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duckhunter315
01-09-2006, 09:35 PM
does anybody have an idea what the purpose of magnetos is?

duckhunter315
01-09-2006, 09:35 PM
does anybody have an idea what the purpose of magnetos is?

Zeus-cat
01-09-2006, 09:42 PM
There was a thread a while back that indicated that a specific type of engine damage or problem could be fixed by cycling through the magnetos a few times. I don't remember what it was, but I think it was rather obscure.

FritzGryphon
01-09-2006, 09:53 PM
The magneto creates an electromagnetic field.

This is necessary to create thrust. The propellor is magnetized too, and repels the magnetos, making the plane go forward. The faster the propellor spins, the greater the current produced, which increases the power of the magnetism which increases the force of repulsion.

But seriously, they send electricity to the spark plugs, or something. There's no practical reason to turn them off. Engine power drops when one is turned off.

Tully__
01-10-2006, 03:28 AM
The magnetos perform the same function in an aircraft that the alternator and ignition coils perform in a car engine. The provide high tension electrical power for the spark plugs. The difference is that an alternator requires stored power (a battery or other source of current) to work whereas a magneto has permanent magnets and will work as long as it's turning.

Aircraft use magnetos to protect against battery/regulator failure and are normally fitted with two magnetos in case one should fail.

In real aircraft you normally use magneto switches only three times in any flight:

1. You turn them on when you start the engine.

2. You turn each one off (one at a time) during the run up before takeoff to check that both are working.

3. You turn them off after landing.

In the game, I'd ignore them altogether as failures are not modelled.

han freak solo
01-10-2006, 07:39 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by FritzGryphon:
But seriously, they send electricity to the spark plugs, or something. There's no practical reason to turn them off. Engine power drops when one is turned off. </div></BLOCKQUOTE>

Yep.

http://science.howstuffworks.com/question375.htm

http://www.avweb.com/sponsors/skyranch/magneexe.html

http://www.hillcity-comics.com/poster_misc/ULT_MAGNETO_POSTER.jpg

WWSensei
01-10-2006, 08:16 AM
Failures aren't modelled but 1C did model the RPM drop when you switch to one or the other....minor, uneccessary detail in the sim that I found nice to discover. Kind of like the pencil in the TB3...

vocatx
01-10-2006, 12:03 PM
Actually, I have found that failures are modeled. Several times I have taken battle damage and had my engine either run very poorly or completely quit. By switching mags I was able to restart my engine, and then RTB. It doesn't always help, but it never hurts to try it.

WWSensei
01-10-2006, 04:41 PM
Really? I'll have to try that...

Tully__
01-10-2006, 04:47 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by vocatx:
Actually, I have found that failures are modeled. Several times I have taken battle damage and had my engine either run very poorly or completely quit. By switching mags I was able to restart my engine, and then RTB. It doesn't always help, but it never hurts to try it. </div></BLOCKQUOTE>Battle damage is modelled, but random failures aren't.

Switching mags should make absolutely no difference as the engine runs best with both on. AFAIK switching either of them off/on should not make it easier to start. If both are off it should not start at all... no spark. If switching mags does make a damaged aircraft easier to start and it isn't just a coincidence, it's a bug not a feature.

vocatx
01-10-2006, 07:23 PM
Tully, maybe my choice of words weren't too clear. What I meant to say is, several times I have recieved battle damage causing my engine to stop running. Despite trying to restart, it would not fire. By trying each magneto individually I was able to restart my engine and continue flying. It does model the rpm loss from running only one mag. I have even done engine run-ups on the ground, and you will notice a drop in rpm by selecting one mag instead of both. I didn't mean to say selecting one or the other would make it easier to start, only that one or the other was keeping the engine from running. By isolating the bad circuit the engine would run.

KrashanTopolova
01-10-2006, 07:26 PM
magnetos are one of the features that make a piston-engined aircraft engine much more reliable than say a car engine (which uses spark plugs to ignite the fuel/gas compresion in a cylinder stroke). Consequently, magnetos assist a conked-out engine to restart in mid-air or to switch off the engine (after a short burst of power to clean out buildup inside a hot engine). These are both modelled in the game.
One of the posts mentions a run-up checklist procedure whereby each magneto is checked seperately and if there is a drop serious drop in one magneto when power is reduced then close down the engine and take the aircraft to the engineer's hangar and go home.
This is also modelled in the game and so other functions relating to magneto's could well be modelled as well (such as power loss and a rough-running engine).

han freak solo
01-11-2006, 10:17 AM
Be sure, Magnetos send electrical energy to spark plugs.

Usually, two magnetos per aircraft engine which fire two spark plugs per cylinder.

One magneto fires one spark plug per cylinder and the other magneto fires the other spark plug per cylinder.

That is why the aircraft engine makes a tad more power with both magnetos switched on. Dual spark plugs ignite the fuel/air mixture a bit more efficiently than one spark plug.

Redundancy is the most important factor, however.

KrashanTopolova
01-11-2006, 08:09 PM
Han Freak Solo...


I'm pretty sure any aircraft I ever flew or would fly would have spark plugs...not that I ever looked or wanted to find out...but if it did I would be carrying a parachute... http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

KrashanTopolova
01-11-2006, 08:56 PM
trivia: Electronic fuel injection in car engines was copied from innovation in aircraft engine design.

Tully__
01-12-2006, 05:43 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by KrashanTopolova:
Han Freak Solo...


I'm pretty sure any aircraft I ever flew or would fly would have spark plugs...not that I ever looked or wanted to find out...but if it did I would be carrying a parachute... http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif </div></BLOCKQUOTE>
...and if it is a piston engine that runs on avgas that doesn't have spark plugs you'll be needing that parachute... well no you wouldn't, 'coz it wouldn't ever have got off the ground http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif