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aviationluver
2nd Oct 2022, 21:01
(Some comments deleted - JT)

I was wondering about Cessna's General Aviation airplanes and the use of the strut that attaches the wing to the fuselage. Some Cessnas like the CE172 use the strut while other similar models like the CE177 and CE210 do not. Does anyone know why some airframes have the strut while others do not?

fitliker
2nd Oct 2022, 22:14
The 172 wing with strut has more flex than the 177 without strut . That flex can be hazardous to the windscreen if someone has pumped too much silicone into the gap . Usually a small sealing bead is in front of felt to give a nice seal . If the felt was removed and just pure sealant used . A dangerous condition can occur .Recovering from a spin in just such a siliconed mess , I lost half the windscreen . I couldn’t get the aircraft to stop phugoid oscillations when slowing down , but still had some pitch control above 90 knots . So that was the first time I had landed a 172 at 90 knots . Fully expecting to go off the end into the fence , but the drag from the missing top of the window slowed the plane down and I got it stopped before the end of the runway . Good times :)
Never spun a Cardinal .

pattern_is_full
3rd Oct 2022, 02:24
It's basically an engineering dance to acheive certain goals for the aircraft (including marketing ;) )

But clearly either will work, since low-wing aircraft of the same general type (e.g. Piper PA-28 variants) very rarely use struts.

For the most part, Cessna deleted the strut in the 177 Cardinal (and probably 210) to:

- improve pilot sight-lines (no blind spot from the struts), also cleaning up the view for using the aircraft for aerial photography
- reduce drag, although that was more important in combination with retractable landing gear. Thereby improving fuel efficiency, range, or speed (at least in theory).
- iremove struts' obstruction to boarding or loading
- "look more futuristic" than the aging C172, which had been on the market for 15 years. Wing struts were something of a hold-over from the bi-plane era - looked a bit "old-fashioned" by 1970.

Cessna did, of course, have to make the 177's internal wing spar stronger/stiffer/heavier, to compensate for the loss of the struts' added reinforcement.

In any case, the C172 is still made today, while the strutless Cessna prop planes have vanished from the marketplace. "The market" apparently seems to have had no problem with the strut.

Less Hair
3rd Oct 2022, 06:13
Struts are even considered by NASA and Boeing for the next generation of airliner wings. They might need extreme span (folding on the ground) for efficiency.
https://www.nasa.gov/image-feature/trans-sonic-truss-braced-wing-may-help-reduce-fuel-consumption