hotrod150 wrote:

a64pilot wrote:As a general rule for most light aircraft, the flap setting that matches the number of degrees of deflection of an aileron at full deflection will be the flap setting that gives the most lift without excess drag..................

I've never heard this one. Is that something you've discovered by experimentation, or did you hear about it somewhere? Now I'm gonna have to see where that flap setting is on my airplane, and see how it works out.

Eric

This is the recommended method for the Mooney. The airplane has hydraulic flaps with no set detents. So you turn the yoke hard right, look out the pilot side window and pump the flap handle until the flaps are equal to aileron deflection.

Emory Bored wrote:

hotrod150 wrote:

a64pilot wrote:As a general rule for most light aircraft, the flap setting that matches the number of degrees of deflection of an aileron at full deflection will be the flap setting that gives the most lift without excess drag..................

I've never heard this one. Is that something you've discovered by experimentation, or did you hear about it somewhere? Now I'm gonna have to see where that flap setting is on my airplane, and see how it works out.

Eric

This is the recommended method for the Mooney. The airplane has hydraulic flaps with no set detents. So you turn the yoke hard right, look out the pilot side window and pump the flap handle until the flaps are equal to aileron deflection.

Just checked the C150 TCDS-- flap deflection is 20* up, 15* down. Although I've never verified this, flap notches are supposed to be 0-10-20-30-40. I usually takeoff with two notches (20*).

fern_hopper wrote:Very little elevator response like you said.

The Pacer has limited up elevator. On mine, the limits were set to +14 degrees. There was some room in the crank and the control wheel shaft to go farther, but the stops were set.

I was interested in changing that on my stock Pacer. I talked to a guy that did- he went through the considerable effort and cost of changing the positive deflection. His reasons were pretty much the same as my own- insufficient elevator on flares during short-field landing speeds.

The flights he had right after scared him so much that he immediately went back to the stock deflection. Why? Apparently, the plane went inverted very fast as it stalled (spun), and the rudder was completely insufficient to keep it from happening when it did, and the elevator would feel completely dead (ineffective) during the tuck. He said he lost well over a thousand feet in a flash.

With the stock settings, the most I could get with full aft CG was slight buffeting with the elevator back at the stops. I couldn't even get a buffet out of mine while flying alone- just a fast and stable descent.

lesuther wrote:

fern_hopper wrote:Very little elevator response like you said.

The Pacer has limited up elevator. On mine, the limits were set to +14 degrees. There was some room in the crank and the control wheel shaft to go farther, but the stops were set.

I was interested in changing that on my stock Pacer. I talked to a guy that did- he went through the considerable effort and cost of changing the positive deflection. His reasons were pretty much the same as my own- insufficient elevator on flares during short-field landing speeds.

The flights he had right after scared him so much that he immediately went back to the stock deflection. Why? Apparently, the plane went inverted very fast as it stalled (spun), and the rudder was completely insufficient to keep it from happening when it did, and the elevator would feel completely dead (ineffective) during the tuck. He said he lost well over a thousand feet in a flash.

With the stock settings, the most I could get with full aft CG was slight buffeting with the elevator back at the stops. I couldn't even get a buffet out of mine while flying alone- just a fast and stable descent.

Thanks for sharing this as I have considered "adjusting" the stops on my Pacer elevator......especially for more down elevator to get the tail up sooner on the T.O. roll. Sounds like Piper knew what they were doing when they set the stops.

The short fuselage on the Pacer also take away some of the elevator authority because of the shorter lever arm.

I have two completely different landing styles with the Pacer. A short field technique requires lots of extra power additions to keep the nose up but allows a much slower touch down speed. I also try and practice power off's incase of an engine failure as the airplane lands completely different and much faster.

skywaggin wrote:
... the PA22 flight manual, the recommended procedure is to begin with 1 notch of flaps, then add the second before rotation (not verbatim). It does specify that this technique reduces ground roll by 20%. This is how I was taught in a PA22/20. I can quote the exact wording if anyone is interested.

The OEM Piper pilot manual says that using the "pop the flaps" technique shortens the takeoff roll by 20%???

You know, I just maybe might be interested in hearing more about that on this forum . Indeed, please post the verbatim text from the manual.

Considering that the visibility and workload factors would make it unsafe to start the takeoff roll with zero flaps, they probably "split the difference"... telling you to start your roll with the least amount of flap setting that you can reach the handle for on the stock airplane gives you some of the benefit, but letting you go after all of the benefit (by starting at zero) creates a safety risk on the stock airplane. So they recommended starting with one notch for maximum idiot-proof-ness for the average skill pilot, when they knew darn well there was a little more to be gained.

This raises the question as to just how much more than 20% of an improvement you could get by starting with even less drag, and less pitching moment (on a plane with limited elevator authority)... assuming of course that there was some fabulous aftermarket upgrade that allowed you to do it without any loss in visibility or safety

Boy I'm in a good mood today

lesuther wrote:

fern_hopper wrote:Very little elevator response like you said.

The Pacer has limited up elevator. On mine, the limits were set to +14 degrees. There was some room in the crank and the control wheel shaft to go farther, but the stops were set. ......

Some Pacer guys are installing the larger supercub rudder & elevators for increased response. I believe Svenn's Aviation holds an STC for this. Also, the MicroAero kit puts VG's on the bottom of the horiz stab in addition to the top of the wing. I didn't get much discernable improvement when I installed a Micro VG kit on my C150, but I do hear good reports about Pacer installations. Might be worth looking into either or both of these mods.

The Pacers I've owned, maintained, and flown
get the most benefit from VG's. Climb props and
lower weight are also a big benefit. Great airplanes.
Dave

EZFlap wrote:The OEM Piper pilot manual says that using the "pop the flaps" technique shortens the takeoff roll by 20%???

Indeed, it does, EZ.

"The application of full flaps as take-off speed is approached, will reduce the take-off run about 20%. Flaps can be pulled down before the take-off run is started but will reduce the acceleration of the plane somewhat if kept down throughout the take-off."

That's from the manual.

I never saw my takeoff distance change between using 20 and 40 degrees. It took a long run to establish a positive rate of climb at high DA with full flaps in the Pacer, and 20 was plenty for landing or takeoff (slips are fantastically effective in the Pacer). I can vouch for the idea of applying flaps after reaching around 45 or 50, though. It made a difference, although I can't recall it being 20%. I do know that flaps really hammered the initial climb out, and my Pacer always got higher in a shorter distance at Vx when flaps were minimized or not used at all on takeoff (135 HP), even though the ground roll was definitely reduced with 20 degrees of flap.

For my pacer ('57 PA 22-20) with a Lycoming 320 (150), and I have VG's and droop tips, for me i have found out with my limited experience, that if you select the first notch of flaps before you take the runway it will minimize the drag and maximize the short field performance. Put in most of the power, or for my airplane put it to the stop in the throttle to the cruise stop with the brakes on. Once you hit the cruise stop, apply full power as soon as possible once the brakes come off. As soon as you get the tail up, which should happen in the first 100 feet or so, count to 1 missippi and then pull the last notch of flaps and you are off the ground, but slow. I have been getting a pretty consistent 3-350 foot ground roll on the takeoff, however getting over the 50 foot obstacle might be a little different. once you hit 50 feet, drop to one notch of flaps and it will fly a little bit better. after that its a general flying it out, and accelerate to 90 (which i have found what my airplane climbs best at) and your golden. As for approaching the landing area is the same. If I have a long runway i use about 80, because it gives a TON of play and stuff to work with when I am coming down, crossing the numbers at about 75, but i learned from a VERY conservative CFI previous owner. Now If i want to do some short field stuff i bring it down to about 75-70 on final, and then once you drop that last notch of flaps leave it at about 65 - 70 and ive been able to stop within 500 feet every time. Im still experimenting. One of the guys im flying with says bring it down to 55 and he can do it shorter, and hes shown me how to do it, but the nose is so high it is a little nerve wrecking. I only have about 60 hours in my pacer, but so far, I LOVE IT!
Its not a Maule, or a super cub, or a 180, but for the price I paid for mine, and with the operating and insurance costs, i literally CANNOT compare my pacer with any of them. It is a great airplane, as long as you keep it light and learn how to control it.

I am pretty much the same as you. I hit 240.5 hours today going for a $100 bbq run. Im always looking forward to an excuse to fly. If you will be around I would be willing to fly around Maine for a while. No problem for me. I need the hours anyway. This spring Let me know if you want to fly and I will be there ASAP. PM me for my cell phone number. I have the same airplane and would love to do the same kind of thing. I am in NC by the way, based out of KBUY

lesuther wrote:
"The application of full flaps as take-off speed is approached, will reduce the take-off run about 20%. Flaps can be pulled down before the take-off run is started but will reduce the acceleration of the plane somewhat if kept down throughout the take-off."

Thank you for posting that.

This information, and pilot reports from customers of certain aftermarket upgrades, further vindicates the points that have been argued by yours truly for over two years running now. The enhanced use of flaps, and more advanced piloting techniques/flap timing/modulation of the flaps, is indeed a valid technique for getting better STOL performance and safety out of a back country airplane. Once you are free to use the flaps fully without any loss of situational awareness... the flaps can become an active, dynamic flight control which will allow a pilot to get more out of the airplane.

The seaplane pilots have known this for many years, working the flaps up and down actively, first to get on the step and then to permit faster acceleration. The off-airport pilots have known this for years, popping the plane off with flaps and dumping flaps to put weight on the wheels. The Maule factory had to tell owners to give up some of this extra performance in the name of situational awareness on landing, and in so doing acknowledged the difference in performance. Now the BCP members have heard it once again from Piper, by way of the short wing manual acknowledging the significant gain in performance.

Some newer participants on this board may not understand that big crashing sound they hear in the background... it's the sound of the rug being pulled out from under a few more of my loyal opposition on this forum. Although there are still one or two folks here that insist the world is flat, most open-minded people have seen the light on this issue. The Ron Popeil theory of flap use ("set it and forget it!!!") is shown to be wrong and sacrifices performance that you might need.

I have to say at this moment that revenge is pretty sweet

EZFlap wrote:I have to say at this moment that revenge is pretty sweet

Well, it's nothing new, and I don't think it's controversial. A King Air manual I once read had a similar note for short field take-offs (from the late 70's, I believe).

A propeller (especially a fixed prop) is only pooping out 1/3 to 1/2 of maximum thrust during most of the ground run, and it seems right that drag reductions could impact the ground run, where a few dozen pounds of drag on take off steal more of the net thrust.

But beyond that, I think most folks know there is a performance increase, but safety and training often dictate getting it all set up before the roll to avoid distractions. I still don't remember it making a 20% difference in the Pacer, but it was significant.

Pacer17 wrote:.....Its not a Maule, or a super cub, or a 180, but for the price I paid for mine, and with the operating and insurance costs, i literally CANNOT compare my pacer with any of them. It is a great airplane, as long as you keep it light and learn how to control it. .....

This comment holds thrue for the C170/172TD, Stinson 108, C150/150TD, and some others. There's a lot of us out there who can't cover the buy-in or operating costs for a supercub 180 or maule, but we can still be in the game (and for lower stakes) if we play our cards right.

As Lt. Columbo from the old TV show used to say, "Oh, sorry, just one more thing..."

I just noticed this or I would have included it in a previous post. For a very good visualization of the proper use of flaps on STOL takeoff , see the video clip that was posted in the "Which One" thread on this forum.

when I had my PA 22 I routinely used the pop flaps method in Idaho... Mine had VG's and I had my prop twisted down to 53 inches... I started my roll with no flaps and at 40 pulled full flaps and she virtually leaped into the air...granted the flat prop had much to do with my performance but the departure from the ground was so sudden and short i used it almost everywhere up there and here in the back country...sure took the strain off that nose wheel.