FADEC is 1980s Technology

[Henning]

It happens a lot in the injected Cessnas. The amount of prime time (haha) recommended in checklists is generally too long.

Continental or Lycoming? Either way they both take more fuel than most people think.

 

[Ted]

Just like the 1970s. Yay.

So would you pay 2x on your overhaul to not have to deal with a red lever?

 

[NoHeat]

Back to the OP --- it's interesting that in 2001 it was expected that Continental would soon offer a FADEC engine for the then-new Cirrus SR22. And I assume for other planes as well.

Flying Magazine article here.

 

[Henning]

Back to the OP --- it's interesting that in 2001 it was expected that Continental would soon offer a FADEC engine for the then-new Cirrus SR22. And I assume for other planes as well.

Flying Magazine article here.

They have, they just aren't being bought because it doesn't make business sense to the MBAs. Remember, it took several decades to get seat belts installed in cars after they came out. The first car made to be sold to the public with airbags was in 1973, an Olds Toronado. They didn't start making it into production cars until the late 80s and didn't become ubiquitous until into the 90s.

The issue is always the same, people value money above all else.

 

[jaybee]

Just some input on the variable valve timing - all it consists of in the car world is a two piece cam gear, with a big spring in it along with a control solenoid that modulates oil pressure. If it all fails the big spring takes over, if for some reason it locks open, the engine doesn't fail, just lose some efficiency at certain RPM. Same for solenoid failure. Not a whole lot of weight that I can see.

Also, its not that complicated really to have a single point system. Fuel injectors normally open and computer controls modulate them partially closed. Fails open. Add an oh **** handle that gravity feeds fuel to a booster venturii in the throttle body - pretty uncomplicated.

Along with cold and hot start issues the major advantage of EFI is feedback control. There is no way on god's green earth that a human can match an EFI in efficiency. The computer processes and corrects millions of bits of data per second. As stated the feedback control allows for optimum engine output and efficiency. Novices don't seem to comprehend however that not all feedbacks are Alpha level, heck for that matter original Oxygen sensors were called Lambda sensors in early Euro cars because that is how low of priority it is given in the food chain.

As far as the concern is about fault detection - I don't remember the figures exactly but I'll throw out some generic numbers - in a Ford for example the Check Engine lamp will not illuminate for a single cylinder misfire until the counter reads like 1500 misfires. Its completely on the engineering end to program what faults are found and what are the thresholds. Now Ford sets limits high so as to reduce warranty costs. No reason it couldn't be lower.

Lastly, I would prefer an individual coil pack on plug and redundant crank and cam position sensors to a points magneto system any day. Two coil packs on plug and two spark plugs per cylinder, likelihood of every coil failing at same time is nil to none. Now we have electrical failure to deal with, replace a puny cranking battery with one that has a pretty standard automotive style of 25 amp/hours of life ! if it takes you 25 hours to land an aircraft with a failed electric system you got bigger problems.

All in all an electrical or computer system failure in this day and age with our level of technology is about as likely as an engine failure with pretty much the same level of risk of an engine failure. The biggest compromise is weight.

 

[wabower]

Are you applauding the MBA's for understanding basic business principles or alluding to some evil-genius motives to deprive the industry of its just desserts insofar as this technology is concerned?

They have, they just aren't being bought because it doesn't make business sense to the MBAs. Remember, it took several decades to get seat belts installed in cars after they came out. The first car made to be sold to the public with airbags was in 1973, an Olds Toronado. They didn't start making it into production cars until the late 80s and didn't become ubiquitous until into the 90s.

The issue is always the same, people value money above all else.

 

[Henning]

Are you applauding the MBA's for understanding basic business principles or alluding to some evil-genius motives to deprive the industry of its just desserts insofar as this technology is concerned?

There is no'evil genius' or any other level of genius involved, it's just plain old greed and shortsighted stupidity that you get when you believe the meaning of life is to amass wealth.

 

[MAKG1]

Jaybee, have you really looked at EFI? Millions of bits per second? No, it's more like dozens. For mixture managment, it's one or two.

A human can match EFI efficiency in perfect conditions. A human can BEAT EFI (substantially) in limp mode. Where you gain for EFI is in rapidly changing environments, with all the systems working adequately. Flight isn't anywhere near as rapidly changing as driving. A well executed flight will have only two or three throttle changes, over hours. A car will have many thousands.

Airplanes are NOT flying cars. The environment is very, very different. An automotive engine that redlines at 2600 RPM is a POS. Most of them make peak torque around there, and redline at least twice as fast. Why? With all the gearing, tire sizes, a weird preference for overdrive transmissions (they don't do anything a different choice of differential gearing wouldn't do simpler), and so forth, that ends up being highway speed.

With two coils per plug, how do you figure out one has failed? If you can't figure that out until they both fail, you've defeated your redundancy. This is easy to accomplish by inspection (a failed coil will have the wrong resistance -- you'll either read twice resistance if the coil fails open, or zero if it fails to a short), but it's impossible while airborne or during preflight. And coils fail with low resistance sometimes, which means they would disable the other coil as well.

 

[Henning]

Jaybee, have you really looked at EFI? Millions of bits per second? No, it's more like dozens. For mixture managment, it's one or two.

A human can match EFI efficiency in perfect conditions. A human can BEAT EFI (substantially) in limp mode. Where you gain for EFI is in rapidly changing environments, with all the systems working adequately. Flight isn't anywhere near as rapidly changing as driving. A well executed flight will have only two or three throttle changes, over hours. A car will have many thousands.

Airplanes are NOT flying cars. The environment is very, very different. An automotive engine that redlines at 2600 RPM is a POS. Most of them make peak torque around there, and redline at least twice as fast. Why? With all the gearing, tire sizes, a weird preference for overdrive transmissions (they don't do anything a different choice of differential gearing wouldn't do simpler), and so forth, that ends up being highway speed.

With two coils per plug, how do you figure out one has failed? If you can't figure that out until they both fail, you've defeated your redundancy. This is easy to accomplish by inspection (a failed coil will have the wrong resistance -- you'll either read twice resistance if the coil fails open, or zero if it fails to a short), but it's impossible while airborne or during preflight. And coils fail with low resistance sometimes, which means they would disable the other coil as well.

While the throttle remains the same, there are an infinite amount of mixture changes that could be made to optimize the operation. While a skilled knowledgeable person with the correct data acquisition devices is operating the red handle, yep, you won't see much difference, however, that is not the reality of GA.

As for the coil, you just put a sensor conductor along side each. If the coil quits working the field will quit collapsing and inducing a current in sensor. The sensor feeds a 'loss of signal' loop which triggers the warning.

 

[jaybee]

Jaybee, have you really looked at EFI? Millions of bits per second? No, it's more like dozens. For mixture managment, it's one or two.

Umm yea, in fact I'm a retired ASE certified Master Auto technician with Advanced Engine performance certificates, I'm very well aware of how many bits per second the multiplexed computers of modern automotives communicate at - you can take my word for it or if you won't I guess I could find the the time to dig up the evidence to prove you wrong because I know for 100 % certain that I have it from a trade seminar I attended YEARS ago.

A human can match EFI efficiency in perfect conditions. A human can BEAT EFI (substantially) in limp mode. Where you gain for EFI is in rapidly changing environments, with all the systems working adequately. Flight isn't anywhere near as rapidly changing as driving. A well executed flight will have only two or three throttle changes, over hours. A car will have many thousands.

Airplanes are NOT flying cars. The environment is very, very different. An automotive engine that redlines at 2600 RPM is a POS. Most of them make peak torque around there, and redline at least twice as fast. Why? With all the gearing, tire sizes, a weird preference for overdrive transmissions (they don't do anything a different choice of differential gearing wouldn't do simpler), and so forth, that ends up being highway speed.

With two coils per plug, how do you figure out one has failed? If you can't figure that out until they both fail, you've defeated your redundancy. This is easy to accomplish by inspection (a failed coil will have the wrong resistance -- you'll either read twice resistance if the coil fails open, or zero if it fails to a short), but it's impossible while airborne or during preflight. And coils fail with low resistance sometimes, which means they would disable the other coil as well.

First of all one coil per plug, two plugs per cylinder.

Secondly, the failure is detected through the same methods that the computer detects any fault. I would have to go into a dissertation on how to monitor burn times, peak Kv, etc, etc through manual observation with an oscilliscope on the primary control side - which the computer can be programmed to do - and quite frankly I don't have the time or desire to teach internal combustion 101 and then move on into advanced engine diagnostic procedures. Google is your friend :wink2:

 

[Capt. Geoffrey Thorpe]

As far as the concern is about fault detection - I don't remember the figures exactly but I'll throw out some generic numbers - in a Ford for example the Check Engine lamp will not illuminate for a single cylinder misfire until the counter reads like 1500 misfires. Its completely on the engineering end to program what faults are found and what are the thresholds. Now Ford sets limits high so as to reduce warranty costs. No reason it couldn't be lower.

Actually, the thresholds for the misfire fault are defined in the OBD-II regulations - faults that set the "check engine" light are generally those that are required by regulation.

Sometimes the regulations require that faults be set for things that are not directly measurable (example - catalyst efficiency) and only loosely correlate to things you can measure (O2 sensor activity). Those tend to be the least reliable. Also, some of the codes required by regulation are to detect faults that do not actually exist in nature. But the thresholds for these faults are, again, defined in the regulations.

Other codes, not required by regulation, are set to provide information for service diagnostics. Those typically do not turn on a light. Thresholds for these faults can be determined by the manufacturer.

And there are faults that do turn on other lights to warn a driver of the possibility that there may be a fault that will result in undesirable vehicle operation.

 

[jaybee]

Actually, the thresholds for the misfire fault are defined in the OBD-II regulations - faults that set the "check engine" light are generally those that are required by regulation. Not even close to true.

Sometimes the regulations require that faults be set for things that are not directly measurable (example - catalyst efficiency) and only loosely correlate to things you can measure (O2 sensor activity). Those tend to be the least reliable. Also, some of the codes required by regulation are to detect faults that do not actually exist in nature. But the thresholds for these faults are, again, defined in the regulations.

Other codes, not required by regulation, are set to provide information for service diagnostics. This is why what you said is not true. Those typically do not turn on a light. That is up to manufacturer, they certainly can turn on a light. Thresholds for these faults can be determined by the manufacturer. As I said :wink2:

And there are faults that do turn on other lights to warn a driver of the possibility that there may be a fault that will result in undesirable vehicle operation Pretty much anything programmed to do so will turn on a light in my 15 years of experience. :wink2:

Exactly my point, OBD - II regulations require that a RANDOM misfire detection fault be availible NOT a single cylinder misfire fault. :wink2:

I'll be quick because I sat through a day long trade seminar on this years ago but there are two sides to automotive computer diagnostics. Generic OBD2 and factory. It like two door in a buidling, one let you go in and talk to the guy at the front counter, the other door lets you walk through the entire building. Guess which door is OBD2

 

[docmirror]

The reason I advised keeping a throttle body with fuel plumbed and a single mag is to ease aviation into the last century. I would rather have fully EFI and elec ignition too, but the fact is the FAA is going to balk at stuff like that. Keeping a mag and a throttle body as a backup is just good marketing for the future.

So, keep the old stuff for the FAA and go to the new stuff for economy. Maybe in a dozen years we'll be able to ditch the old stuff and move toward all digital control.

 

[Capt. Geoffrey Thorpe]

Actually, the thresholds for the misfire fault are defined in the OBD-II regulations - faults that set the "check engine" light are generally those that are required by regulation. Not even close to true.

As the guy who created the algorithms for many of those diagnostics at one of the larger auto companies- it's true.

 

[JHW]

I'll be quick because I sat through a day long trade seminar

wow, one whole day. That's quite an investment.

As the guy who created the algorithms for many of those diagnostics at one of the larger auto companies- it's true.

And I was the guy upstream in the test cell and cold room determining what the thresholds should be for the trigger points. It's always amusing to see the explanations people come up with for how this stuff works, isn't it? Of course the manufacturer's own service network is often among the most clueless.

 

[MAKG1]

Umm yea, in fact I'm a retired ASE certified Master Auto technician with Advanced Engine performance certificates, I'm very well aware of how many bits per second the multiplexed computers of modern automotives communicate at - you can take my word for it or if you won't I guess I could find the the time to dig up the evidence to prove you wrong because I know for 100 % certain that I have it from a trade seminar I attended YEARS ago.

You're confusing network bitrates -- which are irrelevant -- with control system feedback rates.

You claim to be an ASE certified master technician. Then you should know how the fuel trims are adjusted. The feedback rate is the oxygen sensor switching rate -- a few per second. Increased network bandwidth reduces signal latency, but doesn't affect control stability at all.

The fastest feedback in the system is the spark and fuel triggers, which have to function in a few strokes for engine starting. At the redline, that's the order of a few hundred times per second, not millions.

And, frankly, in a thread about 1980s technology, OBD-II is out of bounds. That's 1996. For 1980s, you are stuck with OBD-I and its predecessors like Bosch K-Jetronic. Good luck getting megabit measurements off a VAF sensor....

Computers can't detect "any" fault. They can detect certain classes of faults. They are better at some than at others, and designing a new algorithm can be quite expensive.

 

[jaybee]

As the guy who created the algorithms for many of those diagnostics at one of the larger auto companies- it's true.

Here is just one example of many -

http://www.arb.ca.gov/msprog/obdprog/obdregs.htm

Note: This is the most up-to-date OBD II regulation, section 1968.2 of title 13, California Code of
Regulations (OAL-approved on August 7, 2012). Please note that this is the "clean" version (with no
strike-outs or underlines) of the regulation. Please also note that the official regulations can be found at
Barclays Official California Code of Regulations and at www.oal.ca.gov .
Final Regulation Order
§1968.2. Malfunction and Diagnostic System Requirements--2004 and
Subsequent Model-Year Passenger Cars, Light-Duty Trucks, and Medium-Duty
Vehicles and Engines

(3.1.1) As specifically provided for in sections (e) and (f), manufacturers shall
define monitoring conditions, subject to Executive Officer approval, for
detecting malfunctions identified in sections (e) and (f). The Executive
Officer shall approve manufacturer defined monitoring conditions that are
determined (based on manufacturer submitted data and/or other
engineering documentation) to be: technically necessary to ensure robust
detection of malfunctions (e.g., avoid false passes and false indications of
malfunctions), designed to ensure monitoring will occur under conditions
which may reasonably be expected to be encountered in normal urban
vehicle operation and use, and designed to ensure monitoring will occur
during the FTP cycle or Unified cycle.

Important part emboldened. :wink2:

 

[jaybee]

wow, one whole day. That's quite an investment.

That has got to be one of the most unnecessary, rude and condescending... wait... nevermind - I bow to the presence of God almight himself

**** off wanker.

 

[jaybee]

You're confusing network bitrates -- which are irrelevant -- with control system feedback rates. Fair enough, its been a few years, I just may have.

You claim - no claim, totally unnecessary to conversation comment - to be an ASE certified master technician. Then you should know how the fuel trims are adjusted. The feedback rate is the oxygen sensor switching rate -- a few per second. The oxygen sensor is a Lamba level feedback at best, much more sensor in play that have a more profound effect Increased network bandwidth reduces signal latency, but doesn't affect control stability at all.

The fastest feedback in the system is the spark and fuel triggers, which have to function in a few strokes for engine starting. At the redline, that's the order of a few hundred times per second, not millions.

And, frankly, in a thread about 1980s technology, OBD-II is out of bounds. That's 1996. For 1980s, you are stuck with OBD-I and its predecessors like Bosch K-Jetronic. Good luck getting megabit measurements off a VAF sensor....

Computers can't detect "any" fault. They can detect certain classes of faults. They are better at some than at others, and designing a new algorithm can be quite expensive.

If I can find any fault with an oscilloscope, then a computer can be programmed to find the same fault. The design may be more than its worth but then again how big of a fault do you have to have before it is a very serious problem. A misfire of one coil pack in flight would be handled no different than a misfire of one bad high tension lead from a mag in flight.

 

[MAKG1]

I'm not sure what you mean by a "profound effect." Feedbacks are critically different from open loop operation. Without the lambda sensor, you lose mixture adaptivity. That's quite profound, even if the effect is small on a stroke-for-stroke basis.

It's not true that you can automate any diagnosis. If you can make purely objective specifications on your oscilloscope trace, that can be done (to a point -- you have to trust the measurements, which is a whole 'nother set of potential failure modes when you're dragging the diagnostic system along with you and exposing it to all the environmental conditions that implies). But not all diagnoses are that cut and dried. It's an art to make a statistic that is both sensitive and reliable.

 

[Ted]

Just some input on the variable valve timing - all it consists of in the car world is a two piece cam gear, with a big spring in it along with a control solenoid that modulates oil pressure. If it all fails the big spring takes over, if for some reason it locks open, the engine doesn't fail, just lose some efficiency at certain RPM. Same for solenoid failure. Not a whole lot of weight that I can see.

Point taken, but this is aviation. Weigt savings is a big deal for the manufacturers. And since our engines typically have a 300-500 rpm operating range (650 rpm for the 520s in the 310), there's just not much benefit to variable cam timing.

Along with cold and hot start issues the major advantage of EFI is feedback control. There is no way on god's green earth that a human can match an EFI in efficiency. The computer processes and corrects millions of bits of data per second. As stated the feedback control allows for optimum engine output and efficiency. Novices don't seem to comprehend however that not all feedbacks are Alpha level, heck for that matter original Oxygen sensors were called Lambda sensors in early Euro cars because that is how low of priority it is given in the food chain.

For the systems in aviation, the way it works is an untrained human will benefit from the computer. A well-trained human will beat the computer. This is based on what's currently out there/in the pipeline.

 

[Henning]

You're confusing network bitrates -- which are irrelevant -- with control system feedback rates.

You claim to be an ASE certified master technician. Then you should know how the fuel trims are adjusted. The feedback rate is the oxygen sensor switching rate -- a few per second. Increased network bandwidth reduces signal latency, but doesn't affect control stability at all.

The fastest feedback in the system is the spark and fuel triggers, which have to function in a few strokes for engine starting. At the redline, that's the order of a few hundred times per second, not millions.

And, frankly, in a thread about 1980s technology, OBD-II is out of bounds. That's 1996. For 1980s, you are stuck with OBD-I and its predecessors like Bosch K-Jetronic. Good luck getting megabit measurements off a VAF sensor....

Computers can't detect "any" fault. They can detect certain classes of faults. They are better at some than at others, and designing a new algorithm can be quite expensive.

K-Jetronic, that was the one on the 411 VW way back in the late 60s right? I remember cracking open the airflow metering box and getting them some more fuel. Then I think it was the L-jetronic on the 280z &zx & Cosworth Vega right? That was a POS, but after that Bosch got their act together. GM floundered a couple of years playing with an electronic Chokechester TBI. Then they got their act together with TBI and are producing some pretty amazing performance / economy figures at speed.
Pretty much all the systems anymore are high reliability low maintenance units. We've learned a lot and made great progress in a short time. Amazing what can happen when it effects next quarters bottom line in warranty claims.

 

[Capt. Geoffrey Thorpe]

I'm not sure what you mean by a "profound effect." Feedbacks are critically different from open loop operation. Without the lambda sensor, you lose mixture adaptivity. That's quite profound, even if the effect is small on a stroke-for-stroke basis.

For an aircraft engine that is exposed to leaded fuel, feedback would probably be best done on the exhaust temperature.

 

[Ted]

For an aircraft engine that is exposed to leaded fuel, feedback would probably be best done on the exhaust temperature.

This gets harder than it sounds, especially as the engine wears and its EGT characteristics tend to change a bit. Although what the level of change is probably depends on how hard it's beaten. I had one workhorse engine I ran at 80-100% power most of the time, and its EGT characteristics changed significantly over 1,000 hours.

 

[Capt. Geoffrey Thorpe]

This gets harder than it sounds, especially as the engine wears and its EGT characteristics tend to change a bit. Although what the level of change is probably depends on how hard it's beaten. I had one workhorse engine I ran at 80-100% power most of the time, and its EGT characteristics changed significantly over 1,000 hours.

The peak changes or the difference from peak as a function of air fuel changes?

Oh - while I was at the store, it occurred to me that the stupid crankshaft acceleration algorithms that are a total pain in the behind for auto applications might actually work for an aircraft as a lean limit threshold (onset of slow burns / misfires) detection algorithm. Nice steady state operation with no rough roads, wheel hop, transmission shifting, manual transmissions, someone keeping time with the music on the accelerator, driving with both feet, etc. etc. etc. would make life soooooo much easier...

Given that you have exhaust temperature - that might be a good threshold detection as well - dunno - I never paid that much attention to EGT in the auto since we didn't have that as an input. But if you play around to find peak (near stoichiometric) and then find the lean limit you should have a reasonably good idea where you want to run in between. I think.

 

[Ted]

The peak changes or the difference from peak as a function of air fuel changes?

We weren't measuring air/fuel, but the peak changed and also the peak changed as a function of fuel flow. The power had dropped off a bit on it, but not enough to really matter. As I said, this was over about 1,000 hours of operation, and this was an engine I beat the crap out of. Gave me good confidence in these things.

Oh - while I was at the store, it occurred to me that the stupid crankshaft acceleration algorithms that are a total pain in the behind for auto applications might actually work for an aircraft as a lean limit threshold (onset of slow burns / misfires) detection algorithm. Nice steady state operation with no rough roads, wheel hop, transmission shifting, manual transmissions, someone keeping time with the music on the accelerator, driving with both feet, etc. etc. etc. would make life soooooo much easier...

Most likely. I never played around with such algorithms, but it sounds interesting.

Given that you have exhaust temperature - that might be a good threshold detection as well - dunno - I never paid that much attention to EGT in the auto since we didn't have that as an input. But if you play around to find peak (near stoichiometric) and then find the lean limit you should have a reasonably good idea where you want to run in between. I think.

Well, a lot of turbocharged folk will run strictly based on an EGT (well, TIT) - we did in the Navajo. This seems to work better in turbocharged applications since the power the engine puts out as a function of altitude is pretty much the same until you get up really high. Unless you're in a 340/414/421, higher than you'd likely ever choose to go. Even then, questionable.

As I understand it, the Continental FADEC system actually searches to find peak EGT every so often (not sure how often that is), and then leans or richens out appropriately. I never played with that, but some folks I talked to said that's how it worked. Seemed like an interesting control logic. The part I would find annoying about that as a pilot is that I'd see temperatures and fuel flows moving around without my input, and I wouldn't like that.

 

[spiderweb]

I only flew them for 27 years without using the factory recommendation and can't ever remember any starting issues? What particular problems have you noticed?

Hey, I haven't had problems. What I'm talking about is students and renters following checklists that say to prime for 5-10 seconds. Do YOU do that?

 

[spiderweb]

Continental or Lycoming? Either way they both take more fuel than most people think.

Lyc; and you're obviously right.

 

[spiderweb]

Back to the OP --- it's interesting that in 2001 it was expected that Continental would soon offer a FADEC engine for the then-new Cirrus SR22. And I assume for other planes as well.

Flying Magazine article here.

I remember that.

 

[Ted]

Hey, I haven't had problems. What I'm talking about is students and renters following checklists that say to prime for 5-10 seconds. Do YOU do that?

When it's appropriate.

I do agree that starting these engines is something that's not very well taught, because most don't know. I can start them first try >95% of the time.

 

[spiderweb]

When it's appropriate.

I do agree that starting these engines is something that's not very well taught, because most don't know. I can start them first try >95% of the time.

See, that's my point. I think I have about the same percentage as you, but we are probably the exceptions.

You know what my percentage rate is for successful starts of the engine in my Mazda 6 is? ---100%

 

[peppy]

For the systems in aviation, the way it works is an untrained human will benefit from the computer. A well-trained human will beat the computer. This is based on what's currently out there/in the pipeline.

I disagree. The Continental system installed in an SR22 was able to match a very well trained pilot in a test of two planes head to head. Having looked at the Continental system, it is very complex due to the reliability concerns. I am going on memory here so forgive me if I muck it up but I remember there being two processors per module and 6 modules in total so that two different modules are controlling each cylinder. The system was complex, heavy and expensive. At about 2600 RPM the system would shift to ROP even is set LOP so that full power was developed on go around. In a car you don't have all of the failure mode concerns.

 

[Henning]

We weren't measuring air/fuel, but the peak changed and also the peak changed as a function of fuel flow. The power had dropped off a bit on it, but not enough to really matter. As I said, this was over about 1,000 hours of operation, and this was an engine I beat the crap out of. Gave me good confidence in these things.



Most likely. I never played around with such algorithms, but it sounds interesting.



Well, a lot of turbocharged folk will run strictly based on an EGT (well, TIT) - we did in the Navajo. This seems to work better in turbocharged applications since the power the engine puts out as a function of altitude is pretty much the same until you get up really high. Unless you're in a 340/414/421, higher than you'd likely ever choose to go. Even then, questionable.

As I understand it, the Continental FADEC system actually searches to find peak EGT every so often (not sure how often that is), and then leans or richens out appropriately. I never played with that, but some folks I talked to said that's how it worked. Seemed like an interesting control logic. The part I would find annoying about that as a pilot is that I'd see temperatures and fuel flows moving around without my input, and I wouldn't like that.

I like both. While they provide an overlap in capabilities, it's like a Venn diagram where both have capacities that I desire for early warning and dignostics that are outside the the scopes of each other.

 

[Ted]

I disagree. The Continental system installed in an SR22 was able to match a very well trained pilot in a test of two planes head to head. Having looked at the Continental system, it is very complex due to the reliability concerns. I am going on memory here so forgive me if I muck it up but I remember there being two processors per module and 6 modules in total so that two different modules are controlling each cylinder. The system was complex, heavy and expensive. At about 2600 RPM the system would shift to ROP even is set LOP so that full power was developed on go around. In a car you don't have all of the failure mode concerns.

I never tested the Continental system, so my knowledge of it is limited. From my understanding of it I'd expect it to do reasonably well. I'd be surprised if it did truly match the well-trained pilot in all categories. If it did, I'd expect to see Cirrus installing them.

Even still, how did it match? Did it do equal the whole way around? Were the climb CHTs really hot because of insufficient fueling? How were they in cruise? And who did the study? Continental themselves? Yeah, manufacturers have never given biased results to promote their own products.

And if they did match... Would you pay the extra cost for a computer system that did no better than you could? Matching isn't beating. So you're paying extra for easier starting.

 

[Henning]

I never tested the Continental system, so my knowledge of it is limited. From my understanding of it I'd expect it to do reasonably well. I'd be surprised if it did truly match the well-trained pilot in all categories. If it did, I'd expect to see Cirrus installing them.

Even still, how did it match? Did it do equal the whole way around? Were the climb CHTs really hot because of insufficient fueling? How were they in cruise? And who did the study? Continental themselves? Yeah, manufacturers have never given biased results to promote their own products.

And if they did match... Would you pay the extra cost for a computer system that did no better than you could? Matching isn't beating. So you're paying extra for easier starting.

Cirrus is about bottom line, until something changes in the market they have no financial advantage in developing the true FADEC certification especially when they already have it halfway faked.

I will pay for FADEC when it comes on a Diesel engine, then I can run algae oil and grow my own fuel.

 

[wabower]

My engines didn't have that checklist. Pump on to peak flow, then off. Start on second or third blade every time.

Hey, I haven't had problems. What I'm talking about is students and renters following checklists that say to prime for 5-10 seconds. Do YOU do that?

 

[Henning]

Hey, I haven't had problems. What I'm talking about is students and renters following checklists that say to prime for 5-10 seconds. Do YOU do that?

Yes depending on temp. Here's my procedure hot or cold on both mine they start in two blades every time except once it was -20 and I didn't give it enough and gave it 20 more after I let the heat from the chuff soak in a bit.

Full forward quadrant, eyes on fuel pressure, high boost on pressure rises and stabilizes on full pressure and 1 2 3 4 5 off. Throttle back to between two and 4 depending on temp, mixture back to 4.5 where I taxi and hit the starter with hand on throttle ready to retard as she comes up. Repeat on right.

 

[JHW]

I converted my wife's boat to fuel injection and computer controlled spark, it was easy, just grabbed all the tbi parts off of a chevy pickup. It's running open loop because I was too chicken to try and drill the water cooled manifolds for an O2 sensor. The only goal was to make it start and idle like a car since she couldn't reliably start it hot. It lost a little top end speed (restrictive throttle body compared to the card) and running open loop it's not saving any fuel, but the starting is great. No way in hades I'd do this on my plane though.

 

[wabower]

Which line would you be about if you operated a manufacturing business?

Cirrus is about bottom line, until something changes in the market they have no financial advantage in developing the true FADEC certification especially when they already have it halfway faked.

I will pay for FADEC when it comes on a Diesel engine, then I can run algae oil and grow my own fuel.

 

[docmirror]

I converted my wife's boat to fuel injection and computer controlled spark, it was easy, just grabbed all the tbi parts off of a chevy pickup.

So - your wife has a boat, with a small block V8, which she lets you work on. Then, you slowed it down for her cause it wouldn't start well.