Fantastic Gunny, thanks. As you know I'm flying a RSTOL 185 now and was thinking of just adding the Sportsman this time (no-WingX as I did the last plane) but you've may have changed my mind. One step at a time though.

Great job.

I had a Sportsman installed on my 182F, since then the plane is completely different. It is stable in landing configuration and has a much shorter takeoff distance. I really like the difference and the great improvement.

Phil-

Thanks for the words! BTW I just got to fly a Stock, very light C-185 as well as a C-180K (both out of Cain International Airport in North Texas). Interesting results. Anecdotally, the stock 185 flew very nicely... more so than any 180 I've flown (including that 180K). I flew your 185 when Bob Tullius owned it... this last one was nicer. My 180A with Vgs handles nicely now (it weighs about 50lb more than the 185). I don't know why there is a difference in handling. Interesting.

Results (all in mph):

Configuration C-180K C-185
0 54 53
10 46 50
20 46 49
30 44 45
40 44 44


Of course there are installation errors in the pitot-static systems. And I didn't correct for them. These tests are just a rough comparison for individual airplanes. But the gage is the gage in the airplane so the result is relevant for the airplane.

The most important thing is to know the speeds where YOUR airplane stalls.

So, now the question is do you fly 1.3Vso.... or 1.41Vso? A topic that Dan Gryder has raised. What is your floor airspeed for maneuvering?

gunny

Gunny,

I'm not a numbers guy, but I'm glad you are. It's nice to have actual numbers to verify what my butt has told me.

I use the 185 almost exclusively for scouting SQ2 spots, running to ANC to Costco, Talkeetna for lunch, and long distant trips. As such I don't do a lot of maneuvering- and with the exception of transitioning from cruise to flap speed (where I'm very likely to glance at the ASI to be sure I'm well in the white arc) I fly entirely by aircraft feel.

To me the most obvious "maneuvering" exception would be flying in Idaho which I did with my previous 185 but not with this one. Again I can't give you numbers but I can say that in those instances doing approach turns to the strips ("maneuvering" I guess) the stall horn would just be squeaking at me- don't know what that equates to related to Vs0. I also very very rarely hold altitude in a "maneuvering" turn- including doing a 360 around something I'm interested in. I release back pressure and let the plane fall through the turn. Guess I'd suck as an IFR pilot.

Everything is by feel for me, not at all helpful for the info you are gathering I know, but it's what works for me- and keeps my eyes outside the cockpit which I like.

Thanks again for sharing your info, and doing the videos- was very interesting to see what the air is doing on the wing.

Flying by feel is good. Not saying you shouldn't. In a way the last question was aimed at others that might read this thread. Dan Gryder has raised a ruckus about using a higher speed as a floor for maneuvering. Just wondering where that is going and if it is getting traction.

For my airplane, I'd say Vso is flaps 40, it already has the gear down and with a stall speed of 40 mph that makes maneuver speed (1.41 Vso) 56 mph. I try to use 55 so I guess its close anyway. If you're hearing the stall warning whistle then you're about there, it is set to 3-5 kts above stall. And that is the BOOK number. From what I've seen the Skywagon consistently stalls below the actual book number.

So, are you spending much time in Texas these days? Sounds like you're near permanent Alaska.

gunny

A loosely related question - do all 180 / 182 / 185 aircraft have the same wing aerofoil?

Battson wrote:A loosely related question - do all 180 / 182 / 185 aircraft have the same wing aerofoil?

Pretty much all the single engine Cessnas (except the 177) from the 120 to the early 210s used the same airfoil.

Did the first 180 (not the 180A, the 180) use a different one to the rest?

I recently watched a video with Dan pushing this point. The reason he stated is that the 4 most common causes of fatal crashes in GA are stalls, spin stalls, flying into known IMC and I can not remember the last. Dan stated the first 2 are most commonly associated with take offs and people pulling back on the yoke causing stalls or trying to turn back and causing a spin stall.
In the video Dan relates it to air liner pilots. He asked a bunch of airline pilots and GA pilots what their understanding of Maneuvering Speeds. GA pilots think of it as a maximum not to be exceeded during normal operations where airline pilots think of it as a minimum not to be below in order to maneuver the aircraft during an emergency most commonly and engine out. During the video, they demonstrated that the stall could occur in as little as 5-6 seconds after an engine out scenario. I think the idea of maintaining a minimum airspeed in order to prevent a stall is a smart idea and also gives someone a better idea of the options they have in handling the emergency quickly and safely as possible hopefully not ending in injury to the occupants regardless of the outcome of the air plane itself.
I understand that maneuvering speed in the strictest of sense is about the ability to maneuver the plane safely below a maximum airspeed by test standards. BUT, I believe Dan is on to something if 2 of the most common causes of GA fatalities could potentially be avoided by maintaining a minimum airspeed in an emergency. I will be for sure placing a marker for myself on my ASI as a minimum speed in case of an emergency to prevent me from having a stall or spin stall.

Battson wrote:Did the first 180 (not the 180A, the 180) use a different one to the rest?

No, they all use the same airfoil.

Gypsy-

I'm taking a building block approach to this concept Dan Gryder brought up. I think the first thing you need to know is your Best Glide speed and your Minimum Sink Speed. Since my Skywagon has a completely different wing I plan on doing a full up video on how to determine those speeds. But in the meantime, I just did it in the Bonanza (Best Glide is published) you might find it interesting.

gunny

gypsywagon wrote:I will be for sure placing a marker for myself on my ASI as a minimum speed in case of an emergency to prevent me from having a stall or spin stall.

I think that mark you’re going to add already exists: the bottom of the white arc.

Va is about structures. A single, full control deflection will result in a stall before structural damage happens.

I think the majority of the GA stall and spin accidents happen because folks are target fixated on the runway or some other landmark instead of splitting their scan to include their ASI.

A proficient GA pilot should be able to use seat-of-the-pants to augment the airspeed indications, but I would think that including the ASI in your scan during emergency procedures practice is the best way to prevent encountering a stall or spin.

Gunny,
using your numbers for max glide (110kts/1000fpm) and min sink (81kts/750fpm) I come up with very similar glide ratios: 11:1 vs 10.8:1.
Allow for some measurement errors and they might be almost identical.
On the other hand time aloft from an altitude of 1nm (for ease of calculation) increases from 6 min to 8.1min. It seems to me that giving up those last 0.3 nm in range (if they are indeed there) for an extra 2 min of "getting my act together - time" would be a reasonable trade-off.

Wolf

Battson wrote:Did the first 180 (not the 180A, the 180) use a different one to the rest?

C180 uses a NACA 2412 airfoil.
I think I read somewhere that all the (post-WW2) strutted single-engine Cessnas except the Caravan use this airfoil.

The Cessna airfoil was changed to a “camber lift” airfoil with the C180J SN 52285+ in 1973, so thereafter the airfoil would no longer strictly be a NACA 2412.

Our local air cadets have transitioned from L-19's and Scouts to Cessna 182 for a glider tug. Had a look at one and a brief talk with one of the pilots the other day. A few mods: more horsepower, Sportsman cuffs, VG's, extended wings. Tires are 8:50 mains, 8:00 nose on an Airglas fork. They tried 8:50's on the nose but the fork didn't like it (cracks?). Rock deflectors for the mains, and rubberized protection for the horizontal stab that still looks like it takes a beating. No interior, just the seats, and the metal painted grey.

Karmutzen wrote:Our local air cadets have transitioned from L-19's and Scouts to Cessna 182 for a glider tug. Had a look at one and a brief talk with one of the pilots the other day. A few mods: more horsepower, Sportsman cuffs, VG's, extended wings. Tires are 8:50 mains, 8:00 nose on an Airglas fork. They tried 8:50's on the nose but the fork didn't like it (cracks?). Rock deflectors for the mains, and rubberized protection for the horizontal stab that still looks like it takes a beating. No interior, just the seats, and the metal painted grey.

29767275217_bd20066604_b.jpg

I don't know how they are holding up, but they were really sweet when they came out of Victoria Air Maintenance. I saw a couple in the build and they took them back to bare metal.

140eagles wrote:Gunny,
using your numbers for max glide (110kts/1000fpm) and min sink (81kts/750fpm) I come up with very similar glide ratios: 11:1 vs 10.8:1.
Allow for some measurement errors and they might be almost identical.
On the other hand time aloft from an altitude of 1nm (for ease of calculation) increases from 6 min to 8.1min. It seems to me that giving up those last 0.3 nm in range (if they are indeed there) for an extra 2 min of "getting my act together - time" would be a reasonable trade-off.

Wolf

Wolf-

Awesome! I totally agree... if you need the range do Best Glide. Otherwise, I think time is far more valuable. I am rethinking my takeoff climb speed strategy as a result of this video.

gunny

Gunny,
Great video. I think the only thing that gives me pause is the min sink speed may be too close to stall speeds and definitely close to stall spin speeds if a turn is attempted for my liking. That is why I believe Dan has some good points with a minimum maneuvering speed. I hear him saying (though he did not actually say this) he will give up a landing spot/ distance to a specific landing spot to do what ever it takes to prevent a stall.
In the video I saw you using the published speed for best glide. With the modifications that have been done to the 180/185's to date, I believe that with the stol kits that the best glide speeds have changed. Is there a procedure that one can use to determine the new/ for a specific plane that has had stol changes ect? I would have reasonably considered the determination of the min sink as the best glide but after your video I see my thinking is flawed.
Please be advised I claim no expertise in this area, just a GA pilot with low time that has found myself in an otherwise compromised position inadvertently and wanting to learn as much as I can to prevent drama if the situation where to occur again.
Thank you for your interest in making us safer pilots with your video's.
Gypsy

gypsywagon wrote:Gunny,
Great video. I think the only thing that gives me pause is the min sink speed may be too close to stall speeds and definitely close to stall spin speeds if a turn is attempted for my liking. That is why I believe Dan has some good points with a minimum maneuvering speed. I hear him saying (though he did not actually say this) he will give up a landing spot/ distance to a specific landing spot to do what ever it takes to prevent a stall.
In the video I saw you using the published speed for best glide. With the modifications that have been done to the 180/185's to date, I believe that with the stol kits that the best glide speeds have changed. Is there a procedure that one can use to determine the new/ for a specific plane that has had stol changes ect? I would have reasonably considered the determination of the min sink as the best glide but after your video I see my thinking is flawed.
Please be advised I claim no expertise in this area, just a GA pilot with low time that has found myself in an otherwise compromised position inadvertently and wanting to learn as much as I can to prevent drama if the situation where to occur again.
Thank you for your interest in making us safer pilots with your video's.
Gypsy

Gypsy-

The Beech Emergency Approach speed of 81 knots happens to be the exact speed that Dan Gryder is advocating (1.404 Vso)... I mention that at the end of the video when I talk about using that instead of the actual Min Sink speed I developed. The Min Sink is well above stall speed, but there is very little energy to arrest the sink rate (700 fpm is a heck of a descent and you don't want to land at that rate... the gear WILL go through the wings).

The Skywagon speed is way different with the mods and I plan on doing a video on that in a couple of weeks. The only way I see to test for that is to try several different speeds out in several glides from altitude. So, standby for that.

Thanks for watching! And keep learning!

gunny