Flying jab's over 40 degrees

[Guest Bruit2]

How do Jabiru's perform at temps above 40.

 

I understand that flying at these temps is not recommended.

 

 

[motzartmerv]

Thats right...have you read why it is they don't recomend it??...apart from the performance problem... The composites "weaken" over a certain temp..

 

That really doesn't sound like a fun day out to me...

 

 

[Steve Donald]

the stress ratings are done at 53 c and you mention 40c then you have altitude temp reduction common guy's get with it, there is no issue here, go to Wakerie SA the worlds best gliding centre all composite and they get exited when it is 40c and no structual failures here recorded due to heat, don't get paranoid due to poor information being supplied to you look at the flight manual in the aircraft, not the remarks of the uninformed or ignorant , enjoy cheers Steve

 

 

[quentas]

I recall one fibreglass training aircraft having a spar temp probe that gave a go/no go on hot days...may have been a Grob or something like that. Certainly not a Jab. I think the engine overheating would be the only thing holding back a Jab driver on a day over 40.

 

 

[Guest brentc]

The Jabiru maximum operating temperature is 40 degress. I treat that as gospel and don't fly. Not only would you be voiding insurance (and warranty) if you chose to fly above those temps, but potentially do engine damage amongst any other problems that the designer thought of when he placed the 40 degree limitation!

 

From experience and what people tell me, oil temps could be a problem above those temps so prolonged operation would not be beneficial to the engine.

 

 

[blueline]

And when Cessna flyers start bagging Jabiru's get them to check their flight manuals- for example the 172N performance charts stop at 42 degrees (and no guessing what the performance might be above 42 is allowed!)

 

 

[Steve Donald]

you haven't read the the Manuel, do you think the insurance company would cover you if this was the casw 40c common get with reality and stop trying to scare new aviators use facts and real facts. you fly a jab learn the facts

 

 

[facthunter]

40 degrees.Limiting.

 

There is a certification issue with this temp. and you are technically in no-mans land. the charts don't go there.

 

Having said this there is no reason why the aeroplane will not fly. You would need to have a good reason to do it as the aeroplane not only suffers a loss of performance but the pilot could be suffering from heat exhaustion too, and should carry a lot of water in any case.

 

An informed pilot will calculate a density altitude situation and adjust the weight accordingly, if he is familiar with the aircrafts performance at high density altitudes. Oil and head temps will be higher so they should be monitored and climbing at a higher than normal airspeed, and/or reducing power should be done.

 

Air cooled engines can be a better proposition in this instance as the hot sections of the engine are better able to dissipate heat than an engine with a radiator, due to the greater temp difference between the part and ambient, the rate of heat exchange being a function of the temp DIFFERENCE. Nev..

 

 

[Steve Donald]

nothing about 40c in my flight manual what you talking about/ not fair laying this sort of rubbish on the uninformed flyer

 

 

[Steve Donald]

stress ratings were performed to meet the numbers at 53c look at the Jabiru site and the millons it cost to meet certification, then the facts i pull my plane out of a 50c hangar warm up and take off at about 42c cruise at 33c land at 40c whats the problem as for engine temps hey if it set up right no issue eithter i don't have a temp issue or many others, the j120 can climb full power until lift is non existant and still be in the green even on a 40c day, so dont let that could your judgement, the 160 can to when set up correctly some of us know what is required for this but it is not a case of Iicerouse meets his maker.or however his bloody name is spelt

 

 

[BLA82]

Settle down Boys,

 

Steve everyone on this thread has said valid points, the are not ignorant or ill informed. Just remember that the stress test were done with new airframes and not ones with 100 or so hours on them. That is probably why Jab has put a 40deg limit that they will guarantee. I have a large knowledge of composites not in aircraft but I can tell you than any composite does loose a hell of alot of its strenth at temps above 45deg so that 40 is probably a safety margin. It doesn't fall apart but looses it's hardness and in an aircraft that can cause all sorts of twisting, bowing etc.

 

Manuals arn't the only info out there.

 

 

[Guest pelorus32]

the stress ratings are done at 53 c and you mention 40c then you have altitude temp reduction common guy's get with it, there is no issue here, go to Wakerie SA the worlds best gliding centre all composite and they get exited when it is 40c and no structual failures here recorded due to heat, don't get paranoid due to poor information being supplied to you look at the flight manual in the aircraft, not the remarks of the uninformed or ignorant , enjoy cheers Steve

Steve,

 

there are lots of different views out there and a variety of information about even a single aircraft type. Because those views may vary from yours does not make them "...uninformed or ignorant...".

 

There are much more effective ways of expressing a view which is at variance from the views of others. You might actually learn something!

 

And as for the comparison with gliders at Wakerie - I'm afraid that doesn't help us much. What is the composite construction of the Jab? Is it vinyl ester, is it polyester, is it epoxy? What are the structural elements in the composite? Are they CSM, woven rovings? What weight? Are they carbon fibre? Are they Kevlar? What are the composites in the gliders? Are they the same as the Jab?

 

More questions than answers there and not a useful comparison. Not helping people seeking information much either.

 

Regards

 

Mike

 

 

[Steve Donald]

yep i do see what you say but most active days of composite flyying occurs on 40 + days and in the case of Jabiru are stressed at 53 c what would you consider as a average temp on a stinker i have flown in Marble bar on 52 c in the air dropping dog baits 42 deg at 1500ft, if you were just overflying prob 6500 maybe 33c well away from an issue here, apart from maybe an attempt to comprimise composite construction but then we know how well crash victims have walked from these as well so there goes that argument well in jabs anyway.

 

 

[BLA82]

Spot on Pelorus32:thumb_up:

 

Steve it's your choice to fly when you feel safe and I hope it always works out but don't tell others not to worry about it as it can have and I say CAN not always have a bad result.

 

 

[Steve Donald]

oh mike you just need to fly mate , the facts are there the plane is safe at those temps if you say otherwise do so , but the manufacturer can claim loss against an invalid claim that it considers damaging, in what your claiming that a jab owner is grounded if the temp is over 40c that is crap. polycrap

 

 

[Guest pelorus32]

yep i do see what you say but most active days of composite flyying occurs on 40 + days and in the case of Jabiru are stressed at 53 c what would you consider as a average temp on a stinker i have flown in Marble bar on 52 c in the air dropping dog baits 42 deg at 1500ft, if you were just overflying prob 6500 maybe 33c well away from an issue here, apart from maybe an attempt to comprimise composite construction but then we know how well crash victims have walked from these as well so there goes that argument well in jabs anyway.

I see no evidence from any of these posts that anyone is trying to compromise composite construction. I happen to quite like it just for the record. But there are composites and composites and then there are composite construction methods and composite construction methods.

 

The issue is that the original poster asked:

 

How do Jabiru's perform at temps above 40.I understand that flying at these temps is not recommended.

A variety of people have tried to answer that question to the best of their understanding. Merv expressed a view that the composites in the Jab had a limiting temperature. Why don't we explore that view and ask him for some evidence for that statement? You might actually be surprised.If what Merv has said is in fact the case it may cause you to reconsider the safety of flying in high temperatures. At least it will give you (and others) more information when deciding whether to fly their Jabs or not.

 

If it proves that the situation is not as Merv puts it then we will all learn something too.

 

Because you have not come to grief in a particular situation does not mean that the aircraft is therefore OK in those situations. The reverse is not necessarily the case either.

 

Let's explore this openly so that we get to the facts in respect of the OP's question.

 

Regards

 

Mike

 

 

[Steve Donald]

yep i agree to a point but the aircraft are well proven Nationally, and have accounted for many thousands of hours of training in high temps, no issues, yet this sort of condemnation occurs time and time again, even the administrator of this site said this was verging abuse what the truth? if that is the case i will be happy not to be part of this website, we need to express ourselves and it is not so much as what is said , but how it is received, we have no control of that do we so the thought police win

 

 

[Guest Andys@coffs]

Steve

 

RTFM.... Its online, on the jabiru web site under manuals. In my J230 manual (which is in the aircraft) I thought it was a 40 degree limitation, however in the J230D manual on Page 53 Jabiru clearly define max OAT as 38degrees celcius.

 

Now I didnt bother to look at every manual for every model... in fact to be blunt I couldnt give a stuff for other models because its not what I have, however I suspect that the POH's all evolved from a common starting point and as such would almost go so far to say I'd take a bet that there is a defined max OAT temp defined for yours as well

 

As I started, before you answer RTFM and consider the adage" Better to be thought a fool than open your mouth and remove all doubt....."

 

Andy

 

 

[Steve Donald]

hey guys i fly with my family and grand children so if i find out my new Jabiru is unsafe to fly at 40c which is the local temp regularly here i will be seeking a refund and not fly it. any one like to provide some evidence for me please, so i can pursue this further i fly in the bush Aussie plane and climate end of story.

 

 

[Guest pelorus32]

oh mike you just need to fly mate , the facts are there the plane is safe at those temps if you say otherwise do so , but the manufacturer can claim loss against an invalid claim that it considers damaging, in what your claiming that a jab owner is grounded if the temp is over 40c that is crap. polycrap

Just to be quite clear: I have NO IDEA whether it's safe to fly a Jab at what temperature. Others in this thread have expressed a view about whether it is. I have not - despite your assertion above.

 

What I mortally object to is the kind of statements that you have made Steve, playing the man not the ball. The OP asked a serious question and he/she got a set of considered answers and a very defensive set of assertions on your part.

 

I imagine that the original poster asked for the information so that he/she could determine how they might act in high temperatures.

 

What you choose to do with yourself and your family is your business. Please don't condemn others for seeking information and giving it in good faith.

 

Regards

 

Mike

 

 

[slartibartfast]

Steve - you were being disrespectful and I asked you to stop (privately, but you brought it out). You then came back with "in what your claiming that a jab owner is grounded if the temp is over 40c that is crap. polycrap"

 

That has nothing to with how your words are interpreted, nor with "thought police". It is abuse and will not be tolerated.

 

Aside from your manner, the Jabiru manuals would indicate that you are wrong.

 

The J160, J170 and J230 manuals all state :-

 

9 CLIMATIC RESTRICTIONS

 

Maximum Ambient Operating Temperature ................38°C

 

Flight into known icing conditions................................Prohibited

 

And this is reinforced by no temperature above 38C on the Take-Off Distance chart.

 

Given that the J120 is of the same composite construction as these other models, I would suggest that the J120 manual is incomplete.

 

You should contact Jabiru immediately.

 

Thanks in anticipation of your cooperation.

 

Ross

 

 

[quentas]

I had a look at the J120 manual and it doenst mention any limitations on max ambient unlike all the other J`s which list max as 38 degree ambient. I also noticed the J120 at 2600 rpm using 11 litres ph does 100knots, at 2700rpm using 13.5 lph does 107knts and at 2800rpm using 15lph does 105knots! maybe a misprint of some kind. I expect Jabiru may make an amendment to the manuals for the J120. I would be interested to hear if it has `no` limitations considering all the other factory models are limited to 38.

 

 

[Steve Donald]

hey admin just stick your site wherever it fits mate, don't tell me about disrespect or whatever you XXXXcan planes without all the facts scare some people in the process ,don't talk disrespect to me shove it you are a menace to the sport with that attitude, or an advocate of metal construction anycase i don't care like i said and others the 120 makes no menton of 38 or 40 as you claimed anyway i will leave you guy's with it give this website a wide berth i thinkthumb_down

 

 

[slartibartfast]

I think I'll leave this post here. Something to remind me of why we do this.

 

Would others who are in doubt about whether the 38C maximum ambient temperature operating limit applies only to the J160, J170 and J230 (the manuals I checked) and not to the J120 (even though they are the same construction) please contact Jabiru.

 

In fact, I'll call them tomorrow and post the reply. Who knows? We may save a life yet.

 

Meanwhile, I might help him to "give this website a wide berth". :devil:

 

 

[pudestcon]

I think I'll leave this post here. Something to remind me of why we do this.Would others who are in doubt about whether the 38C maximum ambient temperature operating limit applies only to the J160, J170 and J230 (the manuals I checked) and not to the J120 (even though they are the same construction) please contact Jabiru.

 

In fact, I'll call them tomorrow and post the reply. Who knows? We may save a life yet.

 

Meanwhile, I might help him to "give this website a wide berth". :devil:

Amen to that!!!