What's up with the 2 D cell flashlight?

[A Squared]

A 121 pilot also must observe part 91 regs.

Not these Part 91 regulations. 91.503 is a part of Subpart F which is specifically not applicable to aircraft operated under part 121 (or 125, 129, 135, 137)

Usually (not saying this is the absolute truth) when talking about flashlight equivalents, you are talking about battery voltage. A D-Cell battery puts out 1.5 volts, therefore 2 D-Cells = 3 volts. A mini mag lite uses two AA-cells. One AA = 1.5 volts. So you could say that an equivalent to a 2 D-Cell battery mag light is any flashlight that uses two batteries that put out 1.5V each, i.e. a battery with 2 D-cells, C-cells, AA's, AAA's, whatever. I could be wrong here, but that's how it was explained to me.

you only consider voltage, then 10 AAA batteries would be more powerful than a car battery (15V vs. 12V) think you can start your car with 10 AAA Batteries?

Look again. On the battery it will not say "D-Cell" it will say "D-Size"

Right. That's because its a size "D" dry cell. What we refer to as a "battery" is more acccurately a "cell", a voltaic cell. A "battery" is actually a series of cells, The word is used in the same sense that a collection of artillery is a "battery" A 12v car battery is actually a "battery" of 6 lead acid *cells* of slightly more than 2 v apiece.

1. Cell batteries are not made anymore. (Not the way we think of them anyway)

You can't make batteries without cells. Impossible. the cell is the fundamental element a battery. A "D" size (or "C" size or "AA" size or whatever) battery is a dry cell. The idea that cells aren't made anymore is pure nonesense. Today's dry cells are usually Zinc-Manganesedioxide alkaline dry cells, or "alkaline cells" which perform better than the older Zinc Carbon dry cells, but they are still cells.

Once again look on the battery. It will say D-Size. Thats becuase there is no such thing as a D-Cell battery anymore.

Suggest that you read 91.503. It doesn't say "D Cell" it says :".....having at least two size "D" cells....." A dry cell (correct name for flashlight "battery") that says "D size" on the side of it is probably what the regs mean by size "D" cell, ya think?

 

[X-rated]

Wow, thats probably all I ever wanted to know about batteries. However, you are all only telling half of the story. Voltage in and of itself is meaningless. Power or Wattage is Voltage times Current. (W=VI) Thus 100 volts at zero amps produces no work, or in the case of a flashlight... no light. So, in the car battery example, the fact that the lead acid cells are 2 volts and the AAA cells are 1.5 volts is erelavent. If you put eight 1.5 volt AAA cells together they would make a battery that produces 12 volts, but would have very little capacity to produce high current for very long, and would therefore have no chance of turning the starter in your car.

Likewise, when considering what size flashlight to put in your flight bag, you should be aware that smaller size cells generally have less capacity than larger cells even though the voltage is the same, and therefore will produce less light, or the same light for less time.

 

[NW_Pilot]

Usually (not saying this is the absolute truth) when talking about flashlight equivalents, you are talking about battery voltage. A D-Cell battery puts out 1.5 volts, therefore 2 D-Cells = 3 volts. A mini mag lite uses two AA-cells. One AA = 1.5 volts. So you could say that an equivalent to a 2 D-Cell battery mag light is any flashlight that uses two batteries that put out 1.5V each, i.e. a battery with 2 D-cells, C-cells, AA's, AAA's, whatever. I could be wrong here, but that's how it was explained to me.

Wow!! so what if you use Rechargeable batteries at 1.2V?

 

[Propnose]

I carry a Surefire A2 Aviator with me, although our airplanes all have normal flashlights in them. My A2 uses two 3v lithium batteries. It is so bright that on cool mornings I can see steam coming off the lens! I highly recommend this flashlight.

A good friend of mine has a phenomenal website for flashlight reviews -
www.flashlightreviews.com

Darn near every flashlight you can think of is on there.

 

[I.P. Freley]

A flashlight with C-Size or in some cases even AA-Size can provide the same amount of Candlelight power of the old D-Cell batteries.

There are many non-D-cell flashlights that can exceed the output of even a Maglight 3-cell D flashlight.... A Surefire A2 Aviator (which I carry in my flight case and in my car, and is mentioned by propnose) can easily match and/or exceed a 3D Mag, or even a 4D Mag after that 4D has been running for fifteen minutes. All that and weighs perhaps 1/10 of that 4D Mag and is much, much smaller to boot.

Oh, yeah, they DO happen to cost quite a bit of money, but even a $30 Streamlight 4AA LED flashlight will totally annihiliate a Maglight in everything but range (throw). Technology has caught and surpassed the old FAR requirement, thus the change to the regs.

 

[MauleSkinner]

Oh, yeah, they DO happen to cost quite a bit of money, but even a $30 Streamlight 4AA LED flashlight will totally annihiliate a Maglight in everything but range (throw).

You forget about the...well...let's call it "copilot training" advantages of the Maglite's mass

Fly safe (or else)!

David

 

[Weasil]

At the airline I work for (US Airways express) we are specifically exempt from carrying a flashlight by our Flight Operations Manual. This is because they are in the aircraft.

 

[Dutch]

I still carry my Mag-Light (2 D whatever) because it is one of the most efficient tools for knee-capping a guy.

 

[jknight8907]

I still carry my Mag-Light (2 D whatever) because it is one of the most efficient tools for knee-capping a guy.

No kiddin! Ever seen one of those monster 6-D ones? The ultimate anti-terror weapon, carrying trailer not included. Perfect for beating the stuffin out of someone...

 

[Cardinal]

If you're really horny about flashlights try www.candlepowerforums.com