How would you change the Cessna 172

[golball59]

Firstly, sorry if this is not considered a tech Q.

I am currently conducting an investigation into how to improve the Cessna 172 design (about 60 years old!), taking inspiration from 'next generation' designs such as the Diamond DA40.

I would like to have any of your insights into how you think it would be possible/desirable to change the design (eg. composites/new engine/ higher cruise speed etc). Obviously I need to take into account that all aircraft design is a compromise between performance/price/maintenance etc, but I would value other people's opinion.

Thanks

[Peter Fanelli]

Preferably by burning.
However if you insist, do whatever is necessary to turn it into a 182.

[Tinstaafl]

Before anyone can answer you need to refine your question ie change the C172...to make it better at what?

If hold 4 bums + lots of fuel + some bags then the answer is: Trade it in on a C182. But if the answer is to fly with 2 or 3 adults and only occasionally take 4, and long range isn't too important then the answer might be to do nothing.

I like the C172. I think it does a good job in its niche. Having said that, more nags under the cowling is usually appreciated until I have to buy fuel or maintain additional cylinders &/or turbos. Lots of avionic goodness is always appreciated - unless I have to pay for the installation, repair or subscription weather services.

The sorts of changes I'd make apply to damn near every aircraft I've flown:

* More storage space (racks/bins/compartments) for charts, approach plates & POH size books.
* Bigger vents and more of them so that lots of airflow can be brought in & directed where desired. Except for the BN2 Islander. Why the hell designers from a cool to cold country couldn't manage a steering linkage that didn't allow an icy blast through into the footwell is beyond me.
* Places to put pens/pencils
* Approach plate holder. Not just strong enough to clip on a page removed from Airads/Jepps but also able to hold a bound booklet *and* provide support so anything clipped there doesn't flop around. Also put in a position that doesn't obscure things and has a narrow spot of light directly onto it.
* 12v power outlets all seats, even in 24v aircraft
* Sunvisors that work no matter where the sun is.
* Decent control locks
* All cylinder engine data monitors (and balanced injectors, if appropriate)
* Certified to run on alternate fuels. I tend towards avtur because of its ubiquity.
* Standardised parts eg L&R tailplanes, elevators, ailerons & flaps and the like to be mirror images of each other so that repair & replacement is cheaper
* Centralised warning lights eg the way later PA31s have them all on the coaming instead of scattered all over the bloody place like earlier models.


Probably more if I thought about it longer but it's time for bed...

[Genghis the Engineer]

All aircraft design is, hopefully, aimed at a specific purposes.

The C172 is used for many roles, from flying training to border patrol (yes - really: the Irish Air Corps use them for this).

Before identifying potential improvements, first you need to work out what you want to use it for.

It's also worth bearing in mind that Cessna have been changing that design for most of those 60 years already.


That said, purely speaking from piloting enjoyment, yes, I'd turn it into a C182 !

G

[low n' slow]

I flew the C172 with and without the retractable gear during my training and found it to be a comfortable plane to learn to fly in. The RG version hangs a little better in the air and is a very nice IFR platform for the IR training.

On the basis that this aircraft is supposed to do just this, otherwise, the 182 would be the better choice for travel, perhaps anything that makes it cheaper to operate would be good. Wherever you can, reduce drag, find a more efficient engine etc.

/LnS

[captjns]

Send it to the Gillette Company so they can manufacture more razor blades. or the Coca Cola company so they can make soda cans out of it.

[Janu]

Like others have said - turn it into a 182rg!

[KiloB]

Put the Wing on the bottom, so you can see where you are going in turns!

KB

[golball59]

Cheers for the opinions guys.

My thought was that compared to, for example, a DA40-180 Fixed pitch, the 172 is similarly priced, and has a slower cruise, higher fuel burn (as far as I can tell) and has a similar useful load.

So why would anyone still buy the Cessna over a DA40??

If it was made from something other than coke cans, as captjns said, (ie composites) and used a powerflow exhaust, maybe a new airfoil and addition of constant speed prop....do you think that would appeal to pilots? Or would that cause costs that are unnacceptable (and do you think this is too close to the current 182??)

Thanks again

[bfisk]

On a more serious note: put a parking brake in it that actually works. Never found one!

[bearfoil]

It already is everything it can possibly be. Trying to turn an airframe into wonder woman is a big mistake. Eventually one is spending more money than the cost of acquisition of the "step up to" machine. I thought RG on the Skylane was a waste of money and other things. I simply purchased a T206, "gear down and Fixed". If speed and complexity is your thing, the 210 fills the bill. The 152 is a waste of aluminum, as a trainer, it is too cramped, too noisy, and too old. the Skyhawk is a swell trainer,with FI especially. As a Cross Country bird, it sucks. Not enough fuel, speed or Useful Load. Enter the Skylane,etc. Four Fannies, big Fuel, and cargo means 182, 206,or 208. With the Caravan, every box is checked, and I passed on a nice used Grandy for just under a million bucks twenty years ago.

If one's goal is to make a small fortune in aviation, start with a big fortune. It's all money, marbles and chalk.

[an3_bolt]

I agree - turn it into a C182.

......ohhh and either make it sit a little higher or have a "blunt" trailing edge on the flaps - flap impression on forehead not so cool when one walks into it.....

[fleigle]

Golball
If this is a paper excercise or a thesis project then the sky is the limit at what could be done.
However, the reality in this modern world of certification standards, etc. mean that you are looking a lots of dosh to see things through.
The easiest way to improve performance is to reduce weight, or add power, no way to do this cheaply in a certified design.
In the light-sport/experimental field however there are many good things happening. If you take a look at the classic piper cub-type aircraft for instance, there are a few manufacturers here in the US who are offering their version of a modern "cub", with modern engines, and/or carbon-fibre parts in the structure.
There is an article in the recent Flight magazine about one of these,
http://www.flyingmag dot com/aircraft/lsa/sport/carbon-cub-ss
or you could check out one of the manufacturers website at the following;
http://www dot cubcrafters dot com
I still regard my initial 12 hours of piloting in a 1946 J-3 as being the most fun I ever had while flying.
Cheers,
f

[Private jet]

Slight thread creep apologies but it is pertinent to a 172.

When i did my training in Florida many years ago the examiner on a checkride told me that you could set a specific power (RPM with the fixed pitch prop) and with each 10 deg of flap the IAS would drop 10 kts, and if you timed it right you could fly around the circuit from join all the way to the landing without touching the throttle. Something like that anyway. Anyone know what i'm talking about?

[411A]

How would you change the Cessna 172



Buy up several older models, send to the crusher, and use the aluminium to construct a new 182....with a turbocharger.:ok:

[nomorecatering]

I've done about 500 hrs (instructing) in new G1000 172 SP's (180Hp) in the last 16 months. Great training aeroplane.

Get a better stall warning system, it sounds like someone is strangling a cat.

The airvent system is good, but when taxiing with the wind at certain angles you get that flapping sound through the vents......i sooo hate that.

The seats are the most comfy in the business......are you listening PIPER. You seats suck.

G1000, what can I say, simply stunning.

Landing lights poor, having only 1 stuck out on the left wing, and underpowered at that is simply not good enough. Recently I saw a new 182 with landing lights on both sides...plus wingtip aftermarket landing lights. Lit up the runway like the Sydney Cricket Ground during a 20/20 night game.

Pitch control, way too light, when i converted to the cessna after doing 2500 hrs in the Warrior, every time i tried a medium level turn I i climbed 500ft.

Nav, position, beacon lights all LED or HID. Fantastic, never have to cancel a night nave because of blown globes. And it has drink holders, doesnt that make a difference.

The interior looks nice and professional, especially the instrument panel. But the interior is still flimsy and wont look so good after 4000 hrs TTIS. Sidewall trim, especially on the doors needs to be more durable.

Wish they would replace the toggle switches for landing lights n stropes etc. Pushbutton modern switches would be mush better.

Engine, good reliable unit and easy to start, but needs to be more fuel efficient. Bring on FADEC.

Electical system, S bus, M bus, volts and amps to a decimal place. WTF...Mr Cessna, I came from an era where the alternator was working or it wasnt, and you flight manual doesnt explain anything. Can someone in Cessna please write a flight manual that explains what this fancy stuff says....Im just a dumb instructor.

Overall I love the Cessna, but still would go for an Archer 111 with a G1000, and a better (fuel injected ) engine over the Cessna.

I forgot to add, the windscreen is great except in the corners wher the light distorts. At night there is a hirrible spot after liftoff, the runway light reflects high up in the windscreen as you pass through about 50 feet, the first time I had that happen, for split seconnd i thought I'd gone inverted. very uncomfortable feeling.

Only complaint about the G1000 is at night, there is not enough contrast between the symbols drawn on the screen and the back lighting.So when you turn the backlight up enough to see the data, there is so much light there is almost nil forward vis. Wish Garmin could fix that.

[barit1]

Not having flown a 172 for a few decades -

Make the wing from composites - Lighter, & less parasitic drag

Cut back the inboard LE (a la some old cabin Wacos) for visibility

Restore the straight tail (from the 50s/early 60s) - less friction!

Constant speed prop - and integrate w/ throttle (single control knob)

Optional taildragger (like the original 170B)

Making it into a 182 defeats the purpose - consider cost of operation!

[bearfoil]

Cost of operation is a crucial point for an FBO. But an FBO isn't going to train with the Skylane, except for the HP rating, so cost is a balance between mission and money. A private owner will pay more for gas in a Skylane, but he gets to take three friends and fuel to the fishin' hole. There is a model for everyone, and I stand by my belief that a more expensive (read, capable) Skyhawk, is a poor competitor for a Skylane, a basic Skylane. Lipstick on a Pig, as it were. I would rather have a STOL kit on a skylane than retract. I recently flew the new Skyhawk, with FI and CS Prop. It was delightful, just as sweet as I remember. But I still can only take two friends and half tanks to my destination. All the other "upgrades" I see here shouldn't be considered so. Since when is a nice interior, fit/finish, and capable lighting with decent glass an option? On a 250k dollar a/c?

bear

[golball59]

Thanks very much for all your opinions guys and gals.

Anyway, all the opinions are much valued. Has given me a lot to think about.

fleigle, thanks for your advice and useful link, I want one of those!!! For the report I will of course be considering the cost of the project, however I feel it is not the main focus (the main focus being on how to improve the design if money was not in short supply perhaps), therefore it gives me more freedom to look at different materials etc.

......ohhh and either make it sit a little higher or have a "blunt" trailing edge on the flaps - flap impression on forehead not so cool when one walks into it.....

Something tells me you've had a bad experience of this in the past!! :ouch:

Make the wing from composites - Lighter, & less parasitic drag

This is the sort of thing I was thinking about. I'm trying to imagine a 172 that could compete with the DA40 in terms of cruise speed, economy etc (not placing all my efforts on its cost, although it will be a factor)

I get the impression that everyone (including me, but i'm trying to be impartial) is 'concerned' about the useful load in relation to the 182, and that will be a big consederation. But I am trying to remain within the 180hp range as a maximum, and potentially looking at slightly lower powered diesel powerplants, too.


So, in summary so far, good changes would be the following:

Higher payload?
More efficient -C/S prop and maybe diesel?
Cheaper to buy?

Thanks

[chris.dever]

RR Trent 900 ??? :E

[atpcliff]

Hi!

Take off the ICE and replace it with an electric engine, with at least 2 hours of endurance, so flight training and recreational flying will become affordable, again.

cliff
KGRB

[Sciolistes]

Move the main wheels forward, remove the front wheel and add a small one to the tail. If such a conversion tranforms the 172 the same way the 152 benefited, it would be nearly perfect :ok:

[Less Hair]

Keep it the way it is, rugged, simple, reliable, easy to fly and to repair and long lasting and build plenty of them to make it cheaper. No hightech-plugins required. They will just ruin the price.

If you prefer a cirrus buy a cirrus.

[lynn789]

what about a return to the original tail fin?
the swept back fin was criticised as lacking low speed bite

[Bubi352]

Consider using this book from www.cessna172book.com. It describes all the systems in details.

[A37575]

On a more serious note: put a parking brake in it that actually works. Never found one!

Maybe if pilots had the guts to write up the parking defect in the maintenance document instead of bitching and then relying on Size 10 boots on the brake pedals - thus teaching students wrong technique - then perhaps the mechanics would rectify the defect. There is nothing inherently wrong with the Cessna 150/2 or Cessna 172 parking brake design otherwise it would not have passed the certification process.

In my experience, the vast majority of pilots of Cessna singles use feet on the rudder pedals instead of using the parking brake when stationary. Yet funniliy enough pilots don't use this technique on big jets... And not only that, if by chance the parking brake was inoperative on a 737 et al you can be sure it would have been written up and promptly fixed. The same principle should apply to general aviation types. :mad:

If instructors did their job properly then students would use the parking brake for the purpose for which it was designed. Most parts or systems in aircraft play up occasionally and legally the pilot should record the defect and let the mechanics earn their keep.

[Max Angle]

Give it a low, cranked wing, with the inner and outer portions at different angles of attack, which gives good take-off performance and then excellent cruise performance due to reduced drag once the airspeed increases. Give it a huge wrap around canopy, large fuel tanks and the ability to carry full fuel with 4 people. Finally give a proper stick rather than yoke and pleasant, vice free handling.

Alternatively buy a Robin DR400 which already has all of the above. The best light aircraft in this class by a large margin in my opinion.

[CJ Driver]

Like the previous posters, I agree that the C172 is pretty good at being a C172, so if you think on conventional lines, you will just end up designing the C182.

But, I would rush out and buy a C172+ instantly if it had (1) no extra payload at all, (2) went 10% slower, (3) cost just as much money to buy, but (4) was as quiet inside as a typical modern small car.

[bearfoil]

Let's face it, the Skyhawk is a dinosaur. Struts. Rivets. Wing Fat. Corrodes. Fixed Pitch. Carburetor. Butt Ugly. But I made my all time best landing in one. I first soloed in one. It gets stares from any lady who isn't too into aircraft. It is sweet, docile, and forgiving, which cannot be improved upon, only degraded. Let's leave it alone.

The Robin, Trinidad, Cirrus (Angelina owns one), Swift, Stinson, etc. all have their ......cachet, as it were.

there is an a/c for any mission, even the 172.

bear

[SNS3Guppy]

The 172 was and is an excellent, inexpensive, simple design: both to fly, and to manufacture.

Most of what can be done to the 172 has already been done. That said, one of it's shortcomings was always the interior. Modern iterations of the airplane have improved somewhat, but in the quest for a lightweight, easily manufactured interior, the plastics were never a good solution. They were a pain for removal and installation, and tended to scuff and break easily. Various interior panels covered in carpet were also a royal pain.

Removal of the rear bench seat for inspections, and removal of the side panels beneath the instrument panel were always a pain in the butt, especially for frequent repeat-removals for 100 hour inspections, and the like.

The nosewheel assembly tended to be subject to shimmy; the Lord damper needs frequent rebuilding, especially when tortured by inexperienced pilots. Likewise, the engine mount and nosewheel attachment lends to firewall damage from mishandling; this could stand some improvement.

The use of the muffler shroud for heating lead to longstanding issues with the potential for carbon monoxide in the cockpit; a better design, and not one reliant on the clamping assembly that was used, would be in order. Even something as simple as no-slip slips over the end of the heater sleeve would be a big improvement.

The carb air box is weak, and a carburetor air temperature gauge would have been a positive improvement (as it ought to be on any carbureted piston powered airplane).

Modern improvements with electronic ignition would certainly be an enhancement over magnetos.

More firewall clearance for changing the oil filter, or a remote filter mounting would be nice.

The cowling could stand some improvement; they tend to wear too easily with removal and installation, and the quick fix for screws at the front of the cowling was never a good idea. It's hard to find a cowl assembly, especially on older 172's, that isn't worn through at the screw points, and that isn't using oversized washers to make up for the damage.

Later versions of the 172 used rudder trim. While not necessary, it was a nice addition. Especially for long climbs under takeoff power at higher angles of attack (when heavy).

The original Cessna ARC radios were never stellar. More modern avionics make a big difference.

The Fuel and fuel vent system, using a cross-vent between tanks, and a ram pressure vent on one side, could have stood more improvement. A screen on the vent would be nice to prevent insections such as leaf-cutter bees from entering the vent and plugging it. Likewise, the drain system for the tanks was never great, involving a requirement to raise and lower the tail repeatedly and rock the wings to ensure water/contaminant removal. Later versions of the 172 address fuel drain issues by adding numerous new fuel drain points, but this effort still failed to fix the problem, and only complicated things.

The door, while lightweight, is subject to flexing and a failure to properly lock and seal. It's better than the 152 solution, as it offers a more positive over-center locking ability, but the pawls on the door are still subject to wear and could stand to be a better design.

Slippage from aluminum seat rails has been addressed by AD, but presented an unsafe conditions which could have easily been fixed using steel parts, safety catches (later available), or a different design to allow adjustment. The vertical adjustement concept in the seat was simple, but never very good.

A means for opening baggage from the inside would have been a good idea for egress purposes.

Access to fuel lines in the fuselage, particularly beneath the floor, is a pain; better access should have been afforded in the original design.

The rear tie-down mooring ring attach point was wholly inadequate, and suffered frequent damage from student efforts in short/soft field takeoff and landing technique...leading to damage of the surrounding structure by bending the tiedown point. A retractable ring, same as the wing strut arrangement on many of the 172's would have helped solve this problem. A small wheel on a spring steel skid would also have been helpful, especially on airplanes used for substantial student training.

While the 172 was largely the essence of simplicity, it still suffered from temperature issues at climb speeds on a hot day. Cowl flaps would have been nice. The alternative on very hot, desert days, is to increase climb speed to 100 knots, but when loaded to gross, it makes for an extremely slow climb.

Despite opinions to the contrary, the 172 makes a great short and soft field airplane. I spent a lot of time flying them with people and cargo in and out of tight mountain airstrips at high density altitudes, always loaded to the gills, without difficulty. It's a very economical airplane. I did tours in them for a time, as well as charters, and they had the best profit margin of any of the airplanes we flew. They were the least expensive to operate, quite capable for their use, and in turn left a bigger profit margin than other airplanes like the 182, 206, or 207. Obviously they couldn't haul as much, but then they were different tools for slightly different jobs.

The interior air vents were never very good. Not a bad basic idea or design, but something more robust, a little more simple, would have been nice. Perhaps a simple, rotatable vent, rather than one that pulled out and pushed in, which was often subject to falling out, would have been welcome.

The fuel caps were frequently troublesome on the 172, leading to various efforts to exclude water and add ventilation.

Overall, the 172 is really hard to improve upon. Some here have suggested different spars, perhaps carbon fiber spars. I've worked on a lot of 172's, and operated quite a few, and haven't seen spar issues being a problem. The aluminum structure is easy to work on, easy to repair, and easy to inspect. I'd like to see bigger inspection holes for bellcrank and pushrod access. I'd like to have seen access panels on top of the glareshield, too. A better glareshield, less subject to cracking, with a rigid handhold for making seat adjustments would have been nice; a lot of users grab the glareshield and crack or break it; others grab the bottom of the instrument panel when moving their seat. The panel grab can cause broken wires or cause one to stick one's finger on an interior screw.

The trailing edge of the flight controls has been mentioned; later 172's used a rolled trailing edge to minimize the forehead crinkles that come from wearing a baseball cap around the 172. The original trailing edge serves best for draining the control surface, however, which aids in preventing corrosion, and preventing imbalance.

Many modifications have been STC'd over the years; some are useful, most don't do much but add expense and weight. STOL kits and flap gap seals are typical of expensive modifications that do little to improve the airplane.

Personally, these days it's hard to beat the value when considering the cost of a used 172 for a personal airplane, especially if one doesn't have far to go. Spend whatever you'd spend making modifications on fuel, instead, and enjoy the airplane just as it was designed; a simple, easy-to-fly every-man's airplane that's inexpensive to operate, that can go most anywhere you want to go, still haul a reasonable load, and won't break the bank in the process.

[Biggles78]

Haven't seen it mentioned but the Cessna made you more proficient at crosswind landings than the low wing trainers. However I didn't like the lack of view in the direction that I was turning. Did like flying the C177b an awful lot though.

[SNS3Guppy]

I'm not certain that the 172 makes one any more proficient at crosswind landings, but perhaps more proficient at landing a 172 in a crosswind. Being proficient at crosswind landings in a 172 doesn't make one more proficient at doing them in a J-3 or a B747. Just in a 172.

Much is made of visibility issues in high wing airplanes in a turn, just as much is made of the restrictions to vision in a low wing airplane.

The truth is that in the B747, I can't see cross-cockpit into a turn, either. All aircraft have their limitations, simply because we've got to have some structure around us. Even a hang glider has serious impediments to vision under various conditions. These aren't really blights on the airframe, but merely adaptations we make to each aircraft we fly.

[Machinbird]

However I didn't like the lack of view in the direction that I was turning. Did like flying the C177b an awful lot though.Heck, If they had put top side windows like the Cessna 120/140, that would have pretty well fixed the high wing visibility problem in turns. (But not like the Luscombe window on the centerline-that only helped in one direction.)

[bigjames]

the 'lift wing' maneuver is pretty straight forward and quick to check traffic before turn...

[fdcg27]

To say that the C72 is a mature design would be a severe understatement.
I'm pretty sure that Cessna has improved everything which could be improved without having to design and certify a new airframe, or add an unacceptable amount of empty weight to the airplane as it now exists.
The 172 does a good job of keeping those without a great deal of experience, like me, out of trouble.
It is a durable and forgiving machine, and has had a good record of getting the SOBs back to earth without failure in bad conditions.
The 172 is not a fill the tanks and fill the seats airplane, but it was also designed in an era when the typical American was smaller and lighter.
If you want an airplane that can usually carry four pax and full fuel, Cessna would be very happy to sell you a 182.
If you need yet more useful load, there is always the 206.
Both are more expensive airplanes that will use more fuel and cost more to maintain.

[barit1]

My Taylorcraft had an all-Plexiglas cockpit roof. It was lightly smoked, so glare wasn't much of a problem. It was the only T-craft I didn't feel claustrophobic when flying. :D

[c100driver]

The skylights were an option in the C172M, they helped but lifting the wing worked better.

As others have said the C172 is great at being a C172, if you want more speed buy a Cirrus, more load buy a 182 etc