Engine goes quiet over Tiger Country

[Tecsar]

For all the Tecnam drivers out there.

 

http://www.rotax-owner.com/rotax-blog/item/14-engine-goes-quiet-over-tiger-country

 

 

[Wayne T Mathews]

For all the Tecnam drivers out there.http://www.rotax-owner.com/rotax-blog/item/14-engine-goes-quiet-over-tiger-country

That's a good article... Thank you for pointing us to it, Tecsar... It amplifies what we were talking about a while back on another thread. When we change our fuel configuration, it pays to monitor the fuel pressure and engine until we're sure the new configuration is working for us.

 

Keep the sunny side up,

 

Wayne.

 

 

[dazza 38]

That was a good read.Also it is important to remember to have RH fuel tap turned off while parked on sloping ground. We have seen fuel transferred from the right tank to the left tank and then dumped onto the ground.Same aircraft as above P92 Super Echo.

 

 

[David Isaac]

Excellent article, that is the kind of stuff that can potentially save lives.

 

The old cross feed issue with wings NOT level and parked for some time can cost you a lot of fuel and if you are not switched on, you may not be aware of the loss until it becomes critical in the next flight stage. Managing fuel on the ground is just as important if not more than in the air.

 

 

[fly_tornado]

My feeling is that 1 tap per tank clearly marked on and off makes it pretty much idiot proof. How many times have of this sort of mistake getting made?

 

 

[David Isaac]

Cessna and many other types have a single fuel control valve with one rotating lever that can only be in one of four positions:

 

Off

 

Left tank,

 

Right Tank

 

Both

 

that is pretty much fool proof except when you select a tank that is empty or turn it off in flight by mistake.

 

Other aircraft types like the Savannah have a small header tank that the main fuel valve supplies such that the header tank is always full in normal circumstances. If you inadvertently turn off the main fuel supply, the engine will continue to run while it exhausts the header tank, the header tank is fitted with an audible and visual alarm if the level drops below full. I personally like this idea because it warns you before the fan stops.

 

 

[facthunter]

You need to really know your fuel system. The pass mark in fuel management was 100%, ( for good reason). Why fly over tiger country in a single engined plane anyhow? You can divert a bit generally and have good/better landing possibilities available.

 

Many fuel systems are poorly designed. You can get assymetric fuel easily. and engines don't run on air. Feeding surplus fuel to one tank is likely to cause a hazard, predictably, early exhaustion of one tank and venting overboard of fuel, as a result of the fuel transfer, from the other.

 

Turning the fuel off doesn't always prevent fuel transfer. The Citabria (if I remenber correctly) stays connected across ship and can still vent if the aircraft is parked on a slope. Nev

 

 

[turboplanner]

For all the people who only half read the subject of Human Factors, this is one of the best examples you'll see.

 

Having taps market doesn't fix it, havihng on/off only doesn't fix it, only regular attention to your own HF habits helps.

 

For the life of me I don't know what the aircraft industry hasn't caught up to the much safer car industry standards we have today.

 

 

[fly_tornado]

because that's how the aviation industry works. Who else still uses magnetos?

 

 

[Wayne T Mathews]

For all the people who only half read the subject of Human Factors, this is one of the best examples you'll see.Having taps market doesn't fix it, havihng on/off only doesn't fix it, only regular attention to your own HF habits helps.

For the life of me I don't know what the aircraft industry hasn't caught up to the much safer car industry standards we have today.

You're doing it again Turbs... You're advocating logic...

 

Keep the sunny side up,

 

Wayne.

 

 

[David Isaac]

because that's how the aviation industry works. Who else still uses magnetos?

The physical magneto is very old, but likewise is a reciprocating piston engine. More modern reciprocating engines no longer use what we used to know as physical magnetos but they still use the same impulse induction cycle to generate the initial energy to excite the high voltage spark circuit. We use this system because it does not require battery voltage to run. All cars require battery voltage and if you loose volts in the car electrical system, everything stops, the injection system, the fuel pumps and the spark ignition. These days we use impulse CDI type ignitions and we duplicate them. Similar to the old two stroke systems. Aero engines have to keep running if the main bus voltage disappears. I think the bigger question lies with the questionable fuel systems adopted by the designers in some aircraft.

 

 

[facthunter]

There is nothing basically wrong with magneto's. They are self contained and will (with an impulse) start at virtually zero cranking revs. (This is why they can be dangerous if you don't apply due care around the prop arc.)

 

They are required to be serviced ( particularly in an aircraft situation).preventive maintenance.

 

IF I take the magneto hours I have flown, allowing for 2 per engine and quite a bit of multi time I can account for around 19,000 magneto hours, at least and I can only recall one in a c-180 and it was one of those rotten two in one things and we still got there on one half of it. This is not a bad performance. I have had far more coil/sender cdi failures in cars, by a mile, and as David points out they need power from an external source to function at all. Nev

 

 

[fly_tornado]

This is part of the problem with aviation, the old guys are a bit blind to the limitations of a lot of the technology. I can't explain why I have never had an electrical failure in a car or bike. I just don't understand the reluctance to embrace better ideas?

 

 

[facthunter]

I could equally allege that you are too ready to discard things that work well for things that have yet to prove themselves in the aviation environment

 

For heavens sake don't categorise people. I have backed my argument with FACTS.. When appropriate stuff is available I will asses it on it's merits. We operate on the simple edge of aviation and do not need technology for it's own sake. The more basic the plane is the better it can be to fly if it is designed correctly. To be able to handstart an engine must be a plus. ( If you know how to do it). Hand priming, manual leaning. All good skills to have. or do we just leave it to a microprocessor. Nev

 

 

[fly_tornado]

Consider the hundreds of Lycomings and Continentals that fall out of the sky due to carb ice every year. Or the dozens of Jabirus exhaust valves that implode due to detonation.

 

From a commercial perspective you can see how Jabiru left a door open for ULPower, giving the people more power and fuel economy.

 

 

[turboplanner]

Hundreds? Can you explain all this a bit better F_T

 

 

[fly_tornado]

head over to the http://atsb.gov, plenty of empirical evidence. We are lucky in Australia that we don't have the amount of snow and high altitudes.

 

 

[facthunter]

I can indeed see that FT.

 

The best you can hope for with an infernal combustion engine of the reciprocating type is that the "bugs" have been thoroughly ironed out it, and you are getting something with a degree of quality control which is acceptable for the application. and maintained correctly also.

 

I have never had a problem with carb ice on non-injected Lycs or Continentals. ( Perhaps the training was more thorough) . It is something that has to be reckoned with, I agree, and It can occurr when you would not expect it if you are not fully aware.

 

I actually HATE reciprocating engines. They are a final development of a really bad principle, but the difference between a reasonable one and one that is "not happy" is enormous. You have to keep all the conditions right to have it keep running reliably.

 

For a start , many of our engines sit for long periods and how many are inhibited? 2 we don't have enough control over fuel consistency, ( unless we are running avgas from an aerodrome pump).. Some people fiddle with their engines and are not sure of what they are doing.

 

Mixture ratios can be all over the place.

 

I'm sure that some plugs in use are the wrong heat range. Do you ever see anything printed about this?. With Lycs and conts there are stipulated plugs and the same plug is torqued to a different torque on different motors. A loose plug will run hotter.

 

Exhaust valves can deteriorate quite quickly once the damage has commenced. An overheated exhaust valve distorts and the head may drop off. This is usually an immediate landing situation. It doesn't take much to "kill" an aero engine. A bomb car can often run for years, with clacking lifters and heaps of blowby , but it won't work with a plane engine.

 

When piston engines used to be the norm in Air travel , the ground engineeres used to walk along side the plane, as it taxied in, and listen to the exhausts for the tell-tale noises made by "soft" cylinders, just before they were shut down. Those sorts of skills have gone, but the private ultralight operator can develop similar awareness, and needs to. All engines should be pulled through between flights. This has to be done with all precautions observed, and when engines were handstarted, it was done as a matter of course during that process.

 

The hydraulis lifters "mask" the valve stretch in the later jabiru's. You can still check it with a "U" shaped gauge over the rocker and a feeler gauge , but who does it? You would have to keep a record of the previous measurements. Does anybody do this? Doubt it. Nev

 

 

[fly_tornado]

Probably no one unless they are rebuilding one.

 

I always considered the sound of a Merlin to be one of the greatest accidental convergences of art and technology.

 

 

[facthunter]

like all thing mechanical, it is not perfect. They actually had a service life of only a few hundred hours. The engine was not certified for Civil aviation use in many countries. Nev

 

 

[Guernsey]

I can't put any dates to this but my understanding was that the Merlin Engine was extremely well built however they were loosing them at such a rapid rate (some had done less than 10 hours when shot down) that the later engines were made quicker and less reliable as they were not required to last very long.

 

Alan.

 

 

[fly_tornado]

does 600 hours sound right? they where loosing planes @ 25

 

 

[turboplanner]

head over to the http://atsb.gov, plenty of empirical evidence. We are lucky in Australia that we don't have the amount of snow and high altitudes.

We have to watch you F_T - Nil carb ice reports by ATSB this year, or did you mean the British Empire?

 

What was interesting was "Collision with terrain" and "Robinson" go together like chewing gum and a blanket.

 

 

[fly_tornado]

try http://ntsb.gov

 

 

[turboplanner]

It would only make you grasp at another straw. BS is BS