Brumby wrecked pilot OK

[Ben Longden]

He had an emergency landing and walked away.

 

Bloody good airmanship and brilliant flying skills.... I would be glad to be his passenger any day.

 

Now, tell us, what are the issues with the Lycoming engine, and are they only with a specific batch or affecting only one model of them?

 

 

[facthunter]

IF it is ignition .... there is an engine that is second to none in it's original form, for reliability. I have pushed magneto's for a long time as they are self sustaining and self contained. They operate with nothing but a kill wire that earths the primary coil to stop it.. Pretty foolproof. Just service at the specified intervals. Nev

 

 

[poteroo]

IF it is ignition .... there is an engine that is second to none in it's original form, for reliability. I have pushed magneto's for a long time as they are self sustaining and self contained. They operate with nothing but a kill wire that earths the primary coil to stop it.. Pretty foolproof. Just service at the specified intervals. Nev

Agree - the 0-235 is a great little engine. Spent a lot of time behind them in C152's and have great faith. But the 0-233 is different.

 

 

[Guest extralite]

I think that's what he believed to be the problem. Also some installation issues in the particular aircraft.

 

 

[Keenaviator]

There are probably billions of lawn mower type engines running on the Jabiru magneto style ignition system. Simple, self sustaining and works. Laurie

 

 

[poteroo]

I think that's what he believed to be the problem. Also some installation issues in the particular aircraft.

Dual CDI's are always going to be a calculated 'risk'. Know of several GA EXP aircraft fitted with dual electronic ignition which suffered some issues - resulting in them either changing back to dual mags, or to the Lightspeed Plasma II system using that on R mag and a standard mag on L (starting). On my RV9A, with a Superior IO-360, and fuel injection - I fitted the Lightspeed only to the R side, standard L mag....and no Bendix key switch. Have mags on 2 separate switches so the off/isolated Lightspeed EI cannot interfere with starting. (several instances of this reported).

 

Lawnmower engine reliability? Reckon that could be the start of a whole new thread!

 

happy days,

 

 

[facthunter]

One magneto and the other could be something exotic. When an engine is not revving much and four cylinder 4 stroke magneto's run at 1/2 engine speed, mechanical points well made, are pretty reliable. Vibration is probably the enemy in some situations. Nev

 

 

[Yenn]

Magnetos may be reliable and they may be low tech, but they have been responsible for as many engine failures as anything else machanical. I would rate them as less reliable than the valve train or the carburettor.

 

 

[Bob Llewellyn]

Magnetos may be reliable and they may be low tech, but they have been responsible for as many engine failures as anything else machanical. I would rate them as less reliable than the valve train or the carburettor.

yes, why don't we have twins? Oh, I forgot - twins are too complex for RA people to fly, no matter how qualified they are in other fields of aviation...

 

 

[facthunter]

Yenn, have you got figures on that? I can remember about 3 partial failures in more piston engine hours than most ever see. these days..None required engine shut down . In the same period about 4 engine failures of the "mechanical or more dramatic" type.. Perhaps these days some of the servicing is not up to it. and the magnetos are not looked after.. Spares for some of them might be difficult.Nev

 

 

[Teckair]

yes, why don't we have twins? Oh, I forgot - twins are too complex for RA people to fly, no matter how qualified they are in other fields of aviation...

No because we are supposed to be affordable flying not GA Mk2.

 

 

[Guest ozzie]

Two Mags for redundancy then run both off the same drive. doh.

 

My lazair was a twin, may have had little engines but guess where you end up if one stops during takeoff run.

 

 

[facthunter]

The Merlin did Ozzie. One of it's shortcomings. I think it was a skew gear to make things worse. Everything is driven off the gear at the rear of the crank, in just about everything. A well engineered drive should be more reliable than a magneto although I suggest they are OK done right. The biggest enemy is water. Condensation within the housing. This is removed with dry nitrogen prior to starting where it is formed after the engine cools down, particularly in the tropics. The most troublesome part is the impulse as it is a pretty savage arrangement the way it works, but you don't have to swing the engine fast .That is why they are dangerous.. A trembler "shower of sparks" does the job without the impulse. Nev

 

 

[Guest ozzie]

Lost an Islander due to the common drive gear from the camshaft for both mags. Impulse coupling is usually only on one mag from memory. if that breaks you are stuck.

 

 

[Bob Llewellyn]

No because we are supposed to be affordable flying not GA Mk2.

gee, 2 x Rotax 503s cost so much... hey, a Lazair with 277s instead of 185s would do...

 

 

[Gnarly Gnu]

My lazair was a twin, may have had little engines but guess where you end up if one stops during takeoff run.

How would you handle that with Ra-aus.... register it twice with a photo from each side?

 

 

[Bob Llewellyn]

How would you handle that with Ra-aus.... register it twice with a photo from each side?

Lazairs, like Cri-Cris, were grandfathered - 95:10 does not limit the number of engines, tho' how the Cri-Cri fits into the 95:10 wing loading requirement...

 

 

[facthunter]

If the impulse fails just swing it faster. This is a risk with the non impulse mags, as they are still fully advanced, whereas the impulse one is retarded. You usually select Impulse magneto only (STBD for the DH 82 from memory.) My Citabria had impulse on both. Started like a dream with priming pump, (or manual, Armstrong). Nev

 

 

[Bob Llewellyn]

If the impulse fails just swing it faster. This is a risk with the non impulse mags, as they are still fully advanced, whereas the impulse one is retarded. You usually select Impulse magneto only (STBD for the DH 82 from memory.) My Citabria had impulse on both. Started like a dream with priming pump, (or manual, Armstrong). Nev

The 503 on my Thruster is pretty retarded, and I start it with a string...

 

 

[facthunter]

I presume it is points only. That means there is no hall effect. I remember starting Yamaha's (Motorcycles) with no advance change at low revs . My daughter did her ankle in on my DT1 F..I've string started a few 2 strokes in aircraft with no problems . Perhaps the prop adds a bit of flywheel to help. even with the reduction gears. Nev

 

 

[Teckair]

gee, 2 x Rotax 503s cost so much.

Yep twice as much.

 

 

[facthunter]

Don't you get a discount for two? The second one helps you glide further. Not too far or your foot gets tingly. Nev

 

 

[Guest ozzie]

Lazairs, like Cri-Cris, were grandfathered - 95:10 does not limit the number of engines, tho' how the Cri-Cri fits into the 95:10 wing loading requirement...

Cri cri's don't they are VH.

Lazairs were around long before auf. Mine stalled 18 mph wing loading 2.2lb ft my weight.

 

 

[Bob Llewellyn]

Yep twice as much.

twice as much as a 914?

 

 

[facthunter]

Cri Cri's have a fairly high stall speed. Doesn't that rule them out for RAAus?.

 

Comparo ( I 914 to 2 503's ... 1 x 924 x4 strokes = 3896.

 

( 2 x 503 x2 strokes. = 2012 . The 914 wins easily.. Any other comparisons you want me to do? Very small charge... Nev