Below is the uncorrected machine-read text of this chapter, intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text of each book. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.
130 A P P E N D I X C Determine the Number of Transient Aircraft Parking Positions If an approved master plan and ALP exists, the number of required parking positions should already be known. If not, the forecasts from the approved master plan can be used to determine the number of transient parking positions. Based aircraft parking positions will be determined later. Below are equations and samples to help determine the number of transient parking positions. Equation to Determine No. of Transient Parking Positions Using the operations from the master plan forecast, the number of aircraft parking positions can be calculated using the following equation: X T P2 365 Number of Transient Parking Positions( )â â = where X = number of operations T = percent of operations that are transient (to be determined by Airport Owner/Operator and Consultant based on onsite observations) P = percent of transient aircraft that are parked on the apron at the same time (to be deter- mined by Airport Owner/Operator and Consultant based on onsite observations) Using the equation, the number of parking positions is determined. However, not all parking positions are the same size. Unless there is a known aircraft of a certain size that requires special consideration, Table C-1 provides a general rule of thumb to determine an equivalent number of nested tie-down positions. Determine the Number of Based Aircraft Parking Positions The parking positions and apron areas described above were planned for the transient aircraft only. Apron space for based aircraft also needs to be determined. Each airport is different in the number of based aircraft stored on the apron. The majority of based aircraft parked on an apron are single-engine piston and small multi-engine piston aircraft. Larger and generally more expensive aircraft are usually parked in a hangar. Additional consideration should also be given to spaces for special uses such as flight training school. Approximately half the State Airport System plans have planning guidance on how much apron space and hangar space to provide for aircraft storage. Many provide percentages for aircraft to be stored in a hangar versus on an apron. Several give additional guidance on the percentages based on the type or level of airport for that state. For instance, one state indicates that tie-downs Determining the Number of Aircraft Parking Positions
Determining the Number of Aircraft Parking Positions 131 should be provided for 25% of the based aircraft and 75% of the transient aircraft. That same state indicates that 75% of the based aircraft should be stored in hangars and hangars should be available for storage of 25% of the transient aircraft. Most State Airport System plans that have guidance on storage of based aircraft recommend that 75% to 100% should be stored in hangars. Each airport is different with regards to their needs for based aircraft apron parking. The needs should be based on historical records of based aircraft storage, demand for hangars, available development space, and funding. While funding is available for hangar construction, it is a low priority. An apron is AIP eligible and carries a higher priority. If funds are not available for hangar construction, planning for a greater number of based aircraft being stored on an apron should be considered. A planning guideline for number of based aircraft parking positions should be between 10% and 25% of based aircraft. Example Table C-2 provides information from a master plan for a fictional airport that will be used to determine the number of tie-down positions. For this example, we will determine the near-term needs (10 years) and not the long-term parking needs (20 years) Number of positions for transient aircraft needed in 10 Years at Sample Airport Step 1: Determine number of Transient positions Step 1A: Determine number of parking positions using the formula from Page 1. SEP: [(12,000/2 â 30%) / 365 â 40%] = 1.97 (use 2) MEP/TP: [(6,000/2 â 30%) / 365 â 40%] = 0.98 (use 1) Jet: [(3,500/2 â 30%) / 365 â 40%] = 0.57 (use 1) Rotorcraft: [(300/2 â 30%) / 365 â 40%] = 0.05 (use 0) Other: [(75/2 â 30%) / 365 â 40%] = 0.01 (use 0) Total: 4 positions Table C-2. Operations and based aircraft forecast Sample Airport. Today 10 Years 20 Years Ops Based Aircraft Ops Based Aircraft Ops Based Aircraft Single-Engine Piston (SEP) 10,000 18 12,000 22 15,000 26 Multi-Engine Piston/Turboprop (MEP/TP) 5,000 3 6,000 4 8,000 6 Jet 1,500 0 3,500 1 4,500 2 Rotorcraft 200 0 300 0 400 1 Other (ultralight/glider) 50 0 75 0 100 0 Total: 16,750 21 21,875 27 28,000 35 Source: Delta Airport Consultants, Inc. Aircraft Type (1 parking position) Equivalent nested tie-down positions (Beech Baron 58) Single-Engine Piston 1 Multi-Engine Piston/Turboprop 2.5 Jet 3 Rotorcraft 2 Source: Delta Airport Consultants, Inc. Table C-1. Equivalent tie-down positions.
132 Guidebook on General Aviation Facility Planning Step 1B: Determine the equivalent number of nested tie-down positions using Table C-1. SEP: 2 = 2 MEP/TP: 1 = 2.5 Jet: 1 = 3 Total: 7.5 (use 8) Figure C-1 depicts a possible layout that would satisfy the forecast demand for transient air- craft at Sample Airport. The apron has four parking positions marked, two for small single-engine piston aircraft, one for multi-engine turboprop, and one for jet aircraft. This parking area and tie-down configura- tion allows the flexibility of having eight small aircraft, three larger aircraft, or a combination of both. Step 2: Determine Number of Based positions Using the percentage guideline mentioned above and the based aircraft count in Table C-2, the 27 based aircraft forecast for 10 years with 10% based on the apron, would amount to 2.7 tie-down apron positions, which would be rounded to three tie-down positions. Step 3: Total Parking Positions and Parking Area Layout Adding the three based aircraft tie-down positions to the 8 transient tie-down positions would result in a parking area that would need to accommodate 11 tie-down positions. Figure C-2 depicts a possible layout that would satisfy the forecast demand for transient and based aircraft at Sample Airport. See Chapter 5 and Appendix B to size the total apron and parking area. Figure C-1. Transient tie-down positions marked for Sample Airport. Note: The lighter lines depict other available parking positions Source: Delta Airport Consultants, Inc. Figure C-2. Total tie-down positions marked for Sample Airport. Note: The lighter lines depict other available parking positions Source: Delta Airport Consultants, Inc.
