Tracking the conception, birth and life of the 172

The Cessna 172 is the most produced airplane in the history of aviation, whether commercial or military, domestic or foreign, or by any other categorization. Its big brother, the 182, is the second most produced–but so far behind that neither it, nor likely any other airplane, will ever catch up.

And I had been involved with the 172 from the time it was a glimmer in the eye, or a worried thought in the mind, of Cessna management until the finality of the accelerated service test that proved conclusively the durability of its “new” fixed nose gear.

50s Cessna 172
The original Cessna 172 was basically a 170C with a nose wheel instead of a tailwheel.

On the 50th anniversary of its first flight, I was feted–along with four others who were there “at the beginning”–as one of the designers of this record sales-setting model, along with the pilots who flew the first flights of the prototype and first production airplane.

The ceremony was held in Wichita by the Aircraft Owners and Pilots Association and I quite happily accepted the accolades that went with it.

But I had a couple of shadowy memories that tempered my feelings about my deserving those honors.

In the early 1950s, the sales of the predecessor Model 170 were perking along nicely, but two competitors made available for sale modifications that introduced a novelty that was getting some attention–a fixed tricycle gear. One was by an actual airplane modification company that even did it on our own airplane, the 170, offering a (I think certificated) version with that different type of gear. Our Chief of Flight Test got to fly it, liked the ease of landing but in general was ambivalent about the mod.

The other was more serious – because it was one of our major rivals, who offered a tricycle gear version of their tailwheel airplane, the Piper Pacer. They called it the Tri-Pacer and it was selling well. (Our other major competitor, Beech, had with its Bonanza a single engine, tricycle gear airplane, but it was of the retractable variety. And we were already comfortable with that idea on our recent high performing twin engine airplane, the Model 310.)

So Cessna management wanted to get an assessment of replacing a tail wheel with a nose gear on a modestly performing, fixed gear airplane like the 170. They acquired a Tri-Pacer and our group leader selected a team, pilot and observer, to conduct a mostly subjective evaluation of it. I was the lucky observer who was picked for the job.

Here are the tradeoffs we considered, before and after conducting the trials:

Favorable

  • Easier to fly, in takeoff and landing. With a tri-gear an airplane would be at an attitude where it would almost take off by itself. But most importantly it conclusively resisted the sometimes difficult to control and dangerous ground-loop usually caused by strong crosswinds in landing.
  • Visibility over the nose was much better, an advantage in taxiing.

Unfavorable

  • The increased drag over a tailwheel configuration, which would decrease cruise speed and, relatedly, reduce range.
  • The susceptibility to damage to the nose gear on soft or rough ground–and the 170 was an airplane often used on unprepared fields.
  • Difficulty in taxiing in strong winds, with less moment arm available for the nose gear to provide turns compared to the tail wheel type.

I leave out such later concerns as the ground attitude possibly limiting the propeller diameter that could be used, and the need for a centering device for the nose wheel in flight, to keep it from affecting directional characteristics.

Piper Tr-Pacer
The Piper Tri-Pacer, the airplane that accidentally helped to create the iconic Cessna 172.

Of course our pilot’s opinions on the Tri-Pacer were more important than mine (I had flown the airplane a little during the evaluation), and he was absolutely captivated with how much easier and safer it was to fly, particularly in take off and landing naturally, than a tailwheel airplane.

He even noted that after initial touchdown with a tri-gear the airplane nose lowered, reducing lift and resisting any tendency to rebound into the air. His attitude was even more surprising to me because he was a former fighter pilot who typified the idea that a good landing was any that you walked away from.

My analytical reasoning as an aerodynamicist, and low-time pilot, was that you spent about two minutes each in a flight doing a takeoff and landing, and maybe four hours of cruising where you would sacrifice speed and range. And since I had only flown tailwheel airplanes before this and never had any problem with ground looping, giving up about 5% of cruise performance seemed a large penalty. I was not adamantly opposed to the pilot’s views, and don’t really remember the report we authored, but I’m sure it highly favored the tri-gear approach.

I’ll get ahead of myself here and note that when the sales of the 172 took off (like a tri-gear should) I was embarrassed that I completely missed how important that easy and safe flying was to the host of new pilots it attracted. They were mostly interested in faster transportation (for business or pleasure travel), not just the thrill of flying, and the tri-gear made it possible to conveniently do it for themselves.

That lack of recognition of the importance of easiness to fly to novice airplane owners and users was my first shadowy memory about the 172 development that tempered my satisfaction with my participation.

Still the company was not yet committed and we had proceeded with the next model change to the continuing 170 line, the 170 C. The main change to it was to replace the old elliptical-shaped tail surfaces with modern, more efficient straight ones, like we already had on the 180. And their design was a task I was given, to be done along with the myriad other projects we had going at that time. It was not a technical challenge and sort of slipped my mind, but as a reward it got me the opportunity to fly some of the tests of the 170C prototype, which we went so far as to certificate.

Cessna 170
The Cessna 170 was dropped soon after the introduction of the fast-selling 172.

And then the sales of the 170B begin to slip. Quickly, and secretly, work on a tri-gear version began, using the 170C as a foundation, with the main effort being to design the nose gear and its installation in the airframe. About this time I transferred to Cessna’s Military Airplane Division to work on the T-37, and the next thing I knew was that the tri-gear version of the 170 was introduced, and was called the 172. And its sales were so good that the 170 line was essentially discontinued and any concern of the Tri-Pacer as a serious competitor discounted.

But I got a chance to re-enter the 172 development when it was decided to conduct an accelerated service test of the airplane, intended mainly to prove, and improve, the durability of that new nose gear installation. It was to be done on the first production airplane, which became sort of another prototype, and to quickly accumulate one thousand landings (and takeoffs, it was demanded they be equal) of a practical, perhaps rugged, nature.

So all kinds of Cessna employees who were pilots, but not just professionals, were solicited to participate. It was to be conducted continuously (I guess some got time off work), on the East side of the field at the Pawnee Plant, where the airplane was being made, but way East so as not to interfere with traffic at adjacent McConnell Air Force Base, and to use a pattern altitude of 300 feet to stay well below their approach and departure paths.

That prescription resulted in short “circuit” durations, and got a lot of exposure in a short calendar time. The testing was extended to take a period of about two months, during which over 2000 landings were executed, with a total flying time of less than 160 hours. I flew only a couple of evenings, after work at the cross town T-37 plant, and recorded a case where I did 32 landings in less than the scheduled two hours. That’s about three and a half minutes per circuit, just under the average of all flights in the service test, for which the circuit time was closer to four minutes. There was no traffic control to inhibit you, and no other airplanes were scheduled to use that area.

New Cessna 172
The modern 172 shares many features with the original.

There was a hard surface runway on East Pawnee field, but participants were encouraged to use the adjacent sod as well (I don’t remember it as very rough), and themselves select various takeoff and landing speeds and techniques for a well rounded exposure to real life utilization. Since the test was conducted on the first production airplane, I assume other production airplanes were delivered before the accelerated service evaluation was completed. And although the service test results recommended some modest changes, like some beef up of the supporting firewall, I believe all the airplanes were delivered (though it’s possible some were retrofitted) with a demonstrated and proven durable nose gear installation.

Then many years later I read in a book that I had designed the empennage on the initial 172, the only major change to the 170 other than the nose gear. I thought the author was mistaken, because I had no recollection of doing that. I did concede that I might have forgotten it in the swirl of other activities we undertook at that time. But the author knew more than me, because the 170C airplane was translated wholesale to become the 172, with the exception of the substitution of the nose gear. And I had designed the new empennage for the 170C, so in effect also for the 172.

That I had once, and now again, forgotten about designing the 170C’s new tail was yet another disconcerting thought of mine related to the 172. It served mainly as an admission to myself that the tail design probably wasn’t such a wonderful technical breakthrough. And recognition that, more importantly, the long term record sales of the 172 was a truly unusual business success.

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32 Comments

  • Thanks for a great nostalgic piece. We all love 172s.

    I couldn’t help but note the part where you said: “I’ll get ahead of myself here and note that when the sales of the 172 took off (like a tri-gear should) I was embarrassed that I completely missed how important that easy and safe flying was to the host of new pilots it attracted. They were mostly interested in faster transportation (for business or pleasure travel), not just the thrill of flying, and the tri-gear made it possible to conveniently do it for themselves.”

    All these years later, and we’re still expressing collective scorn about the motivations of “new pilots” who seem to hold transportation in higher regard than aviating (see Dick Collins’ recent piece about Cirrus pilots, and the many comments it drew – including my own).

    • You have made me feel better. I realized we were in a new era when I visited Cessna’s Commercial Division at the Pawnee Plant about two years after the 172’s accelerated service test, and the factory doors were opening about every 30 minutes and a new airplane was rolled out. I hadn’t even imagined that was possible. And then I learned that offering several color choices that matched interior and exterior schemes was more important than the aerodynamic refinements I had spent so much time doing.

      • I have another heresy to relate. About the time for the 172, and with the recent and prospective successes of Cessna’s low wing M310, T-37, and M620 I did a preliminary design of sportier appearing, low wing versions of the 170-172 and 180-182, so we would have a family of good looking low wing aircraft. They didn’t resonate with Cessna management. Given the success of the 172 and 182, they may have been right, though I notice that Wikepedia’s list of later, competetive airplanes to the 172 all are low wing configurations.

        • Harry! Are there any sketches of your “sportier appearing, low wing versions of the 170-172 and 180-182”?? As the former owner of a ’59 Square Tail 172 and sometimes operator of a ’59 182, I’ve always wondered how one might be transformed into a low wing! What did your preliminary designs look like?

          • I kept the conceptual 3-view of one of those designs just for nostalgia purposes when I left the Commercial Division for the Military Division to work on the T-37, and still have it. But it is out in the garage closet, cause my wife won’t let me keep such stuff in the house. Of course it is a drafting table size drawing, not a sketch, and not fancy. I think I could find it, but I’m not sure how to get it reduced in size for handling purposes. If you want to continue with this, write me at: harry.clements@yahoo.com

    • I learned to fly TW a/c (never had and never even saw a ground loop) and probably had a thousand hrs before I started to fly tri gear, so perhaps my comment does not apply for everyone. From my viewpoint, the biggest advantage to tri gear is taxiing is much easier. One sits so to see easily.

      W/ tailwheel airplanes, wheel landings are certain and smooth, though care is needed when lowering the tail.

  • In the early 1970s I flew both the 172 and the 170 on very long cross country trips. I dearly loved both planes. The 170 was my preference only because of the tailwheel. I know it is only wishful thinking but wouldn’t it be a wonderful thing if Cessna would put the 170 back on the assembly line at a reasonable price? 🙂

  • My 172 turns 50 on 29 September this year. It’s a ’63 model D, that was certified on 29 Sep 1962. I’ve had it three years now, and dearly love the old gal. She’s almost a quarter of a century younger than me, but I like younger gals.

    Her name is the “Ruptured Duck”, with appropriate nose art, commemorating the original Duck that hit Tokyo in 1942. She’s fun and reliable. I’ll stick with something simple and straightforward. Thanks for making such a good bird.

  • I had never flown this aircraft before, actually, I flew it in the FSX. But I usually fly C152, so I like so much Cessna aircrafts. Maybe I’ll fly it in my IFR flights…

    Very good article…

  • My L model 172 is over 40 years old. It’s simply a good, economical and very reliable bird. In my 6 years with it I have only had one “no go” due to the aircraft (flat tire). Cessna got it right and the numbers sold prove it. Having previously been co-owner of a Skylane I have tried to find reason to leave the 172 and upgrade. Each time I conclude what so many others have. It serves my mission needs, does nothing great but, does everything well. It’s truly a classic.

  • I started my pilot training in a C152 and finished in a C172R. I now own a variant, a C175B. It’s a 1961 with the geared O-300,[ GO-300 ]. The 6 cylinder Cont is so smooth and the slow turning prop,[ 2,400 rpm] adds to the quieter interior. With the 84 inch, 67 pitch prop, we fly at 148 mph at 3,100 rpm…
    It is truly a good ‘ol bird.!

    • My bird has a DNE speed of 142 mph. I cruise at about 110 mph usually. Lots of countryside to see and enjoy.

  • Abosolutely adore the C172 & C152, spent many a happy hour in them. Thanks Mr.Clyde Cessna for helping me to attain a childhood dream,that of “slipping the surly bonds of Earth”. Also Many ,many, many thanks to my Wife Anita for manipulating the Family budget in such a way, that no-one went short,all the bills were paid and still the “old man” got to fly!

  • Thanks for this story – I’ve spent many hours in the 172 from the N models all the way up to the G1000 sp’s which are my favorite. Being the ripe old age of 39 I would never have known the backstory behind the bird i’ve come to know at almost the molecular level. Thx again.

  • Learned from your story. Have really enjoyed owning and flying the 172….never have any empty seats. We need to share what we enjoy.

    • Sorry for not answering sooner, but had a bunch of visitors from out of town last week. The one place I am sure of for having a photo of the 170C is Bill Thompson’s book “Cessna Wings for the World” the Single Engine edition.If you can’t access that I may have one around but would have to find it.

  • Never liked the 172 for the simple reason that I couldn’t see out of it without leaning forward. Was always blind turning from downwind to base, turning base to final. Really loved my Cherokee, Mooney, and several Bonanzas as well as the C-340.

  • Couldn’t help but catch the ‘big brother’comment about the 182, reminding me of my initial 172 checkout in “a big 150,” as my CFI put it. I can’t help but be saddened, though, to think that the Skyhwak, so classic an example of “Everyman’s airplane,” would ever become, at it’s current pricing, “Everyrichman’s airplane.” When you think that in the late 70s, a new, IFR equipped 172 sold in the low/mid $30s, how many ‘Everyman’ flames are doused by the thought of a quarter million today?

  • Boy, I would sure love to read a similar piece about the 182.

    I have often wondered who I have to thank for such a wonderful piece of engineering. I have a 1979 TR182 and it is truly one of the most prized “things” in my life.

  • Over 47 years ago, I soloed on my 16th birthday in a 150. Transitioned to a 172 a couple of years later and it sure felt like Big Iron to me. Stayed with the 172, later convinced a friend who learned in those low wing types that the 172 was the way to go for an airplane partnership. After all, who ever saw a bird with the wings attached to the bottom of the bird’s body? We bought a 1975 172M in 1982 and flew it for 30 years before moving up to a 182. We flew it from NC to the Bahamas and to Texas for the CAF Airsho. Sometimes we would check the groundspeed and be glad we were IFR and couldn’t see the cars on the interstate below passing us! Sold it to a young pilot who upgraded the engine with a 160hp, added the Powerflo exhaust, did some cosmetic work and is now flying his wife and 3 year old around, enjoying the flying life at a bargain price. Great airplane; Mr. Clements, I would love to be able to shake the hands of you and others who designed it – thank you for helping me to create so many memories.

  • I really enjoy your articles. although they make me wish I’d found an occupation I enjoyed and could be as passionate about, as you obviously did.

    I’ve been long debating on what model of airplane fits best the compromise between the performance and features I want and what my bank account can withstand, and have decided that I will soon be shopping for a C170B. I have a fondness for the older airplanes and went out of my way to take primary training in tailwheels, and will fly off a grass strip. I really wish Cessna had produced them for a longer period of time so it would be easier to find a good clean 170 to buy.

  • Thank You Harry for the “other side” of the 172. As few know there was a rather large gap between the Engineering and the Sales departments at Cessna during the “go go days” of the late 60’s and mid 70’s. For those of us who populated the “marketing” divison you engineers hit most of the right buttons – but without the background of WHY, we sales types, who were challenged with converting all that aluminum into dollars, had to rely on such impotant things as paint, steps and handles, and wheel pants. I represented Cessna in Canada for 7 years and assure you that the tail wheel airplanes converted to skis and floats a whole bunch easier than one with a nose wheel. While I was delivering the 5,000th 180 to a customer at the island airport in Toronto he asked if there was a conversion for that airplane to nose wheel because he learned to fly in a Skyhawk and did not like this “old” style airplane. Not good, not bad, just different. Our dealer had a Skylane in stock but was so oriented toward float operations he had not offered it to the customer.

    • Hello Morris

      Good to hear your name again. They certainly were different times in aviation during the go go days.

      Sandy and I are enjoying retirement in Victoria.

        • As Morris has pointed out the 1960″s and 70’s were an interesting times at Cessna. I’m not sure that everyone remembers the introduction of the 177 Cardinal for the 1968 model year and that the production of the 172 was actually stopped, not a popular move with Canadian dealers. Cessna had great plans for the 177 which was to be the sleek and sexy product to compete with the Cherokee, buyers at the time thought the low wing looked cool, the 177 cockpit view was ahead of the wing for visibility in turns. Morris also pointed out to our customers that you don’t see any birds with the wings on the bottom.

          Well the Cardinal launch was, to be polite a challenge, the 1968 model was not a bad aircraft but it didn’t fly like any of the other Cessna models. One of the issues was that it was under powered, in 1969 it was increased to 180 hp and in 1970 to 180hp with a constant speed prop and cowl flaps and a new wing which turned it in to totally different aircraft.

          The problem for Cessna was they had ordered 150 hp engines like cord wood and the Dealers wanted the 172 back. The 172 was put back into production during the 1968 model year with the Lycoming in place of the Continental 0-300 145 hp. Now I know the increase of 5 hp doesn’t sound like much but it did make a big difference on take off especially on floats as the the 4 cylinder Lycoming seemed to wind up faster than the 6 cylinder Continental. On floats it still wasn’t a great performer but as long as you stayed out of the mountains and didn’t put anything in the back seat heavier than a Tunafish sandwich it was a lot of fun. During my time with Cessna in Canada you didn’t actually have to sell 172’s or 185’s you just filled in the order pads. Morris may remember the day I refused to take a rather large order from a dealer until he gave me an order for a Skylane.

  • Nice article, thanks for your time and contribution…any comments or info on the 620 would be interesting as well

  • To T Ibach: There is another Air Facts article, written by me, entitled “The Cessna Model 620 – the Stillborn Prodigy” dated in April 2012. An interesting aspect is that the decision to scuttle the airplane was a contentious one, so the prototype and all engineering related to the project was destroyed – except the wind tunnel model, which had been stored in the Experimental Hangar attic and forgotten – and is now on display at the Kansas Aviation Museum in Wichita.
    Harry Clements

  • I’ve owned my ’75 C172M for 34 years and still love it. It does everything OK and — for MY flying needs — there’s no reason to upgrade. There are so many around that parts are easy to obtain … that in itself is a major consideration. It likely explains why the “M” models are SO in demand these days. The airframe is essentially the same as a new one save for the flat panel. I upgraded the 150hp to a new 160hp and the performance gain is both noticeable yet uses very little more fuel. I describe the airplane as a V6 stick shift radio and heater airplane.

    Here’s another story. Since I’m now retired and move back and forth between homes in FL and WI, I decided to buy a second airplane to leave up north. I found a creampuff PA28-140 Cherokee and kept it for 16 years. Even though that low wing airplane is supposed to be equivalent to the 172, it isn’t. Starting with climbing up on the wing and down into the cockpit, tight for maintenance and smaller instrument panel, the airplane is just OK. Recently, I decided to consolidate my flight ops to one location so one airplane had to go. Even tho the PA28 was a cream puff, I let it go. At age 71, ingress/egress to the 172 is SO much easier.

    Bottom line on the story … that you’re idea of a low wing airplane didn’t “fly” is probably a good thing. For me, the high wing and two doors and ingress issues is what made me keep IT vs the PA28. For many years, I kept the 172 at Mojave, CA where the winds blow incessantly. I’ve landed that airplane on one wheel dozens of times and it still survives. In a wind … I’ll choose the 172 over the PA28 all day long, too.

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