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Thread: Old vs New Cessna Vertical Stabalizers???

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    Old vs New Cessna Vertical Stabalizers???

    Way back in the 1950's Cessna 140's and some of the early 150's came with a a fairly conventional (for the times) vertical stabilizer. Then sometimes in the early 1960's Cessna started putting "Swept Back" vertical stabilizers on their airplanes-kinda like a much smaller version of the vertical stabilizer found on the then new Boeing 707 Jetliners.

    SO MY QUESTION IS: Does the "Swept Back" vertical stabilizers on Cessna's have any practical, AERODYNAMIC VALUE?

    From a purely practical point of view, WHICH IS BETTER, the "old fashioned" vertical stabilizers found on the 1950's Cessna's OR the more recent "Swept Back" vertical stabilizers?

    Inquiring Minds would like to know!

    THANKS!!!!!

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    Re: Old vs New Cessna Vertical Stabalizers???

    I've read a bunch of articles about the history of the 172 and they always said the tail was swept for marketing purposes. Call me old-fashioned, but personally I prefer the unswept tail and straight back!

    Here's an article: http://www.greencavedesigns.com/else...Jan%202002.pdf

    The 172 as introduced in 1956 was powered by a Continental O-300-D six-cylinder engine
    rated at 145 HP turning a fixed-pitch propeller. Gross weight was 2200 pounds. The original
    172s had an upright vertical stabilizer and a straightbacked fuselage which, to the
    contemporary eye, looks dated. But that wasn’t so in 1956 and Cessna sold 1100 172s that
    year.
    ...
    The 172A, with the vertical tail swept, was introduced in 1960. The new empennage was
    heavier; rudder power was reduced, and directional stability was degraded somewhat. Why
    did Cessna do it?
    Marketing, evidently. And the result is attractive, with the lines of the fastback fuselage
    blending well with the swept tail.

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    Registered User Max Torque's Avatar
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    Re: Old vs New Cessna Vertical Stabalizers???

    No aerodynamic value.
    I have a fair amount of time in both and the"straight tail" (unswept) Cessnas have more rudder authority and they don’t have what I call “nose arching” with rudder inputs like the swept tails. Hop out of one right into another, and it's definitely noticeable. After several different planes, I bought an old straighttail 172, put a Sportsman STOL kit & baggage door on it, re-configured/upgraded the panel, and never looked back. Building a two-seat tandem bush plane now, but that's to compliment the 172 & for bush work, not to replace it.
    Tom
    Last edited by Max Torque; June 17th, 2012 at 12:48 PM. Reason: Changed "aerodynamic purpose" to "aerodynamic value"

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    Re: Old vs New Cessna Vertical Stabalizers???

    According to the textbooks and research pubs, sweeping subsonic surface reduces its effectiveness and lowers its stall AOA.
    When Cessna swept the tails on 152's, 172's, and 182's, they enlarged the tails to makeup for the sweep, so you got more area (more drag) to approach the same effectiveness... Then there are the many people who have flown both. Every one of them I have heard talk about it, have acknowledged that rudder response and yaw damping is superior with the straight tails.

    In our subsonic airplanes, straight (not swept) is the way to put on wings, canards, and tails.

    Billski
    Last edited by wsimpso1; June 24th, 2012 at 07:26 AM.

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    Moderator autoreply's Avatar
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    Re: Old vs New Cessna Vertical Stabalizers???

    On top of Billski's comment, search for tail sweep on HBA for a lot more discussion. Swept fins are notoriously lousy in spin behavior...
    Kennis vermenigvuldig je door het te delen.
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    Re: Old vs New Cessna Vertical Stabalizers???

    The straight back straight tales are faster with the same engine than the swept greenhouse back. The greenhouse actually does the hurting of performance although, the straight tail has a hair more control. There is a one year 172 with the straight back with the swept tail and that is the fastest 172 made before all the modern ones with the big engines.

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    Registered User Detego's Avatar
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    Re: Old vs New Cessna Vertical Stabalizers???

    Quote Originally Posted by Southron View Post
    Way back in the 1950's Cessna 140's and some of the early 150's came with a a fairly conventional (for the times) vertical stabilizer. Then sometimes in the early 1960's Cessna started putting "Swept Back" vertical stabilizers on their airplanes-kinda like a much smaller version of the vertical stabilizer found on the then new Boeing 707 Jetliners.

    SO MY QUESTION IS: Does the "Swept Back" vertical stabilizers on Cessna's have any practical, AERODYNAMIC VALUE?

    From a purely practical point of view, WHICH IS BETTER, the "old fashioned" vertical stabilizers found on the 1950's Cessna's OR the more recent "Swept Back" vertical stabilizers?

    Inquiring Minds would like to know!

    THANKS!!!!!

    I've always preferred the Stinson over the Cessna 120/140/150 (fast back), but do like the round tails on both models.

    Stinson 120
    Old vs New Cessna Vertical Stabalizers???-05sanbp.jpg

    Cessna 120
    Old vs New Cessna Vertical Stabalizers???-ce120-03.jpg


    Cessna 140
    Old vs New Cessna Vertical Stabalizers???-cessna140_nc89109_airportda_kp.jpg


    Cessna 150 - In 1966 Cessna redesigned the tail to sweep back.
    Old vs New Cessna Vertical Stabalizers???-1977.gif
    Last edited by Detego; June 17th, 2012 at 09:05 PM. Reason: Stinson 108 corrected to Stinson 120

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    Re: Old vs New Cessna Vertical Stabalizers???

    I understand that those who are really working to the limits (backcountry) prefer straight tail because you get more control authority, compared to swept...
    Flying Bearhawk kit no.125

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    Re: Old vs New Cessna Vertical Stabalizers???

    THANKS EVERYONE FOR YOUR REPLIES!!!!

    While I have flown a Lot of Cessna 150's and 172's with the "Swept Back" vertical stabilizers, but I have never had the chance to fly an earlier "Straight Tail" Cessna. I had a sneaking suspicion all along that the Swept Back Tail was more for "Marketing purposes" than aerodynamics. Too bad Cessna doesn't offer a "Straight Tail" Option on their new models!!!

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    Registered User Dan Thomas's Avatar
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    Re: Old vs New Cessna Vertical Stabalizers???

    Quote Originally Posted by Detego View Post
    I've always preferred the Stinson over the Cessna 120/140/150 (fast back), but do like the round tails on both models.

    Stinson 108
    Attachment 18117







    That's a 120 or 140. This is a Stinson 108:

    Old vs New Cessna Vertical Stabalizers???-1299-paulaswiftn8299k-2.jpg

    Dan

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    Registered User Detego's Avatar
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    Re: Old vs New Cessna Vertical Stabalizers???

    Quote Originally Posted by Dan Thomas View Post

    That's a 120 or 140. This is a Stinson 108:

    Attachment 18122

    Dan


    Thx Dan.


    1947 Stinson 108-2

    Old vs New Cessna Vertical Stabalizers???-stinson-108.jpg

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    Re: Old vs New Cessna Vertical Stabalizers???

    Aero Commander 100 Darter took the tail to the opposite extreme; ala Mooney.

    Old vs New Cessna Vertical Stabalizers???-1967_aero_commander_darter_100_433400842a8175405385_7.jpg
    Last edited by Detego; June 18th, 2012 at 12:20 PM. Reason: fixed link

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    Re: Old vs New Cessna Vertical Stabalizers???

    Quote Originally Posted by Detego View Post
    Aero Commander 100 Darter took the tail to the opposite extreme; ala Mooney.
    I've seen some Darters with swept tails too, so Cessna must not be the only company to sacrifice good design to marketing demands.

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    Re: Old vs New Cessna Vertical Stabalizers???

    The club I used to belong to had a 1956 straight backed, straight tailed 172, and also a straight backed, swept tail, and I can't recall any difference in rudder auithority in either one to be honest.

    The swept tail was definitely a marketing ploy, especially in the 150. It was meant to make it appear sleaker/faster. I personally prefer the look of the swept tail over the straight tail birds. To me a 150 with straight tail just doesn't look right.....

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    Re: Old vs New Cessna Vertical Stabalizers???

    Quote Originally Posted by bmcj View Post
    so Cessna must not be the only company to sacrifice good design to marketing demands.
    I don't think a swept forward 1/4 chord tail is a sacrifice at all. sweep back makes the lift curve per alpha shallower and the spar may need to be a bit heavier but swept forward doesn't have those effects because the spar can be 90 degrees to the fuselage and the aerodynamic sweep effect is dependent on leading edge sweep not 1/4c. If you compare two tail fins of the same height and area, one constant chord and the other tapered the tapered one has a lower bending moment (which translates to lower torque on the aft fuselage) and a thicker root (assuming that it has the same airfoil section at both ends) which means either a lighter or sturdier tail. Mooney got it right!
    --------.~.
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