Mastering the Aerosoft Twin Otter for Bush Flying Adventures

Bush flying demands a rugged, reliable, and exceptionally capable aircraft. The de Havilland Canada DHC-6 Twin Otter fulfills that role flawlessly, and Aerosoft's detailed simulation brings this workhorse to your virtual cockpit. Whether you are hauling supplies to a remote mining camp, exploring uncharted valleys, or landing on a gravel bar, proper setup and flying technique make the difference between a successful adventure and a costly scrape. This expanded guide covers every phase of operating the Twin Otter in the backcountry, from pre-flight walkaround through post-flight maintenance, with actionable advice for both new and experienced sim pilots.

Pre-Flight Preparation for Bush Operations

Bush flying rarely begins on a paved, 6,000-foot runway. You might be operating from a short grass strip, a frozen lake, or a sandbar. Every flight starts with a thorough inspection and configuration tailored to the environment. The Twin Otter's robust design forgives many mistakes, but preparation is your insurance against surprises.

Detailed Aircraft Walkaround and Systems Check

Begin by verifying all exterior surfaces are free of damage or ice. In the Aerosoft simulation, use the walkaround view to inspect:

  • Engine intakes and exhaust – Ensure no foreign object debris (FOD) is present. The PT6A engines are tolerant but can suffer from ingestion of stones or gravel.
  • Propeller blades – Check for nicks or leading-edge erosion, especially after repeated gravel operation.
  • Landing gear – The fixed tricycle gear is sturdy, but check tire pressure and tread for soft-field operations. If you have the optional tundra tires mod, verify correct inflation.
  • Flaps and ailerons – Confirm full and free movement. Flaps are critical for STOL performance; any binding reduces lift.
  • Fuel vents and drains – Ensure vents are clear of debris. Sample fuel from the three sump drains (left, right, and optional auxiliary) to check for water or sediment.

Inside the cockpit, power up the avionics bus. Verify that the engine instruments show stable oil pressure, torque, and ITT (inter-turbine temperature) reference ranges. The Twin Otter's electrical system is straightforward: batteries on, generators online, and alternators charging. For bush flying, I recommend leaving the fuel pumps in the ON position during all ground ops and takeoff to prevent vapor lock on hot days.

Weight and Balance for Unimproved Strips

Bush strips often limit both takeoff and landing performance. The Twin Otter's maximum takeoff weight (MTOW) is 12,500 pounds (5,670 kg), but you will rarely use that full number on a short or soft field. In the Aerosoft weight and balance menu:

  • Calculate zero fuel weight and ensure you are within CG limits. The Twin Otter loads cargo through a large aft door; heavy items should be positioned near the center of gravity (around station 237).
  • Set fuel load based on required endurance plus a 30-minute reserve. For bush flying, a typical flight might need one hour out and one hour back, so 600–800 lbs of fuel is often sufficient. Avoid carrying excess fuel that degrades climb and short-field performance.
  • Adjust passenger or cargo weight realistically. A common mistake is overloading the aft section, causing a tail-heavy condition that reduces elevator authority during flare.

For soft fields, reduce gross weight by 10-15% if conditions are marginal. The Twin Otter's published soft-field takeoff distance at maximum weight is roughly 1,300 feet on grass. Adding 500 pounds of payload can increase that distance by 30%.

Bush Flying Equipment and Modifications

While the Aerosoft default includes standard wheels, consider installing:

  • Gravel deflectors – Prevents rocks from striking the fuselage and engines. Essential if you operate from unpaved strips.
  • Bush wheels or tundra tires – Allows operation on soft, uneven terrain. The increased flotation reduces ground roll and braking distance.
  • VOR/DME or GPS – For navigation in remote areas without visual references. The Aerosoft Twin Otter includes both a traditional VOR panel and a Garmin 530; learn to use both.

Check third-party add-ons for enhanced bush flying features; many virtual bush pilots use mods that improve gravel and water ops.

Starting Up and Taxiing on Rough Surfaces

Starting the PT6A engines is straightforward, but bush flying introduces unique challenges. Follow the standard start procedure from the Aerosoft manual:

  1. Battery master ON, avionics master ON.
  2. Set throttle to idle (fuel shutoff is automatic when at idle stop).
  3. Press and hold starter button; watch ITT rise. Release at 10% NG (gas generator speed).
  4. At 52% NG, advance condition lever to LOW IDLE – monitor ITT to stay below 1,000°C (typically it peaks around 600°C).
  5. After starter cutout (at 52% NG), check oil pressure rises within 30 seconds.

During taxi on gravel or grass, keep nose wheel steering gentle. The Twin Otter has a steerable nose wheel with about 25° deflection; using differential braking too aggressively can cause flat spots on tires or dig in soft ground. On loose terrain, avoid applying full power to turn – instead, use short bursts of power with a hard-over rudder pedal. If you are operating on very soft ground, keep the airplane moving slowly to avoid getting stuck; stopping in deep mud may require external assistance.

Runaway Safety and Surface Evaluation

Before taxiing, visually inspect the intended takeoff path. Look for rocks, stumps, or washouts. On real bush strips, pilots walk the runway – in the sim, use spot view or drone camera. Pay attention to slope direction; if possible, position for an uphill takeoff to reduce ground roll on short strips.

Bush Takeoff Techniques: STOL Performance at Its Best

The Twin Otter excels at short and soft-field takeoffs when you use the proper technique. The simulation models real aerodynamic behaviors, including ground effect and flap effectiveness. Follow these steps for a maximized performance takeoff:

  1. Set flaps to 20° (the first detent). For very short fields or obstacle clearance, 30° flaps may be used, but climb gradient suffers. 20° provides the best lift-to-drag ratio for obstacle clearance.
  2. Hold brakes, apply power smoothly to the propeller control (beta range) – you want maximum torque (around 1,100 ft-lb on the PT6A-34). Verify both engines are stable. For gravel strips, avoid exceeding 1,200 ft-lb to reduce risk of propeller stone damage.
  3. Release brakes and begin roll. Keep the nose wheel planted for directional control until rudder becomes effective (around 40-50 knots). Then gently lift the nose to a rotation speed of about 55 knots.
  4. Rotate smoothly – the Twin Otter will fly off at about 60 knots. Immediately after lift-off, accelerate in ground effect until reaching the best climb speed of 75 knots. Do not pitch up aggressively; this increases drag and reduces climb.
  5. Once clear of obstacles (typically 50 feet AGL), retract flaps to 10° and accelerate to cruise climb speed of 100 knots. Retract flaps completely at 120 knots or as directed by the manual.

For soft fields (mud, sand, snow), keep the nose wheel lighter than usual during the roll – transfer weight to the main gear earlier to reduce drag. Avoid locking the nose wheel in soft ground by using minimal steering and differential power. In crosswinds, use a touch of aileron into the wind to keep wings level during the initial climb.

Obstacle Clearance and Canyon Flying

Bush flying often requires climbing immediately after departure due to tall trees or canyon walls. Use a short-field obstacle clearance profile: after lifting off, maintain a 55-knot climb with flaps 20° until you clear the obstacle (at least 200 feet), then accelerate. The Twin Otter's climb rate at sea level on a cool day is around 1,700 fpm – but at high altitude or high temperatures, expect 1,000 fpm or less. Pre-calculate your density altitude before flight using the performance tables in the Aerosoft documentation.

In-Flight Navigation and Weather Management

Once airborne, bush flying requires constant situational awareness. The Twin Otter's simple avionics help you focus on flying and navigating the terrain.

Even with GPS, overlay your route on a sectional chart. In the virtual world, use tools like SkyVector for planning. Program your Garmin 530 with waypoints, but also identify prominent landmarks – rivers, lakes, mountain passes – that you can follow if the GPS fails. The Twin Otter's VOR receiver can be used for tracking if you are near a VOR station, but many bush strips are far from conventional navaids. Dead reckoning and pilotage remain essential skills.

Monitor your fuel state closely. The Twin Otter burns approximately 33-35 US gallons per hour at cruise power (about 1,600 RPM, torque 500 ft-lb). With 375 US gallons total (standard tanks), endurance is roughly 5 hours plus reserves. For remote bush operations, always halve that endurance – you may need to divert or hold for weather.

Weather Avoidance in Mountainous Terrain

Bush flying often means dealing with rapid weather changes. Key threats include:

  • Mountain waves and turbulence – Avoid flying downwind of mountain ridges where rotors form.
  • Visibility degradation from haze, smoke, or fog in valleys. If visibility drops below 3 miles, consider landing and waiting it out.
  • Thunderstorm buildup is common in summer afternoons. Leave ample margin to climb over or divert around convective cells. The Twin Otter's ceiling service limit is 25,000 feet but practical maximum for IFR is lower. For visual bush flying, stay below 10,000 feet for safety.

Use real-time weather add-ons if possible, and check METARs before departure. In remote areas, pilot reports (PIREPs) are invaluable – but in the sim, rely on your own observations.

Landing on Rough and Short Strips

Landing is the most critical phase of a bush flight. The Twin Otter's robust landing gear and high lift devices allow touchdowns at speeds as low as 50 knots, but technique must be precise.

Choosing a Landing Zone

From the air, evaluate the intended strip: is it clear of obstacles? What is the surface condition? Look for tire tracks or other signs of recent use. Check for obstructions on final approach – trees, wires, rocks. The Twin Otter's high wing gives excellent downward visibility on final; use a right-hand pattern for visibility if landing on the left seat.

Plan for a flaps 40° approach (full flaps). The airplane will descend steeply with power off; manage descent rate with small power adjustments. Aim to cross the threshold at 60 knots with a slight nose-up attitude. On final, maintain a 500-700 fpm descent rate. If the strip is very short, use a power-on approach with flaps 20° to maintain a steeper descent angle without picking up speed.

Short-Field and Rough-Terrain Landing Technique

  1. On short final, stabilize speed at 55-60 knots. Drop the flaps to 40° once the runway is assured.
  2. Over the threshold, reduce power to idle and begin the flare. The Twin Otter floats slightly – hold the nose off until the mains touch gently.
  3. Immediately after touchdown, apply full flaps (beta range) by pulling the condition levers to the BETA detent. This provides reverse thrust from the propellers. Combined with max braking on the main wheels, you can stop in less than 500 feet.
  4. On rough terrain, avoid aggressive braking – use beta to slow down while keeping the nose wheel light. Once below 30 knots, reduce beta to prevent ground loops.

For soft fields, perform a soft-field landing: keep the nose wheel off the ground for as long as possible by holding back pressure. Use beta sparingly to avoid digging the nose wheel into mud or sand. The goal is to distribute weight on the main gear until the airplane slows to walking speed. Then gently lower the nose.

Post-Flight Inspection and Remote Maintenance

After landing in a bush environment, thorough inspection ensures the aircraft is ready for the next flight. Use the quick turnaround checklist:

  • Shut down both engines using the standard procedure: pull condition levers to CUTOFF. Ensure battery master is OFF after all systems are secured.
  • Walk around and check for stone damage to propellers, leading edges, and radome. In gravel ops, it is common to find small dents.
  • Inspect tires for cuts or partial deflation. If you have spares, know how to chock the airplane safely.
  • Check oil level – the PT6A might consume a quart every 10 hours; top up if needed.
  • Secure the aircraft against wind: tie-down ropes if available, set the parking brake, and if on a slope, chock the wheels or turn the nose wheel toward uphill.

If you are camping with your virtual airplane, set the engine covers and pitot tube cover (the Aerosoft model includes these). Leave the cockpit organized for the next flight.

Conclusion

The Aerosoft Twin Otter is a superb platform for bush flying adventures, offering unmatched short-field performance and durability. Mastering its quirks – from beta ground handling to soft-field takeoff techniques – transforms a routine flight into a satisfying challenge. Practice these procedures on a variety of strips: short, soft, uphill, downhill, and in crosswinds. For further reading, consult the official Aerosoft Twin Otter product page for system details, and check bush flying tutorials from community forums like FS Elite. For real-world inspiration, study the aircraft's history and see how it operates in extreme environments such as Antarctica and Alaska. Safe flying, and may your bush strips always be smooth.