Why can't Cessna ditch the draggy struts on its planes?

[ThrottleUp]

I have been curious about this. Wouldnt it reduce drag a lot if Cessna could make its planes without those wing struts? The NextGen C172, C206, Grand Caravan etc....why cant they make these awesome high-wing planes strutless? See how nice Cardinal looks 

or the Tencam:

Imagine a Grand Caravan or U206 with a wing like that hee hee. Looks so much neater and must add some knots?    But yea...do struts give more strength to hi-wing planes?  I dont know about the physics & mechanics of airplane structures but Im guessing to have a strutless high wing the center-section has to be heavy and strong which will add weight?

Look forward to your (more knowledgable) replies 

[slandreth]

I agree.  I assume it would add weight.  I know the strut on the C172 makes it harder for me to get in the plane. 

[Hugh Johnston]

I reckon Cessna's would look nude without them. I'm assuming they are structural but I'm sure given time that they will probably disappear but I'm also sure Cessna have very good reasons for them. They have been around a while

[Dean (PC Aviator)]

Makes em look like olympic weightlifters holding the bar above their heads

[macca22au]

They're structural.  The wing would have to be strengthened greatly.  I had the feeling that Cessna did put out one of it's faster models without the strut - was it a Cardinal

On the 172 that strut gives drag where its needed.  Keeps it low and slow.  Stable 70kts up, cruise and descent 70kts.

Keeps sprogs alive.

[alan2]

Definetly structural . Maybe the belt and braces philosophy 

[Ross Casey]

The C210 Centurian is also strutless from memory.

[Ausiguy]

If they took them off it would be so fast that it would literally rip the wings off itself! )

[Spirit Flyer_old]

They're structural.  The wing would have to be strengthened greatly.  I had the feeling that Cessna did put out one of it's faster models without the strut - was it a Cardinal

On the 172 that strut gives drag where its needed.  Keeps it low and slow.  Stable 70kts up, cruise and descent 70kts.

Keeps sprogs alive.

Ahhhh...what's a sprog? 

Kind regards, 

[Phil Manhart]

They're structural.  The wing would have to be strengthened greatly.  I had the feeling that Cessna did put out one of it's faster models without the strut - was it a Cardinal

On the 172 that strut gives drag where its needed.  Keeps it low and slow.  Stable 70kts up, cruise and descent 70kts.

Keeps sprogs alive.

Ahhhh...what's a sprog? 

Kind regards, 

Google is your friend!

http://en.wikipedia.org/wiki/Sprog

Sprog can refer to:

    a slang term for a child

    Sprog (software), a graphical tool to build Perl programs by plugging parts together

    a plant that takes the place of grass on the fictional planet Snaiad.

    nickname of Mark Williams (Welsh snooker player)

[ricky76]

Without the wing struts, the wing would fold during steep turns or abrupt pitch changes. I think that over time and advancements in structual engineering have alowed for stronger spars, ribs and joining points while keeping the weight down to allow for the added performance of bigger powerplants. Just my opinion!

[Alan_A]

Interesting to note that the Skycatcher has them.  You'd think if Cessna wanted to lose the struts, they'd do it on a clean-sheet design, but they opted not to.  Of course, the additional drag/stability might help "tame" an LSA...

[skypilot]

In my day (1970) at the then RAN Apprentice Training Establishment (RANATE), a sprog was a first term apprentice; A young lad of about 16 years of age!

[macca22au]

You're right Skypilot, and it then took on a general meaning for beginning pilots and sometimes for beginners in many jobs.

Even as teenagers we were sometimes referred to as sprogs.

Young and green.

But like so many words it seems to have lost that meaning and taken on others:  the list that pmanhart has quoted retains only 'slang for child' from its rich use in the WWII RAF and generally in the years that followed.

And someone else is exactly right, it was the Centurion that went strutless in public.

[sos]

They are different wing types. The C177 Cardinal and C210 Centurion  have "Cantilever" Wings.  Here's some info from Wiki:

Another use of the cantilever is in fixed-wing aircraft design, pioneered by Hugo Junkers in 1915. Early aircraft wings typically bore their loads by using two (or more) wings in a biplane configuration braced with wires. They were similar to truss bridges, having been developed by Octave Chanute, a railroad bridge engineer. The wings were braced with crossed wires so they would stay parallel, as well as front-to-back to resist twisting. The cables generated considerable drag, and there was constant experimentation on ways to eliminate them.

It was also desirable to build a monoplane aircraft, as the airflow around one wing negatively affects the other in a biplane model. Early monoplanes used either struts (as do some current light aircraft), or cables (as do some modern home-built aircraft). The advantage in using struts or cables is a reduction in weight for a given strength, but with the penalty of additional drag. This reduces maximum speed, and increases fuel consumption.

A British Hawker Hurricane from World War II with cantilever wings

The most common current wing design is the cantilever. A single large beam, called the main spar, runs through the wing, typically nearer the leading edge at about 25 percent of the total chord. In flight, the wings generate lift, and the wing spars are designed to carry this load through the fuselage to the other wing. To resist fore and aft movement, the wing will usually be fitted with a second smaller drag-spar nearer the trailing edge, tied to the main spar with structural elements or a stressed skin. The wing must also resist twisting forces, done either by a monocoque "D" tube structure forming the leading edge, or by the aforementioned linking two spars in some form of box beam or lattice girder structure.

Cantilever wings require a much heavier spar than would otherwise be needed in cable-stayed designs. However, as the size of an aircraft increases, the additional weight penalty decreases. Eventually a line was crossed in the 1920s, and designs increasingly turned to the cantilever design. By the 1940s almost all larger aircraft used the cantilever exclusively, even on smaller surfaces such as the horizontal stabilizer.

[tennyson]

Also a term of endearment for a RAAF apprentice, way back when Australia had a defence force and border security!

Frank

[RotorSim]

If they took them off it would be so fast that it would literally rip the wings off itself! )

LMFAO... 

[macca22au]

No, the wings would clap hands.

[spud]

The wing struts are not going anywhere anytime.  To remove them would entail designing a new airplane and have it type certified with the FAA that would cost many millions of dollars.  The struts are structurally inherent in the design and can not be changed without major work by Cessna and bottom line 'they buy our airplanes with struts and it ain't gonna change unless sales go way down'.

[tim_A]

Cantilever wings require a main spar that is bigger, stronger, heavier. Using a strut to brace the wings means you can get the same strength for less weight. In small aircraft such as the Skycatcher, or even the Skyhawk, that weight saving translates directly into useful load and could be significant, particularly when the regs place hard limits on MAUW. Imagine buying a two seat plane where two-up you could only sit on the ground making 'brrrm brrrm noises', because adding fuel would take you over max gross...

Also, cantilever wing spars need to be tied to the opposite wing. This doesn't matter in low wing designs, where the spar passes under the seats (although many bizjets have a hump in the floor where the main spars cross). In a high wing, the cantilever would mean the spars cross high in the cabin. In a small plane that would put the spar right where the pilot wants his head to be...

[CathyH]

Cantilever wings require a main spar that is bigger, stronger, heavier. Using a strut to brace the wings means you can get the same strength for less weight. In small aircraft such as the Skycatcher, or even the Skyhawk, that weight saving translates directly into useful load and could be significant, particularly when the regs place hard limits on MAUW. Imagine buying a two seat plane where two-up you could only sit on the ground making 'brrrm brrrm noises', because adding fuel would take you over max gross...

Also, cantilever wing spars need to be tied to the opposite wing. This doesn't matter in low wing designs, where the spar passes under the seats (although many bizjets have a hump in the floor where the main spars cross). In a high wing, the cantilever would mean the spars cross high in the cabin. In a small plane that would put the spar right where the pilot wants his head to be...

This waas a problem in the Cessna AW, Old Clyde's first design, the wing spar was right between the front and rear seats. There are a couple of FS9 freeware AW's that work in FSX. bit dated but nice birds,

[ThrottleUp]

Thanks for all your very interesting replies, enjoyed reading them a lot!  I had a feeling that was the reason for Cessna sticking to the struts! I didnt think about the fact that it would entail major redesign and re-certification were they to remove them.

But I still think the planes would look grand with them off hee hee. A good point also that the new light sport plane by Cessna has retained the struts....but see how clean one of its rivals looks:

Of course Im sure Cessna engineers must have talked this over and the struts won out!! Also they have designed the doors & strut placement very well on the new LS plane so I guess it doesnt matter too much. I have to admit thought I just cant get it out of my head...they look so draggy! 

[Maurice_King]

The struts contribute to drag yes BUT the drag of the struts is less than the drag of a thicker stronger wing  and the additional weight of a larger donk needed to counteract this drag.

I know a fellow with a 172 that is some 150 Kg's lighter than the original Wet weight. and looks like it is fibreglass due to the extreme smooth finish after the rebuild. even with struts his cruise is 160 Kts @ 60 % power 7.5 GPH  so struts are part of the story yes BUT remember the outer skin of the aircraft contributes far more to the drag co-efficient than the struts do.