AD 1.2 RESCUE AND FIRE FIGHTING SERVICES AND SNOW PLAN

1 Rescue and Fire Fighting Services

At aerodromes approved for scheduled and non-scheduled traffic with aeroplanes carrying passengers, Rescue and Fire Fighting Services and, in some cases, also Sea Rescue Services are established in accordance with the regulations for civil aviation.

Information about service availability and its extent is given on the relevant page for each aerodrome.

Scheduled or non-scheduled traffic aeroplanes carrying passengers are not allowed to use aerodromes without Rescue and Fire Fighting services.

Each individual service is categorised according to the table shown below. Temporary changes will be published by NOTAM.

Rescue and fire fighting services
Aerodrome categoryAmount of water in litres for production of performance level A foam
31800
43600
58100
611800
718200
827300
936400
1048200
Categories 1 and 2 are not used in Estonia.

2 Snow Plan

2.1 Organisation of Winter Service
During the winter period from approximately 1 NOV to 1 APR, the Aerodrome Maintenance Service at the aerodromes listed below conducts the following duties:
  1. surveillance of the manoeuvring area and apron with an intent to detect the presence of ice, snow or slush;
  2. measurement of the friction coefficient or estimate of the braking action when ice, snow and/or slush are present on the runway in question, and at the earliest at taxiways and aprons;
  3. implementation of measures to maintain the usability of the runway, etc;
  4. reporting of the conditions mentioned in a) to c) above.

Winter service is established at the following aerodromes:
  • Kärdla (EEKA)
  • Kuressaare (EEKE)
  • Pärnu (EEPU)
  • Lennart Meri Tallinn (EETN)
  • Tartu (EETU)
  • Ämari (MIL) (EEEI)
2.2 Surveillance of Movement Areas
The Aerodrome Maintenance Service monitors the condition of the manoeuvring area and the apron during the published aerodrome hours of service.
2.3 Measuring Methods and Measurements Taken
2.3.1 The depth of a layer of snow or slush is measured by an ordinary ruler. Measurements will be taken at numerous places and a given mean value is calculated. On runway, the mean value will be calculated for each third of the runway. For removal of ice and compacted snow which cannot be removed with mechanical equipment, chemicals are used.
2.3.2 Friction Coefficients
2.3.2.1 Whenever information on braking action promulgated in accordance with this snow plan in terms of friction coefficients is used as a basis for assessing the stopping and manoeuvring capability of an aircraft, it is of utmost importance to keep in mind that these friction coefficients pertain to a measuring device and therefore, as objective parameters, are valid for that specific device only.
2.3.2.2 The following methods of measurement apply:
  1. continuous method whereby the friction coefficient is determined by friction tester measurements;
  2. retardation measurements with the use of an instrument that only indicates the peak value of the retardation reached during each braking (Tapley meter – TAP).

All measurements and calibrations are accomplished in accordance with the instructions given by manufacturer for the proper use of the instruments. Measurements are taken approximately 4 m on either side of the runway centre line.

2.3.2.2.1 Different friction testers are used at Estonian aerodromes.

Finnish Vammas factory Skiddometers BV11 are used at Lennart Meri Tallinn aerodrome.

English origin Tapley meter Bowmonk AFM2 MK3 is used at Pärnu aerodrome.

Swedish company ASFT friction testers T-10 and Tapley meters are used at Tartu and Kärdla aerodrome.

Swedish company ASFT friction tester Saab 9000 and TAP Bowmonk AFM2 MK3 are used at Kuressaare aerodrome.

ASFT friction tester Škoda MK-4 and T5 trailer are used at Ämari Military Aerodrome.

If a reserve instrument of a type other than the primary is used, it will be announced by ATS and by ATIS, where available.

2.3.2.2.2 Braking action will be estimated if the friction coefficient cannot be measured due to lack of equipment or for other reasons.
2.3.2.2.3 When ice, snow or slush is present on a runway, the friction coefficient will be measured or braking action will be estimated.
Where only water is present on a runway and periodic measurements so indicate, the runway will be reported as “WET”.
2.4 Actions taken to maintain the usability of movement areas
2.4.1 Snow clearance and measures to improve braking action will be implemented as long as conditions at the movement area impede the safety and regularity of air traffic.
2.4.2 Snow clearance, etc will normally be carried out in the following order:
  1. Runway and access road from the fire station.
  2. Taxiway(s) to runway in use.
  3. ILS critical area.
  4. Apron(s).
  5. Other areas and roads.

Measures will be taken to clear the runway to full width but in special cases conditions may dictate that wide runways be opened temporarily for traffic even if cleared to a width of 30 m only. Snow clearance will not be considered completed until the runway is cleared to full width.

2.4.3 Measures to improve braking action will be implemented when the friction coefficient on runways and taxiways is below the maintenance planning level shown in ICAO Annex 14, Volume I, Attachment A, Section 7.

The following chemicals are used for chemical de-icing:

for spreading: UREA (CO(NH2)2).
for spraying: BP Clearway-1.

Chemical de-icing of runways will be carried out to a width of not less than 15 m on each side of the centre line of the runway.

Improvement of the braking action by spreading sand is not used in Estonia.
2.5 System and means of reporting
2.5.1 The Aerodrome Maintenance Service will use SNOWTAM form for the reporting which will be delivered to the ARO/ATS unit for further dissemination.
2.5.1.1 When ice, snow or slush no longer prevail and chemicals are no longer used, the reporting will cease after issuance of a cancellation SNOWTAM. A new SNOWTAM will not be issued until winter conditions appear again.
2.5.2 The following definitions have been adopted:

Slush
Water-saturated snow which with a heel-and-toe slap-down motion against the ground will be displaced with a splatter; specific gravity: 0.5 up to 0.8.

Note: Combinations of ice, snow and/or standing water may, especially when rain, rain and snow, or snow is falling, produce substances with specific gravities in excess of 0.8. These substances, due to their high water/ice content, will have a transparent rather than a cloudy appearance and, at the higher gravities, will be readily distinguishable from slush.

Snow (on the ground):
  1. Dry snow – Snow which can be blown if loose or, if compacted by hand, will fall apart again upon release; specific gravity: up to but not including 0.35.
  2. Wet snow – Snow which, if compacted by hand, will stick together and tend to or form a snow-ball; specific gravity: 0.35 up to but not including 0.5.
  3. Compacted snow – Snow which has been compressed into a solid mass that resists further compression and will hold together or break up into lumps if picked up; specific gravity: 0.5 and over.
2.5.3 The extent of ice, snow and/or slush on a runway is reported on the basis of an estimate of the covered area and given in percentage of the total area of the runway, in accordance with the following:
10%10% or less is covered
25%11-25% of the runway is covered
50%26-50% of the runway is covered
100%more than 50% of the runway is covered
2.5.4 Information on braking action will be given in terms of friction numbers (friction coefficients indicated with two digits, 0 and decimal symbol being omitted) when based on measurements. In addition, the kind of measuring device will be reported. When braking action is estimated, plain language will be used.

In MOTNE transmissions, a special code will be used.

Measured friction coefficientEstimated braking actionCode
0.40 and abovegood5
0.39 - 0.36good to medium4
0.35 - 0.30medium3
0.29 - 0.26medium to poor2
0.25 or belowpoor1
9 - unreliableunreliable9

“Unreliable” will be reported when more than 10% of a runway surface is covered by wet ice, wet snow and/or slush. Measuring results and estimates are considered absolutely unrealistic in such situations. In reports “Unreliable” will be followed by either the friction number given by the instrument used or the estimated braking action. In the MOTNE code, the code figure “99” will be used.

2.5.5 Snow banks will be reported when their height exceeds:
  • 0.3 m on the runway or taxiway edge line;
  • 0.6 m at a distance of 5 m from the RWY or TWY;
  • 1.0 m at a distance of 10 m from the RWY or TWY;
  • 1.5 m at a distance of 15 m from the RWY or TWY;
  • 3.0 m at a distance of 20 m from the RWY or TWY.
2.5.6 When information on runway conditions is given section wise, it is given in the order in which the conditions in question are encountered at take-off or in landing in the runway direction which is indicated by the runway number.
2.5.7 In instructions to landing and departing aircraft, the order of section-wise information of the runway in use will thus always be in accordance with the order in which the conditions in question are encountered during take-off and landing.
2.6 Cases of runway closure
In cases where a postponement of clearance operations would involve a definite risk of the situation developing into a crisis, e.g when a fall in temperature causes water or slush to become solid ice, the snow clearance service is authorised to demand that sections of the movement areas be closed to traffic.
2.7 Dissemination of information about snow conditions

Information on snow conditions at Kärdla, Kuressaare, Pärnu, Lennart Meri Tallinn and Tartu aerodromes will be delivered from the individual aerodrome in a separate series of NOTAM (SNOWTAM) to the NOF for further dissemination.

Information on snow conditions at Ämari Military Aerodrome will be delivered by SNOWTAM on request.

SNOWTAM will be prepared in accordance with ICAO Annex 15, Appendix 2.

Information on snow conditions at aerodromes other than those mentioned above can be obtained at the aerodrome concerned.