AERONAUTICAL SERVICES ADVISORY MEMORANDUM (ASAM) Focal Point: ASD

Transcription

1 Page 1 of 9 1. Introduction This advisory memorandum provides guidance to Air Traffic Service Providers in respect of flights operating in the vicinity of volcanic ash. 2. Purpose The purpose of this memorandum is to ensure that ATS Providers, certified by the National Supervisory Authority of Ireland, are aware of the service provision considerations to be afforded for flights that are operating in the vicinity of airspace which is predicted to be contaminated by Volcanic Ash. 3. Scope This advisory memorandum is addressed to responsible managers and ATCOS at all ATS providers within the State and becomes effective from 0000 hrs UTC on 16th June The ATS procedures detailed herein apply to ATS provision in the following airspace; Shannon Flight Information Region/Upper Flight Information Region All airspaces assigned to Ireland or within which the provision of ATS has been delegated to Ireland, including NOTA and SOTA; Notes 1. NOTA / SOTA consist of that portion of the Shanwick Flight Information Region/Oceanic Control Area with lateral and vertical limits specified at IAIP ENR The procedures herein apply in that portion of the Shannon FIR where the provision of ATS is delegated to UK ANS Providers. 4. Contamination levels In the International Civil Aviation Organization (ICAO) Volcanic Ash Contingency Plan for the EUR and NAT Regions (EUR Doc 019) three ash contamination levels (LOW; MEDIUM; HIGH) have been defined. 1. Area of Low Contamination: An airspace of defined dimensions where volcanic ash may be encountered at concentrations equal to or less than 2x10-3 g/m Area of Medium Contamination: An airspace of defined dimensions where volcanic ash may be encountered at concentrations greater than 2 x 10-3 g/m 3, but less than 4 x 10-3 g/m Area of High Contamination: An airspace of defined dimensions where volcanic ash may be encountered at concentrations equal to or

2 Page 2 of 9 greater than 4 x 10-3 g/m 3, or areas of contaminated airspace where no ash concentration guidance is available. Notes: A three-dimensional volume of airspace should be understood where the word area is used to depict areas shown on published Volcanic Ash Concentration Charts. All modelled ash concentrations are subject to a level of uncertainty. Areas of ash contamination will be displayed on the Volcanic Ash Concentration Chart (VACC) produced by the UK Met Office and available on the Eurocontrol website CFMU/NOP portal. The colours used on the Ash Concentration Charts (see Fig. 1) are: Cyan (Blue) = Low contamination Grey = Medium contamination Red = High contamination

3 Page 3 of 9 Area 3 Area 2 Area 1 Figure 1 Revised Safety Zones 5. Promulgation of NOTAMS Areas predicted to contain High Contamination of volcanic ash will be promulgated via NOTAM as Volcanic Ash Temporary Danger Areas (TDA). Volcanic Ash TDAs will be promulgated with an associated upper and lower vertical extent. The NOTAM promulgating the area of high ash contamination will include a lower vertical buffer zone beneath

4 Page 4 of 9 the level of the high contamination area depicted on Volcanic Ash Concentration Charts. Areas predicted to contain Medium Contamination of volcanic ash will be promulgated via NOTAM. As with Volcanic Ash TDAs, the NOTAM promulgating the area of medium ash contamination will include a lower vertical buffer zone beneath the level of the medium contamination area depicted on Volcanic Ash Concentration Charts. Where there is an overlap of Volcanic Ash contamination between UK Airspace and the Shannon FIR, a UK NOTAM will identify the Shannon FIR (EISN) as one of the affected FIR s. The UK NOTAM will delineate the Volcanic Ash Temporary Danger Area (s) and indicate the levels of contamination. Where the Volcanic Activity data lies solely within the Shannon FIR (EISN), the IAA will publish NOTAMs delineating the Temporary Danger Area/s (for high contamination) and areas predicted to contain Medium Contamination indicating the levels of contamination. Only NOTAMS issued by the UK CAA or the IAA should be used to determine areas of medium and high ash contamination, and any associated Volcanic Ash TDAs. NOTAMS will be issued in sufficient time for aircraft operators and ATS providers to plan for changes in the extent of the Volcanic Ash TDA. It is vital that NOTAM information (not VACC charts) is used for the planning of flight operations since this will be the only definitive source of information on available airspace. It is possible that a NOTAM may not be consistent, on occasions, with the high or medium ash contamination areas that are provided on the UK Met Office Volcanic Ash Concentration Charts. The most likely causes for inconsistencies are: a) Smoothing of the contamination area for ease of interpretation in the NOTAM. b) Observational evidence received since the forecast has been issued and prior to any revised or updated forecast being issued. This may include: old ash that has dispersed more quickly than expected by the model; small areas of high contamination, which may be considered unrealistic; and

5 Page 5 of 9 areas of ash detached from a main plume that are incorrectly modelled. Note: The term Volcanic Ash Temporary Danger Areas should not be confused with the Initial Danger Zone, which is established with a 120 NM radius in the vicinity of the volcanic eruption) 6. Overflight and Underflight of Volcanic Ash Clouds Overflight and underflight of contaminated airspace is a decision undertaken and evaluated by the aircraft operator in accordance with any conditions set by its State of Registry and State of Operation. In certain meteorological conditions, it is possible for multiple separated layers of high ash concentration to exist. However, it is considered inappropriate for aircraft operations to take place in a letterbox between Volcanic Ash TDAs stacked one above the other. Therefore, the design of the TDA will take account of any such circumstances and the vertical limits will be adjusted accordingly to constrain such a possibility. 6.1 Overflight: - It is recommended that airspace with significant ash contamination be treated as a solid object for the purposes of flight planning. This is equivalent to a mountainous area with a high Minimum Safe Altitude (MSA) and no alternate aerodromes within it. In general, the assumed MSA should be at least 2000 ft above the top of the ash cloud. Providing an operator can plan a flight such that in the event of any credible emergency the aeroplane can continue to remain clear of the air mass containing significant concentrations of volcanic particles, there is nothing in the available data that would indicate overflight of such airspace is unacceptable. The minimum lower useable level above a Volcanic Ash TDA will be 2000 ft above the promulgated upper level of the TDA. 6.2 Underflight: - With immediate effect, Volcanic Ash TDAs will be promulgated by NOTAM with an associated upper and lower vertical extent. The publication of this information has been made possible due to improvements that have been made by the UK Met Office during 2011 to the dispersion model that predicts the movement of Volcanic Ash in the atmosphere. These included improvements to the way in which the ash concentrations in vertical layers are calculated. However, in order to mitigate an area of residual modelling uncertainty, the vertical extent of the Volcanic Ash TDA will include a lower vertical buffer zone beneath the level of the high contamination area depicted

6 Page 6 of 9 on Volcanic Ash Concentration Charts. This policy has been agreed on the basis of specialist scientific advice and accounts for the meteorological and eruption strength uncertainties that are inherent in the model. The maximum upper useable level beneath a Volcanic Ash TDA will be 1000 ft below the promulgated base of the TDA. 7. (Extract from ICAO Doc 019) ANTICIPATED PILOT ISSUES WHEN ENCOUNTERING VOLCANIC ASH 1. ATCOs should be aware that flight crews will be immediately dealing with some or all of the following issues when they encounter volcanic ash: a) Smoke or dust appearing in the cockpit which may prompt the flight crew to don oxygen masks (could interfere with the clarity of voice communications); b) Acrid odour similar to electrical smoke; c) Multiple engine malfunctions, such as stalls, increasing Exhaust Gas Temperature (EGT), torching, flameout, and thrust loss causing an immediate departure from assigned altitude; d) On engine restart attempts, engines may accelerate to idle very slowly, especially at high altitudes (could result in inability to maintain altitude or Mach number); e) At night, St. Elmo's fire/static discharges may be observed around the windshield, accompanied by a bright orange glow in the engine inlet(s); f) Possible loss of visibility due to cockpit windows becoming cracked or discoloured, due to the sandblast effect of the ash; g) Cockpit windows could be rendered completely opaque; and/or h) Sharp distinct shadows cast by landing lights as compared to the diffused shadows observed in clouds (this affects visual perception of objects outside the aircraft). 2. Simultaneously, ATC can expect pilots to be executing contingency procedures. This may include a possible course reversal and/or an emergency descent. (End of extract) 8. PROVISION OF AIR TRAFFIC SERVICES. The ACC in conjunction with ATFM units serves as the critical communication link between the pilot, dispatcher and meteorologists during a volcanic eruption. During episodes of volcanic ash

7 Page 7 of 9 contamination within the FIR, the ACC has two major communication roles. First and of greatest importance is its ability to communicate directly with aircraft en route which may encounter the ash. Based on the information provided in the volcanic ash NOTAM and VAAs, the ATCOs should be able to advise the pilot of which flight levels are affected by the ash and the projected trajectory and drift of the contamination. Through the use of radio communication, ACCs have the capability to coordinate with the pilot alternative routes which would keep the aircraft away from the volcanic ash. 9. AIR TRAFFIC CONTROL PROCEDURES a. This paragraph applies to ATS provision in the Shannon FIR, NOTA and SOTA (UK procedures are similar). ATS procedures in other parts of the world may vary. b. Within the various contamination areas it is for the aircraft operator and aircraft commander to determine that it is safe to operate the aircraft in such airspace. It is the aircraft operator s responsibility to comply with any required limitations as imposed by their State of Registry and State of Operation. ATS providers are not required to question a pilot s approval to fly through a Volcanic Ash TDA. There is no requirement to terminate or amend the ATS provided. c. The presence of a Volcanic Ash TDA does not imply that the airspace is closed and such terminology should not be used, either on radiotelephony or in any other form of general communication. Instead, the presence and extent of the Volcanic Ash TDA should be stated. d. ATC does not normally issue clearances into Danger Areas but in relation to flight through Volcanic Ash Temporary Danger Areas, clearances may be provided if requested. e. Volcanic Ash Temporary Danger Areas have lateral and vertical dimensions. No additional lateral separation is required. A minimum of 1000 ft vertical separation shall be applied below the area and a minimum of 2000 ft above the area by ATC unless different parameters are requested by the pilot. f. Flights for the purposes of safety, security and the saving of life (e.g. Search and Rescue (SAR), Helicopter Emergency Medical Services and Police) are not subject to requirements or restrictions herein. g. The Volcanic Ash Temporary Danger Area has the same ICAO airspace classification of the surrounding airspace. h. In the event that an aircraft operating at the maximum/minimum useable level beneath/above the Volcanic Ash TDA receives a TCAS

8 Page 8 of 9 RA climb/descend, this should be dealt with as per normal procedures. i. Prior to any aircraft entering a Volcanic Ash Temporary Danger Areas, aircrew shall be so advised using the following phraseology: (Aircraft call-sign) you are about to enter a notified Volcanic Ash Temporary Danger Area in your (XX) o clock (active from FL (xxx) to FL (xxx)). Report your intentions. j. In the event of an aircraft inadvertently entering a volcanic ash danger area, consider the aircraft to be in an emergency situation and provide assistance to enable a pilot to exit that volume of airspace in the most expeditious and appropriate manner. k. When appropriate, remind pilots that volcanic ash may not be detected by ATC radar systems. l. Pilots operating within an area of contamination may decline an instruction to climb/descend and/or a vector if that would take the aircraft into an area of higher contamination if that would be contrary to the aircraft type and engine pairing tolerance level. A pilot may also request to leave an area if the aircraft is unable to sustain flight within the area. ATCOs should accommodate any such request as expeditiously as operational safety considerations allow. If the ACC has been advised by an aircraft that it has entered an area of ash contamination and indicates that a distress situation exists: i) do not initiate any climb clearances to turbine-powered aircraft until the aircraft has exited the area of ash contamination; and ii) do not attempt to provide vectors without pilot concurrence. 10. ATS providers should ensure that: ATCOs and AFISOs are appropriately briefed before they assume responsibility for a control position, on the potential pilot actions in the event of a significant Volcanic Ash encounter or flight within ash contaminated airspace; ATCO and AFISO workloads are managed such that sufficient capacity is maintained at all times to react appropriately to a Volcanic Ash encounter in ash contaminated airspace or provide additional assistance to a pilot if required. This may include the application of flow control or limitations on the number of aircraft in a defined airspace block or sector; Interface procedures with adjacent ATC sectors/units/control centres appropriately cater for aircraft that are likely to operate on non standard routes and/or levels. Adequate resources are available to accommodate planned aircraft movements, including an unexpected emergency/diversion incident;

9 Page 9 of ATS Providers shall ensure that ATCOs and AFISOs are aware that should an aircraft unexpectedly encounter a significant concentration of Volcanic Ash, the pilot may, possibly without first advising ATC: Execute a 180 degree turn; Descend; Reduce engine power; Disconnect auto-throttle. 12. ATS providers shall ensure the reporting through the Mandatory Occurrence Reporting Scheme, of any encounters with, or experience of, volcanic ash reported by pilots. 13. ATS Service provision in areas of volcanic ash is considered to be an unusual circumstance and is therefore to be included in Training in Unusual Circumstances and Emergencies (TRUCE). 14. The amended guidance above should be considered as interim measures pending further refinement and development in collaboration with industry. References ICAO Volcanic Ash Contingency Plan EUR and NAT Regions (EUR Doc 019). Operations Advisory Memoranda OAM And *OAM *Note: Operations Advisory Memoranda (OAM) supplements the general content OAM 11/10, but supersedes it in the terms used for volumes of airspace containing various predicted levels of ash contamination (Sections 4a, 4b and 4c of OAM 11/10).