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#41
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Emily wrote:
Jay Honeck wrote: Steven, I'm curious to know what your thought processes were in that dire situation. "If I die out here, I'll never hear the end of it from the gang at rec.aviation." Funny as that may be, Steven *was* very cognizant of how he wrote this story up, for fear of being flamed by certain members of this group. The fact is, you're always going to get flamed, no matter what you do. You can't worry about it. I agree. What's to worry about? Flames aren't fatal. They don't even hurt. :-) Matt |
#42
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NW_Pilot wrote:
"houstondan" wrote in message ups.com... i posted a link at a couple of cessna "type" clubs (c.p.a. and c.p.s.). i noticed someone did that on an earlier edition so i guessed it was ok to do that. someone said "a more experienced pilot would have......", well, i think he did just great. turned around, got it back on the ground, figured it out, flew on and made the contract. i think he needs to be congratulated for doing something really big and doing it well. i'm about finished reading "the flying north" and i expect any of those guys would have bought steven a beer and listened to his story. my airplane budget looks at getting a good harness system, fuel and engine monitors and enough gas to do some real traveling so i don't have to worry about a G-1000 any time soon. clearly it is a cautionary tale about putting too many avionics eggs in one glass basket. again, jay, thanks for being the conduit on this. great stuff. dan Thank, You I would feel a bit better about the system if they put manual engine monitors and fuel qty indicators as a back up the cost to Cessna would not be much more they have the panel space and would make the newer models safer with manual back up instruments. I agree. As we've learned and re-learned many times over the years (Therac-25 and many others), it isn't a good idea to have all of your eggs in one basket, especially when that basket is made of software! :-) Matt |
#43
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Matt Whiting wrote:
NW_Pilot wrote: "houstondan" wrote in message ups.com... i posted a link at a couple of cessna "type" clubs (c.p.a. and c.p.s.). i noticed someone did that on an earlier edition so i guessed it was ok to do that. someone said "a more experienced pilot would have......", well, i think he did just great. turned around, got it back on the ground, figured it out, flew on and made the contract. i think he needs to be congratulated for doing something really big and doing it well. i'm about finished reading "the flying north" and i expect any of those guys would have bought steven a beer and listened to his story. my airplane budget looks at getting a good harness system, fuel and engine monitors and enough gas to do some real traveling so i don't have to worry about a G-1000 any time soon. clearly it is a cautionary tale about putting too many avionics eggs in one glass basket. again, jay, thanks for being the conduit on this. great stuff. dan Thank, You I would feel a bit better about the system if they put manual engine monitors and fuel qty indicators as a back up the cost to Cessna would not be much more they have the panel space and would make the newer models safer with manual back up instruments. I agree. As we've learned and re-learned many times over the years (Therac-25 and many others), it isn't a good idea to have all of your eggs in one basket, especially when that basket is made of software! :-) Matt Just as people will plead to let the NTSB give a report before you decide what caused a crash, I think the same thing should be done here. I'm a software engineer and I've dabbled a little in real time systems and there are many things that can cause a system to reboot. It might be a **** poor design or it might be something else. NW_pilot has not given us enough data to know ( because he did not have the data either ) The biggest problem is Garmin does not issue final reports but in this cause it may be possible to find out why. I agree that a out of range fuel sensor should not cause a system reboot. I just went back and re-read the story and realized that this was not truly a garmin problem. The modified fuel system caused the problem and those additions are outside the design envelop of the garmin system. It would appear at first glance that the condition that caused the problem ( over pressure in the fuel tank due to excess fuel could not happen in a standard system and so it was not forseen in the system design) Bottom line is that this was a modified system and to hold garmin responsible and use that are a reason not to have advanced avionics is not good idea. John |
#44
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x-archive-no: yes
NW_Pilot wrote: "Jose" wrote in message Anyway, that's quite an adventure! Would you do it again? Hell, Yeah!!! You Bet !! Steven, Adventure like this was made for adrenaline junkie like you ;-) Congratulations for an exceedingly well done job. Actions speak louder than words, it takes both a cool head and good piloting skill to handle this scary event. I don't think that you can ever silent net armchair critics, Monday morning quarterbacks etc but I hope that you have erased some doubts in the mind of some of your 'frequent' critics. Hai Longworth |
#45
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![]() "Montblack" wrote in message ... ("Jay Honeck" wrote) Steven, I'm curious to know what your thought processes were in that dire situation. "If I die out here, I'll never hear the end of it from the gang at rec.aviation." Truly any pilots version of hell. |
#46
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On Mon, 02 Oct 2006 10:18:13 GMT, Matt Whiting
wrote in : ... , it isn't a good idea to have all of your eggs in one basket, especially when that basket is made of software! :-) It would seem that Airbus has successfully grappled with this issue. Perhaps Cessna and Garmin should get a clue from them. |
#47
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but they do look funny running with their wrists flapping an all... :-)
Matt Whiting wrote: Emily wrote: Jay Honeck wrote: Steven, I'm curious to know what your thought processes were in that dire situation. "If I die out here, I'll never hear the end of it from the gang at rec.aviation." Funny as that may be, Steven *was* very cognizant of how he wrote this story up, for fear of being flamed by certain members of this group. The fact is, you're always going to get flamed, no matter what you do. You can't worry about it. I agree. What's to worry about? Flames aren't fatal. They don't even hurt. :-) Matt |
#48
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On Mon, 02 Oct 2006 11:27:24 GMT, John Theune
wrote in wI6Ug.876$Pk2.497@trnddc08: I'm a software engineer and I've dabbled a little in real time systems and there are many things that can cause a system to reboot. Would division by zero be one of them? It might be a **** poor design or it might be something else. NW_pilot has not given us enough data to know ( because he did not have the data either ) Perhaps. Here's what is on Mr. Honeck's web site at the URL he provided at the beginning of this message thread http://www.alexisparkinn.com/nwpilot's_tranatlantic_flight.htm: [Day 2] After switching to the aircraft fuel (from the ferry tank) strange things started happening. The 100-gallon ferry tank went dry after only 7 hours, burning 8 to 9 gallons per hour! Something just did not add up... [...] Then, the G1000 started to go nuts, with the fuel indicators displaying red X's. Next, I received a CO2 detector failure, then GPS-1 failure! [...] When the G1000 got done rebooting, I found myself missing my airspeed indicator and fuel gauges -- and it was now displaying a bunch of other errors. Assessing my situation, I figured that I had no fuel gauges, the G1000 is continually rebooting, possible CO2 in the cabin, AND an apparent fuel leak! [...] As I grind closer and closer to Narsarsuaq, at about 60 miles out they send up a rescue chopper, locate me, and guide me in, since I am unable to make the NDB approach with the G1000 rebooting itself. (The ADF display is tied to the G1000's HSI.) [...] [Day 3] We finally figured out that the instructions for the ferry tank were not correct, and really need to be changed before the company installing the tank kills someone. The problem was the ferry tank's fuel return line was over pressurizing the aircraft tanks, causing fuel to vent overboard. To prevent this, what needed to be done was to FIRST run the aircraft's left tank down till it was almost empty, THEN turn on the ferry tank. The instructions with the ferry tank said only to "Climb to altitude, then switch to the ferry tank and turn off the aircraft fuel", then run it till the fuel level hits a mark on the ferry tank's fuel level indicator. These instructions turned out to be totally incorrect! Even Cessna engineering was surprised that the FAA had approved the instructions for the ferry tank setup, because it also caused the G1000 to go nuts. Apparently the added pressure in the fuel tanks pushed the floats in the fuel tank up, which got the Garmin confused, causing an error that made it reboot. The loss of the airspeed indicator was caused by fuel vapors entering the pitot tube -- which also caused the CO2 detector failure! [...] [Day 11] Then the tach started being erratic, saying that my RPMs were 4000 -- yeah, right! Then it went Red X. OK, Garmin & Cessna, you need to have better quality control. After everything else that has happened, this makes me not want to every own a newer model Cessna, or anything with a G1000. The biggest problem is Garmin does not issue final reports but in this cause it may be possible to find out why. I agree that a[n] out of range fuel sensor should not cause a system reboot. I just went back and re-read the story and realized that this was not truly a garmin problem. Perhaps you are correct, but It would seem that there is a lot of corroborating evidence absent at this time. The modified fuel system caused the problem and those additions are outside the design envelop of the garmin system. Would you care to share the information to which you refer, detailing the "design envelope of the Garmin system?" It would appear at first glance that the condition that caused the problem ( over pressure in the fuel tank due to excess fuel could not happen in a standard system and so it was not forseen in the system design) Typically wing tanks are filled to the brim of the filler neck. Presumably that leaves some air trapped in the tank. Without knowing the exact placement of the fuel vent pipe intake within the tank, it is difficult to confirm an over pressure condition in this case. Absent knowledge of how Mr. Rhine came to his "over pressurizing" conclusion, it is difficult to substantiate it as fact. Might not the venting fuel have been merely excess fuel draining from the tank as it was designed to do when the tank is over filled? After all, presumably it is the same fuel pump operating in both the factory designed fuel system and the aux fuel system. Bottom line is that this was a modified system and to hold garmin responsible and use that are [sic] a reason not to have advanced avionics is not good idea. Perhaps. I thought you felt it would be more appropriate to reserve judgment until more information was available. |
#49
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On Sun, 1 Oct 2006 23:12:42 -0700, "NW_Pilot"
wrote in : "Larry Dighera" wrote in message .. . On 1 Oct 2006 06:47:05 -0700, "Jay Honeck" wrote in om: http://www.alexisparkinn.com/nwpilot's_tranatlantic_flight.htm Man, if the new details of his story doesn't chill ya, nothing will! A more experienced pilot who had studied the aux tank system may have been able to mentally diagnose the cause of the fuel venting. But Garmin's role in this incident is unforgivable. I did study the fuel system Given the fact that the aux fuel system was a modification upon which your safety depended, did you personally take the time to analyze its intended operation from the schematic diagram and description of system operation (not its use, but how it was engineered to operate)? I believe you are intelligent enough to have done a reasonable job of system analysis without benefit of specific training or an appropriate college degree. and so did the engineer that designed it and wrote the instructions for it's usage! I would also assume so did the faa inspector that approved the system description and usage instructions. Once you go changing the factory fuel system design you go from the engineered description of the now modified fuel system. If I understand your story correctly, the cause of the wing tank venting was a result of the fuel return line pouring fuel that was being feed from the separate aux tank fuel system into the wing tank(s). Is that correct? They left out something very very important in the new systems description! Are you referring to the necessity to burn fuel from the wing tanks before switching to the aux tank, so that there would be adequate room in the wing tanks to hold the fuel being returned from the fuel injection system? Can you provide the manufacturer's name and model number for the aux fuel system installed in the aircraft you delivered? How large is the documentation of the aux fuel system? Is it possible you could make a scanned copy available? In particular, I'd like to see a schematic drawing of the system and the description of its operation, and its operation use instructions, in that order. |
#50
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I just went back and re-read the story and realized that this was not truly a garmin problem. The modified fuel system caused the problem and those additions are outside the design envelop of the garmin system.
I most strenuously disagree. Systems should be designed NOT to fail catastrophically when outside their "intended use". The problem was =not= caused by the modified fuel system, rather, the problem was caused by unexpected sensor input. In this case the unexpected sensor input was caused by the modified fuel system, but it could have come from any number of reasons, and the whole point of aviation systems is that they be robust. Jose -- "Never trust anything that can think for itself, if you can't see where it keeps its brain." (chapter 10 of book 3 - Harry Potter). for Email, make the obvious change in the address. |
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