Shortfield takeoffs in Tri-Pacer

[Subsonic]

1. Please advise your best recommended Short-field (hard-packed dirt) takeoff procedure in the stock 150 hp Tri-Pacer. Not Pacer.

2. Please advise your best recommended Short-And-Soft-field (soggy tall grass and mud) takeoff procedure in the Tri-Pacer.

Thanks.

[tloes]

Your mileage may vary....

Short and hard field:
Do the run-up and last pre-take-off checklist items before turning to the runway take-off heading (assuming you've back-taxied to the takeoff point).
With flaps up, get it rolling briskly, make your turn to runway heading, slowly firewall the throttle.
Accelerate to around 40 mph and pull one notch of flaps
Apply back-pressure to establish take-off rotation
Once off the turf and still in ground-effect, establish best angle of climb speed
Climb with 10-degrees of flaps at best angle of climb until clear of obstacles.
Nose down to best rate of climb and retract flaps

Soggy-field isn't too much different except that you'll likely want 10-20 degrees of flaps from the beginning and you'd be applying backpressure on the yoke from the beginning. In this case you're just trying to get the wheels light enough to have a chance of accelerating to a rotation-ready speed. You must have an abort point established because there's a chance you are not going to get enough speed to rotate and climb effectively to clear an obstacle. You'd probably also do your run-up while on-the-move because momentum is precious on really soft fields.

Best regards,

Todd

[Subsonic]

Ok, thanks. Re: 10-20 degrees of flaps - are you saying you hand hold the flap handle to a middle position between the first and second notch (full-flaps) position?

[tloes]

Ok, thanks. Re: 10-20 degrees of flaps - are you saying you hand hold the flap handle to a middle position between the first and second notch (full-flaps) position?

I rarely went to "full flaps" in this situation. First notch is adequate.

[Pacer42Z]

Not sure how much of a difference there is in the technic between a Pacer and a Tri-Pacer to get them off the ground quickly. You can try the technic I am using in the Pacer to see how it works in your Tri-Pacer.
1) For short field hard dirt runways do the magneto check while you are rolling so you don't pick up stones with the prop. I use one notch of flaps from the beginning. I don't want to reach down for the flap handle while going down a narrow dirt strip, I rather have all concentration outside to stay center on the strip. The take off role is quite busy when the strip is short and narrow. I bring the tail into a tail-low attitude and let the airplane lift off. In a Tri-Pacer you would have to hold some back pressure to keep the nose wheel off the runway and let the airplane lift off. Accelerate in ground affect until at Vx and climb out. Retract Flaps when clear of obstacles. You can watch some of my take offs in the Utah back Country at https://www.youtube.com/channel/UCwQ...ihpE0zmvmbUGgg
2) For soft-short fields the technic (I believe) is identical. One notch of flaps, Yoke all the way back, don't stop moving from starting to taxi till lift off (if you can). Make wide turns to line up with the runway (smooth operation is critical). Apply full take off power and keep the Yoke all the way back until you lift off at a very low speed. Keep lowering the nose, but keep the wheels a couple of feet off the runway until you reach Vx and then climb out.

Juergen
Pacer N3342Z

[Steve Pierce]

Practice, practice, practice and get a good feel for it. I pull it to the first notch of flaps, firewall the throttle and with my hand on the flap handle I pull the yoke and the flaps at just the right time and with my thumb on the flap handle release I nurse the flaps by feel. If you do lots and lots of take offs and landings you will get a pretty good feel for when she wants to fly. Once you get it figured out then start playing with different trim settings to get even better results but it takes more trimming between take off and landing.

[dgapilot]

For short field work, the prop
You have makes the most difference. HP=(RPMXTorque)/5252. The higher the RPM, the more HP your engine is producing. A flat pitch prop that gives the highest permitted static RPM will give the best take off performance, but you will sacrifice cruise performance.

Back when I was towing banners, I had a PA-22-160 with a 53” pitch prop installed and a second oil cooler mounted just aft of the nose gear below the cowl. I used to fly that airplane in and out of a ~600’ gravel strip (clear approaches). My technique was to apply full throttle on the roll(avoid picking up rocks in the prop). As airspeed went through about 45-50 MPH, pull back on both the yoke, and flap handle (full flaps) and establish a pitch attitude somewhere around 20 degrees. In the climb, accelerate to 70 and ease off to one notch of flaps, clear obstacles and ease off the second notch as I accelerated to 80. With that prop, at 80 and full throttle I was turning 2700 RPM and climbing between 1000 and 1500 ft per minute. One person, full fuel. Don’t recall what the actual ground roll was, but likely not more than around 300’.


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[Subsonic]

Reporting back: My TP apparently has a "climb prop" on it and the "058" stamped on the prop hub means it was a 58 inch pitch when it was manufactured. I had it overhauled a couple months ago and the company that did it said they didn't change anything, only refinished it because it "was well within specification". They recorded the pitch at the prescribed "Sensenich stations" which are radial points from the center. That is where I learned the pitch changes radially. At about the 75% point, where the real work gets done, they measured a pitch of approximately 60 inches. Anyway, I've done 5 shortfield takeoffs last week and HOLY smokes this is a wheelie machine deluxe. I'm having so much fun wheeling away as this thing just gets up and leaves the earth in about 300 feet. I'm using Todd and Jeurgen's recommended first notch of flaps, and yoke back and she just gets up and flys like right now. Thank you all for the input. I've been wearing out my tires rolling along the runway for no good reason!

[dgapilot]

Yeah, good short field technique along with a strong engine and good prop will make a TriPacer really perform. A TriPacer can actually out perform a Pacer on take off, all other things being equal. With a TriPacer, due to the gear configuration, you can rotate to a much higher alpha angle and get right to critical AoA while still on the ground.

A Pacer in 3 point is only about 11 degrees, with the TP, you can rotate well past 18 degrees which is about critical AoA.


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[Stephen]

Reporting back: My TP apparently has a "climb prop" on it and the "058" stamped on the prop hub means it was a 58 inch pitch when it was manufactured. I had it overhauled a couple months ago and the company that did it said they didn't change anything, only refinished it because it "was well within specification". They recorded the pitch at the prescribed "Sensenich stations" which are radial points from the center. That is where I learned the pitch changes radially. At about the 75% point, where the real work gets done, they measured a pitch of approximately 60 inches. Anyway, I've done 5 shortfield takeoffs last week and HOLY smokes this is a wheelie machine deluxe. I'm having so much fun wheeling away as this thing just gets up and leaves the earth in about 300 feet. I'm using Todd and Jeurgen's recommended first notch of flaps, and yoke back and she just gets up and flys like right now. Thank you all for the input. I've been wearing out my tires rolling along the runway for no good reason!

I agree about T-Pacers and, I used the same T.O. technique that Steve P wrote as my standard method of take off. I like to get to a safe turn around altitude in a reasonably short time. I set 10 degrees flaps during my warm up check. 10 degrees flaps is nearly nil added drag especially at low speed. Remember to raise flaps before cruise.