A failed flashlight bulb in the cockpit can be serious. Even if theres a spare handy, changing it can be a challenge in the dark or in turbulence.
How about a flashlight with a bulb that never burns out, or at least not for tens of thousands of hours? How about a light with batteries that last days, not hours?
Were talking about flashlights that use LEDs (light emitting diodes) instead of conventional incandescent bulbs. Yes, these are the same LEDs weve seen in electronic equipment-cheap key ring lights and the like-for years. The problem has been that while LEDs came in an array of colors, they werent available in white, until recently, when a white LED was finally developed.
Actually, the LED itself is blue, but a phosphor coating enables it to generate white light. Initial examples were expensive and dim. Now theyre bright enough to make an LED flashlight practical and affordable, at least for some uses.
Testing the Species
We collected an array of such LED flashlights, examined their performance and drop tested each light four times from six feet onto concrete with not a single failure. Thats an impressive showing.
While some makers claim that the LEDs will last upwards of 100,000 hours, experts tell us that LED life varies depending upon what voltage is used and many of these lights push more volts than the LEDs were designed for. Even so, you should expect them to last tens of thousands of hours.
Another advantage of LED flashlights is that battery life is extended beyond anything weve come to expect, although in our tests actual results varied from manufacturers claims, both plus and minus. With no standards for measuring battery life, all claims must be taken with a grain of salt.
As the battery charge declines below nominal, the LED doesnt go out, but merely dims. In many cases, this residual illumination will last as long or longer than the nominal light output and the flashlight may still be useable for many chores at these reduced light levels. We arbitrarily defined battery life as the point at which light output was noticeably dimmer. In normal use, where flashlights are generally used intermittently, battery life may be longer than in our tests.
Even the brightest LED light we tested wont punch a beam out as far as a bright, well-focused halogen or xenon beam from a conventional flashlight. Only the very brightest and most expensive of these LED flashlights would adequately illuminate the top of the tail on a large twin or corporate jet during your preflight, but many would be fine for most GA uses.
Tektite, known for its dive and industrial flashlights, makes three Trek models with two LEDs ($35), one with seven ($60). Two are powered by three 1.5 volt batteries, but the most compact, the Lithium Trek Light, uses a single special 3.6 volt lithium battery which is both expensive ($11) and not easily found.
The lithium-powered light is noticeably dimmer than the others-voltage makes a difference. Still, all three are adequately bright for close-up work, particularly in an enclosed area like a cabin or cockpit.
The seven-LED Expedition has three C-cells, producing enough light for most purposes except long distance lighting. The LEDs combine to produce a decent-sized central area of bright, even lighting. The Mini-Trek Light model includes a molded-in clip that allows you to clip it to a hat brim and an enlarged bite area for the lanyard tab, both of which allow for hands-off use, a handy feature.
For the consumer market, C. Crane Co. has exclusive marketing rights for these lights. The only difference between the Tektite branded lights and the consumer versions is the depth rating, 1000 feet vs. 10 feet, not much of a concern for pilots. The consumer versions are a bit easier to switch on and off since the head turns easier.
Theyre also easier to locate to purchase. An accessory kit for the Trek from C. Crane ($20) includes a red lens which provides a deep red light, elastic headband, a magnetic mounting clip and a black rubber lens shield to prevent side light emissions.
These Pilot lights are clones of the original triple AA-cell Trek light, though of lower quality fit and finish. Besides the Pilot 2 ($30) two-LED model, they also offer both a one- and a three-LED version. The single LED model, Pilot 1 ($20), didnt seem to offer much except extra-long life and it was quite bulky for the light provided.
The Pilot-3 ($35) served as an excellent example of the difficulty that having multiple light sources that are not well aimed can cause. It provided three distinct lit areas, seriously annoying when trying to use the light for close-up work.
The eternaLight three-AA-cell models from Technology Associates offer some interesting capabilities, as well as a few silly ones. The microprocessor-based controller allows you to dim the LEDs electronically.
They claim over 700 hours…on one set of batteries, but thats at the lights lowest power setting, which uses a single LED at reduced power. At full power, the alkaline batteries lasted 36 hours and the lithium-powered model lasted 46 hours. At the next lower power setting, which was nearly as bright, both lasted almost twice as long.
The eternaLights are flat and rectangular. The Classic Model 2 is $55 but we werent impressed by its construction. The better-designed Model 3 Ergo is $80, and a waterproof variant, the Model 3M Ergo-Marine is $90 (both 3 5/8 x 2 9/16 x 7/8 inches). Despite having the LEDs aligned in a row, the actual beam was nicely converging and even, one of the best of the bunch.
The pressure-pad style switches are the eternaLights only failing, being easy to engage inadvertently. A timer incorporated into the power switch turns off the light if you dont push the mode switch. However, its easy to imagine how the switch could be activated repeatedly, so some care must be taken where you store it.
Looking somewhat like a Mini-Maglite, the aluminum-bodied, two AA-cell FlashLED lights from LEDtronics incorporate a pushbutton switch and a range of LEDs, both in color and quantity. We tested both three-LED ($50) and six-LED ($70) lights.
The three-LED was unimpressive, with a brightness level lower than some single-LED models. The six-LED provided more light, but nothing to shout about. The three-LED red was good for cockpit use, the six-LED was too bright. Neither green model provided good quality light.
LEDtronics also makes the KeyLED key chain light. While ruggedly constructed of aluminum, we werent impressed with the white-LED model. The red-LED version worked well around the cockpit, but forget the green-LED.
Note that our LEDtronics products and pricing were supplied by LED-Lite, a master distributor, after LEDtronics failed to respond to queries.
Weve heaped praise on LRIs diminutive Photon II Micro-Light. Theyve taken a good product and made it better with the introduction of their Narrow-Angle White version ($22). The LEDs used in this model focus the beam more like a conventional bulb, the result being an even brighter white light. The beam is wide enough for practical use, theres just less light wasted.
Its the same flat oval shape, 1 9/16 x 1 5/6 x 5/16 inches with both a slide switch and a momentary switch and it relies upon a pair of 3-volt lithium cells lasting about 15 hours. The $16 red-LED Micro-Light (with a single 3-volt battery lasting 125 hours) is almost too bright for cockpit use, but that hasnt stopped us from using it as our primary back-up. The green-LED model still has beam quality problems.
The lights are available with a key ring or a useful and effective clothing clip on a 2 1/4 inch nylon cord lanyard for an extra $2. While not waterproof, weve gotten them soaked, blew the water out and they still worked fine. Add a Velcro spot and they can serve very well in the cockpit.
Rigel offers three 9-volt battery powered models of interest to pilots, the two-white-LED Moonlight, and the Skylite and Mil-Skylight, which also include a pair of red and green LEDs, respectively. For a savings of only $2 over the others at $30, we cant see any reason to consider the white-LED only model.
On top of the case (4 1/2 x 1 1/4 x 1 inches) is a small switch to select white, color, or off. A thumb wheel allows you to vary the intensity from full bright to off. At full brightness, the white light is equal to the best of the other two-LED models. The ability to dial in exactly how much red or green light you need makes this perfect for night use. The red provides an excellent beam, the green, while still inferior in our view, was the best quality green beam of all we tested. Battery life was disappointing, only 16 hours at full brightness. The lights are not waterproof in the least.
LTIs PALight is another 9-volt battery powered light unique in always being on. The single white LED requires just a trickle of current to energize it, just enough to make it easier to find in the dark-sometimes. They claim that the battery will last for years in the off position. In general, we found the light quality to be poor and brightness sub-par.
The Lightwave 2000 from Action Electronic ($30) four-LED, triple AA-cell flashlight provided the best beam quality and brightness of all the AA-cell powered lights in this test with the exception of the more costly eternaLight.
The rotary head switch proved to be a bit troublesome, occasionally allowing the light to come on again after we had turned it off. We had to find the sweet spot in order to be sure it was off for good.
Is the world ready for a $300 flashlight? Is there a pilot alive willing to pay such a price? Thats the question HDS Systems seems to be asking. Their Action Light was originally developed as the ultimate caving light, a use where reliability is key to survival.
The key to its superb performance is an array of 24 perfectly matched LEDs along with a special 3-volt lithium battery ($19) and a triple intensity switch. This one puts out enough light to truly compete with conventional flashlights, except for long- range uses. But its probably too unwieldy and expensive for aviation use.
The seven-LED Tektite/C.Crane Trek Expedition provides generally better than adequate light levels and solid performance. This light will suffice for almost any flashlight chores, except the long-range stuff. Battery life is good and the C-cells are easy to find. This one is a keeper.
Both Rigel Systems Skylite models get a thumbs-up for the thumb-wheel controlled variable intensity capability. For general purpose cockpit light with both colored and white light, this one is far superior to the conventional types weve used. Battery life isnt great, but still much longer than a conventional flashlight.
LRIs Photon II Micro-Light with the narrow-angle white-LED is simply without peer as a handy all-around light youll never be without.
The Technology Associates eternaLight Model 3 and 3M have some nice features, as well as some annoying gimmicks we could do without. If you can live with the pressure switches, it offers superior performance and variable intensity, the best of the AA-cell models-although at a premium price.
The best value of the bunch has to be the Lightwave 2000. Useable brightness and good beam quality, easy to find AA-cells, a nice combination of features at a price that wont stick in your throat. The only failing was the temperamental switching mechanism.
The Tektite/C.Crane two-LED Trek flashlights arent quite as bright and dont have the same beam quality, but construction is excellent. They are a bit more expensive than others in their class, but we like the convenient size of the triple AAA-cell Mini.
The development of LED flashlights, especially those with white LEDs, is in its infancy. This is definitely a product category that will see fairly rapid evolution over the next few years, although we dont expect to see much price relief.
-by Douglas S. Ritter
Doug Ritter is an Aviation Consumer contributing editor and editor of Equipped To Survive: www.equipped.org. For more information on LEDs, see www.equipped.org/ac.