The Mk 6 aircraft smoke and illumination signal (fig. 1-6) is a pyrotechnic device that is launched from surface craft only to produce a day or night floating reference point. One of its principal uses is as a man-overboard marker. It was previously approved for launching from low-performance aircraft as a long-burning marker but has been replaced for this purpose by the Mk 58 marine location marker.

The Mk 6 signal consists of a wooden body with a flat, die-cast metal plate affixed to one end to protect it from water impact damage and to maintain it in the correct floating attitude. There are four flame and smoke emission holes in the opposite end, each capped and sealed with tape. The pull-wire ring, also at the emission end, is also covered with tape.

The Mk 6 signal has a direct-firing ignition system. Ignition results from pulling the pull ring. The pull ring is pulled by hand, and the device is thrown into the water immediately. The pull wire ignites a 90-second delay fuse that ignites the quick match at the top of the first of four candles. The quick match ignites the first candle starting mix, which, in turn, initiates burning of that candle. Expanding gases of combustion force the cap and tape from the emission hole, allowing smoke and flame to be emitted When the first candle is nearly burned out, a transfer fuse carries the ignition to the quick match of the next candle in series. This process continues until all four candles have burned. The yellow flame and gray-white smoke are produced for a minimum of 40 minutes.

After the tear strip on the shipping container has been removed, the following rules apply:

1. The tape over the pull ring should not be disturbed until immediately before hand launching the signal. This tape not only prevents an accidental pull on the pull ring but also protects the igniter assembly from moisture, which might render the signal useless.

WARNING

This signal is initiated by the physical movement of a friction wire through ignition compound Extreme care must be taken to prevent tension of the pull ring during all handling operations.

2. If this device is prepared for launching and is not launched, the pull ring should be securely retaped into

Figure 1-5.-The Mk 58 Mod 1 marine location marker.

Figure 1-6.-The Mk 6 Mod 3 marine location marker.

position at the top of the signal without exerting any pulling force on the pull-wire igniter.

3. Under no circumstances should these signals be stowed or restowed with their pull rings exposed or with any wires, strings, or other material of any kind joined to their pull rings.

All safety precautions pertaining to this signal must be observed. In addition, the following specific rules apply: 1. Do not remove the tape over the pull ring until immediately before launching.

2. The Mk 6 signal should be thrown over the side immediate y after pulling the pull ring. This device contains a maximum 90-second delay element between initiation and candle ignition.

3. In all handling, extreme care should be taken to avoid pulling on the pull ring. The slightest movement of the friction igniter may start the ignition train.

The Mk 6 marine location marker is being replaced by the Mk 58. There are, however, remaining serviceable stocks of the Mk 6 available. If you have any of these markers in your inventory, they should be used first. Man-overboard and navigation drills are good instances where these stocks can be efficiently expended.