HEAD, ROCKET FLARE, A/C, 3" Mk I

OVERALL LENGTH

DIAMETER

TOTAL WEIGHT

CANDLEPOWER

BURNING TIME

TIME TO PRIMARY

EJECTION

TIME TO LIGHT UP

RANGE TO LIGHT UP

GENERAL:

This head is designed for use with 3" Rocket Motors, A/C, described on page 37, and may be fired either from aircraft or from ground launchers.

DESCRIPTION:

The flare head consists of an outer body assembly and an inner canister. The inner canister is brought to an ogive at its foreward end and also serves as a ballistic cap. A parachute, enclosed in a cardboard housing, is contained in the upper portion of the inner canister. The long cylindrical portion of the canister is then brought down inside the main body assembly, and tabs on the bottom edge of the canister are then bent over a metal lid, retaining the lid in position. The lid consists of a metal disc, perforated in the center to accommodate the ends of two lengths of safety fuse. A baffle plate is located between the lid and the flare candle. Lengths of quickmatch extend from the base of the candle through the center of the baffle plate and into a gunpowder charge located between the baffle plate and the metal lid. This charge constitutes the secon-dary ejection charge; and the safety fuse leading to it, the secondary delay.

A socket is fixed to the lower part of the body assembly, and to the socket is wel-ded a spigot. The spigot is threaded externally to screw into the shell ring of the rocket motor and is internally threaded to receive the Ejector, Contents, No. 7 Mk I. The Ejec-tor, Contents, consists of a threaded body, housing a diaphragm operated striker, a percussion cap, and a double length of safety fuse wich extends into a gunpowder charge.

A base fairing is loosely assembled over the lower portion of the body assembly. The after end of the fairing is notched to form several tabs, and a metal clip is placed around these tabs and tigtened up to ensure a firm attachment to the rocket motor. The fairing serves merely to cover the joint between the flare head and the rocket mo-tor, enhancing the streamlining of the complete round.

OPERATION:

The pressure of the propellant gases from the rocket motor reverses the diaphragm of the Ejector, Contents, firing the cap and the safety fuse in the ejector. After the expiration of this primary delay (16 seconds) the primary gunpowder ejector charge is fired expelling the inner container from the flare body assembly. The explosion of the primary charge also ignites the secondary delay.

When the secondary delay expires, the secondary ejection charge is initiated, ignit-ing the lengths of quickmatch beneath the flare candle and blowing the lid out of the after end of the inner container, bending back the tabs on the base of the container.

The flare candle and the parachute assembly are now free to fall out of the after end of the container. The flare has been ignited by the flash from the lengths of quick-match and is now suspended in mid-air by the open parachute. The purpose of the pri-mary delay and ejection charge is to allow the flare ample time to loose velocity suffi-ciently so that an undue strain will not be placed on the parachute.

REMARKS:

(1) The flare head is painted black overall with a 1/2" red band painted around the flare body near the base.

(2) This flare head may be employed with following motors:

Old Nomenclature

Proposed New Nomenclature

1. Motor, Rocket, A/C 3" (Rocket Flare)

1. Motor, Rocket, A/C 3", No. 4 Mk I

Mk I

2. Motor, Rocket, A/C 3" No. 1 Mk I

2. Motor, Rocket, A/C 3", No. 1 Mk I

3. Motor, Rocket, A/C 3" No. 1 Mks II-IV

3. Motor, Rocket, A/C 3", No. 5 Mks I-III