ragedracer1977 Posted October 17, 2022 Report Posted October 17, 2022 Anyone else received this yet? A while back several of us experienced fine wire failures. I guess somebody crashed their plane and they found a broken center electrode and are interested in pinning the blame on tempest. Having read the entire accident report, I’m not sure I agree. Quote
LANCECASPER Posted October 17, 2022 Report Posted October 17, 2022 http://www.kathrynsreport.com/2020/07/cessna-172n-skyhawk-ii-n6328d-fatal.html Quote
LANCECASPER Posted October 17, 2022 Report Posted October 17, 2022 @Yetti also had problems with this Quote
DXB Posted October 17, 2022 Report Posted October 17, 2022 I'd suggest not lifting a finger to help these plaintiffs lawyers at least until there is an NTSB report firmly implicating a spark plug failure. Those vultures latch on to anything that might have happened that could be traced to a manufacturer of in order to leverage a windfall settlement, and they succeed far too often based on the most tenuous evidence. They do little to serve justice but are a major contributor to our operating costs. 18 Quote
LANCECASPER Posted October 17, 2022 Report Posted October 17, 2022 17 minutes ago, DXB said: I'd suggest not lifting a finger to help these plaintiffs lawyers at least until there is an NTSB report firmly implicating a spark plug failure. Those vultures latch on to anything that might have happened that could be traced to a manufacturer of in order to leverage a windfall settlement, and they succeed far too often based on the most tenuous evidence. They do little to serve justice but are a major contributor to our operating costs. It many cases I would agree with you, but not this one. The NTSB ongoing investigation shows that the spark plug was defective. https://www.ntsb.gov/Pages/search.aspx#Default={"k"%3A"N6328D"%2C"r"%3A[{"n"%3A"NtsbNumber"%2C"t"%3A["\"ǂǂ57505232304c41323132\""]%2C"o"%3A"and"%2C"k"%3Afalse%2C"m"%3Anull}]} Then select "Materials Lab Factual Report" 1 Quote
A64Pilot Posted October 17, 2022 Report Posted October 17, 2022 Haven’t read the report, but how does one plug bring down an aircraft? Defects happen, some of us are flying around with defective parts right now, of course we all want zero defects, but it’s just not going to happen, now if it could be proven that defective parts were sold that the manufacturers knew were defective, then that’s a whole different story. Face it, even the Shuttle had defective parts and procedures, and we can’t afford NASA level of scrutiny of parts, I don’t want $1,000 spark plugs Attempted to read, .pdf was corrupted 2 Quote
ragedracer1977 Posted October 17, 2022 Author Report Posted October 17, 2022 (edited) 8 minutes ago, LANCECASPER said: It many cases I would agree with you, but not this one. The NTSB ongoing investigation shows that the spark plug was defective. https://www.ntsb.gov/Pages/search.aspx#Default={"k"%3A"N6328D"%2C"r"%3A[{"n"%3A"NtsbNumber"%2C"t"%3A["\"ǂǂ57505232304c41323132\""]%2C"o"%3A"and"%2C"k"%3Afalse%2C"m"%3Anull}]} Then select "Materials Lab Factual Report" It was. But there was a whole lot of other stuff wrong. How do you get plugs looking like this in 26 hours (and less than a month) with brand new cylinders? Edited October 17, 2022 by ragedracer1977 Quote
N201MKTurbo Posted October 17, 2022 Report Posted October 17, 2022 16 minutes ago, LANCECASPER said: It many cases I would agree with you, but not this one. The NTSB ongoing investigation shows that the spark plug was defective. https://www.ntsb.gov/Pages/search.aspx#Default={"k"%3A"N6328D"%2C"r"%3A[{"n"%3A"NtsbNumber"%2C"t"%3A["\"ǂǂ57505232304c41323132\""]%2C"o"%3A"and"%2C"k"%3Afalse%2C"m"%3Anull}]} Then select "Materials Lab Factual Report" All that report says is the center electrode fell off. We knew that was happening 4 years ago. As far as I know, none of the MSers with the missing tips even knew it was a problem until they took the plugs out for cleaning. The engines still ran fine with the missing electrode. Quote
Shadrach Posted October 17, 2022 Report Posted October 17, 2022 I think the scenario is similar to what happened to another poster in this forum. I single plug failure should not bring down a plane. Hell, a single mag failure should not bring down a plane. However, I can conceive of a scenario where at high density altitudes things go very badly. See you have a pilot that’s ignorant about leaning for takeoff at high DAs. The engines not going to be performing to its greatest potential but will still produce adequate power to depart and climb. Now I fail a plug in climb. Now you have a very rich cylinder with a single point of ignition and a very slow flame front. Most of the power on that cylinder is going out the exhaust. The engine becomes rough because of the power imbalance. The best course of action would be counterintuitive to a new pilot. Quote
A64Pilot Posted October 17, 2022 Report Posted October 17, 2022 7 minutes ago, Shadrach said: I think the scenario is similar to what happened to another poster in this forum. I single plug failure should not bring down a plane. Hell, a single mag failure should not bring down a plane. However, I can conceive of a scenario where at high density altitudes things go very badly. See you have a pilot that’s ignorant about leaning for takeoff at high DAs. The engines not going to be performing to its greatest potential but will still produce adequate power to depart and climb. Now I fail a plug in climb. Now you have a very rich cylinder with a single point of ignition and a very slow flame front. Most of the power on that cylinder is going out the exhaust. The engine becomes rough because of the power imbalance. The best course of action would be counterintuitive to a new pilot. So, given this scenario, is the accident a fault of training or lack thereof? I stupidly took off on a single mag in a C-152 in Tx in above 100F heat, it took me a minute or two after takeoff to figure it out and maybe another minute while I thought about should I touch the mag switch or leave it alone, airplane could barely climb, but it flew with four dead plugs. I can’t image one plug even being detectable without an engine monitor and a scan by the pilot, much less being the cause of a crash. I’ve seen four cylinder engines completely lose compression in one cylinder, only running on three fly to an airport and make a safe landing. This is a lawyer finding something to sue over, nothing more. They could care less about if it was the cause of the crash or not, they are looking for settlement money. Remember some sports guy that flew a Cirrus into a building in New York with a CFI? Hartzell was sure in that case because their propellor “pulled” the aircraft into the building, can you imagine a more frivolous lawsuit? This is what’s driving the cost of flying to be unaffordable 6 2 Quote
Shadrach Posted October 17, 2022 Report Posted October 17, 2022 On 10/17/2022 at 10:22 AM, N201MKTurbo said: All that report says is the center electrode fell off. We knew that was happening 4 years ago. As far as I know, none of the MSers with the missing tips even knew it was a problem until they took the plugs out for cleaning. The engines still ran fine with the missing electrode. True, but if you were launching out of Lake Tahoe (6268msl) on a hot day in a C172 with the mixture set full rich, i’m guessing losing a plug would be very noticeable. The best course of action would be to lean the engine. Indeed single mag operation leaned for best power might be best. Most new pilots wouldn’t know to do that…Indeed many ATPs wouldn’t. Quote
A64Pilot Posted October 17, 2022 Report Posted October 17, 2022 Yes, but that’s a training failure, not an equipment one. It’s like crashing a car from a tire going flat, if driven within legal limits a flat tire should not result in a crash, yet ALL new cars have to have flat tire monitoring systems that I get to pay for because there are so many fools in SUV’s that apparently can’t drive. 1 Quote
GeeBee Posted October 17, 2022 Report Posted October 17, 2022 How does a single spark plug bring down an airplane? It is a C-172 at TVL. Elevation 6262' in July at 1500 LT. I don't even have to do a DA calculation to tell you that is a marginal situation......at best. Bird poop on the air cleaner could bring it down. So much so most the flying clubs I encountered when I lived in SJC would not allow 172's into TVL. Had to have a 182 or larger. 2 Quote
FlyingDude Posted October 17, 2022 Report Posted October 17, 2022 One week into Mooney ownership, I had cyl 1 left plug shorted with lead deposit. Engine runup was smooth at KTAD airport, CO and the engine ran smoothly till Omaha NE. KTAD was like 9000' DA as it was a hot day. Found out at engine runup at Omaha while running on L mag only. I increased power up to 2000rpm that day for a better runup, all smooth with Both mags. I didn't take off with one plug fouled, so I cannot relate to their experience but it must've happened during that flight: didn't notice it when the fouling developed. I dont know how I would've reacted if it happened during climbout. Don't want to jinx myself or anybody. Quote
Shadrach Posted October 17, 2022 Report Posted October 17, 2022 On 10/17/2022 at 10:31 AM, A64Pilot said: So, given this scenario, is the accident a fault of training or lack thereof? I stupidly took off on a single mag in a C-152 in Tx in above 100F heat, it took me a minute or two after takeoff to figure it out and maybe another minute while I thought about should I touch the mag switch or leave it alone, airplane could barely climb, but it flew with four dead plugs. I can’t image one plug even being detectable without an engine monitor and a scan by the pilot, much less being the cause of a crash. I’ve seen four cylinder engines completely lose compression in one cylinder, only running on three fly to an airport and make a safe landing. 100% training. Spark plugs are fragile to handle and if given enough time will all fail at some point. We must all be prepared for that eventuality if it happens while they are still in service. Many many years ago I lost a mag over the Chesapeake Bay with three people on board. I felt it, but it was not dramatic. There was a slight rpm drop that was almost instantly corrected by the prop governor. It caused me to immediately glance over at the monitor which revealed all EGT’s were elevated. If a single plug had failed, I think it would have been noticeable as even back then I was cruising LOP. Quote
LANCECASPER Posted October 17, 2022 Report Posted October 17, 2022 If you read through the entire 5 pages of the 2018 Tempest Fine wire post it appears there were a lot of failures. I don't really feel sorry for Tempest getting sued over this. They were aware of the issue, could have traced to what owners got these plugs with the bad out-sourced welds and replaced them. Obviously they didn't do that. Much more expensive to settle lawsuits than to replace products that cost a few dollars to produce. Whether the bad plug contributed to the crash I don't know, but leaving them out there without replacing them is not a good strategy when you sell critical-to-flight products. 1 Quote
GeeBee Posted October 17, 2022 Report Posted October 17, 2022 I also note he departed RWY 18. In that direction, the terrain rises rapidly. Even with a fully functioning 172 you would need to fly the "Golf Course Departure." That is circle over the Edgewood golf course until you got enough altitude to turn north and head out over the lake. I've had to roll off of 18 in a NA 210 and go to the golf course. With a bad plug, rolling off of 18 in that DA with a 172 he might as well stuck jelly in his pockets. Quote
philiplane Posted October 17, 2022 Report Posted October 17, 2022 (edited) Losing one out of eight plugs would not make any noticeable difference in performance. The second plug in each cylinder is for redundancy. You would see a slight rise in EGT on the affected cylinder, if the plug actually stopped firing. In most cases the engine will run fine after losing the center electrode tip, because the magneto produces sufficient energy to jump the larger gap. However, the plugs shown appear to have been oil fouled for some time. Note the wet, black oil, and the carbon underneath it. This cylinder has been pumping oil for many hours. The problems with #4 cylinder didn't suddenly occur on takeoff, they likely existed for some time, but didn't get anyone's attention. Until a combination of density altitude and failure to lean for the conditions caused the loss of the second plug due to debris bridging the gap of the top plug. At his departure time of 3 pm on July 7, 2020, the temperature was 92 degrees at the airport, which has an elevation of 6269 feet. I don't know what the altimeter setting was, but odds are the density altitude was 9000 feet or greater. This is just another case of ambulance chasers seeking to pin the blame on someone with money, rather than the pilot who must have ignored prior warning signs that cylinder 4 wasn't right. And flew that plane into an airport under conditions that would test its capabilities on the best of days. Edited October 17, 2022 by philiplane 1 2 Quote
kortopates Posted October 17, 2022 Report Posted October 17, 2022 (edited) Full report blames the pilot on improper leaning; over rich. Not only were plugs fouled but exhaust valves 3 and 4 weren't seating from carbon buildup resulting in loss of compression. This all didn't happen in the short flight that day but was building up over time. Overhauled cylinders, if not engine, with only 26 hrs. I am sure curious what kind of runup was done and what the pilot observed during it. Yet understand a 75 hour pilot was not well equipped to perhaps notice he had an issue; especially if he had gotten accustomed to less than satisfactory performance. Report_WPR20LA212_101564_10_17_2022 11_39_01 AM.pdf Edited October 17, 2022 by kortopates 2 2 Quote
jetdriven Posted October 17, 2022 Report Posted October 17, 2022 Looking at the oil fouling of that one spark plug on the number four bottom plus the rust all over the outer jacket of it, makes you think this airplane was not maintained all that well besides Quote
EricJ Posted October 17, 2022 Report Posted October 17, 2022 3 hours ago, ragedracer1977 said: Anyone else received this yet? A while back several of us experienced fine wire failures. I guess somebody crashed their plane and they found a broken center electrode and are interested in pinning the blame on tempest. Having read the entire accident report, I’m not sure I agree. Attorneys in such suits are working for their client and so will only be interested in supporting facts that help their side of the case. As such it can be very frustrating, unproductive, whatever you want to call it to participate, even if you tend to agree with their position. If you don't agree, then there's no point to responding. 1 Quote
Shadrach Posted October 17, 2022 Report Posted October 17, 2022 47 minutes ago, philiplane said: Losing one out of eight plugs would not make any noticeable difference in performance. The second plug in each cylinder is for redundancy. You would see a slight rise in EGT on the affected cylinder, if the plug actually stopped firing. In most cases the engine will run fine after losing the center electrode tip, because the magneto produces sufficient energy to jump the larger gap. However, the plugs shown appear to have been oil fouled for some time. Note the wet, black oil, and the carbon underneath it. This cylinder has been pumping oil for many hours. The problems with #4 cylinder didn't suddenly occur on takeoff, they likely existed for some time, but didn't get anyone's attention. Until a combination of density altitude and failure to lean for the conditions caused the loss of the second plug due to debris bridging the gap of the top plug. At his departure time of 3 pm on July 7, 2020, the temperature was 92 degrees at the airport, which has an elevation of 6269 feet. I don't know what the altimeter setting was, but odds are the density altitude was 9000 feet or greater. This is just another case of ambulance chasers seeking to pin the blame on someone with money, rather than the pilot who must have ignored prior warning signs that cylinder 4 wasn't right. And flew that plane into an airport under conditions that would test its capabilities on the best of days. Disagree with the premise of the first paragraph agree with the rest. Yes dual ignition is there for redundancy, but a side effect of that is more rapid combustion as two flame fronts are propagating across what is a large diameter combustion chamber by internal combustion engine standards. A single failure under most circumstances is minor. Nevertheless, a single ignition failure in and of it self will reduce the speed of combustion on the affected cylinder[s], less of the combustion event will occur at the ideal crank angle reducing power on the affected cylinder[s] and causing the EGT rise as combustion that should be used for power is now burning in he exhaust. Now add an overly rich mixture which is also delaying the development of combustion event. Now add a high DA and you have a recipe for a lousy running engine at a time when the plane needs all the engine power available. A 75hr pilot has no business operating out of Tahoe unless they were trained there and fully understand the limitations. This was a pilot operating on the ragged edge of both his and his airplanes capabilities. In my opinion he was one link away from an accident before he got into the airplane that morning. Suing Tempest is like the estate of a newly minted twin pilot trying to sue an engine manufacture because of a VMC rollover. 3 Quote
philiplane Posted October 17, 2022 Report Posted October 17, 2022 (edited) 19 minutes ago, Shadrach said: Disagree with the premise of the first paragraph agree with the rest. Yes dual ignition is there for redundancy, but a side effect of that is more rapid combustion as two flame fronts are propagating across what is a large diameter combustion chamber by internal combustion engine standards. The engine must make rated HP on only one magneto system, as part of the certification tests. The second system adds redundancy, and a minor rise in efficiency. Dual plugs move the torque curve sightly lower but have little effect on max HP available. So he had 160 HP to start with, minus the 23 HP loss of a stock Cessna muffler. Leaving 103 HP or less at the prop when cylinder 4 went dead. Edited October 17, 2022 by philiplane Quote
Shadrach Posted October 17, 2022 Report Posted October 17, 2022 2 minutes ago, philiplane said: The engine must make rated HP on only one magneto system, as part of the certification tests. The second system adds redundancy, and a minor rise in efficiency. So he had 160 HP to start with, minus the 23 HP loss of a stock Cessna muffler. Leaving 103 HP or less at the prop when cylinder 4 went dead. None of that matters to a 75hr plot departing with a DA of ~9000ft and a full rich mixture. I wish there was ADS-B info available. With 8500' of runway, one wonders if he just mushed along for 1.6 miles of runway before putting it in a field. Quote
ilovecornfields Posted October 17, 2022 Report Posted October 17, 2022 If an attorney found my home address and wanted to have “a brief telephone conversation” with me regarding something I posted in the internet I would decline. I don’t see how participating in this would help you, the family of the deceased or aviation in general. Seems lawsuits like this are exactly the reason an aviation spark plug costs $150 instead of $15. I’m sorry about what happened to the pilot. I own property just a few miles from TVL but fly into MEV instead because it’s much lower and in a valley even though I have a much higher performance plane and over 1.000 more hours than that pilot did. I want to be an old pilot, not a bold one. As @kortopates pointed out, he didn’t die because of a bad plug - he died because he made poor choices and may have lacked the insight, training and experience to appreciate the poor choices he was making. When I took my commercial checkride the DPE commented “you’re the first doctor I’ve flown with who has any common sense.” I doubt that’s true, but I think it does point out a common theme among people who are experts in one field assuming that they will be able to translate that same level of performance into a different field and being surprised when that just isn’t so. 2 Quote
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