500metres or less than 50% of the prevailing visibility, the lowest visibility observed will be also reported

Question 85

The aerodrome operator is responsible for all aerodrome inspections, but when can this duty be delegated to ATC?

Answer 85

1- ATC becomes aware of any unserviceabilities or obstructions that may effect the use of the aerodrome and are able to supply pilots wi tv accuracy’s essential aerodrome information 2- unserviceablities or obstructions that are observed may receive attention

Question 86

When shall aerodrome surface inspections be carried out?

Answer 86

Atleast 1 a day Aerodromes which are 24hours - after first light Non 24 hour aerodromes- inspection should take place before flying commences Additional inspections when- 1- at cessation of work on the manoeuvring area 2- when a runway not previously inspected is brought into use 3- following an aircraft accident 4- following an abandoned take off by turbine engines aircraft due to engine malfunction, or by any aircraft due to burst tyres 5- during snow and ice conditions as frequently as weather conditions warrant 6- when considered necessary by ATC, the aerodrome operator or as detailed in local instructions

Question 87

What is the aerodrome operator checking for when doing surface inspections?

Answer 87

1- the runways, stopways, Clearwater, taxiways and holding areas are free from obstructions, collections of loose stones etc 2- temporary obstructions that exist on, or adjacent to, the runways or taxiways are properly marked or lighted 3- bad ground (partially on non runway aerodromes) is adequately marked 4- runway indicator boards, traffic signs, boundary markers etc are serviceable and in position

Question 88

When shall aerodrome lighting inspections be carried out?

Answer 88

Before night flying commences

Question 89

In snow and ice conditions what is the aerodrome operator checking regarding aerodrome inspections ?

Answer 89

1- badly rutted or frozen grounds is adequately marked 2- runways and taxiways are delineated if covered with snow or ice and a note taken of the extent of sweeping n and sanding carried out

Question 90

Once the aerodrome operator has passed on details of the surface inspections what should ATC do?

Answer 90

Record it in the ATC watch log

Question 91

How should ATC report wet runways?

Answer 91

On RTF and ATIS in plain language

Question 92

What is the definition of dry?

Answer 92

The surface is not affected by water, slush, snow or ice Not passed to pilots

Question 93

What is the definition of damp?

Answer 93

The surface shows a change of colour due to moisture

Question 94

What is the definition of wet?

Answer 94

The surface is soaked but no significant patches of standing water are visible Standing water is considered to exist when water on the runway surface is deeper than 3mm.

Question 95

What’s the definition of water patches?

Answer 95

Significant patches of standing water are visible Water patches will be reported when more than 25% of the assessed area is covered by water more than 3mm deep

Question 96

What is the definition of flooded?

Answer 96

Extensive patches of standing water are visible Flooded will reported when more than 50% of the assessed area is covered by water more than 3mm deep

Question 97

Can a controller pass information on the runway state being better than reported?

Answer 97

No

Question 98

What is the definition of ice?

Answer 98

Water in it’s solid state, it takes many forms including sheet ice, hoar frost and rime

Question 99

What is the definition of dry snow?

Answer 99

A condition where snow can be blown if loose or, if compacted by hand, will fall apart again upon release

Question 100

What is the definition of compacted snow?

Answer 100

Snow which has been compressed into a solid mass, that resists further compression and will hold together or break up into chunks if picked up

Question 101

What is the definition of wet snow?

Answer 101

A composition which, if compacted by hand, will stick together and tend to, or does, form a snowball

Question 102

What is the definition of slush?

Answer 102

A water saturated snow which, with a heel and toe slap down action with the foot against the ground, will be displaced with a splatter

Question 103

What is the definition of associated standing water?

Answer 103

Standing water produced as a result of melting contaminant in which there are no viable traces of slush or ice crystals

Question 104

What is classed of significant change regarding runway conditions ?

Answer 104

1- any change in surface deposit, snow turned to slush, water to ice etc and the effect on braking action where appropriate 2- changes in depth greater than the following 20mm for dry snow, 10mm for wet snow, 3mm for slush 3- any change in the available length or width of runways if 10% or more 4- any change in the type of deposit or extent of coverage which requires a change of the SNOWTAM 5- any change in the distance apart of snowbanks from the criteria declared to be the value from which reporting begins 6- any change in the serviceability of runway lighting caused by obscuring of the lights, with particular reference to the threshold 7- any other conditions known to be significant according to local circumstances