|All of the gear switches are in series - so if a switch fails, or if a gear is not locked, the corresponding light will not illuminate, but there is no indication as to the fault.||Each switch has its own dedicated LED. If a switch is not closed, the LED will not be illuminated and a particular gear can be immediately identified.|
|If a gear switch were
to jam to the "on" position, the pilot would never know and that
particular gear position would no longer be monitored.
If the gear corresponding to a jammed switch were to malfunction, the pilot could have the light on, but the gear in an unsafe situation. (This has happened. This happened to me!)
|If a switch were ever to jam in the "on" position - the corresponding LED would never extinguish. I.e. in the gear-up position, there would be 3 blue LEDs illuminated, and one of the "down" LEDs would also be illuminated. The pilot would know right away that there was a fault in the system. (Instead of waiting until the next annual!)|
|The colors of the
lights are non-intuitive. For an amphibious plane, gear-up is the
desired configuration for a water landing.
A red light doesn't make sense.
|The LED colors have
|Aside from color, the
shape and layout of the indicators is identical.
This allows one to easily confuse which light represents which function.
|From a human factors
points of view, there are three gear LEDs corresponding to three gear.
There are two flap LEDs corresponding to the two flaps.
A quick look at the LEDs gives an unambiguous interpretation of the information.
incandescent lamp system draws a lot of power, gets hot, and the bulbs
have a limited operating life.
(2 lights on = 660ma, or about 9 watts)
|The LEDs draw less
power and for all intents and purposes, they will never burn out.
(5 LEDs on = 100mA, or about 1.4 watts)
|The original system is dimmable by mechanical irises and each lamp has a test function||The system as designed is electronically dimmable and has a test switch which activates all of the LEDs.|
|Weight of lamp units = 180 grams||Weight of LED system = 85 grams|
|Original wiring.||A key feature to this modification is that NO ADDITIONAL wires are required to any of the switches.|
|Original approval.||This modification has been approved by Transport Canada under a Limited STC.|