APPENDIX X: RUNWAY LENGTH ANALYSIS

APPENDIX X: RUNWAY LENGTH ANALYSIS Purpose For this Airport Master Plan study, the FAA has requested a runway length analysis to be completed to current FAA AC 150/5325-4B, Runway Length Requirements for Airport Design, and draft FAA standards identified in FAA AC 150/5325-4C, Runway Length Recommendations for Airport Design (DRAFT). Due to the technical nature of this analysis, a separate appendix has been prepared to arrive at recommended runway lengths for the existing and future design aircraft identified in this planning study. Existing FAA Standard A runway length analysis for other aircraft was performed using the FAA s current methodology found in FAA AC 150/5325-4B. The design approach identifies a recommended runway length based on a family grouping of design aircraft. For ROX the current design aircraft includes small general aviation aircraft with approach speeds of 50 knots or greater and maximum certified takeoff weight of 12,500 pounds or less (Beechcraft King Air B200). The future runway length may be driven from a design aircraft greater than 12,500 pounds but less than 60,000 pounds (Cessna Citation XLS+). Small Airplanes Up to 12,500 Pounds The FAA design approach identified in Chapter 2 of FAA AC 150/5325-4B for most small aircraft less than 12,500 pounds requires several steps to be performed to determine runway length: 1. Identify Number of Passenger Seats: Classify design aircraft as one of two categories; Less than 10 Passenger Seats and 10 Passenger Seats or Greater 2. Select Percentage of Fleet: Airplanes classified as Less than 10 Passenger Seats are grouped into two percentage categories based on the airport s location and the amount of existing or planned aviation activities. The categories include 95 Percent of Fleet and 100 Percent of Fleet. 3. Consider Future Airport Expansion: Consider runway length requirements during Instrument Meteorological Conditions (IMC) or expansions to accommodate airplanes more than 12,500 pounds. 4. Determine Airport Data: Evaluate the airport elevation, mean daily temperature in hottest month and runway condition to make adjustments to runway length. 5. Calculate Runway Length Based on Curves: Utilize FAA runway length curves published in AC 150/5325-4B. Large Airplanes Up to 60,000 Pounds The FAA design approach identified in Chapter 3 of FAA AC 150/5325-4B for aircraft greater than 12,500 pounds and less than 60,000 pounds requires the following steps to be performed to determine runway length: Appendix X: Runway Length Analysis Page 1

1. Select Percentage of Fleet: Group the design airplane into one of two percentage categories based on performance. The categories include 75 Percent of Fleet and 100 Percent of Fleet. 2. Identify Useful Load Factor: Determine the useful load factor for the design aircraft based on the difference in maximum gross weight and the basic operating weight. Useful load consists of passengers, cargo and usable fuel. The categories include 60 percent useful load and 90 percent useful load. 3. Determine Airport Data: Evaluate the airport elevation, mean daily temperature in hottest month and runway condition to make adjustments to runway length. 4. Calculate Runway Length: Utilize FAA runway length curves published in AC 150/5325-4B. 5. Apply Adjustments: The effective runway gradient affects the aircraft s takeoff length. Wet and slippery runways for turbojet airplanes allow for runway length curves to be increased by 15 percent up to 5,500 feet for 60 percent useful load and 7,000 feet for 90 percent useful load. The recommended FAA runway length calculations at ROX for aircraft up to 60,000 pounds are summarized in the following table: Exhibit 1 FAA AC 150/5345-4B Runway Length Requirements (< 60,000 lbs.) Airport and Runway Data Airport Elevation 1,060 feet Mean Daily Maximum Temperature of Hottest Month 78.2 F Maximum Difference in Runway Centerline Elevation 14 feet (+140 feet) Runway Condition Wet and Slippery Runways Aircraft Classification Recommended Runway Length Small airplanes 12,500 pounds or less 10 or more passenger seats 4,300 feet Less than 10 passenger seats at 100 percent of fleet 3,900 feet Less than 10 passenger seats at 95 percent of fleet 3,300 feet Large airplanes greater than 12,500 lbs. up to 60,000 lbs. 100 percent of fleet at 90 percent useful load 8,100 feet 100 percent of fleet at 60 percent useful load (Wet) 5,600 feet 100 percent of fleet at 60 percent useful load (Dry) 5,600 feet 75 percent of fleet at 90 percent useful load 7,000 feet 75 percent of fleet at 60 percent useful load (Wet) 5,500 feet 75 percent of fleet at 60 percent useful load (Dry) 4,900 feet Source: FAA AC 150/5325-4B, Runway Length Requirements for Airport Design Note: Runway length requirements estimated based on charts for airport planning purposes only. The FAA states airport planners can determine the recommended runway length from airplane flight manuals for the airplanes to be accommodated by the airport in lieu of the runway length curves depicted in figures 2-1 or 2-2. This method is recommended to evaluate the runway length needs of turboprop airplanes that require pilots to use the airplane s accelerate-stop distance in determining the length of runway available for takeoff. Further analysis of the recommended runway length for the existing design aircraft (Beechcraft King Air B200) using specific aircraft performance data is contained later in this Appendix. For small general aviation aircraft with less than 10 passenger seats, the runway length requirements of 95 percent of fleet would apply at ROX due to its rural location. The recommended runway length Appendix X: Runway Length Analysis Page 2

for small general aviation aircraft is 3,300 feet. This runway length would accommodate the vast majority of small general aviation aircraft with less than 10 passenger seats. The future critical design aircraft includes a large aircraft greater than 12,500 lbs. up to 60,000 lbs. Fleet mix includes the Cessna Citation XLS+ aircraft. The Cessna Citation XLS+ is classified as 75 percent of fleet. Using the 75 percent of fleet calculation and 60 percent useful load, the recommended future runway length is 4,900 feet under dry runway conditions and 5,500 feet for wet and slippery runways. The ultimate design aircraft is not expected to increase from the 75 percent of fleet classification to the 100 percent of fleet classification. Appendix X: Runway Length Analysis Page 3

FAA Figure 2-1: Small Airplanes with Fewer than 10 Passenger Seats (Excludes Pilot and Co-pilot) Roseau Municipal Airport/Rudy Billberg Field Temperature: 78.2 F / 25.7 C - Airport Elevation: 1,060 MSL Airport Elevation (feet) 95 Percent of Fleet 100 Percent of Fleet Runway Length @ 95 Percent of Fleet: 3,300 feet Runway Length @ 100 Percent of Fleet: 3,900 feet Appendix X: Runway Length Analysis Page 4

FAA Figure 2-2: Small Airplanes Having 10 or More Passenger Seats (Excludes Pilot and Co-pilot) Roseau Municipal Airport/Rudy Billberg Field Temperature: 78.2 F / 25.7 C - Airport Elevation: 1,060 MSL Recommended Runway Length: 4,230 feet Appendix X: Runway Length Analysis Page 5

FAA Figure 3-1: 75 Percent of Fleet at 60 or 90 Percent Useful Load Roseau Municipal Airport/Rudy Billberg Field Temperature: 78.2 F / 25.7 C - Airport Elevation: 1,060 MSL Maximum Difference in Runway Centerline Elevation: 14 feet = 140 feet in Distance (added) Runway Length @ 60 useful load (Dry Runway): 4,780 + 140 = 4,900 feet Runway Length @ 60 useful load (Wet Runway): 5,500 feet Runway Length @ 90 useful load (Dry Runway): 6,200 + 140 = 6,340 feet Runway Length @ 90 useful load (Wet Runway): 7,000 feet Appendix X: Runway Length Analysis Page 6

FAA Table 3-1: Airplanes that Make Up 75 Percent of Fleet Appendix X: Runway Length Analysis Page 7

FAA Table 3-1: Remaining 25 Percent of Airplanes that Make Up 100 Percent of Fleet Appendix X: Runway Length Analysis Page 8

FAA Figure 3-2: 100 Percent of Fleet at 60 or 90 Percent Useful Load Roseau Municipal Airport/Rudy Billberg Field Temperature: 78.2 F / 25.7 C - Airport Elevation: 1,060 MSL Maximum Difference in Runway Centerline Elevation: 14 feet = 140 feet in Distance (added) Runway Length @ 60 percent useful load (Dry Runway): 5,400 + 140 = 5,540 feet Runway Length @ 60 percent useful load (Wet Runway): 5,540 feet Runway Length @ 90 percent useful load (Dry Runway): 7,900 + 140 = 8,040 feet Runway Length @ 90 percent useful load (Wet Runway): 8,040 feet Appendix X: Runway Length Analysis Page 9

Existing Design Aircraft Performance Beechcraft King Air B200 As stated earlier, FAA also allows airport designers to determine the recommended runway length from airplane flight manuals for the airplanes to be accommodated by the airport in lieu of the runway length curves for small aircraft. These were reviewed for the existing critical aircraft, the Beechcraft King Air B200 airplane operated by Polaris Industries. Polaris Industries operates under FAR Part 91, General Operating and Flight Rules and other company-specific safety standards. Beechcraft King Air B200 Takeoff Distance To meet company safety standards, Polaris Industries follows FAR Part 25, Airworthiness Standards: Transport Category Airplanes requirements to calculate runway length to satisfy the longest of these three distances: Accelerate-go distance: The distance required to accelerate to V1 with all engines at takeoff power, experience an engine failure at V1 and continue the takeoff on the remaining engine(s). The runway required includes the distance required to climb to 35 feet by which time V2 speed must be attained. Accelerate-stop distance: The distance required to accelerate to V1 with all engines at takeoff power, experience an engine failure at V1, and abort the takeoff and bring the aircraft to a stop using braking action only (use of thrust reversing is not considered). Takeoff distance: The distance required to complete an all-engines operative takeoff to the 35-foot height. It must be at least 15 percent less than the distance required for a one-engine inoperative engine takeoff. This distance is not normally a limiting factor as it is usually less than the one-engine inoperative takeoff distance. FAR Part 25 safety standards for corporate turboprop and turbojet operators have become more common to support safe flight operations. These standards are incorporated into the Safety Management Systems (SMS) procedures for Polaris Industries operation of the B200 aircraft. The accelerate-stop distance is the longest of the three takeoff distances for the B200. Runway lengths for small aircraft such as the B200 are published only for a dry runway. The B200 does not have any performance charts published for a wet runway based for its FAR Part 23 (Commuter) certification type. Polaris Industries operational SMS standards require a minimum runway length of 4,000 feet for the B200. Appendix X: Runway Length Analysis Page 10

Exhibit 2 FAR Part 25 Takeoff Distance Source: FAA s Pilot s Handbook of Aeronautical Knowledge According to the B200 performance chart, the accelerate-stop distance for a Beechcraft King Air B200 is approximately 3,800 feet with a dry runway and no flaps to produce to shortest takeoff distance. No adjustment is made for a wet runway. The takeoff distance for this aircraft is calculated at 3,800 feet, however Polaris Industries operational minimum runway length is 4,000 feet (see attached letter). Landing Distance The actual landing distance is calculated to be the distance used in landing and braking to a complete stop after crossing the runway threshold at 50 feet. Landing distance can vary depending on local conditions and exact pilot technique. Appendix X: Runway Length Analysis Page 11

Exhibit 3 FAR Part 25 Landing Distance Source: FAA Because landing distance varies, FAA Advisory Circular 91-79A, Mitigating the Risks of a Runway Overrun Upon Landing recommends an additional safety margin of 15 percent be added to Part 91 requirements to avoid a runway overrun 1. To ensure that an acceptable landing distance safety margin exists at [Time of Arrival], the FAA recommends a 15 percent safety margin be applied to the actual airplane landing distance. The 15 percent safety margin is a minimum safety margin to be applied after accounting for all known variables, such as the meteorological, runway surface conditions, landing with a tailwind, airplane configuration and weight, runway slope, threshold crossing height and airspeed, and the timely utilization of ground deceleration devices. Be prepared, know the landing conditions, divert to an alternate, or go around, but do not risk a runway overrun. The landing distance on a dry runway is for the B200 is published at 3,100 feet with full flaps to produce the shortest landing length. The recommended landing distance adding a 15 percent adjustment is 3,565 feet, or rounded to 3,600 feet. Polaris Industries operational minimum runway length of 4,000 feet exceeds the calculated length. Summary The following table summarizes the recommended runway lengths for the existing design aircraft. The recommended length is based on Polaris Industries operational requirements, which is greater than standard aircraft performance charts and FAA s calculations for 100 percent of the total small aircraft fleet. 1 FAA Advisory Circular 91-79A, Mitigating the Risks of a Runway Overrun Upon Landing, Appendix 2(a) Appendix X: Runway Length Analysis Page 12

Exhibit 3 Beechcraft King Air B200 Runway Length Requirements Metric/Operation Runway Length FAA AC 150/5325-4B Requirements 95 Percent of Fleet 3,300 feet 100 Percent of Fleet 3,900 feet Takeoff Length Requirements Accelerate-Stop Distance 3,800 feet Landing Length Requirements Landing Distance (Unadjusted) 3,100 feet Landing Distance (Adjusted) (1) 3,600 feet Company Requirement Polaris Industries 4,000 feet Summary Recommended Runway Length 4,000 feet Source: Beechcraft King Air B200 Airplane Flight Manual, Polaris Industries, KLJ Analysis NOTE: Runway requirements assume maximum gross takeoff weight, 78.2 F, no wind, 1060 MSL elevation, Runway lengths of 30 feet or over are rounded to the next 100-foot interval per FAA guidance. (1) Includes 15% safety margin as recommended in FAA Advisory Circular 91-79A, Mitigating the Risks of a Runway Overrun Upon Landing for FAR Part 91 operators. Appendix X: Runway Length Analysis Page 13

Beechcraft King Air B200 Performance Chart: Accelerate-Stop Distance Roseau Municipal Airport/Rudy Billberg Field Temperature: 78.2 F / 25.7 C - Airport Elevation: 1,060 MSL Maximum Takeoff Weight: 12,500 lbs. Accelerate-Stop Distance: +/- 3,800 feet Appendix X: Runway Length Analysis Page 14

Beechcraft King Air B200 Performance Chart: Landing Distance Roseau Municipal Airport/Rudy Billberg Field Temperature: 78.2 F / 25.7 C - Airport Elevation: 1,060 MSL Maximum Landing Weight: 12,500 lbs. Landing Distance (Unfactored): 3,100 feet Appendix X: Runway Length Analysis Page 15

Beechcraft King Air B100 The 1988 Roseau Airport Master Plan study identified the Beechcraft King Air B100 as the design aircraft. The required accelerate-stop distance was calculated to be 4,400 feet. This study provided the justification to extend Runway 16-34 from 3,900 feet to 4,400 foot runway at Roseau in 1990. The performance chart is included for reference. Beechcraft King Air B100 Provenance Chart: Accelerate-Stop Distance Roseau Municipal Airport/Rudy Billberg Field Temperature: 78.2 F / 25.7 C - Airport Elevation: 1,060 MSL Maximum Landing Weight: 12,500 lbs. Accelerate-Stop Distance: 4,400 feet Appendix X: Runway Length Analysis Page 16

Proposed FAA Standard FAA AC 150/5325-4C, a proposed update to the existing FAA AC 150/5325-4B, uses a different process to determine recommended runway length at airports for aircraft between 12,500 pounds and 60,000 pounds. The design objective for a primary runway is to provide a runway length that will not result in operational weight restrictions. For federally funded projects, the criterion for regular use applies. Small Airplanes Up to 12,500 Pounds The rationale and procedures for small aircraft up to 12,500 pounds are virtually identical to that outlined in current FAA guidance. For small airplanes, the draft AC identifies the differences between the 95 and 100 percent of fleet curves are based on the airport s location and amount of existing or planned aviation activities. FAA guidance acknowledges the selection of percentage of fleet is a planning decision. If the fleet mix to operate at the airport is known, FAA recommends consulting the manufacturer s information to determine actual runway length requirements. The analysis completed in the previous section under FAA AC 150/5325-4B still applies for small aircraft. Large Airplanes Up to 60,000 Pounds For large airplanes up to 60,000 lbs., the draft FAA guidance requires the use of performance charts for individual airplanes. The general design procedure includes: 1. Calculate Take-off Weights: Determine the length of haul that is flown by airplanes on a regular use basis. Use maximum certificated takeoff weight for long-haul routes and adjust weight for shorter routes based on the payload-range chart. Determine and any performancebased weight adjustments. 2. Determine Landing Weight: Use maximum certificated landing weight. 3. Identify Flap Setting: Use flap settings that will result in shortest necessary runway length. 4. Determine Airport Data: Utilize airport elevation, mean daily maximum temperature at hottest month, dry or wet runways and runway elevation range. 5. Calculate Runway Length: Apply procedures to each Airport Planning Manual to obtain separate takeoff and landing runway length recommendations. 6. Apply Adjustments: Apply any takeoff or landing length adjustments, if necessary, to the resulting lengths. The identified future design aircraft fleet mix is a Cessna Citation XLS+ turbojet and Swearingen Metroliner turboprop. Both are large aircraft greater than 12,500 pounds but do not exceed 60,000 pounds. The following section evaluates the performance of each aircraft. Appendix X: Runway Length Analysis Page 17

Future & Ultimate Design Aircraft Operational rules and specific aircraft performance of the future & ultimate design aircraft is evaluated in this section. A review of the aircraft performance charts is used to identify the recommended runway length for aircraft greater than 12,500 pounds up to 60,000 pounds under the proposed FAA AC 150/5325-4C. Where applicable, standards under FAA AC 150/5325-4B are also referenced. Operating Rules Operating rules can have a significant effect on the recommended runway length for an airplane. The two applicable operating rules are identified below. FAR Part 91 The Cessna Citation XLS+ will be operated by Polaris Industries under FAR Part 91, General Operating and Flight Rules. Most general aviation users operate under FAR Part 91 where the pilot in command is responsible for determining the runway lengths required for takeoff and landing based on aircraft performance and personal minimums. FAR Part 91 rules govern non-commercial operations. FAR Part 135 The Swearingen Metroliner III will be flown under FAR Part 135 operating rules. On-demand air-taxi and air-cargo charter operators at ROX operate under FAR Part 135, Operating Requirements for Commuter and On Demand Operations. Under FAR Part 135 operations for large transport category airplanes, additional safety factors must be added to the airplane s performance manual for normal takeoff, rejected takeoff, one-engine takeoff and landing operations. FAR 135.367 and 135.379 requires takeoff operations to be conducted within available runway length assuming safety factors. FAR 135.375 and 135.385 requires landing operations to be conducted within 60 percent of the effective length with an additional 15 percent for wet or slippery runways. Exhibit 4 FAR Part 121/135/91K Landing Distance (Wet Runway) Source: FAA Appendix X: Runway Length Analysis Page 18

Cessna Citation XLS+ The Cessna Citation XLS+ is operated by Polaris Industries and is expected to become the future design aircraft. Aircraft performance charts provided by Polaris Industries were consulted to determined runway length needs. Currently, Polaris Industries does not operate this aircraft to ROX because of the runway length restriction. Based on the analysis conducted in this report, Polaris Industries requires a minimum of 4,934 feet to operate this aircraft to meet SMS operational requirements (see attached letter). Cessna Citation XLS+ (Airliners.net) This aircraft is forecast to be flown by Polaris Industries on high-load factor routes at a maximum takeoff weight. Common routes from Roseau would be to other Polaris plants in Huntsville, AL and Monterrey, Mexico. Returning international flights would clear customs in Laredo, TX. Stage lengths would be as long as 1,565 nautical miles. At this range payload is limited to 1,600 pounds, or enough weight for approximately 7 passengers and baggage. This represents a typical trip for Polaris Industries. Takeoffs would occur at the maximum takeoff operating weight of 20,200 pounds. This aircraft is certified under FAR Part 25 (Transport Category) flight rules. Sufficient runway length to satisfy the longest of the accelerate-go distance, accelerate-stop distance or takeoff distance. According to the Cessna Citation XLS+ performance calculations provided by Polaris Industries, the required takeoff distance is 4,056 feet with a dry runway, 4,414 feet for a wet runway assuming 15 degree flaps to produce to shortest takeoff distance. This length meets FAR Part 25 second segment one-engine climb requirements without restriction. Maximum landing weight of 18,700 pounds is assumed with full flaps to minimize landing distance. Airport elevation, runway gradient and temperature data is utilized. The aircraft will be flown under FAR Part 91 operating rules. The landing distance performance calculations for the Cessna Citation XLS+ provided by Polaris Industries requires 3,307 feet for a dry runway and 4,934 feet for a wet runway (rounded to 5,000 feet) with full flaps to produce the shortest landing length. Based on this operational data Polaris Industries the recommended operational runway length is 5,000 feet to utilize the Roseau Municipal Airport without significant restrictions. Exhibit 5 Cessna Citation XLS+ Runway Length Requirements Metric/Operation Runway Length Takeoff Length Requirements (1) Takeoff Field Length @ MTOW, 15 Flaps (Dry) 4,056 feet Takeoff Field Length @ MTOW, 15 Flaps (Wet) 4,414 feet Landing Length Requirements Landing Distance @ MLW (Dry) 3,307 feet Landing Distance @ MLW (Wet) 4,934 feet Summary Recommended Runway Length 5,000 feet Source: Polaris Industries, Cessna, KLJ Analysis MTOW = Maximum Takeoff Weight, MLW = Maximum Landing Weight NOTE: Runway requirements assume 26 C, no wind, 1060 MSL elevation, 0.3% runway gradient. (1) Per FAR 25, Takeoff Field Length is the greater of accelerate-stop, accelerate-go with one engine inoperative, or 115% of the all engine takeoff distance to a point 35 feet above the runway. Appendix X: Runway Length Analysis Page 19

Cessna Citation XLS+ Range / Payload Capability Chart ROX-MTY: 1,565 N.M. Source: Cessna Citation XLS+ Flight Planning Guide Appendix X: Runway Length Analysis Page 20

Cessna Citation XLS+ Performance Chart: Takeoff Field Length (15 Flaps) Roseau Municipal Airport/Rudy Billberg Field Temperature: 78.2 F / 25.7 C - Airport Elevation: 1,060 MSL Maximum Takeoff Weight: 20,200 lbs. Wet Runway, 15 Flaps Takeoff Field Length: 4,400 feet Appendix X: Runway Length Analysis Page 21

Cessna Citation XLS+ Performance Chart: Landing Performance Roseau Municipal Airport/Rudy Billberg Field Temperature: 78.2 F / 25.7 C - Airport Elevation: 1,060 MSL Maximum Landing Weight: 18,700 lbs. Wet Runway, Full Flaps Landing Distance: 5,000 feet Appendix X: Runway Length Analysis Page 22

Ultimate Corporate Aircraft Additional corporate aircraft types that could potentially utilize ROX in the ultimate period were identified to determine ultimate runway length needs at ROX. It was assumed that the corporate aircraft fleet would remain within the FAA s 75 percent of the aircraft fleet greater than 12,500 pounds up to 60,000 pounds at 60 percent useful load per FAA AC 150/5325-4B. A typical aircraft would be the Cessna Citation 680 Sovereign operated under FAR Part 91. This representative aircraft is classified as FAA Airport Reference Code (ARC) B-II with a maximum takeoff weight of 30,300 pounds. No larger or more demanding aircraft classified under FAA s 100 percent of fleet, 90 percent useful load or ARC C-II are expected to occur on a regular basis at ROX. Commercial operations under FAR Part 135, with additional runway length requirements, are also not expected to occur on a regular basis from corporate aircraft alone. For long-term planning purposes, no specific aircraft performance data was used for a runway length analysis to follow proposed FAA AC 150/5325-4C. It is estimated however that the actual FAR Part 91 runway length requirements of the Cessna Citation 680 would be similar or slightly greater than the Cessna Citation XLS+ analyzed earlier. By utilizing the methodology identified in FAA AC 150/5325-4B, the recommended runway length for 75 percent of the fleet at 60 percent useful load at ROX is 5,500 feet during wet or contaminated runway conditions. Swearingen Metroliner III The Swearingen Metroliner III is a large turboprop (turbinepowered) aircraft operated by Encore Air Cargo for allcargo charter flights. This airplane is operated by one of the on-demand contract carriers used to support Polaris Industries just-in-time delivery of parts to support the local manufacturing plant. This aircraft is expected to become part of the fleet mix for the ultimate design aircraft. Cessna Citation 680 (Airliners.net) The maximum gross weight of this airplane is 16,000 pounds. The aircraft s performance charts from the Flight Swearingen Metroliner III (Airliners.net) Planning Guide was consulted to determine runway length. This aircraft will be flown on high load factor short-haul routes to ROX. The aircraft at ROX will land at maximum landing weight and takeoff from ROX with additional fuel but a reduced payload. The estimated takeoff weight is 14,000 pounds rather than maximum takeoff weight as cargo is typically shipped to, not from, Roseau. The standard takeoff field length flap setting is ¼ to produce the minimum takeoff distance. Airport elevation, runway gradient and temperature data is utilized. This aircraft will be operated under FAR Part 135 on-demand flight rules which required landing length adjustments for dry and wet runways. The calculated runway lengths are identified below. The total recommended length to accommodate regular use of this aircraft under FAR Part 135 operations at ROX is 5,600 feet required during wet or contaminated runway conditions. Appendix X: Runway Length Analysis Page 23

Exhibit 6 Swearingen Metroliner III Runway Length Requirements Metric/Operation Runway Length Takeoff Length Requirements Takeoff Field Length @ 14,000 lbs., Dry (1) 4,350 feet Recommended Takeoff Length (2) 4,500 feet Landing Length Requirements (3) Unadjusted Landing Field Length @ MLW 2,900 feet Landing Field Length @ MLW (Part 135) 4,900 feet Landing Field Length @ MLW, Wet (Part 135) 5,600 feet Summary Recommended Runway Length 5,600 feet Source: Swearingen Metroliner III Airplane Performance Manual, KLJ Analysis NOTE: Runway requirements assume maximum takeoff weight (MTOW), 78.2 F, no wind, 1060 MSL elevation, 14 runway elevation difference. Runway lengths of 30 feet or over are rounded to the next 100-foot interval per FAA guidance. MLW = Maximum Landing Weight (1) Takeoff Field Length is the greater of accelerate-stop, accelerate-go with one engine inoperative, or 115% of the all engine takeoff distance to a point 35 feet above the runway. (2) Runway Length is adjusted based on runway gradient at a rate of 10 feet for each foot of elevation difference between the high and low points of the runway centerline (14 feet of grade change = +140 feet of runway length) (3) Adjusted length includes required 60 percent landing distance factor for stopping operations and additional wet runway factor of 15 percent (if applicable) per FAR Part 135.385. Appendix X: Runway Length Analysis Page 24

Metro III Performance Chart: Accelerate-Stop Distance Roseau Municipal Airport/Rudy Billberg Field Temperature: 78.2 F / 25.7 C - Airport Elevation: 1,060 MSL Assumed Takeoff Weight: 14,000 lbs. Dry Runway Takeoff Distance (Unfactored): 4,350 feet Appendix X: Runway Length Analysis Page 25

Metro III Performance Chart: Landing Distance Roseau Municipal Airport/Rudy Billberg Field Temperature: 78.2 F / 25.7 C - Airport Elevation: 1,060 MSL Maximum Landing Weight: 16,000 lbs. Dry Runway Landing Distance (Unfactored): 2,900 feet Appendix X: Runway Length Analysis Page 26