Author Topic: B17 crashed in CT today  (Read 5865 times)

230RN

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Re: B17 crashed in CT today
« Reply #50 on: October 23, 2019, 12:40:32 PM »
Well, filters don't need to be near the tanks... they can be just before the engine, for that matter.  

One objection I might have is that soluble matter (if any) from the sealing bladders would get through the filters, then deposit in the carbs as the spray evaporated.  But after 77 years, I reckon all the solubles (if any) in the bladders would have been carried away long ago.

If it isn't the fuel after all, I'm betting on the impulse magnetos.  Maybe they ran out of impulse (weak springs?) and they can't quite give the same "snap."

Seems to me something like that would explain the shutdown, the fiddling with the engine, and the final "go" decision.  And I think they said the port engines were overhauled, but not the starboard ones, no?

(Do you guys switch (test) the magnetos at idle, or at run-up RPM?  I can't remember.)

Terry, groundlubber in a nice soft armchair, 230RN

REF (You can hear the clunk-clunk of the impulse magnetos in a lot of radial engine startups):

https://en.wikipedia.org/wiki/Ignition_magneto#Impulse_coupling

(scroll to impulse coupling)
« Last Edit: October 23, 2019, 01:19:00 PM by 230RN »

RocketMan

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Re: B17 crashed in CT today
« Reply #51 on: October 23, 2019, 05:37:36 PM »
Hey rocket man did y’all look at commissioning Goodyear for some custom rubber fuel tanks to replace the original self sealing tanks? Dad had to replace the fuel tanks in our Cessna and that’s who made them.

It was a long time ago and I have slept a time or two since then.  I know we didn't pursue it very seriously at that time in the 80's as it was beyond our means both financially and in manpower.
It's possible that the Az Wing has since replaced the tanks, but I wouldn't know.
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RocketMan

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Re: B17 crashed in CT today
« Reply #52 on: October 23, 2019, 05:41:06 PM »
(Do you guys switch (test) the magnetos at idle, or at run-up RPM?  I can't remember.)

I am pretty sure we always switched between mags at run up.  I do not recall what the acceptable RPM drop was between the mags.
I think I still have my CAF reprint of the B17 engineering manual around somewhere. (At least I hope I do.  It would be very disappointing if I lost it somewhere along the way.)  That info should be in the manual.

ETA:  Thinking about this, it's been over 30 years since I crewed Sentimental Journey.  Wow.
« Last Edit: October 23, 2019, 06:04:24 PM by RocketMan »
If there really was intelligent life on other planets, we'd be sending them foreign aid.

Conservatives see George Orwell's "1984" as a cautionary tale.  Progressives view it as a "how to" manual.

My wife often says to me, "You are evil and must be destroyed." She may be right.

Liberals believe one should never let reason, logic and facts get in the way of a good emotional argument.

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Re: B17 crashed in CT today
« Reply #53 on: March 30, 2020, 08:15:35 AM »
Updates

FAA revokes Living History Flight Experience Exemption for the Collings Foundation due to issues found in the maintenance and management of the crashed B-17.

B 17 'Nine-O-Nine Crash UPDATE 27 March 2020
https://www.youtube.com/watch?v=pkxVSnx1Utg

Poor Maintenance Could Have Led To Fatal B-17 Crash
https://hackaday.com/2020/03/28/poor-maintenance-could-have-led-to-fatal-b-17-crash/
Quote
   Regarding engine 4, to prevent the magneto “P” leads from separating from the
    magnetos, someone had attempted to rig the magneto leads in place with safety wire.

    Inspection and testing of engine 4 left magneto revealed the movement of the safety-wired lead caused grounding to the case, which rendered the magneto lead inoperative.

Further, all of the spark plugs in the number 3 and 4 engines were found to be fouled and had electrode gaps that were out of tolerance. From an examination of the aircraft’s maintenance records, it was also learned that an arcing and burned wire had been replaced without any investigative steps taken to find what caused the failure to begin with.

With basic maintenance tasks either not being performed or at least done incorrectly, the FAA has called into question the culture of safety at the Collings Foundation. The paper is careful not to directly accuse the Foundation or any of its staff with outright negligence, but the implication seems clear.
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Re: B17 crashed in CT today
« Reply #54 on: March 30, 2020, 08:23:48 AM »
Quote
Regarding engine 4, to prevent the magneto “P” leads from separating from the
magnetos, someone had attempted to rig the magneto leads in place with safety wire.

Inspection and testing of engine 4 left magneto revealed the movement of the safety-wired lead caused grounding to the case, which rendered the magneto lead inoperative.

That's not "poor maintenance".  That's *expletive deleted*ing criminal.
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Re: B17 crashed in CT today
« Reply #55 on: April 02, 2020, 06:32:19 AM »
Jesus! Zip-Ties for that crap, people! Safety wire on rubber, plastic, Bakelite, or something carrying high-voltage electricity is a recipe for trouble, and in a plane or household wiring, possibly fatal!
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MechAg94

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Re: B17 crashed in CT today
« Reply #56 on: April 02, 2020, 10:28:54 AM »
When I saw this, I was thinking "bailing wire".  I had to google it.  It isn't quite the same, but similar.  But used on electrical wires?  If I saw an electrician here try to rig something up they would use zip ties and/or a crap load of electrical tape. 
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RocketMan

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Re: B17 crashed in CT today
« Reply #57 on: April 02, 2020, 01:38:47 PM »
It isn't unusual to safety wire connectors when they are made to accommodate it, and especially if they are used in a high vibration environment.  The R1820-97 engine in a B-17 is definitely a high vibration environment.
However, from reading the preliminary report, someone absolutely screwed the pooch on this one.  We safety wired a lot of connectors on the engine accessories, but not on the stuff listed in the report.  Stupid kills in an airplane.
If there really was intelligent life on other planets, we'd be sending them foreign aid.

Conservatives see George Orwell's "1984" as a cautionary tale.  Progressives view it as a "how to" manual.

My wife often says to me, "You are evil and must be destroyed." She may be right.

Liberals believe one should never let reason, logic and facts get in the way of a good emotional argument.