Icarus

Gday Oscar. I spoke to Rod Stiff a couple hours ago ,about another matter [see South Africa MTOW thread]. I asked how his CASA buddies are doing , and he indicated he thinks the restrictions will be extended. He said he was working hard with CASA to get it all sorted. My opinion below They[ CASA] seem to do things in a haphazard manner , with good intentions? Did too many unhappy Jab engine owners scream loud enough that they could not ignore ? Bye Brendan

Have a look at the jabiru forum [on this site]about increasing MTOW. Forward aft would probably mean that the empty C of G would be at its most forward ,aft of the datum line. ie 99mm aft of datum line.[from j230 POH,] Meaning more weight can go in the back while keeping the c of g in the required area, iebetween 99mm- 277mm aft of datum line Just a guess

OK . So Jabiru South Africa passed on my email to Jabiru Australia. Rod Stiff Rang me! He Said that Jabiru South Africa has their own production certificate and different system to Australia. He also said that when Jab Australia manufactures the jab , they allow tolerences for moisture and variations. plus 10% on top . T hey test coupons of the aircraft composite. He is confident that 760kg is fine. They have been tested to 8 g I asked if a letter stating the higher weight could be obtained for C of A , his reply was "yes certainly". He indicated the aircraft is strong enough for even more weight with confidence! Im not sure a letter for more than 760 would be supplied however. So as Jetjr says , give em a call . [i think I read that somewhere ] A Jab 430 at 360 empty with full tanks and 300kg worth of pax and stuff, sounds good to me. just need to watch the c of g

Im sure Jaba Who will enjoy stuffing 60kg more crap in the back. I was looking at the 430 w&b chart last night and it seems 100kg in the back seat is about the limit with a few hours fuel. This is with the forward most ,aft of datum point [99mm]

Dial 1800 760MTOW:cell: Let us know how u go. I will certainly do this BEFORE I purchase a 430 kit if that's the way I decide to go. I am listening jet jr. Don't stress brother , its all good:smoking: Is your j200 760kg? or RAA rego 600 or GA 700kg

Gday . Im new here as well. sounds like fun sloshing around In a foxbat, maybe the Jabs need floats See you around Brendan

[i emailed them to confirm 700kg . I did not ask if I could get a letter to increase MTOW . As I explained to them I was seeing conflicting info on various forums, Wikipedia! etc I have no aircraft so no point in asking for a letter . Was just a query to confirm Australian MTOW. I am curious as to why SA has higher MTOW so I have also emailed them [Jab SA] this afternoon to ask how. Maybe you could make a call to query them[ Jab Aus.] You have more to gain than me. Im just window shopping :cell:do it do it do it

OK I understand info above. So that means buying a Jabiru airframe from South Africa to Get The MTOW of 760kg!? They manufacture the Airframe over there I believe and State 760kgMTOW. I sent them an email to ask if they changed anything in the airframe or just used the Jab test figures and recalculated to 6.44g at 760kg or ......................... Perhaps a letter from Jabiru would convince an AP to up the weight to 760? Ring em up and ask. There may be 60kg in it for ya?! Brendan

Was also playing with 430 W & B chart last night and seems 100 kg in the rear seat would be max with decent fuel. would need some decent ballast up front for more in the back seat me thinks.

Hi Guys Yes the glasair would be a fair hit the bank acc. $56k US for airframe only + currency conversion plus shipping = probably Aus $ 75 -80k + interior + avionics+ engine + mounts + Propeller etc I think they specify Lycosaurus 360 180hp for 134 k cruise at 65% or the 390 210hp for fasta. Would be nice. Was Looking at the Zenith 801 . Just not sure how often I would use STOL and would it be worth the 20-30 knots sacrificed in drag as Nev States. Maybe a Turbo Jab 430 with big tyres and strengthened nose gear would be STOL with Speed!! My plan will be to Get licence first , then see if the mob wants to fly. If they don't like it then something small and cheap 2 seat will do me. Maybe Aeropup . Still at least a year to start lic anyways. No hurry,plenty of time to study as much as possible. Brendan

If you read page 10 of 21-1 above I think it says EAB has no weight limit?!

Yes CASA site ,it is a mess. Try here: http://www.casa.gov.au/scripts/nc.dll?WCMS:STANDARD:283813477:pc=PC_91002 Specifically AC 21-1[1] page 9 AC 21-4[2] Can read it all if you like. I could not find in all that a rule that states that kit manufacturer MTOW must be used. From what I understand you need to convince the person signing off on the certificate of a safe MTOW. I believe the 230 430 were tested to 7.0g at 700kg. see you tube vid https://www.youtube.com/watch?v=XIV1ddkF-uM So you could convince the authorised person that 760kg is safe to 6.44g? hence my original question. fly it to 4 g with at least 2 g for wind gusts! I believe the 700kg figure is for the planes jabiru build and the recommended MTOW for EAB. Brendan

Whattabout a Glasair sportsman. Fast enough, [ would like to cruise at 135 k] 4 seats [ I would like to take the 2 kids up] can convert to taildragger quickly, Folding wings and removable tail section[ big bonus], carbon fibre option! No Radial or aeros but. As nev says there is no perfect aircraft. I reckon the glasair gets close.

Next question. Who here has their 230 or 430 MTOW over 700kg or 760 kg? [i realise this is above RAA MTOW and for GA EAB only] Did you use ultimate G load to determine MTOW ie 700kg x 8g = 5600 kg 5600kg / 800kg =7g So MTOW 800kg at 7g ultimate load or is there another way?

[ I have no plane as yet . I Have been researching how to determine MTOW of Experimental aircraft. Not Having too much luck finding good info. Seems to be ,load the wings with bags of concrete [ bags of plaster in my case :)] then put The bags in aircraft and see if it can fly!? Trial and error method ? Edit: Just read CASA EAB Rules . Seems I could just pick a number between 1 and 1500kg! Thanks Dazza.

Hello. I received a reply email from Jabiru Australia today, confirming MTOW of 700kg. South Africa have 760kg. according to Jabiru Pacific Web site. Does anybody know why the difference? Thanks Brendan

Yes, I have read through many threads here. I just hope CASA is happy with the audit of Jabiru as I believe they are trying to do the right thing by Jabiru ,Jabiru engine owners,potential owners, and the general public. The way they go about it could possibly be improved .Flame retardant suit has been put on standby

Thanks Nev. Yes plenty of time to decide on a plane , if I get one . Would be looking at a kit as I would like to do maintenance myself ,and get a voluntary annual check to have an expert cast a critical eye over the aircraft. I believe you are such an expert Nev?

Hi . I am a 41 yo Tradie [drywall plasterer ] living in Murwillumbah NSW. My interest in in flying started about 12 months ago when I arrived at a house to do some work ,and noticed half a plane in the garage. Old mate had it about 3/4 finished, all home built wood and fabric. Single seat ,not sure what design it was based on. I should pop in again and say gday. I hope to start flying lessons in the middle of next year . In the mean time I am reading all I can about navigation, engines, flying theory , safety etc. Visited the local airfield last week and got the per hour rate for lessons so I can budget in the lessons. Other interests are , golf, amateur radio., restoring old cars , building /modifying engines . My ideal aircraft at the moment would be a Jabiru j430 [GA exp] , with a rotax 914 , or a Camit bottom end with Rotec heads and direct fuel injection. backed up by rotec throttle body with separate fuel pump and battery etc. I will be asking questions and making a general pain of myself. Hooroo Brendan

Maybe some good old fashioned water injection at high loads!!

Thanks for the info guys. I have read some reports that Jabiru suspects detonation in many cases. We know Auto makers have the luxury of knock sensors to retard timing etc. Good to know about the accuracy of the head machining. Seems a shame that a small percentage of these engines are succumbing to this problem. I really like the look of the jabs and hope to own one, one day in the not too distant future. yes, lean +plus hot head + poor fuel possibly? = broken jab?! I wonder if they {jabiru) ask for fuel samples with the busted engines.or if the unlucky owners get the fuel analysed after the event. For my vehicles I only use the one service station in my area as I have had problems with water in fuel, pinging and dirty fuel with all the others. Its also amazing how much more readily an engine pings when your cold air intake comes off and the engine inhales hot air. Brendan

Gday Guys . New here and first post. Will post proper intro in welcome thread soon. A couple questions about these engines. I have no experience with them. 1.......Has anybody used a knock sensor and indicator light on these engines? CHT and EGT are good but dont indicate actual knock 2......What are the cylinder head chamber cc and how much variation between chambers is considered acceptable/normal? 3......What is the normal hot cranking cylinder pressure of these engines? I ask because it sounds like these engines have been operating at near detonation threshold. Possibly one or two cylinder chambers are smaller than the others at manufacture. This would raise the compression in those cylinder s. Combine this with an air cooled head already running hot on that cylinder and post ignition detonation would be likely. Then the cylinder heats up and pre ignition detonation occurs. The exhaust valve will then run extremely hot , as the cool fuel helps the intake valve cool ,but not exhaust valve. Exhaust valve can then fail /jam etc.. These detonation event would be putting massive strain on the pistons ,big end etc. possibly causing the big end to put excess pressure on the through bolts. Running higher octane will help ,but only up to a point. Perhaps this is why compression was dropped? Who knows......... Im no engineer ,just an interested wannabe pilot! The above is just an opinion and should not be taken as factual info Brendan