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Parajet pre flight checks


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To Parajet pilots....

1. Whilst flying today 4/11/07 the choke mechanism vibrated to the closed position causing the engine to cut. Safe landing and no harm done. I am not sure if the ball bearing and spring mechanism has failed or if it wasn't quite opened fully(i believe it was locked open but cannot put my hand on my heart though). I advise that all pilots double check the choke is fully locked in the open position and fully check its functioning ok and locking open tightly.

2. A second Parajet (20hrs running time only) has also failed today. Whilst warming the engine on the ground the engine cut for no apparent reason. On closer inspection the four rivets that hold the magneto casing on have sheared. This is the second unit to fail like this on realtively young machines for no obvious reason.

I will post any feed back I get from Giles as soon as I get it.

End of report.

PARAJETSIMON

[/b]

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As this thread is here it gave me an idea!

As we fly our motors, we all learn from them every day. We 'suss out' little tips and tricks like the 'wipe the oil off' one above.

I think that it would be a great idea if we started a thread for as many motors as possible and listed our 'tips, tricks, and saftey check advice'

SW :D

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Hi Simon, to add to the thread, Pandy was cancelled today cos' of low wind so as a great back up in the short time l had today l flew at Basingstoke (just down the road from me) and had a few problems with the Parajet myself.

A couple of take offs previously at Lambourn and today, observers noticed a "ping" or a "ting" sort of sound half way through the take off phase and have narrowed it down to an obvious point which l will explain tommorow(mon). Just to say l need some penny washers tonight to hopefully rectify the problem.

Looking forward to coming down tommorow and will be down ASAP.

Regards Mike

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I have lost a bit of faith in my motor now. Is the new sourced magneto unit a free modification? What is the modification? high tensile fixings I would assume. How do i get it? For info my unit was born on the 31/10/06.

It was a bit embarrassing today, we wee demonstrating the Parajet motors to two budding pilots and singing thier praises and this happened. :oops:

Have you come across the automatic choke syndrome before Simon!!!!!!? For info the plate was a bit oily but it is cleaned weekly, its to be cleaned every flight from now on! The oil mixture was dead on, I am quite anul about that.

For the saftey thread, I am aware of exhausts on Parajets spinning in thier mounts. One unit burnt a hole in the fuel tank the size of a beer mat. We now check that we can't twist the coloured silencer as part of the pre fligh checks. Some pilots have made a diy aluminium plate that woulfd deflect the exhaust gases should this happen. Despite all of this I am still an advocate of PARAJET.

Parajet simon

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I have lost a bit of faith in my motor now. Is the new sourced magneto unit a free modification? What is the modification? high tensile fixings I would assume. How do i get it? For info my unit was born on the 31/10/06.

It was just a small number (3 so far in total to my knowledge) so you have no need to worry.

Have you come across the automatic choke syndrome before Simon!!!!!!? For info the plate was a bit oily but it is cleaned weekly, its to be cleaned every flight from now on! The oil mixture was dead on, I am quite anul about that.

I have yes, it was yesterday morning with SteveP while on his (pre flight checks, I may add :wink: ) Colin noticed that the choke was 'not quite' closed so we cleaned off the oil and the problem was solved. I have never had it on my machine as I clean it every time I fly it because of it being a demo unit.

For the saftey thread, I am aware of exhausts on Parajets spinning in thier mounts. One unit burnt a hole in the fuel tank the size of a beer mat. We now check that we can't twist the coloured silencer as part of the pre fligh checks. Some pilots have made a diy aluminium plate that woulfd deflect the exhaust gases should this happen. Despite all of this I am still an advocate of PARAJET.

I have to say I have not heard of this happening myself, nor seen the suggested mod. I will of course report here if required with a (official parajet) safety notice about this.

Parajet simon

SW :D

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How about setting up a club’s or an advised ‘Pre-Flight Check List’ for certain motors.

This then can be updated regularly by a reputable person.

------------------------------------------------------------------------

Wing: Synthesis 29

Motor: Parajet

Status: In training

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Safety bulletins.

In a perfect world there would be a mailing list for all motor owners to receive this kind of information, either snail, or email so that the info is timely. Additionally the manufacturers website would have a complete list of notices and bulletins so that owners could check the validity of their own information.

Parajet are currently revamping their website and I am not sure what its new structure would take. We need to be very careful that we don't create multiple sources of information that can sometimes be either conflicting or not 'in-date'.

As an aside, you can test flying machines until you are blue in the face but in service experience amoung operators will still reveal things that you didn't find. Let's try and maintain an 'even strain' here when we look at our treasured motors and remember that the manufacturers do their best to deliver a top notch product. Gilo and his team certainly do!

Just another opinion folks...

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Spoke to Giles, he is not at all happy about the Choke situation and will be sorting out Simons motor as a Priority, and anyone elses choke plate if needed, which I am sure will be minimal :D

As they say at times like this......

Its not the problem thats the problem, its how it gets sorted out. I challange anyone to provide a better after sales service :D:D

SW :D

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How about setting up a club’s or an advised ‘Pre-Flight Check List’ for certain motors.

Simon, have you still got the BMAA pre flight check list that I gave you ? it has a very comprehensive check which would cover all motors. Worth typing up and making a stickie somewhere on here....

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As I said before,

I think if we start a thread for each motor type, (Like Colin has done for his A3) then we can upload the correct check list. (The Parajet has some specific things to check but ALL owners should have the user manual I am going to post the Parajet official pre -flight check list here by the end of play today.

May I suggest you start a HE one and list and hints and tips that you have for it.

SW :D

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Simon

Sorry to say that not ALL owners have user manuals. I did not get any paperwork from my seller.

I have sent a couple of emails to Gilo/Mark asking them nicely to post or email me a price for a documentation package you get when you purchase a new Parajet, but have not received any reply yet!

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flew at Basingstoke (just down the road from me) and had a few problems with the Parajet myself.

Regards Mike

Hi Mike

Great days flying in Basingstoke, was good to have 8 flying at once,not much tea drinking here.

What was that noise we herd as you took off? :shock: a few of us herd it and are interested in your findings.

We had 3 brand new machines taking to the skies, 2 PAP ROS 125s(1 mine :D ) & 1 fresh Breeze,

Neil is still struggling with his Parajets climb rate,did you know if he has managed to sort it?

See you in the Air Monday (have spare motor if you need one) :)

Paul

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In the manual (I have the Volution Manual in hard copy) there is an inference that the prop should be attached and the bolts torqued up to 92 foot pounds. Simon believed that the figure was in error as it seemed very tight, he recommended the correct procedure below which Gilo has confirmed as being correct..

If you use this figure you will crush and over-tighten your prop. Just tighten each retaining bolt to a firm finger pressure alternating that pressure across the bolt pattern as you would tightening down a cylinder head (for example).

The manual figure is an error that Parajet cannot explain. I suspect it came from the manual sample they used to construct their own.

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Torque figures for all fasteners are carefully worked out. They depend on the fastener grade, how they are done up, lubrication and material under the fastener. This is true for everything. Ford have a document which runs to some 15 pages for critical fasteners (I jest not!)

The figure of 92 ft.lbs, which is equivalent to 124Nm which is mid range for a 8.8 grade M14. I don't know what size Parajet use to hold the prop on (6mm or 8mm) but doing it up that tight will a: crush the prop & b: shear the bolt.

Maybe it's a fastener deeper in the engine on the prop shaft which you don't normally see?

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Hi Norman

Being a person that doesn't know too much about torque settings and due to get my Parajet soon.

I find your comments a little disconcerting, that from a product mannual suggesting 92ft.lbs (Error in Mannual) then to 'Finger Tight' verbally suggested by Parajet.

Surely a bit more pressure than finger tight is needed to keep the prop. on during flight.

Are you aware if any other ammended torque pressure been recommended.

Cheers

Terry

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Terry,

Yes, re-reading the text it does imply a little looser than might be desired at 'finger tight'. :)

What I meant to say was a firm pressure as created by fingers rather than a specific torque setting with a tool. I guess you could (some may argue even should) define that pressure as a torque setting, Gilo didn't think it necessary to give a number. Firm but not a 'graunch' he indicated would cover it. It's not seen as critical as long as they are all tightened to roughly the same pressure. There are spring washers beneath the bolt head also. The thing isn't going to come off.

Martin

Yes, I think the 92 figure may be one which applies to the assembly behind the prop attaching it to the reduction drive/motor. That would make the problem an editorial one not a cock up with a wrong number.

Background

I was putting my new prop on at the field and had looked up (and heard discussed) the figure of 92 ft lbs as being the torque setting. It sounded a lot at the time [92lbs of force applied on a lever a foot long) and I approached the tightening with some care with my torque wrench. I got to a very firm pressure and stopped to discuss the setting with Simon and we then came top the conclusion that the figure was incorrect. I didn't apply anything close to 92 ft lbs but the aluminum plate behind the bolts became indented slightly with the pressure just behind each bolt.

Conclusion

I wouldn't get too excited about this, it is pretty obvious if you start to over-tighten the bolts - it doesn't feel right if you have the slightest idea of what you are doing. I think the manual will come under some scrutiny and don't believe it is in its final form yet as it cannot be downloaded from the Parajet website. Yes, I they are a bit behind the curve but will catch up.

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Hi all, yes l thought 92lbs was a bit excessive on the prop bolts. I reckon a maximum of 88 - 90 is ample. As to do it freehand is a bit hit and miss really, so l shall continue to use a torque wrench.

Hi Paul, yes my parajet is getting sorted and hopefully by the end of the month all should be 100% thanks to Giles at Parajet.com. The noise that you heard was caused by the prop at the six oclock position just clipping the bottom of the cage. Temporary spacers have now been introduced which will keep me flying till the end of the month.

Hope to be out flying on Monday as Sunday looks as if its going to be blown out.

Havn't heard from Neil yet reference power on his Macro Parajet, hopefully he will read this and let us know. I will of course look into the power thing on mine at the end of the month.

Happy safe flying all

Regards Mike :D

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