Ultralight crashes at Gawler 16/05/07

[George B]

From Adelaide Advertiser 17/05/07 SA.

 

"Two people survived an ultralight crash near the Gawler Soaring Club yesterday.

 

The aircraft crashed on a public service road adjacent Two Wells Rd, which is next to the club's runway just after 3pm.

 

A police spokesman said a male and female were on board the plane and were taken to hospital for precautionary checks?."

 

Hope they are OK.

 

 

[glenns]

I can confirm that both occupants are perfectly fine and only went to hospital as a part of routine process. It was also a forced landing and not a crash :-)

 

 

[George B]

Thanks for the good new Glenns.

 

Any idea why it lost power.

 

Believe A hired Jabiru 160 lost control on takeoff at Murray Bridge yesterday.

 

Left the runway and flipped on reaching ploughed ground. Pilot apparently is also OK but not the plane.

 

Not a very good week in SA for ultralights.

 

 

[glenns]

To early to say. Will be happy to post here when I know the outcome.

 

Damage to port wing and undercarriage as well as nose wheel and prop.

 

 

[DrDexter1975]

Hi Glenn - sorry to hear about your aircraft...

 

Was it an EFATO situation?

 

 

[Guest Karl FAETH]

Ultralight crashes at Gawler 16/5/07

 

The aircraft was at about 2000' when the pilot experienced a very rough engine. Turned engine off and restarted but no improvement. Turned engine off and headed for nearby airfield. Due to strong winds could not make it back to runway and landed on a service road next to airfield.

 

Cause of engine problem was broken barrell bolts on No. 3 cylinder. Engine had done 450 hours since new.

 

 

[Guest grantisaac]

These cylinder bolts are going to hurt someone soon,i have heard of other planes with the same problem including our own club plane similar sort of hours.

 

 

[glenns]

Hi Grant,

 

Had the bolts been touched since factory i.e. had anyone had reason to torque the bolts since it left the factory. I would be interested to hear as the bolts on this aircraft/engine had not been touched.

 

 

[Guest brentc]

Glenns, I'm wondering why the bolts hadn't been touched on this aircraft? The introduction of hydraulic lifters removed the need for manual adjustment of tappets, however did not remove the requirement for the re-torquing of cylinder heads, hence my question.

 

 

[glenns]

Brent. Good point if we were talking about the cylinder heads but we are not. We are talking about the 4 bolts that hold the cylinder to the block. :-)

 

 

[Guest grantisaac]

Hi there,the cylinder bolts were tight and as a precaution we changed the bolts in our second training jab and found them to be stretched over 5mm from the new ones. we as a club have decided that if the cylinders are removed new bolts will be fitted .

 

 

[Guest disperse]

newbe here .....is this a rotax 912 engine ?

 

 

[glenns]

No Jabiru 80hp 4 cyl

 

 

[Guest brentc]

Thanks glenns, I needed to clarify that as people do get them confused. It also seems that since the hydraulic lifters came about people think that no maintenance is required on the heads.

 

As for those studs breaking. hmmmmm

 

 

[BigPete]

Glenns,

 

Sorry to hear the bad news - although I can't help thinking that you're a lucky boy - engine failure and you lived to tell the tale.

 

Chances of it happening again have to be much, much less - those of us that haven't had this happen are still waiting for it.

 

How many hours on your motor when this happened? - I notice I have slight oil weeps where the barrell mates to the crankcase. Must ring Jabiru and find out.

 

Glad to hear your OK ;)- must have been a bit of a fright. :yuk:

 

regards

 

 

[Captain]

Grant

 

Will you please tell me more about the 5 mm elongation that you have reported in #11 below.

 

5 mm is a heap.

 

Where did it occur on the stud?

 

Was it a uniform extension of all threads giving a greater pitch, or what?

 

Do you have, or can you take, any side-by-side photos of the elongated studs alongside a new one?

 

Any additional feedback that you can give on this would be valuable to us all.

 

Regards Geoff

 

 

[vk3auu]

Bolt elongation

 

Doesn't sound like the sort of thing that should happen to a good hi-tensile bolt. I wonder how many other elongated bolts there are out there?

 

 

[glenns]

Hi Pete,

 

Yes lucky because I was not driving. a very experienced pilot was driving at the time.

 

No one was injured so that was the main concern. planes can be fixed (especially jabs that bend).

 

Should be back in the air in a few weeks.

 

 

[Guest grantisaac]

The studs that broke on our plane was the through bolt that is shared between the two cylinders. The bolt stretch was measured over the whole length. There was no damage to any thread.We put the stretch down to the stress placed on the through bolt by the 2 opposite cylinders

 

 

[Captain]

Thanks Grant

 

Shows how much I know as I wasn't aware that any of those are thru bolts.

 

Had any of your barrel bolts been torqued up regularly?

 

Regards Geoff

 

 

[Yenn]

Why would the fact that the bolt is between two opposed cylinders be a cause for it to fail. The bolt should have been designed to take the load. Something else must be the cause. Faulty bolt, overtorqued at assembly, or anything else you care to think of.

 

 

[Guest brentc]

True Ian, I'm thinking the same thing. They are to be replaced at 1,000 for the top end as a precautionary, so I'm surprised they could stretch 5mm. 5mm stretch from a solid stainless steel bolt to me defies the laws of physics and metalurgy. If you've seen them they appear to be around 1.5cm across and very heavy. I just removed my studs after 440 hours and they are within original spec on my 6 cylinder.

 

 

[Guest grantisaac]

Maybe the new bolts were made longer than the old ones.As far as the reason why they are breaking who knows. The fact is they are breaking and when they do you lose two cylinders.

 

 

[Geoff]

(As far as the reason why they are breaking who knows. The fact is they are breaking and when they do you lose two cylinders.)

 

How many times has this happened? As a Jab Driver I must admit I have not heard of this.

 

 

[Yenn]

Geoff that is a good question. It ties into another thread and I think if it has happened before, then our safety reps would know. It becomes a problem if it is a common occurrence and we are not advised.