When is it safe to lift the tail?

[dmaher]

This is for a simulator model again.
For tail dragger pilots, is there an airspeed at which you raise the tail?
Is it safe to bring the tail up with elevator – or best to let it come up neutral?
Could forward pressure actually force the nose over?
I think I've watched a video or two that shows the tail can fly within say 150'.

For the sim tuning I’m basically trying to find the takeoff airspeed at which the elevator can lift the tail.

Danny

 

[scsmith]

Soon as possible is plenty safe.

If you hold forward stick, and just wait for the tail to lift, it will come up when it can, and that's just fine.

 

[Mel]

Like Steve says, hold the stick forward 'til the tail comes up.

How soon it comes up will depend greatly on how the airplane is loaded. Since everything but fuel is aft of C/G, the more loaded, the longer the wait.

 

[glenn654]

There are a couple of techniques which taildragger pilots most often use, I like to change types depending on the surface I am taking off from.

For hard surfaced runways, I like to let the tail stay down until it is ready to fly on its own. What this does for me is give me positive steering control while at low speed and high engine torque and poor rudder authority.

For soft field runways, I immediately force the tail up upon full throttle to reduce rolling drag from the tailwheel. This takes more effort since when at low speed, high engine torque and poor rudder authority I really have to be quick and use most if not all of the rudder travel depending on the quality of the surface and acceleration and wind conditions. It takes a lot of "dancing on the rudder pedals" but as speed comes up and I gain rudder control it soon becomes like any other takeoff.

Hope this helps.

There is also a very good book on flying taildraggers called "Taming the taildragger" by John Ball. It should probably be required reading for all new taildragger pilots.

Glenn Wilkinson

 

[dmaher]

Thanks, this is great information. I should explain a bit more, I’m writing the flight model for a simulator. So my mission is to specify when the tail comes up. The elevator’s reaction to the prop-wash is adjustable. I need to try and find a setting that resembles the RV7 most. Here’s an example of two tests with the current setting…

RV7 180HP CS prop

Location: sea level
Wind: none
Balance: undetermined
Power: 100%
Stick: full forward

1)
Weight: 1800lbs
V stall: 57.9 mph
Tail flies at: ~37mph (64% of Vs)

2)
Weight: 1400lbs
V stall: 51.1 mph
Tail flies at: ~27mph (53% of Vs)

I’m tempted to reduce the effect and push these speeds a bit higher. Or do the speeds seem in the ball-park. Getting them reasonably realistic is good to do…it has a big impact on elevator authority generally.

Danny