Runway Selection at an Uncontrolled Strip with Conflicting Traffic
You arrive at a non-towered aerodrome with two runways: 09/27, 1,100 m sealed, and 14/32, 800 m grass. The wind is reported by a ground observer as 180° at 12 kt, gusting 18 kt. A powered parachute is already in the circuit on 14 and calls downwind. Your aircraft needs 600 m to land and 700 m to climb out over a 15 m obstacle. Density altitude is 2,000 ft above the aerodrome elevation. You are 5 NM out and have heard no other traffic on the CTAF for two minutes.
1. Choose a runway and justify the choice with crosswind and performance reasoning.
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Wind 180° at 12 gusting 18. On runway 14 the crosswind component is roughly sin 40° × wind, about 7.7 kt at 12 kt and 11.6 kt at 18 kt; on runway 09 it is sin 90° × wind, effectively the full 12–18 kt. Runway 14 is the better wind choice but is 800 m grass, and at 2,000 ft density altitude your 700 m obstacle clearance figure is a sea-level or book figure that must be increased - grass and density altitude both erode it. Runway 27 is 1,100 m sealed but gives a near-full crosswind with gusts beyond many light aircraft limits. The defensible choice is runway 14 if your performance chart, corrected for grass and density altitude, still shows margin; otherwise wait. Do not select 27 merely because it is longer.
2. Explain how the powered parachute and the silent CTAF affect your decision.
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The powered parachute is established on 14 and has made a standard call; joining a different runway creates a conflict you must resolve by radio, not by assumption. Make a broadcast stating position, altitude, and intention, and listen for a reply. The two minutes of silence does not mean the aerodrome is empty - it may mean the parachute is on a discrete frequency, or that other traffic is not radio-equipped. Treat the strip as potentially occupied: overfly to inspect, or join wide and sequence behind the known traffic. If you cannot establish separation by radio, the safe option is to hold clear and re-join, or divert. The absence of calls is not evidence of absence of aircraft.