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RV-12 glide performance

Dgamble

Well Known Member
The glide ratio of my RV-6, while not completely "brick-like", is inarguably somewhat steeper than most, if not all, of the other airplanes I've flown.

Have any of the newly-minted RV-12 pilots made any in-flight measurements that they'd like to share?
 
No I haven't measured it but I can guarantee you its long. The biggest problem you will have in the 12 is getting it to come down. Even with full flaps and 55 knots I still end up slipping it most times. On the other side, that same wing makes for wonderful stall characteristics...they are a non-event. It would take some real foot stomping to kick this thing into a spin. I love this plane...as my friend Martin Sutter says, "it has Van's dna".
 
Pete, You may want to set the throttle to be able pull the idle lower while you are on final. On the ground I can get 1400 RPM (not advisable for idling), but on final I pull it back to this setting and I get 2000 RPM or less. Makes the "float" a lot less, and I can get a decent rate of 500 FPM.

To answer the OP's question I have dead sticked the -12 in from 10,000' MSL to 1,500 MLS and landed. As best as I can remember (I did not write it down) it was 3-400 FPM decent at 95 MPH IAS. That seemed to be the best glide that day. Needless to say it glides extremely well.
 
At your mid figure...

...
To answer the OP's question I have dead sticked the -12 in from 10,000' MSL to 1,500 MLS and landed. As best as I can remember (I did not write it down) it was 3-400 FPM decent at 95 MPH IAS. That seemed to be the best glide that day. Needless to say it glides extremely well.

...of 350 FPM, that works out to just under 21 to 1 - or around 3 1/5 mn per 1000 ft altitude.
 
Glide Info

This evening, after contemplating some procedures.... I took the -12 up to 5K Above the airport, slowed up and shut the engine down. Some observations

1.) The prop windmilled for about 20-30 seconds. I had to slow to about 60kts to get it to stop.

2.) The -12 did not want to fly faster than 80-85 kts straight and level. I had 12 gal and just myself (170lbs)

3.) It took much more down on the stick than I anticipated to keep a descent going. I've heard this is common with any airplane minus a turning prop.

4.) I noticed some extra "buffeting" over the stabilator

5.) Gliding at 70kts gave me a 500-600 FPM rate. Did not glide very far away from the pattern area as I wanted to land on the runway. Which I did at midfield where I was aiming.

6.) The Rotax fires right up when you turn the key.

I wanted to know how it flew without power and now I do. No big surprises.
 
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The book says that max glide is 85Kts. Minimum sink (Vs1...no flaps stall...times 1.3) is 61 Kts. I assume the book assumes no power and the prop windmilling although it doesn't say that; it says only that 85 Kts is the speed to fly if the engine quits.

I'm new to the bird so I need more knowledge and data but I find the following:
1.) At 85 knots at 3000 feet and idle power the airplane loses about 700 feet in a 180 degree turn....as in back to the airport.
2.) It absolutely hates the ground :).....will float to China if you don't nail something under 55 Kts on final.
3.) I LOVE THIS AIRPLANE!.....except for the danged throttle.

EBB:)!
 
RV-12 glide ratio

21.5 seems hight to me. If my math is correct, data from a later post suggest about 14:1 which sounds reasonable. Have others found similar results?
 
What revision are you using? At the moment POH rev 3 is the latest stating max glide speed is 63kts, minimum descent 59kts.

Gagarin is correct. Those are the speeds for max glide and minimum sink.
They are in the current POH. The POH I was using is dated as above (11/13/12) and the speed for "maximum gliding distance" is shown as 85 Kts and Minimum sink is 59 Knts (1.3XVs1).

Guess more data was gathered by Van's as time went on. I'll toss my old POH.

EBB
 
Skyview and gliding range

Going through this thread, I came with a potentially helpful improvement on Skyview: The Skyview could easily display on the GPS map a circle showing the limits of the glide range, based on a user defined parameter giving the gliding ratio of the plane at a given speed. One could even imagine a more sophisticated approach based on the gliding ratio under different speeds updating the circle size as the speed changes and also taking into account the wind and gliding path. I understand that this is a Dynon more than an RV-12 issue but as the subject of gliding range was addressed in this thread, I am interested in hearing my fellow RV-12 pilots chiming on this.
 
Going through this thread, I came with a potentially helpful improvement on Skyview: The Skyview could easily display on the GPS map a circle showing the limits of the glide range, based on a user defined parameter giving the gliding ratio of the plane at a given speed. One could even imagine a more sophisticated approach based on the gliding ratio under different speeds updating the circle size as the speed changes and also taking into account the wind and gliding path. I understand that this is a Dynon more than an RV-12 issue but as the subject of gliding range was addressed in this thread, I am interested in hearing my fellow RV-12 pilots chiming on this.

You still have the cyan "banana". While gliding I select ground level as altitude in the Dynon. The banana gives the gliding distance with present speed. I do the same with the B777 when training for a dual engine failure.
BTW Skydemon has this feature with the circle around your position.
 
You still have the cyan "banana". While gliding I select ground level as altitude in the Dynon. The banana gives the gliding distance with present speed. I do the same with the B777 when training for a dual engine failure.
BTW Skydemon has this feature with the circle around your position.

I love this and I'm going to see how it works out. I fly in the San Juan Islands and I used to fly from KFHR to 0S9 in my twin without hesitation at 3000' but now with the RV12 I'll be making different choices.

Seems to me that when fully loaded my sink rate is about 500 fpm. As a general rule I've been thinking two NM glide distance per thousand feet AGL as a guideline. In that case I would want at least 2000' MSL when flying from 74S to KFHR which is 8 miles? Would you feel safe flying the 29 NM mostly over water from KFHR to 0S9 at 7000'?
 
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The book says that max glide is 85Kts. Minimum sink (Vs1...no flaps stall...times 1.3) is 61 Kts. I assume the book assumes no power and the prop windmilling although it doesn't say that; it says only that 85 Kts is the speed to fly if the engine quit.

3.) I LOVE THIS AIRPLANE!.....except for the danged throttle.

EBB:)!

Do yourself a favor and install the vernier throttle from Mcfareland. You will love it, and not even realize that the carbs are sprung full open. I absolutely love mine!!

Tom
 
6A glide data

The glide ratio of my RV-6, while not completely "brick-like", is inarguably somewhat steeper than most, if not all, of the other airplanes I've flown. [snip]

CAFE tested the 6A and got a best L/D of 11.39.

Just saying..
 
RV12 Glide

Search RV12 on YouTube. There is a video of a dead stick landing...the guy flies forever with the engine off.
 
I put both the Vernier throttle and the new carb spins in my RV12. I never use the vernier feature because the throttle works so well I don't need it.
EBB
 
Do yourself a favor and install the vernier throttle from Mcfareland. You will love it, and not even realize that the carbs are sprung full open. I absolutely love mine!!

Tom

Please correct me if I'm wrong....I thought Van's was shipping the vernier throttle w/light spring in latest engine/fire wall forward kits?
 
I have been running with Home Depot springs for two years now. My throttle is smooth with almost no creep. Before that I had some Harbor Freight springs that failed. I did not notice any symptoms of the failure and picked it up on preflight. I know some people consider the springs as a major safety issue, but I can only relate my personal experience. My cables were stiff enough to mask the HF spring failure.
 
What is the honest glide ratio now that's been determined for a RV-12?

As in how many FPM with plane trimmed dead stick for 63 kts air speed?

Is this correct, about 13:1 ? 13000 ft traveled per 1000 ft loss in altitude.

1 kt = 6072 ft... 13000 ft/6072 ft per minute so you can travel about 2.14 kts per 1000 ft loss of altitude. That would make sink rate just under or over 500 fpm? Distance traveled is 63 kt/hr / 60 min /hr, or 1.05 kts per minute. 2.14 kts/ 1.05 kts traveled per minute. About 500 fpm for a decent rate?

https://www.pilotsofamerica.com/community/threads/dead-stick-landing-rv-12.57282/
 
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What is the honest glide ratio now that's been determined for a RV-12?

As in how many FPM with plane trimmed dead stick for 63 kts air speed?

Is this correct, about 13:1 ? 13000 ft traveled per 1000 ft loss in altitude.

1 kt = 6072 ft... 13000 ft/6072 ft per minute so you can travel about 2.14 kts per 1000 ft loss of altitude. That would make sink rate just under or over 500 fpm? Distance traveled is 63 kt/hr / 60 min /hr, or 1.05 kts per minute. 2.14 kts/ 1.05 kts traveled per minute. About 500 fpm for a decent rate?

https://www.pilotsofamerica.com/community/threads/dead-stick-landing-rv-12.57282/

Man, that was an old thread.. but yes, 13:1 is the clean glide ratio of an RV12.. I'm not following all your other calculations and figures.. I believe you have lots of mixed up abbreviations, terms and results..
 
Holy smokes you -12 drivers get some awesome glide! My -7A sink rate is significantly more than that, around double.
 
You never know what Google can do unless you ask. Type "63 knots / 13 ft/min" minus the quotation marks into the search field. . .

It's smart enough to divide the glide speed by 13 then convert to feet per minute.
 
Yep

Holy smokes you -12 drivers get some awesome glide! My -7A sink rate is significantly more than that, around double.

Jeremy, if you look at the -12’s wings, you’ll notice much larger area and remember, the airplane is a lot lighter as an SLA. Mine is close to flying with the UL engine.

Regards,
 
Jeremy, if you look at the -12’s wings, you’ll notice much larger area and remember, the airplane is a lot lighter as an SLA. Mine is close to flying with the UL engine.

Regards,

Very true Pierre, just didn't realize it would be THAT big of a difference. haha
 
one thing not mentioned in the video was whether that was 13:1 with pants on or off (or does it even make that much of a difference?)
 
Some guys only have one thing on their mind, no matter that the engine has quit and there are only a few minutes gliding time left to join the mile high club. :D

"We're at 9,000 feet, and the engine just quit. I've got us trimmed for best glide speed, and I've already made the radio call. There's a good place to land a few miles out. By my calculations, if we hurry we can do this before we dip below 5280 MSL, and then I'll have another few minutes before I have to actually fly the plane again."

That's efficiency. :)

On a more serious note, I wonder how much better (or just different) the picture would be with the prop stopped. I've seen that done, but don't think I'm brave enough to do the testing on that.
 
Excellent demo. Not sure I would recommend it. If anything had gone wrong I doubt the FAA would have been sympathetic to intentionally shutting down the engine for an impromptu test.

Chernobyl started as the result of a safety test checking to see how long the coolant pumps would run after a scram. Different technology, but the lesson applies.
 
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