Jab down in Wentworth 2 Jan 23.

[facthunter]

Like most small planes I feel the compression and know the owner and consider the Airport. All my Jab flying has been instructing, a few times in the (different) owner's plane. So far, I've NEVER had a  Jab motor falter, but any motor CAN fail. I'd happily fly a 3 cylinder Anzani from the RIGHT aerodrome and over appropriate country. I don't take any plane into the air with a KNOWN fault that can affect your safety on principle  Nev

[Old Koreelah]

Trying not to join a pointless debate between valued members of this forum, but it occurs to me that too many flyers have died due to too much faith in their engine, such as the fatals resulting from Rotax failures.

I fly behind an early hydraulic Jab 2.2 which is approaching the statistical “danger zone” of 300 hours. I accept that it is more likely to stop than a 912- but less likely than a 2 stroke or a dak dak- and fly accordingly.

 

I’ve happily flown in lots of aeroplanes, including those with a Jab engine, but getting into a gyro or helicopter is outside my comfort zone.

[old man emu]

I don't think that it is fair to be dissing the Jabiru engine in 2023, based on the pre-2010 products. That engine was in development pre-2010. If Jabiru had not continued development to correct identified faults, the company would be like Humpty-Dumpty at the base of the wall.

 

Do you think that the first Rolls Royce Merlin was perfect in every way? In a lecture to the de Havilland Aircraft Technical Department in November 1945, Mr A.C. Lovesey told the attendees that "It is well known that a completely new design of piston engine takes nearly five years from the date of its inception until it can start quantity production." And he was referring to design and development by a company that had (in 1935) been building engines successfully for thirty years. And the 1935 Merlin was a doddering grandfather to the later 51 different Marks of that design. And that development was kicked along by a savage war. http://www.wwiiaircraftperformance.org/merlin-lovesey.pdf

 

It's probably wise not to place one's absolute faith in one of the early Jabiru engines, compared to a 2022-built one. However, if that early engine is still performing within specs, then I'd say the owner has scored a good'un. 

 

We go on and on about these engines suddenly stopping, but you must consider all the possible ways to stop an engine, from catastrophic component failure to an insect blocking a fuel line.

 

[BrendAn]

i have been told they were taking off. if roscoes theory is correct and the jab was sluggish in the heat with a full load maybe they could not gain height quick enough and clipped the trees which caused the crash. just an idea but i thought you would cut the throttle and drop back onto the runway if it did not feel right.

[facthunter]

You'd best decide before then. Hitting something at  flying speed is always worse than when slowing up from a lower speed.. Nev

Edited January 3, 2023 by facthunter

[onetrack]

Engine performance drops dramatically in hot conditions, so you had better be very familiar with the performance graph if you want a successful takeoff.

 

Doesn't the Jab POH recommend a maximum of 40°C ambient outside temperature for operations? The forecast for the area was 41°, so definitely a very dicey day to try and get airborne.

[facthunter]

It's the Density Altitude that matters (as you know) Aircooled motors are more tolerant of high ambients than liquid cooled ones are.  The places I've been most compromised are Gyra, Benambra and  Mt Hotham.  Nev

[coljones]

A topic which is rarely discussed is the setting of flaps on take-off. It can mean a long flat flight into the fence or a Harrier Jump jet take-off depending on the conditions and settings.

[old man emu]

Let's get back to the initial post. I ask: "Where did BirdDog get what he posted from?" To me it reads like a media release - therefore I am suspicious of "The 'Jabiru' ultralight lost power". That reeks of ignorant journalism.

 

Now, let's inspect the aircraft. Am I wrong in suggesting that the flaps were extended to a degree? That the elevator position indicates a controlled flare? I'll concede that the position was caused by the twisting of the rear fuselage that could have shifted the control connections. Are they cables to the elevator and rudder? Wing position in relation to the cabin seems normal. 

 

 

 

The plane clipped trees That mark on the leading edge of the right wing looks more like a slap than a whack, and a single impact with something - tree, not "trees". I can't see a likely tree back along the approach path.

 

Can a Jab pilot tell me what the yellow thing hanging out of the engine bay is? That cowl is held in place by the axle of a piano hinge. I can't see the hinge having been broken at impact. I surmise that the cowl was opened by the Evidence Eradication Team "to disconnect the battery to prevent a fire".

 

The distortion to port of the lower engine cowl tells me that a force was applied from front starboard side to the rear port side. I surmise that it was as a result of the nose wheel hitting the ground under the water.  That force, acting on the aircraft forward of the CofG would induce an anti-clockwise rotation to the airframe, resulting in the bending of the rear fuselage to starboard. The rotation could account for the separation of the left wing at the root.

 

 

This final photo doesn't take us any further in the analysis, except to say that the pilot got selecting the best place to land correct.

 

 

[RFguy]

Jab's are fine. Gen1,2,3 : do not fly with leakdowns < 65/80 or  CHT > 160C or  EGT > (770 - fuel flow percentage). (EGT values for air cooled heads)   

40 deg C, 'sea level ' density altitude is  3000' ! ....  and if there was a low overhead, add another 300 feet maybe....

so performance is down about 20% !
add to this higher chances of ULP (?) fuel vapourization (was fuel pump turned on in takeoff to pressurize the lines etc ) ?? etc etc

so it probably has a climb rate of  400 hundred feet a minute two up.... at best 

then to all that- add a thermal SINK , for example......
(OME the thing hanging out is the oil catch can) 

Edited January 3, 2023 by RFguy

[old man emu]

3 minutes ago, RFguy said:

(OME the thing hanging out is the oil catch can) 

To get it to come loose would require a good whack in the direction of force I indicated, and a good deal of oil in it to give it the inertia to stay put while the firewall moved away from it.. Even if it did, how do you explain the unhinged cowl?

[Flightrite]

The people at Jab must hate this, oh no, not another one!😉Every Jab out there is free advertising for the Co (as they all are) and social media is a cruel enemy😂

[FlyBoy1960]

2 hours ago, old man emu said:

I don't think that it is fair to be dissing the Jabiru engine in 2023, based on the pre-2010 products. That engine was in development pre-2010. If Jabiru had not continued development to correct identified faults, the company would be like Humpty-Dumpty at the base of the wall.

 

Maybe the +7 mil in govt grants in the worst unemployment region in AU helped.  (to stay in business)   before you ask it was in the courier mail

Edited January 3, 2023 by FlyBoy1960

[Roscoe]

7 hours ago, Flightrite said:

At the end of the day it’s just another Jab engine failure, they are well known for that and there will be more (as long as they’re not mine😉) The guys lived to tell the story, that’s the main thing, the rest will just go into the stat books!

What proof do you have that it was an engine FAILURE!

The engine may have been operating normally but the ambient weather, weight, density height and Wind may gave degraded the performance and affected the climb profile.

How about waiting for the investigation results before saying, just another Jab engine failure!

 

[Roscoe]

2 hours ago, onetrack said:

Engine performance drops dramatically in hot conditions, so you had better be very familiar with the performance graph if you want a successful takeoff.

 

Doesn't the Jab POH recommend a maximum of 40°C ambient outside temperature for operations? The forecast for the area was 41°, so definitely a very dicey day to try and get airborne.

Its 37degC according to the Handbook

[Methusala]

Sometimes, even fairly experienced pilots succumb to fixed ideas such as, "Ive taken off many times in this aircraft with no problems", and continue attempting to levitate even as the end of the strip is approaching fast. Having achieved faltering flight in ground effect next one wing hits a low branch which yaws the plane and further degrades the climb. The pilot and passenger are now hapless spectators to the ensuing ground contact. I subscribe to the high density altitude as the best possible explanation. This view has no connection to the real circumstance, just an armchair theory. Don

[derekliston]

5 hours ago, Flightrite said:

That about sums it up, personal choice, well said👍 The same here, but for me I’d never go flying in a Jab unless I was in command, I value my life a LOT👍

I fly a Zenith CH701 with a 2200 Jabiru solid lifter engine. I am always aware the engine can fail, just as I was always aware when flying behind Lycomings, Continentals and Rotaxes. The Jabiru is a beautiful little engine of which they have now sold more than 4,000 I believe. It is lightweight, simple and relatively cheap, as much as anything in aviation can be cheap! 

[derekliston]

21 minutes ago, Methusala said:

Sometimes, even fairly experienced pilots succumb to fixed ideas such as, "Ive taken off many times in this aircraft with no problems", and continue attempting to levitate even as the end of the strip is approaching fast. Having achieved faltering flight in ground effect next one wing hits a low branch which yaws the plane and further degrades the climb. The pilot and passenger are now hapless spectators to the ensuing ground contact. I subscribe to the high density altitude as the best possible explanation. This view has no connection to the real circumstance, just an armchair theory. Don

Absolutely! In my 60yrs in aviation both ad a LAME and PPL I can think of quite s few pilots, including high time instructors who have died attempting manoeuvres that they would have been trained to avoid. EFATO 180° turn backs, turn into the dead engine on a twin, unqualified flight into IFR as just a few examples!

[Roscoe]

14 minutes ago, derekliston said:

I fly a Zenith CH701 with a 2200 Jabiru solid lifter engine. I am always aware the engine can fail, just as I was always aware when flying behind Lycomings, Continentals and Rotaxes. The Jabiru is a beautiful little engine of which they have now sold more than 4,000 I believe. It is lightweight, simple and relatively cheap, as much as anything in aviation can be cheap! 

Well said, and if the engine is maintained as per Manuf specs, they are pretty much trouble free!

[Jabiru7252]

If you can't stop spilling your schooner then the air's too rough.

[BrendAn]

3 hours ago, FlyBoy1960 said:

Maybe the +7 mil in govt grants in the worst unemployment region in AU helped.  (to stay in business)   before you ask it was in the courier mail

I would say money well spent. Jabiru are an Australian success story in aviation worldwide. The government gave Gerry Harvey more money than that to keep his employees during covid even though Harvey Norman made record profits in that time.  

[Kenlsa]

I think it’s time

[turboplanner]

He hit a possum?

We used to feed the possums when we stayed in the Wentworth Caravan Park.

[Cyrano]

9 hours ago, jackc said:

Use the POH as a guide, then  add your own experience and knowledge….

You may find that the insurance company will beg to differ on intentionally operating outside of the specifications.

[onetrack]

2 hours ago, Roscoe said:

Its 37degC according to the Handbook

That's odd. Why does the American Jab POH say maximum ambient operating temperature is 104°F (40°C)?

 

It surely can't be the way the Americans measure everything differently to us? (see page 1-11).

 

https://ussportplanes.com/wp-content/uploads/2018/04/JSA_SM230SP-A2.pdf