Swifts vs Cessna 170's (Split from Exhaust stack topic)

Post by **GAHorn** » Sat Mar 15, 2003 8:20 pm

If you can get approval for straight pipes, and have provision for carb heat, then I see no reason you absolutely have to have a muffler. Cabin heat is a luxury you could go without perhaps, even, but it'd be just as simple to include a heater muff for the cabin. I suspect that by time you go to all the trouble you'll be right back up in the cost with muffers that are already approved however.

Swifts are definitely good looking and a testosterone rush, ...but only for looks. Mechanically, economically, practically, and by design, the Cessna 170 is a far better airplane, especially the A and B models. They haul more, farther, less expensively, and more reliably than the Swift, and look damn near as good doing it. They are a lot cooler than Swifts in the summer, and far stronger structurally. And you can spin 'em, too. Fran is so mad at Goody for tradin' the B-model for a Swift,

, he may not get any for the rest of his natural life. (Of course, he mightn't have any time for it anyway. He's kept too busy rebuilding and rebuilding the gear trying to stop the oleo's from leaking back down.)

zero.one.victor · Post by **zero.one.victor** » Sat Mar 15, 2003 10:40 pm

Everything is a trade off--which airplane is "better" depends on the mission. True,you have to pack pretty light (toothbrush,change of socks,and a six-pack!) with a Swift,and it's only a two seater,but they're more aerobatic than the 170 and cruise at over 140 mph on 145 horses. A friend sez he sees close to 150 at 2550 with his. Some people say the Cub is the best one of them all,it can't carry much either and only goes around 80!

Eric

Post by **GAHorn** » Sun Mar 16, 2003 5:28 pm

The Swift is specifically limited to 140 mph in level flight and is placarded against spins. It's a high maintenance airplane. It is not as structurally sound as any 170 model (you'd certainly not want to be in any of those Swifts that have nosed over upside-down.) Unlike the Swift, the 170 does not have a history of inflight wing-failure and loss of wing skins. The 170 has a protective, structural "cage" consisting of doorposts that surround it's cockpit, and all 170's may be spun in the utility category.
Swifts are pretty, in the imagination of Walter Mitty fighter pilots like me. But good-looking and useful? I chose a 170 after examining numerous Swifts.

Post by **GAHorn** » Mon Mar 17, 2003 4:10 pm

Getting back to the original discussion under this topic: The correct PN tailpipes are neither "forward" or "rearward". They actually exit slightly forward and to the outside (left/right).
Relative wind is insignificant with regards to "backpressure", etc. The cut-face of the tailpipe was oriented to minimise exhaust staining and heat upon the lower cowling.

sj · Post by sj » Mon Mar 17, 2003 4:16 pm

Thanks, George!

That is the way mine look now.

sj

Watkinsnv · Post by **Watkinsnv** » Sat Mar 22, 2003 5:04 am

Sorry it took so long to get back, but I went to a IA seminar today and I knew the Continental rep would be there. He said he owns a C-140 with a Cont C-85 and had the same question. He says it has to do with the Cessna certification not Continental. They found that with the slant facing aft creates a burble that actually increases the back pressure and that with the slant facing forward there is a low pressure created on the aft side that helps the exhaust exit. Hay, did I run the tests? No Was the plane certified with the slant facing forward? Yes Lance.

zero.one.victor · Post by **zero.one.victor** » Sun Mar 23, 2003 6:26 am

gahorn wrote:The Swift is specifically limited to 140 mph in level flight and is placarded against spins.

George,(how can I put this diplomatically?), I suggest that you check your source of information on Swifts. It's true that they're placarded against intentional spins,but I asked a Swifter friend of mine about the speed limitation you cite and he told me there is just the VNE (like any other airplane),which for the Swift is 185 mph. He is very knowledgable,an A&P & ex-airline capt,lots of aerobatics and formation time,has had several Swifts,& has owned his current mount (IO-360 Lycoming equipped) for over 20 years. So he knows his shi....er,stuff.
I would have to guess that any in-flight wing failures and skin-shedding by a Swift are not necessarily due to any inherent weakness as compared to a 170,but more likely are due to the airplane being accidently over-G'd by a pilot doing aerobatics &/or getting over-enthusiastic with his recoveries. Not a lot of 170 pilot's out there doing aerobatics,so naturally you would less of these types of failures.
I really like 170's,or else I wouldn't own one,but I'm not afraid to admit that there are some other good ones out there.

Eric

Post by **GAHorn** » Mon Mar 24, 2003 7:31 am

Eric, my source of information was the Type Certificate Data Sheet, available online at the FAA website. It specifies the 140 mph limit, as I stated.
There are many who believe that since the old certification standards did not specifically prohibit certain aerobatic manuevers, that many of those old aircraft (including the Swift) are therefore up to aerobatic standards. This is neither correct nor prudent. An excellent example are the early Aeroncas. Although a Champ may eventually have developed into a Citabria, it would be very foolish to perform the manuevers approved for a Citabria utilizing an old Champ, legal though it may be. (There are lots of legal ways to kill yourself.)
Airplane owners are a proud lot, and pride of ownership can sometimes exceed actual design limits. Therefore many pilots, qualified aerobatically and not, have attempted such manuevers in such airplanes and found themselves in a smoking hole in the ground. The Swift had several serial numbers in which the incorrect rivets were used to attach wing skins. Many years of polishing further removed sufficient metal to effectively weaken the bond even beyond the erroneously original flaw. My information regarding the loss of airplanes from wing failure came from actual photographs shown me by the accident investigator, a retired Eastern Captain, who spent his last years in the Philadelphia GADO, at lunch immediately following a check-ride he administered to me. They were not pretty.
Notwithstanding those examples and statements, the Swift certainly is a fascinating and attractive airplane, although with a mediocre record when compared to the 170.

zero.one.victor · Post by **zero.one.victor** » Wed Mar 26, 2003 6:44 pm

Well,shut my mouth and call me Shorty! I checked the Swift TCDS and by George! (get it?) you were right--"airspeed limitations--level flight or climb: 140 mph"! I apologize for doubting you (this time!)

Now to take my Swifter friends to task for not knowing about this--or admitting to it.
But I have to say that it's kinda wierd to have more than one VNE limitation--never heard of that before. Why would it be OK to go 185 in a dive but be limited to 140 in level flight?

Eric

zero.one.victor · Post by **zero.one.victor** » Wed Mar 26, 2003 7:00 pm

Well,I just got an email from one of my Swifter buddies. He sez that the 140 mph limitation,under the old CAR certification regs (specifically CAR 4A),is "the top of the green".The top of the green is the maximum structural cruise airspeed in smooth air. For the Swift (under CAR 4A), this is the same as maneuvering speed--the speed where full application of elevator will result in maximum G load for the airplane.The redline is 185. Between 140 and 185 is in the yellow.
For the 170 (certified under CAR 3A), maneuvering speed is 115 while max smooth air speed is 140. Yellow is 140-160,redline is 160.
Seems like the CAA could have worded it better,but that's how it was explained to me,and it seems to make sense. But that's not how it seems to read on the TCDS.
Oh,I went for my first ride in a Swift yesterday. I can see why those guys like them so much! Even with only a C-125,it was a rush. Love them rolls!

Eric

Post by **GAHorn** » Sat Mar 29, 2003 6:03 pm

zero.one.victor wrote:Well,I just got an email from one of my Swifter buddies. He sez that the 140 mph limitation,under the old CAR certification regs (specifically CAR 4A),is "the top of the green".The top of the green is the maximum structural cruise airspeed in smooth air. For the Swift (under CAR 4A), this is the same as maneuvering speed--the speed where full application of elevator will result in maximum G load for the airplane.The redline is 185. Between 140 and 185 is in the yellow.
For the 170 (certified under CAR 3A), maneuvering speed is 115 while max smooth air speed is 140. Yellow is 140-160,redline is 160.
Seems like the CAA could have worded it better,but that's how it was explained to me,and it seems to make sense. But that's not how it seems to read on the TCDS.
Oh,I went for my first ride in a Swift yesterday. I can see why those guys like them so much! Even with only a C-125,it was a rush. Love them rolls!

Eric

Eric, be careful with how little salt you take your buddy's comments. The "top of the green" for the Swift AND the 170 are both 140 mph. That IS NOT THE MANUEVERING SPEED! (Nor is your definition mentioned above, the correct definition of manuevering speed.) Also, the top of the green is not the "max smooth air speed". It is merely that speed at which 1800 fps vertical gusts are tolerated by design. (The yellow arc is 900 fps vertical gusts. The yellow arc is sometimes referred to as a "smooth air only" range. ) That data is applicable to a new, undamaged, and/or properly maintained airplane. No data exists for 50-plus year old airplanes that do not meet their original design. In his prideful enthusiasm of Swift ownership, your buddy may be playing test-pilot with you aboard. And unless he's a CFI and giving flight instruction to you which pertains directly to the aircraft's handling/performance within it's approved flight envelope or an additional rating, the flight manuevers you imply he is demonstrating are likely violations not only of the aircraft limitations but also of operating regs. (Rolls are definitely a no-no unless the above requirements are met and/or parachutes are worn.) See FAR 91.307(c)

zero.one.victor · Post by **zero.one.victor** » Sun Mar 30, 2003 3:43 pm

Well,he is a CFI,but no parachutes were worn--I'm sure he wouldn'ta broke any regs so I guess we didn't really do any rolls--I musta just been spacially disoriented!
I think I didn't explain the speed limitations thing very well. Top of green IS 140 for both the 170 & the Swift,maneuvering speed is 115 for the 170 but IS 140 for the Swift per the TCDS as I recall.
George,please explain maneuvering speed parameters for me,thanks.

Eric

Post by **GAHorn** » Tue Apr 01, 2003 9:12 pm

Manuevering speed is that speed at or below which full, coordinated, abupt control inputs will not result in permanent deformation of the airframe. In such cases, the airplane will either successfully complete the manuever, or it will stall (thereby relieving the flight loads.) It is arrived at by comparison of design flight loads against actual loads imposed during such manuevers, and relating them to loads incurred during 45 fps gusts during the manuever. If it is not possible to apply full, abrupt inflight control inputs without damage to the airplane or exceeding design load factors, then a manuevering speed is not published.
The Swift has no published manuevering speed. Manuevering speed is not mentioned in the Swift TCDS. One cannot simply derive one because it would be convenient to have it coincide with the top of the green arc. The Swift is placarded against any aerobatic manuever. Unlike the Cessna 170, the Swift is not approved for Spins, simple Chandelles, Lazy eights, or even Steep turns. Some Swift owners would like to convince others that because the Swift looks like a some fighter airplanes that it is capable of certain fighter-like manuevers. They like to claim that the only reason a Swift isn't approved for aerobatics is because the maker didn't want/couldn't afford the costs of such certification. Baloney.
The reason Swifts are placarded against any aerobatics is because the maker didn't want/couldn't afford the costs of design and manufacture necessary to make the airplane safely manueverable even in mild aerobatics. The airplane was already too heavy for it's original horsepower and the alterations and strength necessary to make the airplane aerobatic would have driven it beyond the limits. Later horsepower upgrades didn't address the problems of strength and unpredictable handling in unusual attitudes the airplane suffers.
A barrel roll is certainly a 1-G manuever if properly performed. The airplane doesn't know about it. Only a conscientious and intelligent pilot would know if he's violating the airworthiness certificate limitations, if the manuever is properly performed. The legality of a particular manuever is the responsibility of the pilot. I'm not trying to be the judge of that. I'm only addressing the issues of relative strength and flying qualities of the two airplanes.
Do you imagine for a moment that a manufacturer of an airplane capable of aerobatics wouldn't at least have the airplane approved for Accelerated stalls, Chandelles, or Steep Turns even? The makers of the Swift said "No." The test pilots said, "No." The airworthiness authorities said "No." (I used to have an instructor who'd ask, "What part of - "No" - don't you understand?")

The Swift does not have a manuevering speed listed for a reason. It's the same reason it's placarded "No Aerobatic Manuevers".
Unlike the Cessna 170.
This msg thread is way off topic.

sj · Post by sj » Wed Apr 02, 2003 1:53 am

And the people said "Amen" and let's eat...

N170BP · Post by **N170BP** » Wed Apr 02, 2003 5:59 am

So what was the group called that flew 4 (I think)
Swifts in a formation aerobatic routine on the airshow
circuit for awhile (I saw them at Sun & Fun a few years
ago).

Did these guys beef up their Swifts? Or just keep one
eye on their wingmen and one eye on the G meter?

Not trying to be argumentative, just wondering how
these gentlemen dealt with what they most surely
knew (i.e., the Swift was never certificated for aerobatics).

I fully realize other aircraft have been put through their
paces on the airshow circuit which were never built to
do aerobatics per-se, but I'm still curious about what
said operators do to hedge their bets so-to-speak.

Bela P. Havasreti
'54 C-170B N170BP