TM 55-4920-390-13&P
NOTE 2
Several helicopter types are equipped by the manufacturer with "n" wipers (one for each
blade), thus producing one pulse per blade. Thus equipped, the helicopter can use the
previous Strobex Trackers, 135M, 135M-2, 135M-5, 135M-7.
The 135M-9 can be used with this set-up also if the locked oscillator is de-activated by turning
the vernier control on the rear of the hand-held lamp full CCW (See Fig. 1-4). (The other
models, however, cannot be used with a one-per-rev pulse.)
4-5. RETRO-REFLECTIVE TIP TARGETS . The helicopter must be fitted with retro-reflective tip reflectors, one on each
blade tip as follows-
a) The flat numbers provided (Part No. B2764) are secured to the underside of the blade tip by means of
their adhesive backing. These numbers are especially made so that their retro-reflective properties are
effective when viewed at unusually "flat" or oblique angles and are shaped to be very long in relation to
their width so that, when viewed at the flat angle from within the helicopter, the numbers will appear bright
and foreshortened to normal proportions. (The effect is similar to the reflective paint sign in the school
crosswalk on the pavement.) These numbers are to be applied in the following manner -
1) Determine a suitable location on the bottom of the blade tip. It must be a fairly flat area, back from
the leading edge to avoid excessive wind erosion. It should be near a screw or a rivet line or a seam
so that uniform location can be determined on each blade.
2) Clean the selected area with a non-oily solvent to remove dirt, oil and moisture.
3) Remove backing from adhesive coating on selected retro-reflective number (label).
4) Apply number to cleaned area of the blade with its top inboard (toward rotor head).
5) Roll number down flat, with rubber roller provided, with special attention to the edges.
6) Apply proper number to each blade in succession, as above.
1
NOTE
Blades are generally identified by number and/or color. It avoids confusion to apply numbers
in accordance with number convention where possible.
4-2
