I am going to start using the glide range ring on Garmin Pilot. It’s a pretty cool feature that can factor in terrain and winds aloft; creating an irregular ring rather than a simple ring. Foreflight apparently has this also.



My airplane is too old to have a published glide ratio, and I’m trying to get some reasonable numbers to input. So far I have these three numbers:

C-180K wheels 9:1
C-180K floats. 6:1
C-185 wheels 8.1

I think my Pponk, MAC 401 180 will probably glide more like a 185, so can someone share the 185 floatplane glide ratio? Yes, I realize each airplane glides differently with all the mods; I am trying for a baseline here. The app has an adjustable safety buffer, by percentage.

Thanks!

Things hanging out and pulling air actually help, I think. Even forced landing from low level. 75% of forced landings touch down in the last half of the forcedlanding site. I have found, many times, that going just there works.

I don’t mean to be harsh here, but in the event of an engine failure, the last thing you should be looking at is your iPad.

Glide range in a seaplane is really pretty simple: Look out the window, find something close and head there. Now, work emergency checklist.

To me, trying to use that iPad feature would take too much time and attention away from primary duties, and perhaps best case, just confuse matters.

Or not. But as you alluded to, there’s no such thing as “standard” glide ratio far any seaplane. Pick a number, a VERY conservative one.

But, me, I’d lose that “feature”. And, that’s based on three power failures in flight.

MTV

I figured this would generate some discussion, which is great.

Yes, I get that down low this is not a good idea. I have lost a couple of engines myself at low altitude. Picture this scenario, though. 9000' over the Adirondacks, IFR. The airplane is often operated in situations like this. The ring is continuously displayed, and could be used as an aid to the ongoing identification of landing sites.

mtv wrote:I don’t mean to be harsh here, but in the event of an engine failure, the last thing you should be looking at is your iPad.

Glide range in a seaplane is really pretty simple: Look out the window, find something close and head there. Now, work emergency checklist.

To me, trying to use that iPad feature would take too much time and attention away from primary duties, and perhaps best case, just confuse matters.

Or not. But as you alluded to, there’s no such thing as “standard” glide ratio far any seaplane. Pick a number, a VERY conservative one.

But, me, I’d lose that “feature”. And, that’s based on three power failures in flight.

MTV

I agree with Mike! Also, the higher you are when the engine quits the more options you have. For example, the difference between 1,000 feet vs 2,000 feet after an engine failure is huge, more altitude more time and options. Think about that when you pick a cruise altitude in any airplane.

Kurt

Aviate, Navigate, Communicate, any guidance thereafter that elevates your "situational awareness" is a bonus if used as a "slave", not a "master"

Not to be looking down at your iPad after an engine failure seems obvious, but I mean come on, the guy has the right to play around with cool little features like that.

I use 8:1 for most high wing cessnas. I don’t know why, I just saw that somewhere and it seems close enough. I dont trust the absolute data, but the trends and info it gives is informative. Seems like 6:1 would be a good estimate for you on floats, maybe 5.5? Pull the prop back and maybe you get 5.612i.

I think it’s fun to look at the glide ring and see what it’s telling me in cruise. Sometimes when the wind isn’t as obvious or if terrain slopes in a way you weren’t quite familiar with, it can be pretty interesting to see that you can theoretically glide 3 times as far if you turn right instead of left for example. It can also be somewhat informative of winds crossing big water, and when you’ve reached the straight ahead glide vs the turn back glide. Also like Kurt said it is a visual reminder that when you’re down at 200’, there’s not much of a glide range but all of a sudden at 5000’ you can go grab a burger 3 towns over if the engine quits. I tend to glance at it regularly just like I try to always have “out” options in my head when flying in the mountains, or have meadows picked out if something stops turning.

It’s information you can learn things from.

I check out Foreflight’s glide ring all the time in normal flight and I think it’s a great educational tool. Assuming it’s accurate, I now have a much better idea of where I can make it to, when I’m looking out of the window and flying the airplane, in an actual emergency. For that, I think it’s an amazing asset.

asa wrote:\
It’s information you can learn things from.

I'm with asa, I think the feature ads an element of safety, not because I would focus on it after losing an engine, but because if I integrate it into my cruise checks I will make a more informed decision if the poop hits the fan.

-0-

The difference with the prop stopped vs windmilling is pretty large. Stop the prop on a 182, and the glide ratio increases from 8:1 or 8.2:1 to nearly 9:1. A lot of that improvement is available in a windmilling prop if you pull the prop control all the way to low RPM. You can literally feel the aircraft slow down when you return the control to high RPM again.

lesuther wrote:The difference with the prop stopped vs windmilling is pretty large. Stop the prop on a 182, and the glide ratio increases from 8:1 or 8.2:1 to nearly 9:1. A lot of that improvement is available in a windmilling prop if you pull the prop control all the way to low RPM. You can literally feel the aircraft slow down when you return the control to high RPM again.

Which is true, IF you have had time to go through your engine restart checks, and have concluded the engine isn't coming back. I wouldn't go there, however, until and unless, I was absolutely convinced my engine is not going to re-light. As Dogpilot said, there are a lot of potential scenarios involving engine failures.

MTV

I have a sportsman cuff on my C180. I use 11:1 - although there is data performed on a 1955 C180 showing a 13:1 glide ratio on the model they tested. The C170 data also was recorded as 13:1. Certainly a great selling point for the Sportsman STOL kit is the extended glide ratio. I have had 2 engine failures both prior to a having an IPad and I don't think having the range circle for glide display would have helped me but they both occurred close to the ground - 3K and 800 feet AGL respectively. I do however have my IPad set up with the glide display. I use the information to cross reference visual information for suitable places to land during my flight. Surviving an engine out is more about staying focused landing the plane at the slowest speed possible in the most crash worthy location. Looking at an Ipad will be the last thing I am doing if the engine quits, but I should have the place picked out to land before there are any engine problems. This is where the Ipad is useful - in combination with visual information. I will be activating my SOS on the Garmin-In-Reach if I am in a remote part of the world on the way down - surviving an engine out also means staying alive on the ground. I otherwise will be 100% focused on running the emergency checklist and flying the plane.

There is no reason to stop the prop- it is surprisingly hard to do, and distracting. I brought it up more for the glide ratio one can expect in a 182. I've heard people claim they can get 12:1 or whatever, and it never pans out. I've seen 9.5:1 when actually measured, and that was with a great deal of expensive aftermarket fairings on a newer 182.

I'd much rather be at minimum sink speed in an actual engine out...I'm assuredly going to plan a spot close by that is survivable, with more altitude to maneuver and plan, and boatloads more time to make restart or a safe landing happen than bother with a distant LZ unless the difference is stark. Min sink in a 182 with half tanks and one person is around 800 feet per minute. The sink rate at the published glide speed is somewhere between 1000 and 1100 feet. That is a lot of extra time in the air- around 30 more seconds from 2000'. Just a personal preference. For a biennial, I throw it out the door and use the more dogmatic POH glide speed.

A week ago I spent some time to determine the power off descent gradient in my 180. I tried various speeds from 60 to 90, clean and with 10 degrees flaps. The best I got was right about 80mph indicated clean from 10,000' down to 8,000'. According to the Ipad I was dropping at 750 feet per nautical mile. 8:1 doesn't seem all that great to me, but that's what I got. My data is anecdotal at best, the weather did not cooperate in allowing me to repeat the test multiple times. I only got one run at each speed, and one run with 10 degrees at 70 and 80. My 180 has a very forward CG, right at the front limit. I was solo with full tanks, and probably another 15 pounds of crap behind the rear seats. I have a sportsman, and 3 blade prop. Throttle was at idle, prop control was at 2400 rpm before I pulled the power and left there until recovery.

It was posted that its a good idea to pull the prop control all the way back to reduce drag from a flat prop. It is my understanding that without oil pressure the prop will go flat on its own. I know when I come in to land I can leave the prop control alone (usually 2300), and feel the prop go flat after I pull the throttle. I can then push the prop control in with no noticeable change.
What am I missing?

I find the ForeFlight glide ring interesting on my iPad, but I'd never be looking at it once I'd concluded I was going down. I've had only one total engine failure (if you don't count my engine quitting on short final to Merrill Field when I was a student), which was from about 800' AGL, so if I'd had ForeFlight back then (which didn't exist yet), it would have been no help at all. And I have no idea how accurate it is, because I just plugged in a typical 172 glide ratio rather than my airplane's actual glide ratio. As a result of that engine failure, I spend more time looking for places to set down than I did before, although I don't obsess about it.

As for StillLearning's question, your governor can only do so much. At lower engine speeds and lower airspeeds while gliding for a landing, your prop will be flatter, no matter where the prop control is between cruise setting and take off setting. That's why you don't have an increase in rpm when you push in the prop on base or final. However, if you pull the prop control all the way out at those lower engine speeds and airspeeds, you will feel a distinct increase in your glide speed, and you'll increase your glide distance.

Cary

Let's see a few more posts answering the OP, rather than saying his tech is bogus.

You can watch the "instrument" periodically to maintain situational awareness. Or if the engine failure is slow on-set, then you have time to review it. It only takes a two second glance to see your options, and that may be faster than trying to see through a broken cloud layer, or on a hazy day. Especially useful in strong winds. The point is, it's pretty common tech, and its not a bad arrow to have in one's quiver.

I don't own a 180 / 185 on floats. I would suggest maybe going out over a large lake on a flat calm day, pull the mixture and glide for a few minutes to measure the descent rate. If the engine didn't restart for any reason, then land on the lake.

I would also observe that 6:1 isn't a glide ratio, more of a fall ratio

Well Battson, seaplanes do exhibit a somewhat “enthusiastic” sink ratio. Some more than others, of course.

But you’re right: let’s stick with the OPs question, which pertained to seaplanes, and fairly heavy ones at that.

I will tell you that when things get real quiet in one of these noisy machines, there is not much time to make a number of decisions.

So, let’s say your “magic ring” shows a lake right over there, just near the limit of your alleged glide. So, off you go. But, in fact it turns out that lake is shallow, or surrounded by big trees, or for any of a dozen other reasons would be a poor choice for a power off landing. Point is, by the time you realize that, you will (May) have used up a lot of altitude.

I prefer choosing something close, probably real close, especially on floats. That gives me time to look it over, and quickly change my mind if need be. It also may give me a little time to maneuver to land......still want to land into wind if there is any.

But, again, I don’t spend a lot of time cruising along at 9000 agl, especially on floats. I get nosebleeds over 1500. When I was flying seaplanes a lot, it was often pretty warm, and burning buckets of fuel to get to a relatively high agl never made much sense to me, particularly since the planes were nearly always heavy. In a seaplane, on most flights, I got as high as necessary, but not much higher.

At those heights, there’s really not a lot of time to muck about. If indeed you’re watching this “ring” as you fly along, maybe it’ll do you some good. In my experience, most pilots don’t actually spend a lot of time contemplating Engine failure in flight. If you do, you probably won’t fly long.

But, for those of you who fly seaplanes at high agl heights, this feature might offer some entertainment while enroute.

MTV

I probably should have put this comment, from my follow-up post a little ways into the thread, into my original post...

“Yes, I get that down low this is not a good idea. I have lost a couple of engines myself at low altitude. Picture this scenario, though. 9000' over the Adirondacks, IFR. The airplane is often operated in situations like this. The ring is continuously displayed, and could be used as an aid to the ongoing identification of landing sites.”

On the other hand, we might have missed out on a spirited discussion of glide technique, appropriate technology use, etc. Keep it coming!

If it strikes some as odd to be at 9000’ in a floatplane; this is a huge part of why I fly a 180. Example trip: 400NM nonstop from my lake to my buddie’s pond in Maine, crossing three mountain ranges. (Eastern ones, albeit) File for 115ktas and usually do better. Drop off some gear, reduce the fuel load and it’s back to a STOL machine.

BTW, does anyone have the 185 POH?

aqua wrote:BTW, does anyone have the 185 POH?

Aqua, I found this while looking for the tire pressures for my EDO amphibs: https://www.washingtonseaplanepilots.or ... %20POH.pdf