Light-Sport Aircraft Yahoo group Re: Sting Sport Woodcomp blade loss

Hi Frank,

I'm a great fan of fuel injection.
(Too bad the fuel-injected Rotax is about $10,000 MORE
costly than the carb version).

But actually, the first t2o thrown prop incidents we've had reported (below) here recently MIGHT make a case AGAINST fuel injection:

In both cases the engine almost instantly shut down when the prop threw a blade from the horrific unbalance vibration shaking the carbs off the engine.
If those had been fuel injected it's likely the engine would have run longer and could have ripped the engine right off the mounts leaving the pilots with planes totally out of balance and uncontrollable. No nice emergency landing in that case and just an NTSB report of fatality.

As I said in my earlier post, having those carbs thrown off may have saved the pilots' lives.


I can see why this topic would make you think about what type of prop material to go favor ----- But I'm really not sure what you saw in THIS thread to make you suggst fuel injection might reduce the chance of prop failure/loss?

Curiously,
Alex



--- In Sport_Aircraft@yahoogroups.com, Frank <frankiebpr@...> wrote:
>
> Thanks, Ed. I guess the more reason I have been inclined in moving to Fuel Injection and solid wood prop.

>
> On Sep 7, 2012, at 12:55 AM, "pwrsport@..." <pwrsport@...> wrote:
>
> > Rotax 912 80 hp. The engine was running perfectly, nice and smooth up until event.
> >
> > Ed
> >
> >
> > On Sep 6, 2012, at 2:37 AM, "pwrsport@..." <pwrsport@...> wrote:
> >
> >> I had the same situation a couple of years back flying a Rans S12xl. Composite hollow blade sheared at the hub. Never found the blade, went into orbit? There was no warning. In an instant, a loud bang followed by a one tremendous shutter, then total quietness, except for cockpit chatter that starts with “what-the-hell was that”, as you have no idea what happen because the engine is in back. After gliding to a non-event field landing found both carbs were out of their sockets from the initial shock; that stopped the engine. Other than that, no other damage. It is a very, very fast experience.
> >>
> >> Ed
> >>
> >>
> >> -----Original Message-----
> >> From: Brian
> >> Sent: Sep 5, 2012 10:41 PM
> >> To: Sport_Aircraft@yahoogroups.com
> >> Subject: Light-Sport Aircraft Yahoo group Re: Sting Sport Woodcomp blade loss
> >>
> >>
Oh yeah the whole front end of the plane was vibrating rather violently - but the whole process lasted maybe 2 to 3 seconds before it was all over. I had enough time to pull back on the throttle and level out (quickly mind you) to at least try to see what was going on - but by the time I reached a level attitude the engine had quit.
> >>
> >> I haven't seen the plane since we've moved it, but from my understanding from one of the plane partners (who is also an A&P) the carbs shook loose from the rubber mounts - and that's what probably led to the engine quitting.
> >>
> >> I also would imagine if the engine would continue to run it could certainly vibrate off the plane. As it stands now the engine mount is bent and the firewall has a crack at one of the mount points. I'll get up to the airport and see it in person on Sunday. Right now I'm working off of reports from other partners in the plane who have seen it first hand.
> >>
> >> The FAA was out today and the insurance adjustor should be out soon.
> >>
> >> Brian
> >>
> >> --- In Sport_Aircraft@yahoogroups.com, "circicirci" <acensor@> wrote:
> >> >
> >> > Really glad to hear the report in this form rather than the "error chain that lead to fatality" type.
> >> >
> >> > Couple of thoughts and questions:
> >> >
> >> > I was pleasantly surprised to see a news report of an incident (any incident really, but particularly for one about an aviation crash) that that was straight forward, reasonably factual, resonably complete, and not meadering off into often baseless speculation and hyperbole. Some local reporter/writer deserves at least a small pat on the back IMO.
> >> >
> >> > Yeah, any kind of prop can fail. I suspect that failure of carbon composites are fewer, but have NO stats to support that suspicion.
> >> >
> >> > I'm curious: When the prop threw its two blades (appears to be the case from your description and the photo with the article) didn't the engine start vibrating/shaking horribly immeadiatly from the one unbalance blade on the hub?
> >> > I would think in some cases such a configuration/situation the unbalance might be able to even rip the motor right off its mounts leaving the pilot with a plane so badly out of balance as to be uncontrollable?
> >> >
> >> > Alex
> >> >
> >> > --- In Sport_Aircraft@yahoogroups.com, "Brian" <brian@> wrote IN PART:
> >> > > ...... today I have something of interest!
> >> > > For a good brief "newsy" overview - the news report -
> >> > > http://www.timescall.com/news/longmont-local-news/ci_21450136/longmont-e\
> >> > > mergency-crews-investigate-report-plane-down
> >> > > <http://www.timescall.com/news/longmont-local-news/ci_21450136/longmont-\
> >> > > emergency-crews-investigate-report-plane-down>
> >> > >
> >> > >....a catastrophic failure of prop blades,
> >> > >......the initial prop blade loss completely evacuated the mount.
> >> > > The screws and bolts are still in the mount. When the first blade left the mount, it must've collided with the second blade, causing the
> >> > > shearing and loss.
> >> > > I knew doing a power-off/engine loss was going to be part of my day, but I really thought it was going to be simulated rather than an actual.
> >> >
> >> > >.... I suppose the same type of scenario could happen on
> >> > > any prop type huh?






















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