RE: Pietenpol-List: Grade 8 Prop bolts forced landing--wrecked AirCamper

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RE: Pietenpol-List: Grade 8 Prop bolts forced landing--wrecked AirCamper

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Original Posted By: "Steve Eldredge"
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RE: Pietenpol-List: Grade 8 Prop bolts forced landing--wrecked Air Camper

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Original Posted By: owner-pietenpol-list-server(at)matronics.com
Huh? I just checked Aircraft Spruce, and they are showing $2.50 eachfor AN6H-43, or AN6H-43A. You can buy the undrilled ones a littlecheaper and drill them yourselfJack Phillips, PESr. Manager, Disposables Product DevelopmentClinical Technologies and ServicesCardinal HealthCreedmoor, NC(919) 528-5212-----Original Message-----
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RE: Pietenpol-List: Re: A/N Hardware

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Original Posted By: "Steve Eldredge"
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Pietenpol-List: Grade 8 Prop bolts forced landing--wrecked Air

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Original Posted By: Steve Ruse
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Re: Pietenpol-List: Grade 8 Prop bolts forced landing--wrecked Air Camper

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Original Posted By: "Michael D Cuy"
When the DAR did my inspection, one of the strongest warnings he gave me was to check and re-check the torque on the prop bolts every 30 days. Wood will continue to give and the most common reason fo prop bolt failure is bolt fatigue dut to the lack of torque. I used AN bolts mostly on mine but there a few non structural places with stainless and my engine mount bolts at the firewall are Grade 8 because I needed a longer thread area so to double as cowling attach points. The inspector was fine with that.Dick N.Dick N.----- Original Message -----
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Pietenpol-List: Grade 8 Prop bolts forced landing--wrecked Air

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Original Posted By: Jim Courtney
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Re: Pietenpol-List: Grade 8 Prop bolts forced landing--wrecked AirCamper

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Original Posted By:> Steve Ruse
SteveThe proper way to re-torque a prop is to looosen the bolts a lot and let itsit for at lease an hour.Then start over and torque to the proper setting.Dale Mpls,> [Original Message]
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Re: Pietenpol-List: Grade 8 Prop bolts forced landing--wrecked Air Camper

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Original Posted By: "Dick Navratil"
Subject: Re: Pietenpol-List: Grade 8 Prop bolts forced landing--wrecked Air CamperIn a message dated 8/11/2005 12:43:49 PM Central Standard Time, steve(at)wotelectronics.com writes:Michael,I'm curious what the failure mode was on these bolts. Surely they didn't justbreak in tension. And they shouldn't have broken in shear unless they weren'ttorqued properly (or maybe they loosened over time, but that shouldn't be dueto them being grade 8). Any idea? I'm not saying anyone should use Grade 8 ona prop, I use AN bolts and will continue to, but I'm curious what characteristicof the grade 8 bolts caused them to fail in this case.Steve RuseI remember this occurance. They both neglected to re-torque the prop as routine maintenance. This is why I re-torque my prop at least 5 or 6 times in the course of a 12 month period, and record each date in my log book. I remove the safety wire, loosen and break the bolt loose, then re-torque to the spec that I have writtenon the inside of the skull cap...I think it is 15 to 17 ft. lbs. The method that Dale mentioned, about loosening the bolts and letting it sit for an hour,makes sense. It allows the wood to breath a little. I've never done it that way, but I think I'll change my task planning to accomodate that method. Don't forget to re-check the track.Chuck G.Chuck G.________________________________________________________________________________
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Re: Pietenpol-List: Grade 8 Prop bolts forced landing--wrecked Air Camper

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Original Posted By: Rcaprd(at)aol.com
One other small follow up point is that the Model A engine only has 4 prop boltsso this becomes more critical.Dick N. ----- Original Message -----
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Re: Pietenpol-List: Grade 8 Prop bolts forced landing--wrecked Air Camper

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Original Posted By: Gary Gower
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> > Pietenpol-List: Grade 8 Prop bolts forced landing--wrecked Air

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Original Posted By: Mike Volckmann
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> Re: Pietenpol-List: Grade 8 Prop bolts forced landing--wrecked

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Original Posted By:> > "Michael D Cuy"
> Subject: Re: Pietenpol-List: Grade 8 Prop bolts forced landing--wreckedAirCamper>>> Speaking of re-torquing prop bolts, I need to do that before I go upSaturday> morning. I'd like to get the opinion of the experts here before I do so.>> To avoid overtightening of prop bolts when checking the torque, do you > typicaly> loosen the bolts a little (1/16 turn), then re-torque to spec? Or just > set the> wrench to the max recomended torque value and check the bolt? If youdon't> loosen the bolts first, and they don't budge at the recommended torquevalue,> do you then loosen the bolts and re-torque (since the proper torquereading is> taken when the nut is moving)?>> Thanks,>> Steve Ruse> N6383J - KFTW>> Quoting Dick Navratil :>> > > >> > When the DAR did my inspection, one of the strongest warnings he gaveme was> > to check and re-check the torque on the prop bolts every 30 days. Woodwill> > continue to give and the most common reason fo prop bolt failure isbolt> > fatigue dut to the lack of torque. I used AN bolts mostly on mine butthere> > a few non structural places with stainless and my engine mount boltsat the> > firewall are Grade 8 because I needed a longer thread area so to doubleas> > cowling attach points. The inspector was fine with that.> >> > Dick N.> > Dick N.> > ----- Original Message -----
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> Re: Pietenpol-List: Grade 8 Prop bolts forced landing--wrecked

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Original Posted By:> > "Michael D Cuy"
> Subject: Re: Pietenpol-List: Grade 8 Prop bolts forced landing--wreckedAirCamper>>> Speaking of re-torquing prop bolts, I need to do that before I go upSaturday> morning. I'd like to get the opinion of the experts here before I do so.>> To avoid overtightening of prop bolts when checking the torque, do you > typicaly> loosen the bolts a little (1/16 turn), then re-torque to spec? Or just > set the> wrench to the max recomended torque value and check the bolt? If youdon't> loosen the bolts first, and they don't budge at the recommended torquevalue,> do you then loosen the bolts and re-torque (since the proper torquereading is> taken when the nut is moving)?>> Thanks,>> Steve Ruse> N6383J - KFTW>> Quoting Dick Navratil :>> > > >> > When the DAR did my inspection, one of the strongest warnings he gaveme was> > to check and re-check the torque on the prop bolts every 30 days. Woodwill> > continue to give and the most common reason fo prop bolt failure isbolt> > fatigue dut to the lack of torque. I used AN bolts mostly on mine butthere> > a few non structural places with stainless and my engine mount boltsat the> > firewall are Grade 8 because I needed a longer thread area so to doubleas> > cowling attach points. The inspector was fine with that.> >> > Dick N.> > Dick N.> > ----- Original Message -----
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