We've made another small update to the Bushbaby
So you'll remember that the door lower halves were covered, well um take a look at this
Okay how awesome is that? And credit for this goes to my dad who put it in
like it was absolutely nothing, didn't take him very long at all
But I think it's freaking awesome, and today we're going to see what it looks like to fly with them
One mississippi, two mississippi, three mississippi takeoff
It is so cool to be able to see straight down. I can literally see straight below me
Definitely a worthwhile upgrade.
I recently made a video about micro vortex generators
which after installing didn't make any difference in our stall speeds
Granted we placed them too far back, I didn't, and still don't believe
that is the full reason why the addition of VG's made no difference. Hear me out
Not again
As we know VG's only work at extreme angles of attack, and since we cannot get the tail down to
get that extreme angle of attack, as a result of the far forward center of gravity due to the
heavy engine up front, moving the VG's forward - in my opinion - isn't going to solve our problem
What I mean when I say we can't get the tail down is specifically with regards to landing with full flaps
As we know taking flaps with a Junkers-style flapperons actually raises the tail
making the horizontal stabilizer and elevator work harder to get the tail back down.
To illustrate it I attempted a bunch of short landings in three point configuration
And I'm gonna make the numbers my aiming point. The numbers; two seven. Okay so the end of the numbers.
Rhino park traffic, IJC turning final approach, runway 27, full stop landing
Ok full flaps
Yeah that was quite long I think
probably 200 meters
As you can see landing after landing the tail wheel isn't even coming close to touching, even
though I'm stick fully back. To solve this problem I started looking at ways to energize the tail to
help get it down more. For details on everything we considered doing to help get the tail down more
see the previous video I made, the link is in the description below. The one thing we didn't think of
was actually increasing the upward deflection of the elevator. Thanks to Stefan from KFA who noticed
it wasn't going up as far as it should and quickly adjusted it for us. I measured it very crudely
but the maximum deflection of the elevator went up from about 22 degrees to 27 degrees
I was stoked at the promise of this little change and went to the general flying area
to do some stalls and see the improvement
The first one I'm going to do is a clean stall.
Decelerating very slowly
Now at 58
I'm gonna have to take all the power away because I'm doing power-off stalls.
Ok power off completely
Okay that's about 43
Recover
All right, so let's turn around and do one in the other direction
All right, so let's do one full flaps
ok full flaps
43, 42, 40
39, 38
Yah it's just stuck at 38
Ok lets recover
I was kind of gutted that the increase in elevator deflection didn't make any improvement in stall
speed, but this brought me back to my original suspicion that with the far forward center of
gravity being the problem, we were not going to get the tail down more by making minor aerodynamic
improvements on the horizontal stabilizer. However I knew of something else I could try
I'll reveal it in a few moments but if you religiously watch Trent Palmer's Youtube videos
you already know what I'm about to do next. So I made the change
and headed to the GF to go test it out
And then we're going to do a stall, clean configuration first
Okay. Decelerate very slowly okay
Lets do this
39
Ok so I'm already seeing quite a significant improvement
Lets do one full flaps
Slow down first
half flaps
full flaps
Thirty four
Lets do one in that direction
flaps
What!? Full flap power-off stall speed down from 38 miles per hour to 34 miles per hour
That's a four mile per hour increase in stall speed, and it cost me a whole of 12
dollars. So for those who haven't yet figured it out, the change I made was tying a weight
to the tail of the aircraft to get the center of gravity further back
This is probably where I will get told that I'm playing with fire or something profoundly wise
after all, an aft C of G makes it harder to recover from stalls and spins as well at making the plane
more prone to ground looping. But it also makes the plane cruise faster, makes it harder to nose over
so you can brake harder, stalls at slower speeds and importantly, it gets that tail down
I also didn't just attach a random weight. I carefully calculated and recalculated the center
of gravity with different amounts of weight and then I still played it on the safe side
I then went and did some short three-point landings and the tail is now coming down
a lot more with the tail wheel almost touching on power-off, three-point landings
That landing was less than 80 meters or 260 feet, and that is on a 4,000 feet density
altitude day. That's almost half the distance of the shortest landing I was able to do
without the weight on the tail, so I'm pretty satisfied with that result.
So now I would like to ask something of you.
You're asking me?
I've been doing quite a few
of these technical videos. Hit like or leave a comment below and let me know if you like
this sort of performance tinkering and testing type of videos, or not
I'm not really sure what you're asking me
And then I'll see you in the next one
Recalculated with different whales
different wales