C172 Still In Production After 60 Years.
Onetrack, I've done expert reports as a consultant for the stock market float of "new engines". The reality is that current aircraft engine technology is well understood, light and easy to maintain.
Overhead cams, variable valve timing, etc. etc are heavy and produce no worthwhile result for an aircraft engine. Advanced manufacturing techniques such as plastic flow head bolts, etc. are of no use to engines that must be rebuilt. The current automotive manufacturing technology is NOT designed for rebuilds, overhauls, etc., it is designed on the basis that the engine is going to be thrown away.
Without starting the whole Lean of peak thing again, the BSFC of the old Lycoming engines is just fine, of course there is stuff like direct injection, etc, but the technology is not only complex but Heavy and unmaintainable in the field.
There is a world of difference in design philosophy between an automotive engine that spends most of its life at 20% of rated output and an aircraft engine running at least 55% of power at a fixed rpm.
Overhead cams, variable valve timing, etc. etc are heavy and produce no worthwhile result for an aircraft engine. Advanced manufacturing techniques such as plastic flow head bolts, etc. are of no use to engines that must be rebuilt. The current automotive manufacturing technology is NOT designed for rebuilds, overhauls, etc., it is designed on the basis that the engine is going to be thrown away.
Without starting the whole Lean of peak thing again, the BSFC of the old Lycoming engines is just fine, of course there is stuff like direct injection, etc, but the technology is not only complex but Heavy and unmaintainable in the field.
There is a world of difference in design philosophy between an automotive engine that spends most of its life at 20% of rated output and an aircraft engine running at least 55% of power at a fixed rpm.
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Looking at the majority of posts in this C172 thread, I swear I was reading an 'Auto Engine' forum.
I wonder if the 'Auto Engine Forum' are talking about that 60 year old, Classic sturdy Four seater, Cessna 172, that many a PPL and CPL has flown at one time in their past, (or present as they are still producing them). Might do a google search and check.
I did predict it though.
Carry on!
I wonder if the 'Auto Engine Forum' are talking about that 60 year old, Classic sturdy Four seater, Cessna 172, that many a PPL and CPL has flown at one time in their past, (or present as they are still producing them). Might do a google search and check.
I did predict it though.
Carry on!
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I like it say 1200 -1500 throw away quick change engines.
Would increase units sold (bring down unit cost) and reduce many other maintenance costs.
What's a overhaul/new 172 motor with all fruit cost these days? $40,000+? What ever it is it is redickyouless!
If they were $15,000 for a rubbish bin job after 1,500 hrs/15 years it is $10 bucks an hour or $1,000 a year.
Would increase units sold (bring down unit cost) and reduce many other maintenance costs.
What's a overhaul/new 172 motor with all fruit cost these days? $40,000+? What ever it is it is redickyouless!
If they were $15,000 for a rubbish bin job after 1,500 hrs/15 years it is $10 bucks an hour or $1,000 a year.
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Looking at the majority of posts in this C172 thread, I swear I was reading an 'Auto Engine' forum.
Overhead cams, variable valve timing, etc. etc are heavy and produce no worthwhile result for an aircraft engine.
Something which in auto engines is really only a 'recent' innovation!
Merely a thought.
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There is no reason why the engineering advances in automotive engines cannot be engineered into aircraft engines, along with numerous other sound and progressive ideas such as rotary or sleeve valves, using current high technology.
For Gods sake man, engines are still using poppet valves, the shortest life, worst and weakest part of any IC engine design, and it's the same valve design as used in the 1890's!!
For Gods sake man, engines are still using poppet valves, the shortest life, worst and weakest part of any IC engine design, and it's the same valve design as used in the 1890's!!
But the main point seemed to be that the early advantages of sleeve valves disappeared with improved poppet valve design, and improved fuels.
Of course, it's possible that modern technology metallurgy, lubrication and fabrication could put sleeve valves on top, but if so, wouldn't the auto-manufactures have done it already?
Such R&D purely in piston aero-engines would be cost prohibitive. Any major developments such as re-introducing sleeve valves into mass-production IC engines are going to have to come from the auto industry.
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It may be thread drift, but what I'm getting at, is the companies that innovate and reduce costs whilst increasing the efficiency of their products, are the ones who are successful for longer periods of time.
I note the old line about, "sales levels of light aircraft aren't sufficient to introduce robot manufacturing".
Well, perhaps if some company had the wheelbarrow-sized cojones to introduce robotic manufacturing, the cost of the 172, or its modern equivalent, just might halve - and then more people could afford them, production would increase substantially, and cover the cost of the robotics - and GA might once again flourish.
It's unfortunate, but the following is a typical story of innovation stifled. An innovative Australian company produces a stunningly effective rotary valve for F1 engines - and the controllers of F1 racing pass new engine design regulations, effectively banning the new rotary valve, such is its inherent efficiency.
The F1 head honchos, just like the manufacturing corporations, prefer to keep the status quo in place.
Unfortunately, this innovative company, Bishop Innovation, went into liquidation in 2015 - no doubt due to one its sources of income drying up, and probably because no manufacturer was prepared to risk anything, to put the Bishop Rotary Valve into everyday production engines.
Auto Technology - the Bishop rotary valve.
I note the old line about, "sales levels of light aircraft aren't sufficient to introduce robot manufacturing".
Well, perhaps if some company had the wheelbarrow-sized cojones to introduce robotic manufacturing, the cost of the 172, or its modern equivalent, just might halve - and then more people could afford them, production would increase substantially, and cover the cost of the robotics - and GA might once again flourish.
It's unfortunate, but the following is a typical story of innovation stifled. An innovative Australian company produces a stunningly effective rotary valve for F1 engines - and the controllers of F1 racing pass new engine design regulations, effectively banning the new rotary valve, such is its inherent efficiency.
The F1 head honchos, just like the manufacturing corporations, prefer to keep the status quo in place.
Unfortunately, this innovative company, Bishop Innovation, went into liquidation in 2015 - no doubt due to one its sources of income drying up, and probably because no manufacturer was prepared to risk anything, to put the Bishop Rotary Valve into everyday production engines.
Auto Technology - the Bishop rotary valve.
Thread Drift? Not quite! I love these old "innovation stifled" stories! They always turn out to be rather far from the truth. If we take the "innovation stifled" thing to its logical conclusion "robot technology", etc., is supposed to drive the cost of everything to zero and produce marvellous things like engines that run on water (suppressed by the oil companies) and now cheap Cessna 172s.
Now about Bishop. My memory tells me that Bishop made their money by making a major innovation in automotive power steering technology that was taken up by all the worlds car manufacturers forthwith. However they may have then made the somewhat rash decision to keep innovating.
Mr. Onetrack, innovation is very, very expensive and highly risky. It mostly fails. This is why smart managers don't do it. If they are smart, they copy other peoples innovations and save their money. They only innovate as a last resort ( I can substantiate this but I'll save it for my doctorate).
So yes, robot produced cheap Cessnas with multi valve petrol EFI engines are being suppressed by Lycoming and Teledyne in a conspiracy to make flying expensive??? The truth is more prosaic.
The Bishop rotary valve was a solution looking for a problem - and it found one - an F1 engine turning at 18,000 rpm! It had little relevance to current automotive technology, which anyway appears to be going electric, it would be at least ten years from actual production and delivers no performance increase apart from perhaps reduced weight and possibly complexity (or not). And that is without taking into account the designers little devil NVH (noise, vibration and harshness). For all we know, a Bishop engine might sound like chalk screeching on a blackboard, which renders it useless.
So did the evil FIA squelch another innovation by a little Aussie battler? I don't think so. Same reason they squashed gas turbines, no relevance to todays automotive problems. Furthermore, if you think FIA isn't innovative, look at the regenerative braking systems on F1 cars.
As for aircraft and robots, my aircraft kit and the Mahindra/Gippsland GA 8 have one thing in common - their sheet metal is CNC cut and drilled to the point where the parts are interchangeable, which is more than can be said for the FA-18 and a whole lot of Boeing products which still have pilot holes on corners and require you to match drill everything.
As for robotic assembly, you need to redesign the aircraft for that and then recertify it as a new product, in any case since when is the American labour cost in assembling a Cessna going to the deciding factor in aircraft cost??
However I like innovation stories, but they don't usually have a happy ending - didn't Rotax announce they were building a multi valve, fuel injected V6 300 HP engine to take on Lycoming and Continental? Remember how that panned out? The Thielert diesels on the Diamonds? Lycoming is going to be around for a while longer.
Now about Bishop. My memory tells me that Bishop made their money by making a major innovation in automotive power steering technology that was taken up by all the worlds car manufacturers forthwith. However they may have then made the somewhat rash decision to keep innovating.
Mr. Onetrack, innovation is very, very expensive and highly risky. It mostly fails. This is why smart managers don't do it. If they are smart, they copy other peoples innovations and save their money. They only innovate as a last resort ( I can substantiate this but I'll save it for my doctorate).
So yes, robot produced cheap Cessnas with multi valve petrol EFI engines are being suppressed by Lycoming and Teledyne in a conspiracy to make flying expensive??? The truth is more prosaic.
The Bishop rotary valve was a solution looking for a problem - and it found one - an F1 engine turning at 18,000 rpm! It had little relevance to current automotive technology, which anyway appears to be going electric, it would be at least ten years from actual production and delivers no performance increase apart from perhaps reduced weight and possibly complexity (or not). And that is without taking into account the designers little devil NVH (noise, vibration and harshness). For all we know, a Bishop engine might sound like chalk screeching on a blackboard, which renders it useless.
So did the evil FIA squelch another innovation by a little Aussie battler? I don't think so. Same reason they squashed gas turbines, no relevance to todays automotive problems. Furthermore, if you think FIA isn't innovative, look at the regenerative braking systems on F1 cars.
As for aircraft and robots, my aircraft kit and the Mahindra/Gippsland GA 8 have one thing in common - their sheet metal is CNC cut and drilled to the point where the parts are interchangeable, which is more than can be said for the FA-18 and a whole lot of Boeing products which still have pilot holes on corners and require you to match drill everything.
As for robotic assembly, you need to redesign the aircraft for that and then recertify it as a new product, in any case since when is the American labour cost in assembling a Cessna going to the deciding factor in aircraft cost??
However I like innovation stories, but they don't usually have a happy ending - didn't Rotax announce they were building a multi valve, fuel injected V6 300 HP engine to take on Lycoming and Continental? Remember how that panned out? The Thielert diesels on the Diamonds? Lycoming is going to be around for a while longer.
Perhaps, the Cessna XMC was the way to go.
I know an operator that purchased a brand new 1974 Cessna 172M, from Rex Aviation for the sum of $19,750.
The aircraft averaged 100 hours a month for the first six months of operation and was sold 18 months later with 1500 hours total time to private owner.
I know an operator that purchased a brand new 1974 Cessna 172M, from Rex Aviation for the sum of $19,750.
The aircraft averaged 100 hours a month for the first six months of operation and was sold 18 months later with 1500 hours total time to private owner.
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Sunfish, I wasn't getting on the old, "suppression conspiracy" bandwagon - I was referring to the inertia of corporations towards innovation and design improvements, as they prefer to keep the status quo in eternity, and will resist change as long as they can.
Robotic substantially reduce expensive labour costs, I thought, by eliminating large amounts of tedious labour requirements? Or did I get that wrong, too?
Robotic welders put your current production vehicles together at much lower cost and with far superior accuracy than any welding done by hand.
Stationair8, the XMC was a prototype design, produced to try and find improvements in basic light aircraft design layout. The XMC apparently provided no substantial aeronautical efficiencies, and actually incurred higher levels of cabin noise.
The basic design layout of the 172 appears to be highly satisfactory, what I am saying is that there could have been a number of build and material improvements in the construction, as well as engine efficiency improvements in the last 60 years, that haven't happened.
In the same period we have seen substantial improvements in the build and material improvements in motor vehicles, as well as at least a 30% improvement in fuel efficiency.
That fuel efficiency improvement has largely been driven by legislation, not by any competition or innovation on the part of manufacturers.
Yes, I understand certification is a big bogey in aircraft manufacture, but it hasn't stopped a vast number of aircraft design improvements in other aircraft. The European "plastic fantastic" composite offerings prove that.
It's a shame that everything European-built seems to come with a substantial cost component that I am convinced has little to do with actual build cost, and a lot more to do with the heavy levels of European socialist taxation, and a desire to ensure very substantial levels of profit.
Robotic substantially reduce expensive labour costs, I thought, by eliminating large amounts of tedious labour requirements? Or did I get that wrong, too?
Robotic welders put your current production vehicles together at much lower cost and with far superior accuracy than any welding done by hand.
Stationair8, the XMC was a prototype design, produced to try and find improvements in basic light aircraft design layout. The XMC apparently provided no substantial aeronautical efficiencies, and actually incurred higher levels of cabin noise.
The basic design layout of the 172 appears to be highly satisfactory, what I am saying is that there could have been a number of build and material improvements in the construction, as well as engine efficiency improvements in the last 60 years, that haven't happened.
In the same period we have seen substantial improvements in the build and material improvements in motor vehicles, as well as at least a 30% improvement in fuel efficiency.
That fuel efficiency improvement has largely been driven by legislation, not by any competition or innovation on the part of manufacturers.
Yes, I understand certification is a big bogey in aircraft manufacture, but it hasn't stopped a vast number of aircraft design improvements in other aircraft. The European "plastic fantastic" composite offerings prove that.
It's a shame that everything European-built seems to come with a substantial cost component that I am convinced has little to do with actual build cost, and a lot more to do with the heavy levels of European socialist taxation, and a desire to ensure very substantial levels of profit.
Nope. Not even close.
A well-managed Lyc/Conti should be good for 235/240g/kWh (0.39lb/hp.h) in the cruise and most modern auto diesels are lucky to be any better than 210-220-ish
Where the Lyc/Conti loses is that they require the largely-uneducated to manage the mixture knob.
A well-managed Lyc/Conti should be good for 235/240g/kWh (0.39lb/hp.h) in the cruise and most modern auto diesels are lucky to be any better than 210-220-ish
Where the Lyc/Conti loses is that they require the largely-uneducated to manage the mixture knob.
Onetrack, with respect, the costs of tooling up for robot based production are extraordinary. While Boeing and Airbus have automated plenty of processes over the years, not every process is amenable to it.
For example Boeing had water jet cutting of interior panels years ago and also automated some wing spar riveting. However aircraft are series production projects not mass production and "design - for -easy - assembly " does not take priority over design for performance and low weight.
I would say a lot of interior work and engine components like blades are now produced on robotic lines, but primary structure? I think not, with the exception perhaps of some automatic layup of composites. Of course anything that can be inc machined will be. I also seem to remember that Boeings latest paint shop is robotic.
For example Boeing had water jet cutting of interior panels years ago and also automated some wing spar riveting. However aircraft are series production projects not mass production and "design - for -easy - assembly " does not take priority over design for performance and low weight.
I would say a lot of interior work and engine components like blades are now produced on robotic lines, but primary structure? I think not, with the exception perhaps of some automatic layup of composites. Of course anything that can be inc machined will be. I also seem to remember that Boeings latest paint shop is robotic.
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60 or 70 Years?
It could be argued that in June next year the Cessna 172 will be 70 years old?
After all the first 172 was just a Cessna 170B with a nose wheel and nothing more. After owning a beautiful Cessna 170A for many years and also instructing on Cessna 172's for many hundreds of hours there was little difference, even more the 170 was cleaner, shorter take and landings and the beautifully smooth and the C145 6 Cylinder motor ran like a switch watch. Did the addition of training wheels really justify a name change??
Hopefully this diatribe will get this thread back on Track? He He
After all the first 172 was just a Cessna 170B with a nose wheel and nothing more. After owning a beautiful Cessna 170A for many years and also instructing on Cessna 172's for many hundreds of hours there was little difference, even more the 170 was cleaner, shorter take and landings and the beautifully smooth and the C145 6 Cylinder motor ran like a switch watch. Did the addition of training wheels really justify a name change??
Hopefully this diatribe will get this thread back on Track? He He
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60 or 70 Years? It could be argued that in June next year the Cessna 172 will be 70 years old?
After all the first 172 was just a Cessna 170B with a nose wheel and nothing more. After owning a beautiful Cessna 170A for many years and also instructing on Cessna 172's for many hundreds of hours there was little difference, even more the 170 was cleaner, shorter take and landings and the beautifully smooth and the C145 6 Cylinder motor ran like a switch watch. Did the addition of training wheels really justify a name change??
Hopefully this diatribe will get this thread back on Track? He He
After all the first 172 was just a Cessna 170B with a nose wheel and nothing more. After owning a beautiful Cessna 170A for many years and also instructing on Cessna 172's for many hundreds of hours there was little difference, even more the 170 was cleaner, shorter take and landings and the beautifully smooth and the C145 6 Cylinder motor ran like a switch watch. Did the addition of training wheels really justify a name change??
Hopefully this diatribe will get this thread back on Track? He He
Your post got me googling.
1948 C170 Introduced
1952 C170B Introduced (cost $7245 USD) how does that stack up to today price of around $275,000USD.
1956 Nose Equipped C170B with square tail called the C172. (All C170 production stopped).
Id 'Argue' the C172 is 61 years old.
Never flew the C170 unfortunately.
The O-1 Bird Dog had 60* Fowler Flaps. That would slow it down.
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Nope. Not even close.
A well-managed Lyc/Conti should be good for 235/240g/kWh (0.39lb/hp.h) in the cruise and most modern auto diesels are lucky to be any better than 210-220-ish
Where the Lyc/Conti loses is that they require the largely-uneducated to manage the mixture knob.
A well-managed Lyc/Conti should be good for 235/240g/kWh (0.39lb/hp.h) in the cruise and most modern auto diesels are lucky to be any better than 210-220-ish
Where the Lyc/Conti loses is that they require the largely-uneducated to manage the mixture knob.
Andy.......Post of the Year Award from me at least. Nailed it.
And it is not their fault. They were ignorant due the system. But there is a solution,
https://www.advancedpilot.com/livecourse-au.html
Speaking as a fully paid up member of the largely educated, why in the year 2017 do I still need to manage the mixture knob at all?
I don't understand why my fuel injection system isn't at least half as clever as the one on the average current Toyota. I guess I just need to be educated in those black art theories and techniques of 1935.
Just as a matter of interest does anyone know what date the last car had a mixture control other than a choke? I'm guessing 1930.
I don't understand why my fuel injection system isn't at least half as clever as the one on the average current Toyota. I guess I just need to be educated in those black art theories and techniques of 1935.
Just as a matter of interest does anyone know what date the last car had a mixture control other than a choke? I'm guessing 1930.
The advantage Toyota have is that they can amortize the development over not just one engine model, but across their entire range - the production volumes of which has more than a few extra zeros on the end compared to even the entire lifetime of O-360's
And, most cars with carbs needed mixture control, even when they didn't have it, say for when you started driving up mountains. Carbs did tend to disappear around 1986 though, at least here in Aus - only 30 years ago - blink of an eye really.
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Just as a matter of interest does anyone know what date the last car had a mixture control other than a choke? I'm guessing 1930.
Early cars (prior to about 1932) had manual spark advance/retard controls, usually mounted on the steering column - so perhaps you are confusing the spark advance/retard mechanisms with mixture control.
Don't knock the old 172. Is anyone aware that 2 Americans bought a stock 172 and took off on Dec 4 1958 and did not land till Feb 4 1959 ?
Google it for more info. I think the record still stands.
Emeritus
Google it for more info. I think the record still stands.
Emeritus
Imagine the regulatory ructions if someone tried to refuel a 172 from a truck today!
The cabin must have been a bit festy after 2 blokes spent a couple of months airborne in it...
The cabin must have been a bit festy after 2 blokes spent a couple of months airborne in it...
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The cabin must have been a bit festy after 2 blokes spent a couple of months airborne in it...
Maybe it was just the old "ABC" that the grunts in SVN did, out of a waterbottle! ([under]Arm, Bum & Crotch, in case you needed to ask).
The history of the record-breaking light aircraft flights around AZ, NV and CA
Last edited by onetrack; 15th Mar 2017 at 12:35.
