Crow braking is a specific aerodynamic technique primarily used in gliders and large-scale RC models to reduce lift and increase drag, allowing for controlled, slower descents without gaining speed. Unlike traditional flaps—which simply lower to increase lift and drag simultaneously—crow braking involves a coordinated movement of both flaps and ailerons in opposite directions. When crow braking is engaged, the flaps deflect downward, while the ailerons raise upward slightly. This creates a “drag brake” effect, reducing lift at the wingtips and preventing any unwanted increase in airspeed.
The key difference between crow braking and standard flaps is that flaps alone increase both lift and drag, which can sometimes lead to more lift than desired, especially when approaching a landing. Crow braking, by contrast, keeps the plane steady and slows it down effectively by reducing the lift created by the wings’ outer sections. This method is especially useful for maintaining control on descent without causing a rapid gain in speed or altitude, making it ideal for precise landings on shorter runways or for navigating challenging landing approaches.
This setup can be extremely useful in a few key scenarios:
• Controlled Landings: Crow braking allows you to descend smoothly without gaining extra speed, giving you more control during the final approach and touchdown.
• Short Runways: For landings on shorter runways or restricted landing areas, crow braking helps reduce your stopping distance.
• Precision Gliding: For glider pilots, crow braking makes it easier to control altitude and approach speed, allowing for precise, soft landings.
• Preventing Tip Stall: By raising the ailerons slightly while lowering the flaps, crow braking reduces the amount of lift generated at the wingtips, shifting more lift toward the center of the wing. This helps prevent the wingtips from reaching a critical angle of attack, which is the main cause of tip stalls. In other words, crow braking keeps the tips from stalling before the rest of the wing, ensuring a more stable and controlled descent, especially at slower speeds. This is particularly beneficial during landings and low-speed maneuvers, where tip stall can be a concern.
This setup is especially helpful in situations where you need the plane to descend quickly but still want a stable, controlled approach.
How to Set Up Crow Braking: Video Guide
In my latest video, I go over the full process of setting up crow braking on a Futaba transmitter, covering everything from initial programming to fine-tuning each control surface for optimal performance. This tutorial walks you through the process step-by-step, helping you set up crow braking correctly and customise it to suit your aircraft’s specific needs.
I use my Turbo Bushmaster to demonstrate how to setup crow braking; however I wouldn’t typically use it on this type of aircraft.
Here’s a quick overview of what’s covered in the video:
1. Programming the Ailerons and Flaps: I’ll show you how to program the transmitter to control the ailerons and flaps independently, with settings to adjust each control surface for smooth crow activation.
2. Setting Up Flight Conditions: We’ll go over how to assign crow braking to a specific flight condition, so you can toggle crow braking on or off during flight without affecting other controls.
3. Fine-Tuning the Controls: I’ll walk you through how to adjust the degree of flap deflection and aileron lift, allowing you to customise the braking effect based on your specific model’s performance and flight characteristics.
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