Trying to cure "Bird Landing on a Wire" Syndrome

[John Bickham]

I thought some might find this interesting, so I'll share for "geek" leaning Bearhawk flyers out there. I'm a novice at this stuff so claim ignorance may be involved.

My New Year's resolutions were to:

- Improve the consistency of my landings and landing distances

- Learn something new

A little background:

I participate in backcountry flying in all the wonderful places like New Mexico, Arizona, Utah, Idaho, and Oregon. Truly living the dream! I concentrate totally on backcountry techniques and always trying to improve skills. That said, this is backcountry oriented and not intended for GA flying. They are two different worlds and require different skillsets, commitment, and approaches.

11-17-2021 Bearhawk - Mexican Mountain 0.jpg
At Mexican Mountain, last fall.

So the goal is STOL and landing short. I had migrated to some bad habits in the quest for super short landings. Short version - pretty slow, steep approaches that would require some pretty "perfect" timing and skills to "land on the wire". I would hit a 230 landing distance then the next try would be a 825 distance. It was frustrating me and I couldn't get it right every time. I had no consistency. That 825 meant that the shortest strip my personal limitations (2 x longest) would put strips shorter than 1650 out of consideration. that sucked!!! So giving up on participating in STOL contest and going for consistent, short landings. Don't have a spare airplane in the barn if I bend or break this one!

The learn something new thing? Some people learn a foreign language as a brain exercise. My version of that is to learn Excel which is truly a foreign language.

So I am starting over. First step, define and improve my approaches with should result in more consistent landings.
Second step is develop tools that are easy to use to evaluate those approaches and landings. That is where the Excel comes in and makes this truly a project!!! I truly wish my project was a new LSA kit but time and money (AVGAS ) won't allow that.

So attached you will see my first attempts at starting over. Go and determine new glideslopes and sight pictures to improve approaches. see the attachment

Can't explain the difference on the 1600 RPM graph. I did move to a different spot to give a friend some room for his acro box. Closer to the mountains which may a have a different "mechanical" lift going on. The blue line on that graph was the expectation.

What I learned:

• I need to work and concentrate on controlling my airspeed more. My eye sees something different than what the data reveals. I have a knack for only visually scanning my AS when it is on or very near 50.
• If these calculated glide slopes are correct that means I had migrated to a pattern of very steep approaches in excess of 10 degrees. That may explain the "bird landing on the wire" inconsistency I was experiencing.
• I included the average pitch and descent rates. The are simple averages of both passes combined. 743 FPM on the 1300 rpm???

Glide Slope Test GraphsREV1.pdf

Peace, Fly Safe

[Nev]

A very interesting discussion John. I'm at a roughly similar stage. Here's a few thoughts.

The steeper red line is probably due to a headwind component (possibly very light). This means that the glide path when measured over the ground is steeper, but if it were able to be measured through the (moving) air it would be the same as the blue line.

When landing into a headwind and flying the same geometric glide path (say an ILS), the pitch angle is higher, power required is higher, descent rate is lower, flare required is less. On a GA aircraft like ours, we don't usually have a geometric reference and so the approach path itself tends to steepen up with a headwind, or flatten out with a tailwind, and the pitch and power tend to stay the same. It might explain why your blue lines are flatter than the red ones.

Your density altitude is reasonably high, but shouldn't affect anything on the chart. If you had groundspeed plotted it should be commensurately higher in proportion to altitude.

I've spent many hours trying to improve my landings. The first several hundred were done using a high pitch attitude and after a quick flare, checking forward to put the wheels on. It works reasonably well, but is hard on the airframe because the touchdowns are firm. More recently I've been getting very good success by using a slightly lower pitch angle (lower AOA) which allows me to see the aim point over the nose. The approach is very slightly flatter (you wouldn't notice it) and I'm keeping a trickle of power on into the flare. The resulting touchdown is smoother, and the landing distance very similar. Probably around 100m (330ft) at 2050lbs with no wind component and 2000ft da.

Heres a very grainy low res video from a landing yesterday. This strip is one way due to high terrain behind the camera. It's about 280m (1000 ft) long with a slight slope. We had about 7 kts crosswind yesterday.

[John Bickham]

Hey Nev,

Sounds like we are at a similar stage. You mentioned one of my criteria that is important here for backcountry. That is over the nose visibility for directional control. I have to see the prairie dog holes and am not able to stay on the two track without seeing it till things slow way down. I'm a tail low, to mains guy for visibility Think you are too.

just checking, those landing distances hard or soft surfaces. Your DA?

thanks

[Nev]

Reasonably hard surfaces John, although the one in the video had grass and might be slightly soft but not an enough to be an I ssue.The D.A. in the video was around 3300ft (2600 amsl). In general our density altitudes are much less than yours. We were in another airstrip yesterday that is 4500 amsl, and yesterday the density altitude there was 5700ft. We had a 10kt headwind and landing slightly downhill due to the wind direction, but probably stopping around 130m. (Hard to compare apples with apples when there's a headwind).

I definitely prefer to see where I'm going over the nose. For me it's about a 2 kt increase in speed on short finals. I can now judge the pitch attitude which is essentially a 3-point attitude just before touchdown, then a slight pole forward to a tail-low wheel attitude. Sometimes the tailwheel still touches first and I'm fine with that.

[Utah-Jay]

Fly Oz has some great videos

https://youtu.be/J5_MEMCg3jg

I’m still building, but from history I’d say control your speed with pitch, add a bit of power and with a bit of practice you should be able to hit your spot +/- 50’ going in the mid-40’s mph. At that touch down speed you’re gonna be well under 400’ distance even at our DA’s

In the Fly Oz vids they discuss AOA. Note: brakes should not need to be heavily used for a 400’ or less rollout

500’ per minute decent is just over 8 feet per second, with a blip of power are the flair that decent should be arrested a bit and you get a nice soft landing.

So a question, what is your IAS speed on final? If you are in the Vs1.5 to Vs1.1 range on short final things should be very controllable barring gusty winds

[Utah-Jay]

Btw, Nev pretty much nailed the AOA technique described in the video

[Utah-Jay]

Here is a good, bad and ugly practice session. I practice religiously for backcountry ops

This is a Rans S-21 with a Rotax 915, so much less capable than our Bearhawks

https://youtu.be/e5Dx9_vrSr0

[Nev]

Jay how do you get the airspeed displayed in the top corner of the video ? Is it IAS or GS ?

[Nev]

Looks like a lot of fun there Jay. What IAS does it stall at in that config (one POB?, half fuel etc).

[Utah-Jay]

Another great video discussing AOA

https://youtu.be/CrPJac80W9Y

[Nev]

Yep that's a good one.

[Nev]

Landing video compilation

For a bit of fun I put together a video of practicing landings in the backcountry. (It's definitely not instructional )

On these days I flew 3 airstrips. Each of them is about 250 - 300m (800 - 1000 ft) in length. The IAS I am flying applies only to my aircraft due to variations in position error. I'm aiming for 60 KIAS while maneuvering which gives me a margin if I need to steepen the turn, and for wind gusts etc. On finals it's generally about 50KIAS, and touching down at about 40-42 KIAS at 2050 lbs. The final strip has a tailwind so every landing roll was longer. I notice that my better touchdowns are occurring when I chop the power after the wheels are on rather than slightly before.

[Utah-Jay]

Nev

That is GS displayed on the video, it is a GoPro function when you use their QUIK app. I think Hero8 and above have the ability, obviously GS is much faster than the IAS at my DA’s. Typically 6-8mph faster to be honest.

[Utah-Jay]

Great Video Nev

Looks like you have the feel for sure

[John Bickham]

Hey Nev,

Impressive video. You've got skills in both video production and master of your aircraft.
Just a quick "lemons to limes" check??? Full flaps on final??? That is what it looks like on the video. If it is full flaps, wondering what power setting is for the 500 FPM (roughly) and how that compares to mine. Understand the weight consideration.

[Nev]

Mostly full flap although a few of them would have been F3. Incidentally I'm getting about 30° with F4 and air loads. Taking a closer look at the descent rate, it appears to be around 250 ft/min on finals which seems about right for 50 kts. Power setting is varying, but around 9-12" MAP.

[whee]

Great discussion with lots to think about. I think I started a similar one a while back and I like to hear about what others are doing. I still don’t have my landings nailed down to the accuracy I’d like and I certainly can’t describe the pilot stuff I do to make it happen.

I don’t look at my rpm on final but do refer to my MP when working on approaches. 11” seems to be where I like to be. I do practice power off landings regularly just in case things so south.

The 600ft practice strip I use is a lot less scary now except on those high DA days when my wheels drag through the weeds at the end during departure.

John, I’ll be down your way in the spring. If I can convince my employer to let me take my plane rather than ride a smoker I’ll hit you up. Maybe we can go have some fun if there is some fun to be had near Las Cruces.

[John Bickham]

Please do.
Spring tends to be early flights cause the wind can howl later in the day.
We could meet in the middle and do Gila Wilderness strips. Me-own, Beaverhead, Negrito, Rainy Mesa, Sacaton (newly reopened).

Take a look at it. Always welcome at E98. Let me know.

[Utah-Jay]

Nev

Responding here rather than a comment:

The Rans S-21 I was flying with the Rotax 915 stalled at 41.5-42mph IAS. Yes I fly slow, typically VS1.1 on mid to short final with my hand ALWAYS on the throttle. I will be looking forward to my non-turbo 200hp O-360 so as not to have the dreaded turbo delay. I learned in a Rotax 912 which was super responsive, but the 915 flying at my speeds you really had to anticipate all the way to the touchdown.

Videos with my wing strut camera were pretty good, but the setup I had in the cockpit with my GoPro recording audio typically had a horrible noise I think due to unshielded wires. I do believe my build will eliminate that extra and annoying noise. I have a fair amount of video I did not post to Youtube because of the bad audio, but I typically used the in cockpit camera and audio to debrief and learn. I like to have the camera over my shoulder looking both out the windscreen and at the PFD for post flight review. I am typically calling out my IAS in practice hence I have a pretty good feel that my GS is about 6-8mph over my IAS at my typical DA’s.

If you go to 19:38 in this video I have just switched from strut camera (it died on final) to the in cockpit camera and you can hear my silly way of calling out speeds for review later. YES I am OCD and always trying to squeeze every bit of education out of every single flight. 19:38 is a final approach into Happy Canyon (UT97). I visited 5 different backcountry strips on this day just working on my piloting.

https://youtu.be/6ADSVANzMI8

Edited to add, I am going to have 4 “hardwired” camera locations on my Companion. Each wing will have a camera mount, one behind and over my shoulder and another on the glare shield. I will likely never have 4 cameras, but will move them around depending on the day. I will always have the one over the shoulder, the right wing will be the view in the video above (prior to 19:38), the left wing will be straight forward, and the glare shield will be at the pilot. The glare shield will possibly never be used, but I figure you only have one chance to really dig in and wire prior to completion so I am gonna put it there just in case.

Here is a camera view from a buddies Maule, I am thinking with a forward facing left wing camera I may use this shot/camera angle for the right wing cam. The guy in the Maule is a professional videographer and he has an amazing app (certainly not the GoPro app) to control his cameras simultaneously with one button press.
14F8800B-7122-489D-A485-E900834FECB4.jpg
Here is a link to the “hard wire” camera power I am going to use, one in each wing working off of a panel rocker switch to turn on and off:

https://flightflix.net/product/aircraft-camera-power-supply/

Anyway, I think I have now hijacked this thread, so sorry

[Battson]

So I am starting over. First step, define and improve my approaches with should result in more consistent landings.
Second step is develop tools that are easy to use to evaluate those approaches and landings. That is where the Excel comes in and makes this truly a project!!!

So attached you will see my first attempts at starting over. Go and determine new glideslopes and sight pictures to improve approaches. see the attachment

Can't explain the difference on the 1600 RPM graph. I did move to a different spot to give a friend some room for his acro box. Closer to the mountains which may a have a different "mechanical" lift going on. The blue line on that graph was the expectation.

What I learned:

• I need to work and concentrate on controlling my airspeed more. My eye sees something different than what the data reveals. I have a knack for only visually scanning my AS when it is on or very near 50.
• If these calculated glide slopes are correct that means I had migrated to a pattern of very steep approaches in excess of 10 degrees. That may explain the "bird landing on the wire" inconsistency I was experiencing.
• I included the average pitch and descent rates. The are simple averages of both passes combined. 743 FPM on the 1300 rpm???

Peace, Fly Safe

Very cool to see you're working hard to improve.
The data is really interesting, good to have. In my opinion the view out the front window is the key to improving

I am sure you're flying a stabilized approach, but just in case that doesn't ring true, then you'd want to look into that in great detail.

With that out of the way, controlling airspeed should be very easy. Just trim the plane for the speed you want, and maintain your sight picture any time the power changes. In other words, keep your target (i.e. the threshold) fixed in the same place on your windscreen. These days I only check the ASI occasionally, perhaps one or two times each approach, but initially it was more often while I was honing the technique.
The point is maintaining the attitude of the aircraft is the most important thing and only occasionally referred to the ASI to confirm you haven't drifted off target.

I am personally a big fan of steep approaches. It reduces the dependency on engine power to make the landing site, increases obstacle clearance, increases visibility, and provides improved go-around options - all increasing safety. As long as you fly a slow approach, then a steeper approach has few downsides.