IFR Power Failure

[Roger Roger]

I am trying to find a reference in the CAR’s or CAO’s which stipulates what the requirement is for electrical power to be supplied should an electrical failure (alternator only) occur in flight while IFR. i.e. the battery must be able to supply power for 60 minutes or something like that.

In addition are the requirements different for IFR CHTR and IFR PVT Category aircraft.

I remember reading about this some years ago but cannot recall where I read about it.

Regardless of what the regulations say is it likely that the “battery must be able to supply power” requirement can be met in most single and twin IFR GA aircraft.

Cheers

Over and in…

[swh]

Roger,

Sounds like something that would fit in the CAO 100 series design standards, could try look at FAR 23/25 if the aircraft is designed in the USA.

:ok:

[SLAV MAN]

if you are looking for info about power failures when under ifr ask eddy dubsky as he has manged to do wouderful things when in a primary control; zone in IMC and has had an avionics power. i was led to believe by young eddy that he was halfway down the ILS ad YPAD when the radios went out on his trusty seneca so what did eddy do, well most of us would just continue down the ILS and land but not old EDDY decides to p!ss off to Goolwa using the garmin 100 and then descend off shore breaking through cloud at 200 ft amsl then landing at goolwa and thryin to pretent that it did not happen when casa came knocking on his door

[ITCZ]

Roger Roger,

first up from CAO 20.18 Appendix II, applicable to RPT and CHTR >5700kg:
(k) in turbo-jet aeroplanes having a maximum take-off weight greater than 5700 kg and in turbo-prop aeroplanes having a maximum take-off weight greater than 18 000 kg a third attitude indicator which:

(i) is powered from a source independent of the electrical generating system;

(ii) continues to provide reliable indications for a minimum of 30 minutes after total failure of the electrical generating system; ....

There are no references to battery life in the CAO 20.18 appendices for PVT, AWK or CHTR < 5700kg.

CAO 101 series no longer contains airworthiness orders for normal/utility and transport category.

CAR 1988 has instructions for maintenance, but not airworthiness.

CASR 1998 has Part 23, airworthiness for normal and utility category aircraft:

CIVIL AVIATION SAFETY REGULATIONS 1998
- REG 23.001 Airworthiness standards

(1) The airworthiness standards for an aeroplane in the normal category, utility category, acrobatic category or commuter category are:

(a) the airworthiness standards set out in Part 23 of the FARs, as in force at the commencement of this regulation, with the changes provided under this Part; or

(b) the airworthiness standards set out in JAR-VLA, as in force at the commencement of this regulation, with the changes provided under this Part; or

(c) the airworthiness standards set out in JAR-23, as in force at the commencement of this regulation, with the changes provided under this Part.

(2) An aeroplane in the normal category, utility category, acrobatic category or commuter category that meets the airworthiness standards mentioned in paragraph (1)_(a), (b) or (c) is taken to meet the airworthiness standards for an aeroplane in the normal category, utility category, acrobatic category or commuter category under these regulations.

For USA manufactured normal and utility category aircraft the FAR Part 23.1353 is:

Part 23 AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES
Subpart F--Equipment
Electrical Systems and Equipment
Sec. 23.1353

Storage battery design and installation.

(a) Each storage battery must be designed and installed as prescribed in this section.
(b) Safe cell temperatures and pressures must be maintained during any probable char....

{snipped by ITCZ}

(h) In the event of a complete loss of the primary electrical power generating system, the battery must be capable of providing at least 30 minutes of electrical power to those loads that are essential to continued safe flight and landing. The 30 minute time period includes the time needed for the pilots to recognize the loss of generated power and take appropriate load shedding action.

Amdt. 23-49, Eff. 03/11/96


Interestingly, the corresponding airworthiness regulation for transport category 'airplanes' (they are aeroplanes goddamit!) is FAR 25.1315 which makes no mention of a minimum time to supply essential loads. It does refer back to FAR 25.1309 which puts the onus on the manufacturer to work through what is required for all possible multiple failures and modes of failure. But no minimums expressed in hard numbers.

Phew! Not sure if that is the lot... maybe a Pprune AME/LAME might be lurking.....

==================

With your question re "is there enough battery power?"....

Worth noting that if your aircraft is started off internal batteries, rather than an APU or ground cart, your battery will not be charged to its full capacity for a significant period of time.

If you lost your generators/alternators shorty after takeoff in your light single or twin, or in your Metro/Saab after an internal battery start/battery plus cross genny start, you would not likely have very many 'herbs' in the battery if you were down to emergency/battery power in the climbout.

I had an alternator failure in a C210 at night (aargh the night freight!!) about thirty minutes after departure, and there was three fifths of eff-all in that battery. On that night I told flight service about the problem, gave a SARTIME for my (CAVOK) destination, and turned the battery off.

Batteries in the topend had a hard life. High temperatures, thirty minute sectors, etc.

I did not bank on having that abovementioned 30 minutes. Especially if you like to see green lights for gear down, and have electric gear and flap motors, and might need to shoot an approach at the other end.

FWIW, go to your engineer or maintenance controller and ask to take a peek at your aircraft's Electrical Load Analysis. Take a photocopy for your little black book. Very useful for anything you fly from C152 to Metro.

[Roger Roger]

SLAV MAN

Not sure I have met EDDY DUBSKY. Can't seem to find any info on the chap anywhere.

ITCZ

Great help thanks alot.

So to sum up. In an PVT IFR S/E aircraft the best you should hope for is 30 minutes with reduced electrical load, if it's more it's a bonus however if you have just departed and started the engine with your own battery it may be somewhat less than 30 minutes.

Correct me if I'm wrong.