Short Takeoff Technique 95HP Super Cub No Flaps ( Light / Heavy )

[Eric84]

Hello Everyone,

Looking at a 95 Horse Super Cub, First let me say I know shes not going to win any Stol Contests but just want to hear peoples opinions on how to best get the low hp SCs in the air quicker.

Assuming the Following:

Standard Gear
No Flaps
29" Airstreaks
VGs
Hopefully right around 1050 pounds Take off (Pilot Weight included) weight lightly loaded Vs full Gross 1500 pounds heavy.
Density altitude 1-5k feet (Im based in Ohio)
Mainly Short Grass Strips, But occasionally Smooth gravel bars and smooth farm fields and the like.

What are you all finding is the actual stall Speeds with these configurations?

What methods see the best results? How do they change with added weight?

Thanks Everyone

Eric

 

[AKjurnees]

Keep it light, remove unnecessary added junk. Put the stock wheels back on. You’d be surprised how well it does. You don’t need flaps either, just learn to fly it. I consistently landed shorter in one over the 160 hp monsters with flaps, and take off too.

 

[Eric84]

Keep it light, remove unnecessary added junk. Put the stock wheels back on. You’d be surprised how well it does. You don’t need flaps either, just learn to fly it. I consistently landed shorter in one over the 160 hp monsters with flaps, and take off too.

Oh trust me it will be light, I was more curious wether you took off tail low, with a level attitude tail up for a bit then pull? The actual way you found worked best to take off shorter than that 160?

 

[mvivion]

Hello Everyone,

Looking at a 95 Horse Super Cub, First let me say I know shes not going to win any Stol Contests but just want to hear peoples opinions on how to best get the low hp SCs in the air quicker.

Assuming the Following:

Standard Gear
No Flaps
29" Airstreaks
VGs
Hopefully right around 1050 pounds Take off (Pilot Weight included) weight lightly loaded Vs full Gross 1500 pounds heavy.
Density altitude 1-5k feet (Im based in Ohio)
Mainly Short Grass Strips, But occasionally Smooth gravel bars and smooth farm fields and the like.

What are you all finding is the actual stall Speeds with these configurations?

What methods see the best results? How do they change with added weight?

Thanks Everyone

Eric

I owned an essentially stock PA-11 for several years. Frankly, you need to get in the plane and try different techniques such that you convince yourself what works and what doesn't. There aren't a lot of options with these planes, actually, so practice, practice and more practice is the single best answer to your question.

MTV

 

[cubdriver2]

Oh trust me it will be light, I was more curious wether you took off tail low, with a level attitude tail up for a bit then pull? The actual way you found worked best to take off shorter than that 160?

Just follow Bill Rusks plan. Watch the "Grams" and the ounces and pounds will take care of themselves

Glenn

 

[DENNY]

Lets work backward on what is happening when the plane leaves the ground. Basically you have enough airspeed and AOA to generate enough lift for the plane to leave the ground. AOA is basically main gear + tire hight and location of the tail. So the taller the tire/gear and the lower the tail the better. You want the tailwheel to be as low as possible so the big question with blowing/lifting the tail up high is when do you rotate. Too early you hit the ground and slow the takeoff too late and you give away distance. One technique to have consistent short takeoff distance is to adjust you nose down trim so it just picks the tail wheel off the ground when you start your takeoff, and will do a noticeable lift of the tail at takeoff speed, that way any wind factor will be taken into account. Rotate smoothly on the second lift and it should fly without hitting the tailwheel. Adjust trim until it works, adjust for CG changes. Several factors affect reaching proper airspeed Prop, RPM, Mixture, Tire size/pressure, Weight, Wind, wing drag, ect. Unless I really need to see and avoid something ahead of me I do a tail low takeoff and let the plane tell me when it is ready to fly. DENNY

 

[cubdriver2]

Lets work backward on what is happening when the plane leaves the ground. Basically you have enough airspeed and AOA to generate enough lift for the plane to leave the ground. AOA is basically main gear + tire hight and location of the tail. So the taller the tire/gear and the lower the tail the better. You want the tailwheel to be as low as possible so the big question with blowing/lifting the tail up high is when do you rotate. Too early you hit the ground and slow the takeoff too late and you give away distance. One technique to have consistent short takeoff distance is to adjust you nose down trim so it just picks the tail wheel off the ground when you start your takeoff, and will do a noticeable lift of the tail at takeoff speed, that way any wind factor will be taken into account. Rotate smoothly on the second lift and it should fly without hitting the tailwheel. Adjust trim until it works, adjust for CG changes. Several factors affect reaching proper airspeed Prop, RPM, Mixture, Tire size/pressure, Weight, Wind, wing drag, ect. Unless I really need to see and avoid something ahead of me I do a tail low takeoff and let the plane tell me when it is ready to fly. DENNY

Your first part is correct if you have extra hp. I run Datum skis( Pa18-0200) for 6 months, biggest tire I can run is a 600x6. I normally I run 31 BWs. I was totally amazed when I took the skis off and I got off 50 to 75' shorter with the much lighter 6" tires and climbed better. AOA and flaps are awesome if you have the thrust to pull you along.

Glenn

 

[bob turner]

I think the experts finally decided that raising the tail added to the takeoff roll. Remember, the drag of the aircraft in the 3-point attitude is not much different from that with tail high at low speeds.
I get 200' ground rolls at sea level 70 degrees no wind. That's a J-3 Stroker with wood prop.
A good 160 Super Cub takes closer to 300'.
You really need a marked runway to figure this out for yourself - it does not take long to compare ground rolls using various techniques, but try for a calm day so you are not messing up your data with wind gusts.

 

[Brandsman]

This is one on which I can chime in a bit although I am no expert. I have a J-3 with an ex SC C-90 engine so not exactly the same as a 95 SC - more drag and if I am correct a different thrust line and wing AOA. It has the flat wing tips with the Flotrol Splates. I also have a 160 hp much modified J-5 (essentially a 12 with SC gear and balanced SC tail feathers) with a Borer prop and standard wingtips. Where I am based we have a short northerly “runway” which is a tarred taxiway for around 60 -70 yards from the access gate to where it crosses the threshold of the main runway and grass after that. The airfield is at 5 450’ and temperatures run 69 - 75 F this time of year with light winds generally straight down that runway. Most Sundays I fly the two aircraft back to back and I have been working on short take offs. My son is typically with me - he weighs in at a light 120 lbs but I am quite heavy at 210, the empty weight is 823 so the J-3 is close to gross with just the nose tank full. Both aircraft fly before the end of the tarred section- the J-3 likes neutral trim and flies a little quicker than the 5 - the tail comes up about 30’ into the run and I keep the tail a little low and lift her off when she feels ready - about 35 - 38 mph - my airspeed indicator is only marked from 40 and she flies below that so I can’t be precise. The J-5 seems to prefer almost full nose up trim failing which it feels like I am fighting the trim to wrench it off the ground which is uncomfortable and that flies at just over 45 mph. Neither aircraft has flaps. I read a similar thread here a while ago and some of the experts were suggesting nose down trim, but that doesn’t seem to work on the 5, possibly because the CG is quite far forward with me in the front which would be similar to a SC. The empty weight on the 5 is 980 and I generally have 25-30 gallons on board so it is also just around gross, so around 300lbs heavier than the J-3. It also flies before the tar runway but not quite as quickly as the 3 and the tail slightly low attitude certainly seems to work best.


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[Crash Jr.]

I think the experts finally decided that raising the tail added to the takeoff roll.

I'm not sure what experts these are but I would vigorously disagree. Perhaps it's the better technique for a smooth grass runway but for my purposes the tail is the first thing to leave the ground and the last thing to land. My takeoff rolls are 150-200ft depending how soft the ground is.

 

[DENNY]

Both tail high and tail low are tools to have in the box. Nothing wrong with a tail high takeoff and rotation in the right setting, However, I now loose the benefit of the plane telling me when it is ready to fly by the second nose dip and stoping the rotation without hitting the tailwheel is difficult timing. It is pretty easy to feel when a plane will fly tail high on rough ground because the bump loft will start to last longer. Off field is pretty easy use just pick up the tail and use all the runway you have lowering the tail near the end. Pulling a plane off the ground before it is ready to fly with good control leaving good runway below you is the cause of several off field accidents. I think you could come up with an aircraft tell for when to rotate with tail high on smooth surface I just have not worked on it for STOL comps because the method I described is very consistent and short. As always several factors are involved as Glen mentioned HP is a huge one as is the prop. But simple things help like tire pressure, cheat into the wind if possible, Start 5-10 degrees angel right and let P factor pull you straight (less rudder drag) and ground distance will be longer than keeping straight. If you just add power on the line and let it roll you can get a bit shorter by dragging the brakes for a few seconds allowing the engine/prop to come up to speed, it don't seem right but it works and helps protect the prop a bit. Every plane is different, just keep trying stuff until you find what works for you. DENNY

 

[RaisedByWolves]

I fly the same way at stol contests as I do when I land on gravel bars. Tail comes up to protect it and to see where you’re going.


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[courierguy]

This post has made me realize, I have never bothered to accurately measure my takeoffs between the tail up right away mode, and the letting the plane/tail low tell me mode. I do know that if viz is the issue, that tail is coming up, if not, I just let the plane tell me, my gut tells me there is not a major difference between the two. As long as I make it off without crashing into something, that's all that matters.

 

[BC12D-4-85]

Best T/O configuration test is done on skis in snow (or on mud/soft soil) where tracks land down are visible. Same for landing. Having the tail in the snow/mud/grass creates drag. Having the prop in snow/mud/grass cuts thrust. Somewhere in between - tail low - is best. On tires try partial to minimum throttle takeoffs at various tail attitudes. Low power makes the wing work harder.

Gary

 

[bob turner]

I have measured it. Tough to see any difference in a Cub, but in the 180 I am airborne 3-point at the same point where I can get the tail up to the level flight attitude.

What kind of Cub can get airborne in 150 feet no wind? I can see a stripped J3 with flaps doing that, but I haven't flown a Super Cub that can do it. Didn't get a chanceb to measure the Carbon Cub takeoff roll, but maybe . . . It did go straight up!

 

[DENNY]

BOB
I can can get my cub 1200 lb cub up in 150 ft most any day at 70 ft ASL 60 degrees with full fuel and no wind. That is with gun boot, and belly pod. 70 degrees, full fuel passenger it may take 250-300. 1951 pa18A with 160hp Borer 82/43 stock wing, 3 in gear 31 in Bushwheels. HOWEVER!! It took me a long time and a lot of fuel to figure it out. When I leave the ground I have to be a real pilot for about 3 seconds because it is close to the edge. My plane is made to rip a load off the ground, then put on the play list because it is going to be a while getting home. If I am playing at Valdez it is 7 mph slower!!! I suspect you do not have a prop that will let the plane turn 2450 or better static. The problem we have is a PA 18 can be everything from a pig to a beast! The other issue is most pilots do routine takeoffs in a safe and conservative manner, if you push the edge and fail to make a short take off 80 percent of the time people just stop trying. But if you are willing to fail after a few years you will learn what it takes!! It took several years of failure but I saw it as a chance to learn (I started flying at 50 so failure was an old friend). The other advantage I have had is I am at a runway that everyone is willing to share generations of STOL/bush flying with new pilots.
DENNY

 

[flagold]

Hello Everyone,

Looking at a 95 Horse Super Cub, First let me say I know shes not going to win any Stol Contests but just want to hear peoples opinions on how to best get the low hp SCs in the air quicker.

Assuming the Following:

Standard Gear
No Flaps
29" Airstreaks
VGs
Hopefully right around 1050 pounds Take off (Pilot Weight included) weight lightly loaded Vs full Gross 1500 pounds heavy.
Density altitude 1-5k feet (Im based in Ohio)
Mainly Short Grass Strips, But occasionally Smooth gravel bars and smooth farm fields and the like.

What are you all finding is the actual stall Speeds with these configurations?

What methods see the best results? How do they change with added weight?

Thanks Everyone

Eric

Assuming the above configuration. Similar to Denny's (you'll be on the edge a few seconds and need to practice this):

I can't tell you any speeds since this was by feel:

1. Go to neutral trim and crank one full turn forward trim
2. Pull all the way back on the stick & let it go back to the trim position (get the feel of both)
3. Full power & hold brakes until it winds up fully
4. Max rpm let the brakes go and count to 3 (thousand one . . .)
5. Stick all the way back and haul it into the air in ground effect & release back pressure to the trim position (fly it off in ground effect)
6. Watch the airspeed & feel for the climb out speed - stick will shudder if you try climbing out too early.

This simply gets you off the ground quickly - you really have to watch climbing out of ground effect to early in SC's - it can happen quick.

 

[stewartb]

To the OP, assuming smooth, firm ground, take-off trim, neutral stick, let it fly off. Your 3-point attitude is the best you’ll get so use it. That would apply whether heavy or light. What you should experiment with is your CG. Find the CG that works best in your plane.