Glide Ratio

[Pacer bush plane]

What is the glide ratio of a stock Pacer? Do wing extentions and wing tips help the glide ratio?

[Pacer bush plane]

I guess no one wants to talk about glide ratio? As many PA 20 and 22 there with wing extentions, I figuer there has to be a reason for it.

[Kurts]

Unfortunately, the crickets you hear probably indicate that none of the 6 people who post on these forums knows the answer.

Kurt

[rwdurham]

Lift / Drag x height = Glide ratio

There you go Kurt. My contribution.

In all seriousness, I believe it does. If a wing extension increases lift and reduces drag, then it makes sense it would. But . . what do I know?

[Kurts]

Perhaps if we had more than one Technical Advisor (an excellent one by the way) who would post on the forums (as opposed to referring to doing so as "playing on the computer", our membership could get timely answers to their questions.

[rwdurham]

What? You don't like my technical advice? That's hurtful Kurt. Just hurtful. Is my answer wrong? Just because you don't like droopy tips doesn't mean nobody should try to increase lift and decrease drag.

[Kurts]

Rick, I have no idea what you're talking about. I'll chalk it up to humor.

[rwdurham]

Of course it's humor. My twisted, often misinterpreted version of humor. That's where I live.

[Kurts]

Just checkin...

[pacer44k]

OK, Boys! Don't make me stop this car!
I have tried to find definitive data about the glide ratio of a SWP, but to no avail. What I do know, is that if you want to see a big rate of descent, maintain about 90 MPH with the power off. If you really want to suck the sheepskin off the seat, slow it down to about 55 MPH with the power off!
The ability to put these planes just about anywhere you want, is one of their best attributes!

[Steve Pierce]

Good thread here on glide ratio. http://www.shortwingpipers.org/forum...22-Glide-Ratio

[pacer44k]

Good thread here on glide ratio. http://www.shortwingpipers.org/forum...22-Glide-Ratio

Great discussion! Thanks Steve.

[Tom Anderson]

There are some other threads on this forum on glide ration if you want to do the search. However, the glide ratio for the PA-22 as best I can find is between 8 and 10 depending on a lot of factors. A Tri-Pacer will have a lower glide ratio than a Pacer due to the increased drag of the nose wheel. Wing extensions and or wing tips that square off the wing tip increase the effective wing area, decreasing the wing loading and thus the induced drag and should increase the glide ratio. Vortex generators which increase the low speed lift should also help. Other factors such as whether the prop is windmilling or not will also have an effect. A windmilling prop will increase the drag. Your best bet to get an estimate of the glide ratio for your plane is to take it up on a calm day and test it. Cut the power and set up for best glide speed which is approximately 75 mph and record your decent rate and ground speed using a GPS. You can do this for various trim settings to determine the best settings for your plane. It should be a fun test. There is so much variability from plane to plane that it is almost impossible to establish a fixed number for glide ratio. That is probably why you don't see it published in any official documentation.

Tom Anderson

[David Hedditch]

I found the glide ratio on my pacer is approximately the same as that of the F-4 fighter I used to fly, 5 to 1.

[jwbruce]

if you could just figure out how to get the same take off performance...

[David Hedditch]

jwbruce, the takeoff performance between the F-4 and a SWP is no contest. The SWP wins. Takeoff roll for the F-4 was an average of 4000 feet and landing roll about the same. It is just before lift off that the F-4 takes over the SWP. Also, during takeoff the F-4 is burning 144,000 lbs per hour of fuel equaling about 22,000 gals per hour in afterburner. Naturally, we didn't use afterburner very long.

[dcflyer84]

i did a fairly extensive and moderately scientific flight test on my Pacer (O-320) and posted the results somewhere on these forums. Anyway, not to bore with all the details, but 75 mph was best speed for forward distance traveled versus altitude lost. Glided with windmilling prop, no flaps until last 300' as I slowed to 70 mph Vapp speed. In still air-equivalent conditions over a 2000' altitude loss: 3:14 time, 3.2 sm forward distance traveled, 750 fpm descent rate. Incidentally, I did a second test where you reduce power to idle/windmill, trim to level flight attitude then allow to descend. That equated to 75 mph IAS and 750 fpm, as well.
BTW, standard wing tips, no VGs on my bird. All descents with 0 flap until last 300'. I have found that having a few extra mph for mom and the kids (70 vs. 68 or less) as you come in to touchdown at that fairly rapid rate of ground closure, makes a big difference in how much energy you have remaining to trade for up elevator to prevent a 'firm' landing. Come in too slow and you won't have anything left to flare with. Bungee test, anyone? Anyone? I'm am always amazed at how fast this plane falls out of the air.

[dcflyer84]

Here's my original thread reply "Best Glide, V speeds" http://forum.shortwingpiperclub.org/...8036#post28036