Is a field approved 150hp PA-20 12 rib wing plane legal? Is the 13th rib only for the increase in max gross weight you get with the STC?
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Is a field approved 150hp PA-20 12 rib wing plane legal? Is the 13th rib only for the increase in max gross weight you get with the STC?
Number of ribs has nothing to do with gross weight, they effect the Vne
What is the Vne of the 13 rib wings? Mine is a '52 original Pacer 12 rib (I think) and it's Vne is 158 MPH.
This is all kind of a moot point anyhow, as I never fly close to that speed, the fastest I decend at is around 140, and thats way to much wind noise for me. How about others, how close do you get to Vne?
For the opening poster....
With the Copper River STC (SA1-167) it is, and you get to up the gross weight from 1800 to 1950 with it as well.
I am pretty sure the 160 hp PA-20 I had only had 12 rib wings and it also had the gross weight increase. I don’t know what it took to get it past the FAA but they signed off on it.
Gross weight has more to do with horse power and climb.
PA22 O-290-D:
Airspeed Limits:
(CAS)
Vne (never exceed) 158 mph (137 knots)
C.G. Range: (+17.5) to (+24.0) at 1800 lb.
(+10.0) to (+24.0) at 1380 lb. or less
Straight line variation between points given.
Vno (maximum structural cruising) 126 mph (110 knots)
Vp (maneuvering) 106 mph ( 92 knots)
Vfe (flaps extended) 80 mph ( 70 knots)
PA22-135 O-290-D2:
Airspeed Limits:
(CAS)
Vne (never exceed) 158 mph (137 knots)
Vno (maximum structural cruising) 126 mph (110 knots)
Vp (maneuvering) 106 mph ( 92 knots)
Vfe (flaps extended) 80 mph ( 70 knots)
C.G. Range: (+17.5) to (+24.0) at 1950 lb.
(+10.0) to (+24.0) at 1380 lb. or less
Straight line variation between points given.
PA22-150 O-320 13 rib wing:
Airspeed Limits:
(CAS)
Vne (never exceed) 170 mph (148 knots)
Vno (maximum structural cruising) 135 mph (117 knots)
Vp (maneuvering) 112 mph (97 knots)
Vfe (flaps extended) 95 mph (82 knots)
C.G. Range: Normal Category:
(+17.5) to (+23.0) at 2000 lb.
(+12.0) to (+23.0) at 1800 lb.
(+9.5) to (+23.0) at 1400 lb. or less
Utility Category:
(+13.5) at 1680 lb.
(+12.0) to (+13.5) at 1665 lb.
(+9.5) to (+13.5) at 1400 lb. or less
PA22-160:
Airspeed Limits:
(CAS)
Vne (never exceed) 170 mph (148 knots)
Vno (maximum structural cruising) 135 mph (117 knots)
Vp (maneuvering) 112 mph ( 97 knots)
Vfe (flaps extended) 95 mph ( 82 knots)
C.G. Range: Normal Category:
(+17.5) to (+23.0) at 2000 lb.
(+12.0) to (+23.0) at 1800 lb.
(+9.5) to (+23.0) at 1400 lb. or less
Utility Category:
(+13.5) at 1680 lb.
(+12.0) to (+13.5) at 1665 lb.
(+9.5) to (+13.5) at 1400 lb. or less
Interesting thread, how about first shortwings, are the PA-15 16 and 17 wings the same as the 20 with 12 ribs? I am going to my hangar today and count ribs, how many ribs should I find? The spacing looks even starting from the tip to the fuel tank, than they are closer together. The Clipper has a lower Vne than the Pacer, it only has 11 ribs I think, explains the lower maximum speed.
My PA-16 has 12 ribs, if I counted correct. Is the Pacer wing the same as the PA-16 wing with exception of having flaps and shorter ailerons? 1A4 in fact shows different Vne speeds for PA-20-115 and PA-20, the PA-20-115 wing may have fewer ribs than the PA-20 http://ohio.shortwingpiperclub.org/M...a/TCDS/1A4.pdf
It was a field approval and, as far as I know, it is the only one. It started life in 1950 with an O-290-D and was upgrade to a D2 before the O-320-B3B and CSP was installed in the mid ‘70s. I don’t recall if there were any changes to the airspeeds. Around 2003 I got a field approval to alter the field approval and installed a fixed pitched prop. That was kind of a tough sell to the feds but a little time (6 months) and patience got me through the hoops. I lost some performance but the aircraft flew much better without the extra weight. The last I heard was someone out west had it and was adding all of the Alaska mods.