Appendices Vol 2

APPENDICES – VOLUME 2 St Helena Access Feasibility Study Final Report ___________________________________________________________________ CONTENTS ___________________________________________________________________ Appendix H: Specification for Gathering Met Data……………………………………. Appendix I: Use of Wideawake Airfield…………………………………………………. Appendix J: Fuel Storage Requirements..…………………………………………….... Appendix K: Ticket Price Estimates..…………………………………………………….. Appendix L: Air Cargo Supply Arrangements..………………………………………... Appendix M: Technical Feasibility – Air Access………………………………………. Appendix N: Reduction of Long Runway Sub Option………………………………... Appendix O: Long Runway………………………………………………………………... Appendix P: 1400m LDA/1650m TORA Runway……………………………………….. Appendix Q: Air Traffic Systems Specification………………………………………... Appendix R: Provision of Sea Cargo Under Air Access………………..……………. Appendix S: Environmental Impact Report…………………………………………….. Appendix T: TOR for ESIA……………………………………………………………….... Appendix U: Island Visit and Other Meetings………………………………………….. Appendix V: Comments on SHG LDC (Environmental)………………………………. Appendix W: Description of Economic Model…………………………………………. Appendix X: Risk Analysis of Long Runway Option………………………………….. Appendix Y: Procurement Approach: RMS Replacement………………………….... Appendix Z: Air Service Contract Approach………………………………………….... Appendix AA: Review of Procurement Routes………………………………………... Appendix AB: DFID / SHG / Contractor Funding Structure………………………….. Appendix AC: Market Interest…………………………………………………………….. Appendix AD: Review of Telecoms Infrastructure……………………………………. Appendix AE: Portfolio Management of Projects……………………………………... Appendix AF: Commentary on Implementation Plan…………………………………. St. Helena Air Access Met data gathering requirements APPENDIX H: SPECIFICATION FOR GATHERING METEORLOGICAL DATA Appendix H - Metereological Requirements Public Domain St. Helena Air Access Met data gathering requirements Contents Preface...................................................................................................4 1. Meteorological Requirements.......................................................5 Background .....................................................................................5 Runway Strip Requirements ............................................................5 Decision Heights..............................................................................6 Meteorological Data Requirements..................................................6 2. Costs and Recommendations ......................................................8 Methodology....................................................................................8 Recommendation ..........................................................................10 Appendix A: Cloud-break Procedure on St Helena ..........................11 Appendix B: Automatic Meteorological Station – Specification & Budget Estimate.............................................................13 Appendix H - Metereological Requirements 2 Public Domain St. Helena Air Access Met data gathering requirements Glossary of Terms AAL Above Aerodrome Level DFID Department for International Development DVOR/DME Doppler Variable Omni Range/Distance Measuring Equipment HMG Her Majesty’s Government ICAO International Civil Aviation Organisation m metres MDH Minimum Descent Height MOC Minimum Obstacle Clearance NDB Non Directional Beacon OCH Obstacle Clearance Height PANSOPS Procedures for Air Navigation and Operations SHG Saint Helena Government Appendix H - Metereological Requirements 3 Public Domain St. Helena Air Access Met data gathering requirements Preface Atkins estimates that the construction costs to design and build an aerodrome on St Helena are of the order of ¦¦¦¦ million. This estimate assumes an instrument runway approach. Having a visual runway approach could reduce the cost of an aerodrome by about ¦¦¦¦. This report explains the conditions which need to be fulfilled to allow a visual runway approach. There is a dearth, however, of meteorological evidence available in relation to the proposed runway site and orientation. In particular, there is no information about the height of the cloud base on the approaches to, and above, the proposed aerodrome. This information is critical in deciding whether a visual runway would be viable for St Helena. This paper discusses the technical issues and recommends how the required data can be obtained. Appendix H - Metereological Requirements 4 Public Domain St. Helena Air Access Met data gathering requirements 1. Meteorological Requirements BACKGROUND The only credible diversion for flight operations is Ascension Island (ASI) located 700 nautical miles to the NNW of St Helena. Civilian Flights into ASI are currently limited to two rotations per week under the 2003 note, between the UK and the USA, agreeing civilian flights into Wideawake Airfield, ASI. Whilst there is provision in the original 1956 agreement for Wideawake Airfield to be used in emergency, the US authorities would still have to accept the use of Wideawake Airfield as a planned diversion. It is, therefore, a requirement that any aerodrome on St Helena should have as high a usability factor as practicable. Further, high diversion rates, because of weather, will not encourage the growth of tourism. As a consequence, an aerodrome on St Helena will be required to operate in nearly all weather conditions. The Evaluation report proposed a runway usability of greater than 98% to be achieved. For these reasons, the current estimates for the construction of the new aerodrome on St Helena are based on building an instrument runway1. RUNWAY STRIP In order to be licensed, an instrument runway needs to be REQUIREMENTS surrounded by a runway strip measuring 150m either side of the runway centre line and extending 60m past each runway end. The 150m strip in turn comprises two levels of ground work: land 105m either side of the runway must be cleared and graded and the land from 105m to 150m either side of the runway must be cleared with no upstanding obstacles. For a visual runway, i.e. one where only visual approaches are made, the requirements are less stringent. These are for a cleared and graded area 75m either side of runway centre line, extending 60m past each runway end. For a visual runway of 2200m length, the reduction in the area of land to be cleared and graded is considerably reduced with associated reductions in construction costs. We estimate these savings (in earthworks and reduction of navigational aids) to be ¦¦¦¦. Further savings may be possible during detailed design as the narrower strip can be positioned better on the site to optimise construction cost. 1 See the Evaluation and Supplementary reports for more explanation. Appendix H - Metereological Requirements 5 Public Domain St. Helena Air Access Met data gathering requirements MINIMUM DESCENT HEIGHTS An initial assessment by Atkins has concluded that, with correct runway alignment, a minimum descent height (MDH) of c.400ft could be used for non-precision instrument approaches from the North of the site and a MDH of c.380ft for approaches from the South. There is a procedure for descending through cloud and establishing visual contact with the aerodrome commonly known as a cloud-break procedure but more properly called “an instrument approach with circle to land” or “approach to visual manoeuvring”. Whilst this is an instrument procedure, because it is an approach to the aerodrome, rather than the runway, such a procedure may be carried out for landing on visual runways. Attached, at Annex A, is a paper examining the use of such a procedure at St Helena. The paper concludes that MDHs of c.600ft could be obtained in this case. Although the difference between the MDHs for non-precision instrument and visual approaches would appear small, this could make the difference between achieving 98% usability and falling considerably short of this target. Although meteorological data about St Helena has been collected by the Meteorological Office for some years, the observation site is located remote to the proposed aerodrome site. Further, the information being gathered is not completely aligned with the requirements for determining whether or not a visual runway would provide adequate usability. It is necessary, therefore, to gather meteorological data relevant to the decision. At least one year’s data should be obtained before a final decision is made is made on the runway approach. METEOROLOGICAL DATA In order to achieve the aims outlined above, data should be REQUIREMENTS gathered from the spot height 71/21 (318), looking North to The Haystack. This spot equates closely to the location of the northern threshold of the proposed runway. It is important (because of the costs involved with, say, building a visual runway and then having to enlarge this to cater for instrument flying [¦¦¦¦] and the potential savings [¦¦¦¦]) to gather the most accurate information in relation to the Minimum Descent Heights and to runway visibility. Readings taken from spot height 71/21 will enable such, accurate, information to be gathered. Analysis of old meteorological taken at other locations on the Island will not yield the necessary accuracy and confidence. Detailed information needs to be gathered on the following: : 1. Cloud base; Appendix H - Metereological Requirements 6 Public Domain St. Helena Air Access Met data gathering requirements 2. Wind speed & direction; 3. Pressure; 4. Temperature; and 5. Visibility

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