DA 50 exploded in flight...

[NZ Scythe]

A friend of mine bought a Wild Hare Extra with a DA 50 off me recently and today while out flying the motor made a loud bang the the prop flew off... He managed to land ok but upon closer inspection the bang was the sound of the DA 50 exploding and the the whole front end of the engine came off including the prop and spinner.

The propellor was broken in half when he found it and half of it was missing, the propellor bolts were all still nice and tight and the spinner was also still in place.

I'm not really sure what happened, I am sending the motor to Mike Briggs (DA Rep in New Zealand) and he can take a look and sort out the problem, I just thought I'd share with the Flying Giants community to see it this has happened before and to try and work out what might have happened to prevent it from happening again.

The motor was just run in, having done about 15 - 20 flights previously using a 30:1 mix with run-in oil. This was the first flight using a synthetic motorbike oil still at a 30:1 ratio. It appeared to be running fine and the motor was only at about half throttle heading down wind when it happened.

I'm sure DA will be very supportive as they are great like that, but I just really want to find out what happened? Any thoughts?

[Ando]

That is some damage there...it was probably just one of those freak happenings that come around every now and then.

[SleepyC]

That looks like the crank or piston ceased and the rotational force of the prop and hub spun it off..

Strange it happened when you switched oil. What oil did you use?

[DATech]

Hello
Is the serial # pre 3100 ?
Something locked up the engine internally. If it is a pre 3100 engine, it may have had a soft lower rod pin leading to lower rod bearing failure, which in turn can allow deflection of the rod and possibly rod failure.
Regardless of what may have happened, contact Mike Briggs and we will have the engine replaced.

[SleepyC]

Ahhhhh.... yes ladies and gentlemen... you have witnessed The Legendary DA customer service in Full EFFECT!

[jongurley]

[NZ Scythe]

Yes the engine was an early model, serial No. DA 0468 and I suspect you are correct about something locking up internally. Either way it will be sent to Mike today.

Thanks for the input. Cheers

[rmothers]

DATech,

Should we be concerned about pre 3100 engines? I have not checked mine just was curious. Should we do anything different if we do have a pre 3100 engine. Thanks for the info.

NZ sorry bout the engine good thing he was able to land it with no issue.


Rodney

[DATech]

The soft rod pins were random in pre 3100 motors (= pre March 2005). The majority were/are fine. Anyone who has a pre 3100 motor can have it checked/updated free of charge. Normaly if one fails, it will make a lot of noise long before a major failure.
The 5000 units produced since March 05 have been fine.

[NZ Scythe]

Thanks for the info, I was a bit concerned when I first bought the motor as I was aware of the problem with the soft rod pins. I had contacted Mike Briggs before I ran it and he said just what you did and that they usually make a lot of noise before failure. He suggested keeping an eye on it and if I had any concerns he (DA) would repair it free of charge.

Personally I would be suggesting anyone with a pre 3100 DA 50 take DATech up on the offer to get it checked/updated for free because it better to be safe than sorry.

DA provide great service that matches the performance of the engines they sell, world class - Thanks DA.

[Dan J]

	Quote: Originally Posted by SleepyC
	Ahhhhh.... yes ladies and gentlemen... you have witnessed The Legendary DA customer service in Full EFFECT!

What he said that's why I only fly w/DA

[MikeC3D]

W O R D