heyerflyer

My Feedback: (46)

Can someone tell me how to Program crow braking on Boomerang xL using a DX18 with 2 flaps and 2 ailerons
Thanks Steve

bcovish

My Feedback: (8)

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Gordon W

Ensure you do as BCovish says.

Then mix flap with left aileron. As flap goes down, both ailerons will go either up together, or down together. If down, reverse direction of mix. This is an example of "back mixing" mentioned in the DX18 handbook.

Gordon

bcovish

My Feedback: (8)

While you are doing the mix, the value in the rate line controls how much the ailerons raise.

Gordon W

If you've programmed dual rudders as well as 2 Ail 2 flaps, you can also mix flap with left rudder to get an airbrake effect. As flap goes down, rudders will deflect inwards or outwards depending on reverse switch setting.

I haven't tried this last one yet, but as my new flying field has a short runway and is bounded by trees which necessitate a steep initial approach, I'm about to give it a try with my Nano Boomer's rudders going outwards. I'll activate the mix with a separate switch. Hopefully there'll be a noticeable amount of extra drag which will help me to control the airspeed on the steep approach before levelling out to land.

Incidentally, if you make the flap mix with right aileron or right rudder, the surfaces will deflect normally - not what you want! But worth experimenting with on the bench to see it happen.

Gordon W

Further to the last post, I've now had 6 flights with my Nano employing crow braking, split rudder airbrakes and Cortex gyro, all for the first time ever. My reason for using these three features is to help me to land the jet on a short grass strip with a steep approach over a nearby tree line, often with turbulence. The Cortex set to 40% rate (I'm not using hold) stabilizes the plane nicely during the approach, and the crow and split rudder braking keeps the approach speed constant and slow. By itself, crow didn't provide enough drag as the Nano's flap is too small to provide the amount of air braking needed. The split rudders add a useful extra amount of drag.

When deployed, the split rudder causes a nose-up trim, so I've programmed a little extra down-elevator trim to compensate.

Because of the split rudder feature, you can't simply mix nosewheel steering with rudder as the nosewheel would be offset with rudder braking active.

The way round this is to go into channel assign and link the nosewheel channel with the rudder stick. To vary the NWS deflection, mix the NWS channel with itself and choose a suitable percentage to suit what you want.