I don’t think it is made by Gill.
The Cirrus no. 2 battery is a very small one with 7 amps. It’s actually two 12 volt batteries in series to give 24 volts total. Together, they are about a quarter of the size of a normal aircraft battery. Manufacturer recommendation is to change them every two years. I do them every four or so.
I see nothing wrong with Gill flooded cell batteries. However, I haven’t heard much good about Gill sealed batteries but weren’t they supposed to release a completely new generation? I haven’t bothered going from a flooded cell battery to a sealed on, the benefits are limited.
were you trying to be offensive in that post?
No; just stating that there was not enough useful information!
The Cirrus no. 2 battery is a very small one with 7 amps. It’s actually two 12 volt batteries in series to give 24 volts total. Together, they are about a quarter of the size of a normal aircraft battery. Manufacturer recommendation is to change them every two years. I do them every four or so.
Normally, under AC43 Appendix A, if you are not making a “basic change to the electrical system”, you can put in a different make of a component very easily. On an N-reg there is no requirement for the same manufacturer. This is e.g. the supporting basis for the Gill-to-Concorde changeover. Perhaps the Cirrus ones are Yuasa or something like that; they are the biggest player in the smaller sealed lead-acid batteries. If changing one in an old product, one often has to go for one with a similar spec but slightly different dimensions.
On an EASA-reg, I don’t know how the argument pans out but I would be really amazed if there was a reg which directly states that a component must be made by the same company and be the same P/N. If such a reg existed, most of the EASA-reg fleet would be permanently grounded, because stuff changes all the time. For example I have just bought the Annual parts kit for my TB20 and each time this gets ordered, there is a number of like for like substitutions. And self evidently it is not necessary to use a Part 21 company to certify a replacement.
The problem is that the whole aviation business is full of FUD and people working in companies often refuse to stick their neck out. This is one of the great strengths of the FAA system – the stuff in the field is done by individuals whose interests are aligned with keeping their customers flying i.e. interpreting any regulatory ambiguities in the customer’s favour.
I haven’t bothered going from a flooded cell battery to a sealed on, the benefits are limited.
The Concorde batteries have a much lower internal resistance so you get better performance, starting with (no pun intended) better starting. They also fail in a more gradual manner, usually failing the load test long before you see any inability to turn the starter motor. Whereas IME the Gill ones just die and given bad luck it will happen somewhere very inconvenient.
Looks like the manufacturer is genesis (formerly yuasa). The price (for one of 12-volt ones) is 20$ in the US retail.
Well that was a lucky guess… buy one off the shelf, from a reputable top-price-everything wholesale electrical supplier (e.g. RS or Farnell) who will supply a CofC “so you know it’s not a fake”, hey ho, and stick it in there.
Logbook entry as normal. It’s a lifed part so you need the logbook entry.
There is no requirement AFAIK, under any Eur reg or N-reg, to buy a part from an “aviation” supplier (despite all the FUD telling you that).
Don’t buy it from Ebay or Amazon, obviously, because nearly all batteries sold there are fakes. Even the full price (i.e. “can’t possibly be a fake”) ones are usually fakes. Even when it says “genuine [mfg name]” it is usually a fake.
Examples like the famous crash in Switzerland were so obviously unairworthy that they only show that the paperwork focused Part 145 supervision in EASA land is defunct. No person I know in aircraft maintenance would have signed off that Piper in Switzerland and the most amazing thing about it is how long this airplane actually flew.
(Bold added by me)
That would be my thought too, if I believed the report’s estimated power reduction and understood how much degradation in climb performance that amount of reduced power would have brought about on every takeoff. The accident report was interesting to read, but I think their ‘estimate’ of reduced power due to a flat cam lobe is worthless unless they provide a better basis for it. The valve lifters/tappets look identical to those I’ve commonly seen coming out of Guzzi motorcycle engines – apparently its very typical in that (motorcycle) application, and as ugly as they are they go a long time in that state and don’t break up completely.
Beyond being not 101% convinced by the conclusions of that particular accident report, I’m left wondering how many engines in the real world run like this for a long time, particularly as I have a Lycoming with a similar life chronology prior to my ownership. A guy I know overhauled his O-320 having flown it since new and found a flat cam lobe, but told me he noticed only a subtle degradation in climb performance. They certainly do not come out of the sky often. I sort of suspect that regardless of the wisdom of doing it (I prefer to keep in closer touch with my plane!), if you keep good mags and a good fuel system on a Lycoming, it will keep running in very degraded condition and meanwhile tell you through reduced power that something is wrong. A bearing failure or dropped valve would stop it, but these don’t seem to be frequent failure modes. I’m guessing that in many cases this is the real life of an engine – it slowly stops making good power and that’s when it gets overhauled, or top overhauled plus bottom end inspection. It’s never much closer to actually failing than a new engine. Just my observations.
You think you are smart enough to build your own experimental which will be “airworthy” but you do not accept that trained maintenance personnel can reliably determine the airworthiness of an engine.
I’m 100% sure I am smart enough 
I have been a trained maintenance personnel myself in the Air Force, working on F-16s. Loong time ago though. Besides, smartness has very little to do with building an aircraft, and building one and maintaining one are also two different things, related but different.
You get me all wrong. I fully 100% accept that trained maintenance personnel can determine the airworthiness of an engine, why do you say I don’t accept that? That is not the issue at all. The issue is that it is the CAA that has to have verification that the engine is airworthy. The airworthiness of an engine has to be verifiable. This is basically like any other quality assurance system. The engine has to be verified to be airworthy within this system on a continuous basis. These engines are certified, they are not experimental engines. With a TBO this is dead simple. A mechanic in an approved maintenance shop simply does an overhaul according to whatever specs applies (manufacturers preferably), sign some paper and voila, the engine is as good as new and the CAA has all the verification it needs. This is the system, because the CAA and the engine manufacturer has agreed that this is OK.
A better system, a more accurate system, a system that takes into account the actual condition: a condition based system. Again, we are not talking about experimental engines where functionality is the only factor. We are talking about a quality assurance system that is based around the actual condition of the engine. This condition has to be verifiable on a continuous basis. How is this going to be done effectively on a continuous basis without an array of on-board measurement and acquisition systems that actually monitors the condition, reports faults, does self diagnosis etc? This is how such systems work, on cars, on ships, on powerplants, everywhere, and also on the F-16 some 25-30 years ago. Still, such systems can be combined with set times for overhaul, because you generally want to replace parts and subsystems before they report faults in awkward situations. But now you have the opportunity to set the overhaul/replacement based on more factors than just operating hours.
If it were up to me, all recreational GA would be experimental based (no certifications). I still don’t see how this fundamentally excludes set times for overhaul though. Things do get worn out, and doing planned overhaul is much better also for recreational GA.
Be very careful selecting parts for your VW conversion, there’s quite a lot to learn and not everything commercially available is good. Many years ago my dad did his own (very experimental) conversion and two engine failures and two forced landings followed, one due to the fuel system (I was in board for that one) and one from the ignition system. Propeller mounting is also a particular issue depending on the crankshaft you use, but I’m guessing you know that… Be careful anyway, I’m fairly fortunate to have an 85 year old dad today
Obviously, and back in topic, N-registered certified aircraft are run under condition based maintenance regulations and always have been. The FAA receives no periodic data on airworthiness, the only product of an annual inspection is the mechanic (IA) logbook entries. The issue under discussion in the original linked article is how the owner chooses to operate with respect to his individual plane.
The issue is that it is the CAA that has to have verification that the engine is airworthy.
There is no logical requirement for a “CAA” (or any other organisation) to receive this assurance. Take the FAA regime. The FAA trains (or supervises training of, via licensing a school) the A&P. The A&P now has the authority to make the airworthiness determination. This is also fully ICAO compliant.
The reliance on an “organisation” is a European concept. I am not a philosopher but I think it’s fair to say that Europe has a long history of drifting in that direction. In my business (industrial electronics) I see this all the time. There is an “approved organisation” for everything under the sun.
I suppose we need them otherwise all the people who can’t do a real job in which they exercise real judgement and make decisions on real stuff and carry a real responsibility personally would end up driving the truck which takes away my garbage and then I would have serious problems because they would examine the garbage to make sure it is genuinely domestic and leave behind the stuff which isn’t. I have already had that; somebody went through it and determined some of it was discarded business invoices (about 30kg of them) and they didn’t take them away. Nowadays it all gets taken so I guess whoever was doing that is now working as an ISO9000 quality manager somewhere.
The airworthiness of an engine has to be verifiable. This is basically like any other quality assurance system. The engine has to be verified to be airworthy within this system on a continuous basis.
The a/w of an engine is verifiable, using various indicators, determined visually, by oil filter inspection, etc. This has been proven to work over decades in the USA.
Ultimately you cannot have zero risk.
Anyway, the traditional European QA systems (ISO9000 e.g.) have rapidly been turned into marketing shams – another topic I am intimately familiar with, unfortunately.
