Do we have this requirement here in AUS for RAA aircraft.

[SSCBD]

Sweden - Rotax requires 30 minutes of emergency battery, to run the engine and basic avionics (if the generators fail).

[kgwilson]

Afaik all aero engines are independent of the battery so it keeps running if the battery dies. If you have steam instruments the ALT, ASI, VSI & some thermocoupled engine instruments will still work so the only problem is communication which is why there are procedures for radio out at controlled aerodromes.

[facthunter]

Any IFR compliant A/C requires an electrical system that meets certain specified standards of load and other .Taking off with a flat battery would be illegal. Nev

[jackc]

Any IFR compliant A/C requires an electrical system that meets certain specified standards of load and other .Taking off with a flat battery would be illegal. Nev

 

iF your battery is flat, the starter won’t get you running UNLESS you are stupid enough to to jump start it, in which case you should not be flying anyway......

[facthunter]

Plenty do jump start their planes engines or even propswing them. Lots of planes use a ground cart. A serviceable battery (charged) is required for IFR flight. Being able to restart a motor in the air is a worthwhile aim. An idle test is required taxying out, for RAAus planes to check your idle is stable. IF radio is not required for your op, I can't see why you need a battery .Some use a handheld radio. and you can use a mobile phone if it helps.. Nev

[marshallarts]

Taking off with a flat battery would be illegal.

 

Hmm interesting. Is that only for IFR? It brings back a memory from my aircraft ownership in a previous life - someone had hired my Debonair and it wouldn't start after they had landed at Cervantes (I think), about 100nm up the WA coast from Perth. I had to hire another plane and take my maintenance LAME up there to try to get it going. It was just a flat battery (cause was found some time later), so the LAME hand-propped it to start it (looked quite scary to me), and we got it back to Jandakot perfectly ok. Would that have been technically illegal (bearing in mind this was around 1992)? The only other option would have been to truck it back, a massively complex and expensive exercise. Even as it was it was quite costly!

Edited May 26, 2020 by marshallarts

[jackc]

Plenty do jump start their planes engines or even propswing them. Lots of planes use a ground cart. A serviceable battery (charged) is required for IFR flight. Being able to restart a motor in the air is a worthwhile aim. An idle test is required taxying out, for RAAus planes to check your idle is stable. IF radio is not required for your op, I can't see why you need a battery .Some use a handheld radio. and you can use a mobile phone if it helps.. Nev

 

Preflight and battery is flat, IF fitted?.....that’s it, finished until the battery is charged AND load tested for capacity, or it’s replaced. RAA type aircraft don’t have a high capacity charging system either.

IF you jumpstart an aircraft with a flat battery AND it has a collapsed cell, what then? You are stressing the charging system because everything is running off it because that battery is open circuit, ie useless. Would not like trying to hand propping a Rotax 912, probably being the most common engine around.

J3 Cub owners don’t have any of these worries!

[Thruster88]

Sweden - Rotax requires 30 minutes of emergency battery, to run the engine and basic avionics (if the generators fail).

 

To be compliant any electronic fuel injection engine would have to be installed IAW the manufacturer recommendation.

 

Pilot understanding of the aircraft systems is critical to safe operation. The article below is a very good example of what can happen.

Accident ignites DA42 engine row

[Flightrite]

Afaik all aero engines are independent of the battery so it keeps running if the battery dies. If you have steam instruments the ALT, ASI, VSI & some thermocoupled engine instruments will still work so the only problem is communication which is why there are procedures for radio out at controlled aerodromes.

That's incorrect. Plenty of Lyc's running around wth battery/power dependant ignition systems in experimental. A second battery would be a smart thing?

[Yenn]

We have no requirement for any battery at all. We cannot fly IFR and don't need all the electrical gauges. We can legally hand prop an engine, but it seems so few people have done it that it is frowned upon.

Most RAAus aircraft do not need a battery for anything except starting.

I have several times over the years jump started my aircraft. If you jump start before the battery is run down too far, it will recover quickly. If you an Odyssey PC680, which is a very common battery, it will runout of puff on a cold day. Remove the metal jacket container it sits in and it will work much better.

[jetjr]

Plenty of aircraft jump started, lots struggle when cold

Jab run 8-10 charge setup, CAE and Rotec have 45 A altenator

[kgwilson]

A Jab engine requires 300 rpm to create a spark from the transistorised ignition system so trying to hand start one is virtually impossible. That said I have had situations when the starter has baulked at TDC, then flicked over & started before the first full revolution of the prop.

[Old Koreelah]

A Jab engine requires 300 rpm to create a spark from the transistorised ignition system so trying to hand start one is virtually impossible. That said I have had situations when the starter has baulked at TDC, then flicked over & started before the first full revolution of the prop.

Jab's Cold Start kit sparks at much slower revs, but for safety is activated from the starter solenoid.

[facthunter]

Determining the condition of the flat battery would be essential for safety reasons.

Propping a thing like a Debonair is not easy but can be done with CARE. FOUR (4) cyl motors are more simple the compressions are always in the same place.

..IF a battery is flat you may not be able to energise (start) your alternator at all so if you switch off in flight ( when everything was working on the alternator) you now have no elect power at all as you won't get the (serviceable) alternator back on line and there's a lot of things not working as well as the radios (like flaps, fuel pumps, landing gear and gyro instruments.) Simple planes like some Cubs and Tiger Moths have NO electrical system to go wrong. Ah, the beauty of simplicity. Nev

[walrus]

The Rotax 912 iS are electronically fuel injected. This means “no volts = no engine”. To guard against this there are two oil cooled alternators, one for the engine ECU an fuel pumps and one for the aircraft and battery charging.

 

If alternator A fails, alternator B dumps the aircraft and battery and instantaneously takes over the engine load. If B then fails you will use emergency battery power to start and run but the draw is about 13 amps. You need to size the battery to give you 30 minutes+.

[APenNameAndThatA]

The Rotax 912 iS are electronically fuel injected. This means “no volts = no engine”. To guard against this there are two oil cooled alternators, one for the engine ECU an fuel pumps and one for the aircraft and battery charging.

 

If alternator A fails, alternator B dumps the aircraft and battery and instantaneously takes over the engine load. If B then fails you will use emergency battery power to start and run but the draw is about 13 amps. You need to size the battery to give you 30 minutes+.

 

I have an iS and an emergency power button on the dash. I was wondering what it was for. if alternator B fails, then won't alternator A keep the ECU and fuel pumps going. So, why would I need to restart if alternator A stops? I assume I misunderstood what you were saying.

 

I have read the POH but it did not go into the emergency power button in much detail. Reference to read up on?

 

Thanks!

[Thruster88]

All the redundancy appears to have failed in this incident involving a 912is. Be nice to get some follow up for owners. https://www.recreationalflying.com/threads/gympie-25-1-20.72065/

[kgwilson]

I am happy in the knowledge that if my battery goes Pfff and the alternator goes out in sympathy or the other way round I can continue to fly and get down when I like with all of the normal precision I had before these things happened.

[facthunter]

Like some Kids.. When they're good they're really good, and when they're BAD, they are awful. Nev

[Yenn]

As said above someone has read the POH but not taken much notice of part of it. I like to always be fully conversant with whatever I fly. My reasoning is that it is what you don't know that can kill you.

I don't intend this as criticism but ask that you consider my point of view, because I think it could save a life.

[facthunter]

No more "I wonder what happens when you move THIS switch"? Yes Yenn, take the guesswork out of being close or you are just another passenger, going along for the ride.. Nothing beats actually knowing what you are doing, or in the case of a "modern" FMS what's the Bloody THING doing now? moments...Nev

[walrus]

Reference pages 4-5 and 4-6 of engine operators manual. If the aircraft in question ran out of voltage, then perhaps it was miswired. Some operators try to handle the logic of the system with key switch and relays. Rotax recommends mil spec toggle switches - seven of them (ECU A and B, pumps 1 and 2, start power, emergency power and start).

 

Start power ties the two alternators and battery together and powers ECU and fuel pumps until alternators take over. You open that after start because then if the engine stops, the fuel pumps stop - which you definitely want to happen..

 

Similarly emergency power connects ECU and pumps to battery. That should also be normally open, else you won’t know if the alternators fail, - until you run out of battery.

[saccani]

We have no requirement for any battery at all. We cannot fly IFR and don't need all the electrical gauges. We can legally hand prop an engine, but it seems so few people have done it that it is frowned upon.

Most RAAus aircraft do not need a battery for anything except starting.

I have several times over the years jump started my aircraft. If you jump start before the battery is run down too far, it will recover quickly. If you an Odyssey PC680, which is a very common battery, it will runout of puff on a cold day. Remove the metal jacket container it sits in and it will work much better.

The metal jacket is an extra cost, optional feature. Being Australia, they import what they want to sell, not what we want to buy. The great irritation is that we are forced to pay extra for a “feature” we don’t want and really should be removing for aircraft use. For those employing a LAME on their experimental or LSA, the removal comes at extra cost....

[Jon Bown]

Afaik all aero engines are independent of the battery so it keeps running if the battery dies. If you have steam instruments the ALT, ASI, VSI & some thermocoupled engine instruments will still work so the only problem is communication which is why there are procedures for radio out at controlled aerodromes.

[Snoopy]

As said above someone has read the POH but not taken much notice of part of it. I like to always be fully conversant with whatever I fly. My reasoning is that it is what you don't know that can kill you.

I don't intend this as criticism but ask that you consider my point of view, because I think it could save a life.