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AMOFSG/7-SN No. 17
AMOFSG/7-SN No. 17
22/7/08

AERODROME METEOROLOGICAL OBSERVATION AND FORECAST STUDY GROUP (AMOFSG)

SEVENTH MEETING

Montréal, 9 to 12 September 2008

Agenda Item / 5: / Aerodrome observations

Lightning Detection in support of Airport Authority decision making

(Presented by Kees Blom)

SUMMARY
IATA requires for safety reasons some or all handling operations to be suspended when lightning occurs at or near an aerodrome. This paper describes the method used by KNMI for Amsterdam Airport Schiphol and proposes introduction of a requirement for a lightning detection system to be installed to enable the MET provider to adequately support the Airport Authority in decision making on this subject.

1.  INTRODUCTION

1.1  In the IATA document: Airside Management and Safety; 6.5 Severe Weather Notification (25th Edition, January 2005) three notification phases for the occurrence of lightning are listed:

For lightning the notification process may be broken down into 3 phases:

—  Alert: Lightning activity is detected at a distance in excess of 8 km (5 miles) from your operation.

—  Stop/Suspend activities: Lightning activity is detected within 5 km (3miles) of your operation.

—  All Clear: Lightning activity has moved beyond 5 km (3 miles) and is heading away from your operation.

The distances referred to above may vary dependent upon local climatic parameters.

1.2  EAGOSH (European Aviation Group for Occupational Safety and Health) has translated this into the following:

Alert and warning system

Airports Authorities are to institute arrangements with the Meteorological Office for the receipt of stormwarnings.

Lightning storms in close proximity to the airport, 3 to 10 miles

Precautions and Cautions

When thunderstorms come within seven to ten miles:

Stopping the use of headsets for ground to flight deck communication, do not touch metallic ground support equipment etc.

However, when thunderstorms come within three miles:

Fuelling operation should be suspended and all employees should start to find shelter (aircraft inside, car, buildings etc.).

Because of the variation of circumstances which differ from airport to airport, detailed procedures have to be worked out.

2.  DISCUSSION

2.1  Suspension of certain airside operations on an aerodrome can seriously affect the operation of an airport as a whole. The suspension of certain airside operations such as pushback, fuelling, disembarking passengers, boarding, docking, etc… has great implications on the planning of the movements, the planning of parking stands, punctuality of arrivals and departures, taxi time, the validity of the Flight Plans and the adherence to airport and CFMU slots. The adverse condition also creates substantial delays. These effects have an impact on the operations of all actors on an aerodrome, such as the Airport Operator, Airlines, Handlers, Air Traffic Control and CFMU. This list is non-exhaustive.

2.2  A particular effect is the likelihood that the FPLs become suspended. This means that the flight (which may already be boarded) can no longer depart unless the whole process of start up and clearance delivery is re-started.

2.3  To reduce these effects and to allow the various actors to anticipate the arrival of such conditions and to allow them to prepare in any way the recovery from these conditions it would be required to obtain as precise as possible information on the following parameters:

—  estimated time of occurrence

—  estimated duration of the occurrence

—  estimated end of the occurrence

—  updates of these estimates every 15 minutes

2.4  In the EUR region the IATA lightning phases have been introduced in the daily operations at several airports, where different solutions have been chosen to implement them.

2.5  At Amsterdam Airport Schiphol (AAS) the introduction of the lightning warning system has been triggered by the existing Expert Group Ground Safety (part of VPS, Safety Platform Schiphol) . The main driver behind this process was the personal safety of staff working at the airport. This group stated after extensive consultations a formal requirement to KNMI to extend the already existing procedure for TS warnings related to suspension of aircraft refuelling at the airport in such a way that all handlers at the airport could fulfil the IATA and EAGOSH recommendations.

2.6  The request included the requirement that an uniform alerting and warning system would be introduced for all stakeholders at the airport and a uniform response from all stakeholders to the alerts and warnings.

2.7  KNMI indicated that the use of the Dutch/Belgian FLITS lightning detection network could result in detection of lightning in the Schiphol area with a resolution of approximately 2.0 kms or better. (Fig. 1) The update frequency of the display is 1 minute.

2.8  Therefore it was decided to develop a dedicated display of the Dutch Radar display system (BRAS) on which, centered at the threshold of RWY 24, two circles where drawn, with a diameter of 5 and 10 kms. (Fig 2.)The display system was made available to both the aviation forecasters and the Airside Operations Managers (AOM) to have the required common picture of the lightning situation at any given moment.

2.9  In normal daily routine there are 4 telephone conferences between the aviation forecaster, sup. APP, KLM OCC and HCC and AAS AOM. In these briefings the forecaster provides the detailed forecast for the next 6 hours and an outlook for the rest of the period. If any TS activity is forecasted in the Amsterdam FIR during these 6 hours this will be indicated by a colour code.

Fig. 1: General Lightning Display

Fig. 2: The 5 and 10 kms distance markers

2.10  The following codes have been agreed:

—  Red: Electrical discharges occurring (actual) within the 5 km (~3 NM) circle.

—  Amber: Electrical discharges occurring (actual) within the 10 km (~6 NM) circle but not yet within 5 km..

—  Yellow: Electrical discharges occurring (both actual and forecast) within the AMSTERDAM FIR and risk that these will enter the 10 km circle.

—  Green: No risk for electrical discharges at the airport. The colour code Green shall also be used to cancel other colour codes.

2.11  Furthermore the aviation forecaster is tasked to contact the AOM (by telephone) (TheAOM is responsible to inform all parties on airside when handling is to be stopped and when the stop is cancelled again) as soon as he notices an unexpected lightning stroke or whenever a lightning stroke, be it cloud-cloud or cloud-ground, appears and calls for a change/update in the colour code. After this has been done the other parties as ATC and KLM Hub control are to be informed as well.

2.12  ICAO Annex 3 — Meteorological Service for International Air Navigation , Appendix 6, 5.1.3 recommends that aerodrome warnings should be issued for a.o. thunderstorm. The associated template (table A6-2) allows for up to 32 characters free text in an Aerodrome Warning so in principle the phases mentioned by IATA could be included.

2.13  Since the AOM has so many duties and so many signals to monitor and to react upon, it has been decided that issuing an aerodrome warning according the template would not be sufficient, and instead the direct phone call should be used to inform him immediately whenever deemed necessary. In near future the AOM will make use of a yet to be installed acoustic and aural warning system to inform all workers on airside when a red alert is given or cancelled again.

2.14  To be able to provide the AOM (or generally: The Airport Authority) with the required data it is necessary to make use of an (automated) lightning detection system which provides the MET service provider in a timely and consistent manner with location, polarity and frequency of lightning discharges both cloud to ground and vice versa as inter- or intracloud.

2.15  The way in which these data are distributed has to be defined locally between the MET service provider and the airport actors individually or via a collective notification system as may be available.

3.  CONCLUSION

3.1  A requirement exists (from users, i.e. IATA and airport authorities) to provide lightning data in support of collaborative decision making in respect of safety and airport capacity planning on aerodromes.

3.2  ICAO Annex 3 is completely lacking any SARP requiring provision of essential meteorological data to Airport Authorities, while there is the CHAPTER 10. INFORMATION FOR AIR TRAFFIC SERVICES, SEARCH AND RESCUE SERVICES AND AERONAUTICAL INFORMATION SERVICES.

3.3  It is proposed that the ICAO secretariat takes action and prepares, as part of the next amendment to Annex 3, a proposal to include in Annex 3:

a)  a recommendation to provide airport authorities with essential meteorological data, and

b)  a recommendation to make use of an automated lightning detection system, as described under para 2.14, wherever meteorological conditions and airport capacity do require such.

4.  ACTION BY THE GROUP

4.1  The group is invited to:

a)  note the content of this paper; and

b)  consider the proposals in para. 3.3 and, if supported by the group, formulate a draft amendment to Annex 3 for incorporation in Amendment 75.

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