AIRPORT OBSTRUCTIONS
- 3. Airport Planning Airport planning requires more intensive study and fore-thought as compared to other modes of transport. Because aviation is the most dynamic industry and its forecast is quite complex. Airport planning is mainly concerned with three aspects: 1. Adequate access to the metropolitan area 2. Securing sufficient airspace for access to air 3. Sufficient land for carrying out ground operations
- 4. Types of Airport Planning Studies There are various types of airport planning studies which are to be carried out before carrying out construction of an airport 1. Technical feasibility studies 2. Forecasting requirement studies 3. Facilities Planning 4. Financial Planning 5. Economic Planning 6. Organizational Planning 7. Strategic planning 8. Environmental Planning
- 5. Types of Airport Planning Studies 1. Engineering and Technical Planning Studies: These studies involve various activities like Approach zone surveys, Drainage surveys, Meteorological Surveys, Natural Resources Surveys, Soil Surveys, Topographical Surveys and Traffic Surveys. 2. Forecasting Requirement Studies: These studies involve determining parameters like Annual Passenger Volume, Annual volume of aircrafts, Peak day and peak hour volume of passengers and aircrafts, Air Cargo, Air mail and General Aviation etc.
- 6. Types of Airport Planning Studies 3. Facilities planning, which focuses on future needs for airfield infrastructure such as runways, taxiways, aircraft parking facilities, associated lighting, communication and navigational systems, terminal buildings and facilities, parking lots, ground access infrastructure, and support facilities such as fuel farms, power plants, and non-aeronautical land uses such as office parks, hotels, restaurants, or rental car locations. 4. Financial planning, which is concerned with predicting future revenues and expenses, budgeting resources, and planning for financial assistance through grant programs, bond issues, or private investment. 5. Economic planning, which considers the future of economic activity, such as trade and commerce, and the activity of industries that exist on airport and off-airport property and are either a direct or indirect result of airport operations.
- 7. Types of Airport Planning Studies 6. Organizational planning, which entails the management of future labour requirements and organizational structures for the airport administration, staff, and associated labor force. 7. Strategic planning, which encompasses all other planning activities into a coordinated effort to maximize the future potential of the airport to the community.
- 8. Types of Airport Planning Studies 8. Environmental planning, which concentrates on maintaining or improving existing environmental conditions in the face of changes in future airport activity. Environmental planning includes land use planning, noise mitigation, wetland reclamation, and wildlife preservation. The environmental factors must be carefully considered in the development of a new airport or the expansion of an existing one. In this connection, the following three studies are made to assist the project authorities in planning the airports. 1. Environmental Impact Assessment (EIA) 2. Environmental Impact Statement (EIS) 3. Environmental Management plan (EMP)
- 9. Master Planning It refers to the planner’s idealized concept of the form and structure of ultimate development of an airport. The plan is not simply the physical form of ultimate development but a description of the staging and both the financial implications and the fiscal strategies involved Master plan can apply to new airports and the extension of existing airports
- 10. Master plan Federal Administration Aviation (FAA) suggests 4 phases. 1. Airport Requirements- anticipated demand and status of existing facilities 2. Site Selection – study of airspace requirements, development, access, availability of utilities, land costs 3. Airport Plans-Plans of layout, land use, terminal area, airport access 4. Financial Plan-Schedules, estimates, economic & financial feasibility analysis.
- 11. • Airport plans – Airport layout plan: configuration , location and size of all physical facilities – Land use plan: details of land use within proposed airport boundary – Terminal area plans: size and location of various buildings – Airport access plan: proposed routings for various access modes
- 12. • Financial plan – Schedules of proposed development – short, intermediate and long term stagings of development – Estimates of development costs – conform to the scheduled development strategy – Economic feasibility analysis – expected revenue generation will cover the anticipated costs – Financial feasibility analysis – scale of facility consideration can be financed within the fiscal capability
- 13. Regional Planning • Airport planning should be done considering the air traffic needs of the nation as a whole • Airport planning not done on regional basis would seriously impair the effective air traffic services of the country • Results in surplus or shortage of airports on regional basis • Aims at the formation of an effective network of airports on national basis. • It avoids creation of separate airports by individual jurisdiction. If airports located in close vicinity & not properly coordinated, total capacity & efficacy gets reduced. • Planning on regional basis enables to implement zoning laws in the areas where new airports are needed in future.
- 14. Regional plan provides the following Approximate locations of airports in national map Classification of airports Location of air strips Routes of air travel
- 15. Data required for Regional Planning • Population – Population growth of area, character of population based on the income groups and activities • Topographical and Geographical Features – Geographical location of the area to be served • Existing Airports in the vicinity – Distance, population and economic character of the adjoining area having air service to be studied – Two nearby airports should be located sufficiently apart • Air traffic characteristics – Various existing modes of transport, future expected volume of air traffic
- 16. Development of New Airport • Before deciding to develop a new airport, full consideration should be given to the possibility of improving the existing airport capacity so as to make it suitable for the increased future air traffic. • Efforts should be made to accommodate new types iof aircrafts likely to ply in the near future • Steps to improve the existing airport includes 1. Traffic forecast 2. Determination of the capacity of existing airport 3. Improvement of airport capacity 4. Planning of a new airport
- 17. Traffic Forecast Following data is to be collected for traffic forecast • Area to be served • Origin & destination of the residents and non-residents of the area • Population growth in the area • Economic character of the area Income level per capita Types of business activities and labour employed Trends in existing local & national air traffic volume. Population growth & economic standards of adjacent areas. • Estimate the future volume of air traffic. • Peak hour volumes of passengers, cargo and mail are required for proper allocation of space in the terminal building and for determining the size of the building
- 18. • The forecast of the traffic for future years, say 15 years is carried out reviewing past trends of the local air traffic and future anticipated trends of the national air traffic.
- 19. Determination of capacity of existing Airport Ascertain whether the existing airport can handle the amount of anticipated traffic. Points considered are: • Suitability of approaches for the type of airports • Capacity of runways & taxiways to handle the peak hour traffic • Adequacy of terminal building for handling passengers and cargo • Adequacy of aprons & serving facilities
- 20. Improvement of Airport Capacity If the existing airport is inadequate to handle the anticipated traffic, the possible method for improving the capacity of the present airport should be investigated. The improvement can be done in the following ways: • Runway extension, new or parallel runway and high speed exit taxiways. • Rearranging or increasing the size of terminal building and/or loading apron. • Improving the traffic control devices.
- 21. Data required before Site Selection • Peak hourly volume of air traffic to be handled. • The present & future, types of aircrafts which may use the airport. • Facilities to be provided for the passengers, baggage and cargo, for landing and take-off and servicing of aircrafts should be determined.
- 22. Airport Site Selection – depends upon the class of airport under consideration 1. Regional plan 2. Airport use 3. Proximity to other airports 4. Ground accessibility 5. Topography 6. Obstructions 7. Visibility 8. Wind 9. Noise Nuisance 10. Grading, drainage and soil characteristics 11. Future development 12. Availability of utilities from town 13. Economic considerations.
- 23. • Regional plan – the site selected should fit well in to the regional plan • Airport use – civilian or military operations, site should provide natural protection to the area from air raids in combat zones • Proximity to other airports – considerable distance from other airports so that landing operations are not interfered • Ground accessibility – readily accessible to the users, not exceed 30 minutes • Topography – natural features like ground contours, trees, streams. A raised ground is usually considered to be ideal – Less obstruction – Natural drainage – More uniform wind – Better visibility due to less fog
- 24. • Obstructions – long clearance areas required on either side of runways called approach areas, areas free of obstructions • Visibility – site should be free from visibility reducing conditions such as fog, smoke, haze • Wind – runway oriented such that landing and take-off is done by heading into the wind. Wind data (direction, duration and intensity of wind) should be collected over a minimum period of about five years • Noise nuisance – extent of noise nuisance depends upon the path of aircraft, type of propulsion and the gross weight of aircraft. Runway path free from residential or industrial development • Grading, drainage & soil characteristics – possibility of floods, high water table, desirable type of soil – pervious soil like gravel
- 25. • Future development – more number of runways, terminal facilities , additional traffic control devices • Availability of utilities from town – water supply, sewer, telephone, electricity • Economic considerations – cost estimates should be prepared. Estimate includes land cost, clearing and grading of land, drainage, removal of hazards, paving, turfing, lighting, construction of buildings, access roads and automobile parking areas
- 26. Surveys for site selection 1. Traffic survey – amount of air traffic including the anticipated traffic for future 2. Meteorological survey – wind, rainfall, fog, temperature data 3. Topographical survey – contour map and obstruction map 4. Soil survey – soil type and ground water table 5. Drainage survey – quantity of storm water, natural streams 6. Material survey – availability of construction materials
- 27. Drawings to be prepared 1. Topographical plan – all properties 2. Obstruction plan – safe approach zones and turning zones 3. Drainage plan – drainage network 4. Airport master plan – construction stages
- 28. Future air traffic needs Forecasting in Aviation and Airport Planning 1. Annual passenger volume 2. Annual volume of aircrafts 3. Peak-day and peak-hour volume of passengers and aircrafts 4. Air cargo 5. Air mail 6. General aviation
- 29. TAXIWAY DESIGN
- 30. TAXIWAY Taxiway provides access to the aircrafts from the runways to the loading apron or service hangar.
- 31. Factors controlling Taxiway Layout • Taxiways should be arranged that the aircrafts which have just landed & taxiing towards apron should not interfere with the aircrafts taxiing for take-off. • The taxiway should be located at various points along the runway so that the landing aircraft leaves the runway as early as possible. Such taxiways are called “exit taxiways”.
- 32. • Exit taxiways should be designed for high turn off speeds of aircrafts so that runway occupancy time gets reduced. • The route should be a shortest distance from the apron to the runway end. • Intersection of taxiway & runway should be avoided.
- 33. GEOMETRIC DESIGN STANDARDS • Length of taxiway • Width of taxiway • Width of safety area • Longitudinal gradient • Transverse gradient • Rate of change of longitudinal gradient • Sight distance • Turning radius
- 34. TAXIWAY GEOMETRICS AS PER ICAO Classifica tion by ICAO Taxiway width Max. Longitudinal gradient (%) Mini. Transverse gradient (%) Max. rate of change of longitudinal gradient per 30m (100ft) in % Safety area width Meter Feet A 22.5 75 1.5 1.5 1.0 Turfed or paved shoulders are not mandatory but are suggested if need exists. B 22.5 75 1.5 1.5 1.0 C 15.0 50 3.0 1.5 1.0 D 9.9 33 3.0 2.0 1.2 E 7.5 25 3.0 2.0 1.2
- 35. EXIT TAXIWAYS Factors controlling location of exit taxiways: • Number of exit taxiways • Exit speed • Type of aircrafts • Weather conditions • Topographical features • Pilot variability
- 36. • No.of exit taxiway: number decides the location. Two exit taxiways, at the ends. If more, distributed. • Exit speed: maximum speed of aircraft at the turns. Aircraft requires certain length of runway to reduce the speed from landing speed to turn-off speed. • Type of aircrafts: The type of aircraft affects the location of taxiways. • Weather conditions: wind, temperature, fog, etc. affect the landing speed of aircraft. • Topographical features: high altitude or deep valley affects visibility affect the landing speed of aircrafts. • Pilot variability: rules for landing are precise. There may be some variability among different pilots, in the distance from runway threshold to the touch down point and in the application of brakes on the runway.
- 37. Optimum location of Exit Taxiways: The acceptance rate of runway with a system of exit taxiways = Arrival rate of aircrafts ARRIVAL RATE AVERAGE ACCEPTANCE RATE BALANCE PT. ARRIVAL RATE WAVE-OFFS ACCEPTANCE RATE
- 38. • The point beyond which the acceptance rate deviates from the ideal relationship of equal arrival and acceptance rate is “balance point”. • Balance point occurs when the runway is loaded to its full capacity and such situation is “runway saturation”. • At higher arrival rates, the runway cannot accept all aircrafts and hence few are waved off. For a given set of conditions, the exit taxiways should yield the highest possible rate of acceptance. Such location of exit taxiway is “Optimum location”.
- 40. Airport Obstructions 1. Imaginary surfaces Approach surface Conical surface Horizontal surface Take off climb surface Transitional surface 2. Objects with actual heights Any object which exceeds certain limiting height above the ground is considered as obstruction.
- 41. Imaginary surfaces • Primary = aligned (longitudinally) with each runway and extends 200 ft. from each runway end • Approach = longitudinally centered with the runway and extends beyond the primary surface • Horizontal = horizontal plane 150 ft. above the established airport elevation. Constructed by swinging arcs around the end of the primary surface • Conical = 20:1 slope surface extending beyond the horizontal surface • Transitional = constructed to join approach and horizontal or approach and transitional surfaces
- 48. Approach zone • Wide clearances areas known as approach zones are required on either side of runway along the direction of landing and take-off. • Over this area, the aircraft can safely gain or loose altitude • It should be free of obstructions • Plan of approach zone same as the approach surface • Approach surface is an imaginary surface whereas approach area or approach zone is the actual ground area
- 49. Clear zone • Indicates the innermost portion of the approach zone & provided at ends of runways. • Length of clear zone is the distance required to reach a height of 30 m for the appropriate approach surface • Not necessary to grade this area, but all obstructions are removed • Level area is preferred, but it is not essential • Fences, ditches and other minor obstacles are permitted
- 51. Instrument Landing System • An Instrument Landing System (ILS) is a radio beam transmitter that provides a direction for approaching aircraft that tune their receiver to the ILS frequency. • It provides both lateral and a vertical signals. • It is a ground-based instrument approach system that provides precision guidance to an aircraft approaching and landing on a runway. • It uses a combination of radio signals and, in many cases, high- intensity lighting arrays to enable a safe landing during instrument meteorological conditions (IMC) • Mainly during reduced visibility due to fog, rain, or blowing snow.
- 52. Turning zone • It is intended for turning operations of the aircraft in case of emergencies. • The area of airport other than the approach area, used for turning operations of aircraft is called turning zone. • Aircraft operates at a considerably low height in the turning zone. • It is necessary that the area of turning zone is free from any obstructions.