SMN 10-55-2

Which parameters define its operation?

The 1,500-hour reference life supports regular indication when the lamp is operated at its rated voltage. It gives local, controlled light rather than broad illumination, so the position of the bulb inside the optical element matters. The electrical rating should be considered together with light output and operating duty. Overvoltage raises filament temperature and will normally shorten service life.

How is the lamp constructed and installed?

The 3.2 mm bulb is about 7 mm long; with flexible leads the complete lamp measures approximately 27 mm. Direct connection removes the need for a socket but requires correct lead forming and careful soldering. Before installation, compare bulb diameter, overall clearance and the exact connection method. The lamp must not be forced into an unsuitable holder, loaded through the glass envelope or fitted by changing the original mounting arrangement.

Where is this execution used?

Lamps in this group are used for local indication and illumination inside compact instruments, annunciators and illuminated controls. Installation in a particular aircraft, helicopter, panel or instrument must be confirmed by the applicable parts list or equipment documentation. The SMN or MN family name alone does not establish aircraft applicability.

How should the correct lamp be selected?

The -2 suffix is essential because it defines the lead construction. Compare the current, available mounting length and terminal arrangement with the original lamp; do not substitute the based SMN 10-55 without checking the holder design. Related products on the card help compare nearby executions in the same narrow subgroup; they do not establish automatic interchangeability. An enquiry should include the marking of the removed lamp, circuit voltage, holder or lead type and the required quantity.