deadstick

MM, the prop didn't come loose its like the wood has swelled and cracked, I suspect there may have been a small crack in the composite finish that allowed moisture ingress. there is a strip of delamination straight down the middle of the back ace of one of the blades. I have experienced the delamination before, One prop didn't even last the ground run post install from new before it threw a leading edge and others have delaminated within a few hours of use. I would really like to throw on a Sensenich W62HJ-48G but its a C model Jab so I am stuck with the factory wooden prop it was certified with unless I could afford the coin to have a car35 Eng certify a mod prop but alas the two Jabs I have keep my hand in my pocket as it is LOL

Had a prop fail on my J160, the story goes as follows:- CFI reported that there was an intermittent vibe that he noticed over a few flight recently. I cast my eye over everything including prop and could not find any fault, so he took me for a fly, I did notice a change in harmonic frequency when climbing though 1k feet and put it down to a sticky diaphragm in the carb due to the exhaust being a bit darker as well. Anyway after sitting idle for over two weeks due to terrible weather and flooding the aircraft is prepped for flight and started, there is now a massive vibe at idle and across the RPM range so its shut down and I begin looking for the culprit, I was pretty sure it was the propeller as it was a 1 per revolution style of imbalance. Well as the attached pics will show there was major cracking between the prop hub bolt holes and a crack running down the back of the blade, I can only assume the cracks were present before and the wet weather has allowed the wood to soak with water and swell.... I repeat the prop was inspected on the aircraft prior to the bout of wet weather without any indication of cracking...

Hi, does anyone in the Sydney area have a jabiru J160 prop for sale? I have a cracked propeller and need a new one for this weekend as the one from Jabiru will not make it here prior. New or second hand is ok.

Here is an extract from an independent report into the damage from the old through bolts to new 12 point nut AD on my engine, interestingly the engine never gave a single indication of fretting even when the bottom end was inspected during the through bolt AD. Crankshaft, Crankcase & Bearings Examination of the Crankshaft and two alloy Crankcase halves and the matching main bearing shells contained within the crankcase halves revealed unusual wear to the crankshaft bearing journal surfaces in the nature of a significant score mark at the centre of each journal. This score mark matched the centre oil grove in the mating bearing shells. There was also evidence of fretting on the mating surfaces of the crankcase halves. Jabiru has suggested that the adverse wear to the Crankshaft journals has been caused by an initial loss of torque on the through bolts resulting in fretting of the Case halves and a loss of material. Hence when the through bolts were subsequently replaced with modified bolts in accordance with a Jabiru Service Bulletin the increased torque setting on the bolts caused a reduction in main bearing clearance. The preferred bearing clearance is 0.05 mm. The minimum clearance is 0.04 mm. The measured clearance at disassembly was found to be less than 0.04 mm and that this has resulted in excessive bearing preload and wear to the crankshaft journals.

I have run Caltex 98 for a long time, no tank problems thus far.

The manuals i use are current and are downloaded from the website every-time there is a change. I received an email today from Jabiru thanking us for pointing out the error in the maintenance publications and warranting some new rubber mounts for both aeroplanes. I understand what you are saying avocet and when i noted that the rubbers seemed soft after installation i rang jab who not only stated that they were made softer but also confirmed the orientation of the male rubbers going on the mount first and confirmed the torque numbers i had ( it was a friday arvo) suspect the gent may have been looking at the same incorrect installation manual as I. Unfortunately i cannot just fit the rubbers the way they used to go, and I am sure you would testify, jab change things all the time in response to a defect or other trigger! this is one of the reasons i must comply with the book and ensure it is kept up to date with any amendments. The LSA regs are black and white as are the regs governing my conduct as an l2 and LAME, N-ot aimed at you but for clarity if you fit a component the way you've always done it without reference to the latest pub's you are playing russian roulette, you may get away with it for a long time but eventually it will catch you out especially if its a procedural change to stop unseen damage caused by the way it used to be done.

Mike, Jetjr , sorry in my early morning insomnia I forgot to add the page and figure number for the link, page 38 figure 42 shows the male to the rear: http://www.jabiru.net.au/Manuals/Engine/JEM3302-4_Inst.pdf At odds with the construction manual page 3: http://www.jabiru.net.au/Manuals/Airframe%20Construction/Sections/Pre-Paint_Fuselage_Firewall_Fit%20engine%20and%20mount_J2400.pdf

Bucketing down in Nowra ATM

Mike your lucky to be still with us, amazing that you got out of that and well done for pushing on and rebuilding it.

WOW. well done, based on a jab kit? are they cargo doors in the rear? just making a cup of tea and will search for the thread, bloody insomnia!!! teach me for falling asleep on the lounge at 5 only to wake at 11 pm ready for work lol. long night ahead I think

Avocet, what's the plane in your avatar?

lol smashing the computer does nothing, I tried it once!!!!

Avocet, what's that plane in your avatar?

Avocet, Jetjr, Thanks for the info guys, I spoke with someone at jab on the day about configuration as I was concerned with the amount of movement, they confirmed to me the male to the back and gave me the torque figure for the bolts of around 11nm IIRC and stated that the rubbers were being made softer now days for vibe reduction, The Jabiru aircraft tech manual is extremely vague on the install of these mounts here's what I used in conjunction with the info from Jab link page 10: http://www.jabiru.net.au/Manuals/Engine/JEM3302-4_Inst.pdf Since your info here I dug a little further and went into the airframe construction book for the J240 and found this (page 3): http://www.jabiru.net.au/Manuals/Airframe%20Construction/Sections/Pre-Paint_Fuselage_Firewall_Fit%20engine%20and%20mount_J2400.pdf Thanks again for the info I will be amending the defect report for the 230 to include this discrepancy, on the J 170 though, the picture attached is of the lower mount on the J170 it is starting to do the same, going by either reference it is installed correctly, could the rubber be too soft or something else? ideas??? Motz: I had a chuckle when reading your comment, I understand your frustration and sympathise. Looks like a case misinformation on the correct configuration lol... Think Jab should have this clearly set out in the LSA tech manuals and not hidden in the construction log for a home built.

Here's a defect from the weekend, happened to my aircraft was on it test flight post new engine install. After installing the 3300 I noticed that the rubbers were quite soft and allowed a bit more movement of the engine so I rang Jab who informed me that the compound of the rubbers was recently softened to reduce vibration. End result after 0.6!!!!

Hi Errol. I have a new 3300 of the latest configuration, I don't have any flight hours on it yet but from the ground run, the engine appears a lot smoother than the previous versions. The idle was set really low from the factory for some reason so on the initial ground run, surprisingly it idled at 650rpm without a problem until I shut it down.

sorry for the small pics, heres the link :http://www.recreationalflying.com/posts/153913/

This was the latest intake incarnation prior to the cast setup for the 3300

Vev, The Plenum is a one piece cast with the sump, same o-ring and sealant installation by the looks...

Heres a few pics of the latest 3300 that I'm installing in my 230 ATM. The pics show an old 12 point nut up against the larger new ones, the pushrod tubes, the sump and intake plenum are cast as one unit, and the cast starter motor housings.

Should be a good day out, cant wait...

Jetjr, thread title wasn't meant to be derogatory or misleading in fact they are the words of mark in the engine shop. I am sorry if it gets your goat so to speak but certainly was not my intention. I really don't get it hey, frustrating as it is if there is a requirement to check for case chafing prior to carrying out the AD then it should be included in the proceedure, I am bound to not deviate one inch from the manufacturers spec and I never have. When I had the barrells off I checked the bottom end as much as I could without performing a full bottom end and there was not one indication of anything sinister. I really hope the larger through bolts and roller cam sorts out the issues and I wait patiently, I have invested a lot of my $ in both my jabs and really need a solution for longevity in the training environment, cause no one will fly them I am currently considering fitting a Rotax to the 160 but am stuck with the 3300 in the230 due the LSA regs

Ozbear, Nev, I agree with what your saying and it was the opinion of Jabiru that the cases may have fretted prior to the AD being C/O but they could not be sure. This engine provided no evidence of fretting and the through bolt and nut install was done with the barrels off and a bottom end inspection with no defects evident. It is a hard one to dignose without speculation as I didnt strip it, I can only go on what the engine shop said, The engine was running rock solid up until it was cooked (240c) noting that the airflow over the crankcase would be pretty stagnant I suspect that the case halves would have been very hot as well, I am talking with the insurance company today and hope they opt for a complete replacement, but the assesor did mention the words normal wear and tear when referring to the bottom end, You could be forgiven and given the benifit of the doubt if you were to say that the scoring was a byeproduct of the overtemp and case swell but it is an insurance company... LOL the quoted rebuild cost is damn close to the cost of a replacement so fingers crossed... Not sure if its true but I did hear a rumour some time ago that the bottom end isn't dynamically balanced, would be interesting to have this done if not and see if theres any notable difference in reliability....

I'm sure you would champ, you can read about it like I had to when I was undergoing that lackluster AME training (that you eluded too earlier) in order to get my license so I can certify that it's not my fingers causing the problem. Yep I do have a dead engine being repaired under an insurance policy! Your point? Lol rebuilding engines in a motel carport, and you have a go at others swinging $2 spanners lol sounds like your justified on that one also.

Turbo, the heading is not an accusation it's a quote from mark in the engine shop at jabiru! The old ms nuts were out of round self locking the new 12 point nuts are not, hence the lock tight. Don't think these nuts or the new we're ever vibrating loose as the torque seal line never moved. The movement of the case halves might be due to a not so interference fit on the dowels, since been addressed by jab.a few of your comments to do with nuts, bolts, torques leaves me to believe you don't understand the concepts involved fully ( not an attempt to upset you). You can indeed achieve different clamp forces at the same Torque of the nuts.