American Projectiles and Explosives - Drift Signals and Navy Flares (Part 1)

American Projectiles and Explosives

Aircraft Pyrotechnics







Day Drift Signal Mk 1

Length: 10 inches
Maximum diameter: 3.5 inches

Thickness of case: 0.07 inches
Color of slick: Chrome yellow


Use:  This signal may be used for a reference point for air navigation.


Description:  The case is composed of a water-proofed paper pulp shell pressed in the form of a tear drop, with four fins formed on the tail cone with a diameter approximately the same as the greatest diameter of the nose section.  The only other element of this signal is the very fine metallic powder filling which nearly fills the cavity.


Operation:  When the signal is dropped into the water, the shell breaks, allowing the powder filling to spread out on the surface and form a slick visible to 15,000 feet.


Remarks:  The Day Drift Signal Mk 1 is a Bureau of Aeronautics item.  This marker has replaced the Drift Signal M25, which is now obsolete.









Night Drift Signals AN-Mk 4 and AN-Mk 5 Mods 1 and 2; Aircraft Float Light Mk 6 Mods 0-2

AN-Mk 4
Length: 13 inches
Diameter: 3 inches
Weight: 2 pounds

Burning time: 3 to 3.5 minutes
Time from impact to ignition: 8 to 12 seconds
Release altitude: Under 500 feet
Visibility: Night - 6 to 7 miles



AN-Mk 5
Length: 19 inches
Diameter: 3 inches
Weight: 4 pounds

Burning time: 15 to 17 minutes
Time from impact to ignition: 8 to 12 seconds
Release altitude: Under 500 feet
Visibility: Night - 6 to 7 miles


Uses:  These signals are employed as follows:

-To determine the drift of the plane from which the signal was dropped.
-To mark an object to which an aircraft desires to call attention of a surface vessel.
-To determine the wind direction before landing.
-To mark the landing deck on aircraft carriers for night landings.
-To mark the location of the surface of the water for emergency night landings.


Description:  The Night Drift Signal AN-Mk 4 has an ogival shaped, die-cast nose with a lug on one side so that the signal will turn and not strike the bottom in shallow water, while the Night Drift Signal AN-Mk 5 Mod 1 has a flat die-cast nose.  In both cases the die-cast nose contains a water-impact fuze.  The bodies of both signals are made of hollow wooden cylinders, with one end tapered, on which the tail assembly is mounted.

The pyrotechnic mixture is formed into pellets approximately four inches long and 1.25 inches in diameter, with a 0.022-inch hole concentric with the longitudinal axis through which the delay fuse passes.  One pellet is used in the AN-Mk 4, and three pellets are used in the AN-Mk 5 Mod 1.  The pellets are enclosed in a pyrotechnic tube to keep the hygroscopic material from absorbing moisture through the wooden body.  Originally, pure tin was used for this purposed\l but in recent lots lead and zinc have been substituted.  The nose end of the signal is closed with a paraffin-treated sealing disc, while the tail is sealed with a metal cap.

Aircraft Float Light Mk 6 Mod 0 consists of four Drift Signals AN-Mk 5 Mod 1 which are contained in a square wooden body and burn successively.  The box is 20.25 inches long and 5.125 inches square.  The weight is 16 pounds, and the burning time is 45 minutes.  The float light is released by hand from an altitude of from 300 to 5,000 feet.  It gives off a grey smoke and a flame 10 or 12 inches high.  The Aircraft Float Light AN-Mk 6 Mod 2 is ignited by a pull igniter which is pulled when released.  The light can be dropped from an altitude over 5,000 feet.


Operation:  When launched from aircraft, the drift signal falls nose-down.  On impact with the surface of the water, the paraffined paper sealing disc is broken and the water drives the firing pin up against the primer.  The flame from the primer ignites the time fuze which runs the length of the hole through the center of the pyrotechnic pellets in order to give the drift signal enough time to return to the surface and right itself.  The time fuse ignites a length of quick match which, in turn ignites the starting mixture and then the pyrotechnic pellets.  The gases evolved by the pellets break open the pyrotechnic tube and force out the cap which seals the discharge tube in the tail.  A bright flame 12 to 15 inches high and a white smoke are produced.  These are visible for six to seven miles on a clear night.


Remarks: These signals may be used for day signals, but under certain conditions observation is difficult.

The Mod 2 is a moisture-proofed version of the Mod 1.

Retro-Rocket Drift Signals

No picture available

General: These 3-inch rockets are designed to be fired aft from a plane to eliminate the effect of forward motion, allowing the signal to fall straight down.  This is called retro-firing.


Description: The rockets have the 3-inch Heads Mk 5 Mod 1 and use the Motors Mk 2 or Mk 3.  With the Motor Mk 2, they weigh 4.8 pounds; with the Motor Mk 3, 4.6 pounds.  They use the Launcher Mk 2.


Operation:  Firing of the rocket motor initiates a delay train in the signal in the head, which delay sets off the flare 10 to 20 seconds later.  The motor separates from the head during the free fall, and the signal hits the water and floats on it, burning from 10 to 15 minutes.

Navy Flares

1 1/2 Minute Parachute Flare

No picture available

Length: 18.75 inches

Diameter: 2.24 inches
Weight: 4.31 pounds

Burning time: 1.5 minutes
Light intensity: 110,000 candlepower

Color: White
Maximum release altitude: 1,200 feet

Rate of fall after ignition: 550 feet/min

Use:  It is used to illuminate an area for emergency night landings by certain commercial-type aircraft in use by the Navy.

Description: The flare is issued in a hermetically sealed aluminum case called a projector tube.  One end of this tube is closed by a metal cap and sealed by a gasket. The other end narrows down into a small knob with an electrical terminal in the extreme end.  The tube is cylindrical for most of its length.

The projector tube contains an inner case and a propelling charge of black powder.  The inner case contains an ejection charge, the pyrotechnic candle, and a parachute.  The ejection charge is in the after end of the inner case, and the delay fuse and interrupter mechanism are mounted on the outside of the same end of the inner case.

The electrical terminal at the end of the projector tube is connected through a toggle switch in the pilot's compartment to the lighting system of the plane.


Releasing: The projector tube, which is constructed as an integral part of the flare, is fixed by clamp bands to a bracket in the after end of the fuselage, where the firing circuit is connected when the flares are loaded.  The projector tube remains in the bracket when the flare is released or expelled by closing the switch in the cockpit.

Operation:  When the electrical circuit is completed in the cockpit, the propelling charge is ignited and the inner case is forced out of the projector tube.  The propellant ignites the delay fuse, which burns until the inner case is approximately 40 feet from the plane and then, through an explosive lead-in, ignites the ejection charge which, in turn, forces the pyrotechnic candle and attached parachute from the inner case.  Simultaneously, the ejection charge ignites the candle.

An interrupter mechanism between the delay fuse and the ejection charge in the inner case prevents the functioning of the flare until the inner case has left the projector tube and is clear of the plane.

Remarks:  A proprietary item, this flare has a commercial designation of "1 1/2 Minute Parachute Flare Mk 1 Mod 1", but this Mark designation is not that of the Navy.

Mk 4 and Mods

  

Length: 25 inches

Diameter: 4.75 inches
Weight: 18 pounds

Burning time: 3 minutes
Light intensity: 300,000 candlepower

Color: White
Maximum release altitude: 1,200 - 5,000 feet

Rate of fall after ignition: 350 feet/min

Use: Primarily, this flare is used to illuminate an area to permit the landing of aircraft.  Occasionally, it is used for reconnoitering, bombing, and blinding anti-aircraft defenses.

Description: The complete flare consists of a parachute and illuminant contained in a shellac-impregnated chip-board tube closed at the ends by chip-board discs which are held in place by gummed cloth and sealed with paraffin.  There are two metal steadying bands fastened around the case, against which the steadying forks of the bomb rack rest.  The complete flare is issued in a waterproof metal container.

Operation:  The Navy Flare Mk 4 may be released from bomb racks or shackles, from an adapter, or manually.  As the flare is dropped from the plane, the arming plate of the rip cord is retained by the plane and the rip cord is pulled from the side of the flare case to which it is fastened by gummed cloth tape.  As the flare continues to fall, the rip cord, which is wound around a wooden spool inside the of the flare case, is unwound, tearing away the end of the flare case.  The end disc and spool fall away as the parachute tube is pulled from the flare case and retained by the rip cord.  The parachute is pulled out of its tube by the weigh of the illuminant and flare case, which causes the parachute and parachute shrouds to straighten out.  When the parachute and parachute shrouds are fully extended, a small cord attached to the release key pulls the release key down, allowing the rip cord to slip through the key, and the flare falls free.

An ignition wire is attached to the suspension cable in such a manner that it is pulled before the cable is fully extended.  Four friction wires are attached to the ignition and run through primer cups of match compound.  This ignites a double quick-match train, which burns down the outside of the illuminant case and ignites the primer composition, which, in turn, ignites the first fire and illuminant.  When the parachute opens, the illuminant is pulled out of the flare case, and flare case falls clear.  full suspension and ignition occur about 30 to 50 feet below the plane.

 

Next Time: Drift Signals and Navy Flares (Part 2)

American Projectiles and Explosives - Pistol and Hand-Size (Part 2)

American Projectiles and Explosives

Aircraft Pyrotechnics







Tracer With Two Stars Mk 4 Series

Length: 3.85 inches
Diameter: 1.52 inches

Burning time: 5 seconds
Burning time of tracer: 3-4 seconds
Height: 250 feet


Use:  Double-star signals are used as a method of emergency identification of aircraft.


Projection:  The Pyrotechnic Piston AN-M8 is used for fire the signal.


Description:  The outer case is similar to that of the Mk 3.  The star charges are contained in an inner case which also houses an ejector charge and tracer element.  Star color bands are the same as the bands on the Mk 3 and, in addition, a narrower band, before the star identification bands, indicates the color of the tracer.

Color combinations are:

-Red-red with Red tracer
-Green-green with Red tracer
-Red-red with Green tracer
-Red-yellow with yellow tracer
-Red-green with Red tracer
-Red-green with Green tracer


Operation:  The firing pin strikes the primer, igniting the propelling charge, which, in turn, ignites the tracer in the inner case and expels the inner case from the barrel.  The tracer becomes visible after traveling about 20 feet.  At approximately 250 feet altitude, the tracer ignites the ejection charge through the quick match, the stars being ignited by the ejection charge through the quick match as they are expelled from the inner case.











Aircraft Signal AN-M53 to AN-M58 Series

No picture available

Description:  Signals of this series are similar to the Mk 4 series.

Star Signal Mk 6

Length: 6 inches
Diameter: 2.5 inches
Weight: 1.4 pounds

Burning time: 25 seconds
Interval between launching and suspension: 2.75 seconds


Use:  Signals of this series are used primarily for emergency identification purposes at night.


Description:  The body of the signal is an aluminum cylinder with a bouchon type of grenade-firing mechanism on one end and a metal cap on the other.  Contained in the body are the ejection charge, the pyrotechnic candle, and a silk, rayon, or paper parachute.  The type and color of the signal star are printed on the side of the cylinder.  The closing cap on the lower end of the signal is embossed for night identification as fllows: red star, one dot; white star, straight line; and green star a wide "V".

All three signals have an arc of a circle, one inch in length, embossed near the edge of the cap.


Operation:  The signal is initiated in the manner prescribed for all bouchon-fuzed grenades.  The 2.75 second delay, having been ignited by the primer, ignites the ejection charge.  The ejection charge pushes off the closing cap, expelling the pyrotechnic candle and the parachute, at the same time igniting the starting mixture through a quick match.  The parachute opens and suspends the candle, which burns for 25 seconds.










Smoke Signal Mk 7

No picture available

Length: 10 inches
Diameter: 2.5 inches
Weight: 2.5 pounds
Color: Red, Yellow, Green, or Black

Burning time: 25 seconds


Use:  This smoke signal is used for emergency identification in daylight.


Projection:  The Pyrotechnic Piston AN-M8 is used for fire the signal.


Description:  The Smoke Signal Mk 7 is the same as the Star Signal Mk 6, except for its length and the composition of the pyrotechnic candle.  Also, the closing cap of the smoke signal is not embossed, but is painted the approximate color of the smoke produced.

Two-Star, Red, AN-M75

Length: 5 inches

Diameter: 1.125 inches

Burning time: 6-8 seconds

Color: Red

Height: 100-200 feet

Use:  This distress signal is used as an emergency rescue signal.

Description:  The signal is contained in a cylinder which houses the stars and the firing mechanism.  This mechanism consists of a pull release fork and a spring-loaded firing pin.

Operation:  The tape is removed from the top cover and the cover is removed.  The release fork is pulled; the firing pin is released and hits the primer, initiating the delay.  After two to four seconds, the first red star is ejected, and after three to five seconds the second red star is ejected.

Remarks:  This signal is not procured by the Navy.

Smoke Grenades AN-M8, M16, M18, and AN-M4

Length: 5.7 inches
Diameter: 2.57 inches
Weight: 1.68 pounds

Burning time: 3.5 seconds
Delay time: 3 seconds


Use:  These smoke grenades are used to attract attention to aviation personnel who have made a forced landing.


Description:  The cylindrical sheet-metal case is nearly full of a solid smoke mixture.  A circular zinc cup containing a starting mixture is located in a depression left in the top of the smoke mixture, and is designed to be initiated by a bouchon type of grenade-firing mechanism.  Adhesive tape covers four quarter-inch holes in the top of the case until the signal is ready for firing.  The grenade is painted gray and marked in yellow with one band, the symbol of the filler, "H.C.", and the word "smoke".


Operation:  The release lever cotter pin having been removed, the release lever is freed by the operator as the grenade is thrown, and is forced off by the striker, which is at all times under tension of its spring.  The striker moves on its hinge and fires the primer, which ignites a delay element that in turn ignites the starting mixture.  The starting mixture burns through the zinc cup and starts a chemical reaction in the smoke mixture, generating considerable heat with the formation of zinc chloride.  The zinc chloride escapes into the air as a gray-white smoke composed of finely divided solid particles.  These particles are highly hygroscopic and become very obscuring liquid particles.  The grenade burns for about three and a half minutes at full volume.


M-16 (Obsolescent):  Same as AN-M8.  May have red, yellow, green, orange, violet, or black smoke.


M18: Same as M-16, with burning reduced to one minute for a more dense smoke.  Available colors are red, green, yellow, or violet.


AN-M4:  Has a shorter fuze lever and is issued in a metal container with three flaps designed to be bent outward to provide additional bearing surface for use in mud of snow.  The AN-M4 is not procured by the Navy.

Next Time: Aircraft Pyrotechnics - Drift Signals and Navy Flares (Part 1)

American Projectiles and Explosives - Pistol and Hand-Size (Part 1)

American Projectiles and Explosives

Aircraft Pyrotechnics





Parachute Star M11, also M10, M14, M15, and M16

Length: 7.69 inches
Diameter: 1.58 inches

Burning time: 30 seconds
Intensity: 20,000 candlepower

Color: Red
Height: 200-250 feet


Use:  This is a distress signal from grounded planes.


Projection:  The Pyrotechnic Piston AN-M8 or Hand Projector M9 is used for firing the flare.


Description:  The cylindrical, aluminum outer case has an extraction groove at the end containing the primer.  A press-fit identification top is cemented to the end opposite the primer and has the embossed letters "R.P." for night identification.  This cartridge is classified by the Army as the rimless type.


Operation:  The firing pin of the pistol sets off the primer, igniting the propelling charge.  The propelling charge ignites the delay fuze and propels the inner case outward.  The delay fuze burns for 2.5 seconds and ignites the expelling charge, which in turn ignites the candle and expels the candle and parachute from the inner case.


Remarks:  The Army has other parachute signals which are similar to the M11.  These are obsolete or limited standard items.

Double Star AN-M28 to AN-M33 Series (Obsolete)

Length: 3.02 inches
Diameter: 1.58 inches

Burning time: 7 seconds

Height: 250 feet

Use:  Double star aircraft signals are used as emergency identification by aircraft.


Projection:  The Pyrotechnic Piston AN-M8 or Projector M9 is used for firing the signal.


Description:  The signal cartridge has an aluminum, plastic, or steel barrel with an extraction groove at the closed end which houses the primer.  A press-fit identification top is cemented into the opposite end, finished with embossed letters to identify the colors of the stars.  Appropriately colored bands around the outer case also identify the colors of the stars, in addition, the identification top is appropriately colored.  These signals are also classified by the Army as the "Rimless Type."


Operation:  The firing pin of the pistol strikes the primer, igniting the propelling charge.  As the stars are expelled from the pistol, they are ignited by the propelling charge through the quickmatch.  The stars reach full brilliance after travelling 40 or 50 feet, and rise to a height of approximately 250 feet.

Single Star AN-M34 to AN-M36 Series (Obsolete)

Description:  This series has the single star instead of the double star of the AN-M28 to AN-M33 series, but the dimensions are the same.


Remarks:  This series is not procured by the Navy






Aircraft Signals AN-M37 to AN-M42 and AN-M37A1 to AN-M42A1 Series

Length: 3.85 inches
Diameter: 1.54 inches

Burning time: 7 seconds

Height: 250 feet

Use:  These signals are used for emergency identification of aircraft.


Projection:  The Pyrotechnic Piston AN-M8  is used to fire this signal.


Description:  A metal or plastic head contianing the primer is crimped to the paper board or metal case, the opposite end of which is closed with a cardboard wad.  The colors of the stars are printed and painted on this wad, there being no means of night identification.  Colors of stars are also indicated by the appropriately colored bands on the case near the forward end.  These signals are classified by the Army as the Cartridge Type.


Operation:  These signals are similar to the AN-M28 to AN-M33 series in operation.


Remarks:  The A1 series has an aluminum case.

Single Star AN-M43 to AN-M45 and AN-M43A1 to AN-M45A1 Series

Description:  This series has a single star instead of the double star of the AN-M37 to AN-M42 series; dimensions are the same.





Two Star Cartridge Mk 3 Mod 3



Description:  These are interchangeable with the AN-M37 to AN-M42 series.  There is no means of night identification.  Color combinations available are: red-red, yellow-yellow, green-green, red-yellow, red-green, or green-yellow.

Next Time: Aircraft Pyrotechnics - Pistol and Hand-Size (Part 2)

American Projectiles and Explosives - Aircraft Pyrotechnics Introduction

American Projectiles and Explosives

Aircraft Pyrotechnics

General


These chapters on pyrotechnics deal with items whose principal function is either signalling or illuminating.  For instance, signalling smokes are treated as pyrotechnics, but screening smokes are discussed elsewhere, under the ordnance items which carry them.

The effectiveness of pyrotechnics is dependent on three major factors: design, position, and the atmospheric conditions prevailing at the time of use.  Variations of design govern the candlepower of the flare or signal, the color produced by the charge, and the continuity of the burning candle.  The color and reflective characteristics of the objective often affect the visibility of pyrotechnics.  Open ground, such as an airfield, will reflect three to four times as much light as will woods or deep water.  Position, distance, relative position, background, or angle of observation also alter visibility, while the degree of light or darkness, fog, haze, or other atmospheric conditions have obvious effects.

Composition

Pyrotechnic compositions are complex chemical mixtures.  On burning, they produce illuminations ranging in intensity from the "dark fire" used as an element of blinker signals to the brilliant flash produced by the photoflash bombs.  Standard pyrotechnics, in general, consist of compounds to provide oxygen for burning, such as chlorates and nitrates; aluminum or magnesium for fuel; salts of barium, copper, or strontium for color; and agents such as asphalt and paraffin for binding and waterproofing.

Pyrotechnics usually function by means of an igniter train similar to an explosive train.  In general, ignition is initiated by a primer mixture and intensified by a "first-fire" composition which ignites the luminous candle.

Handling and Stowage

All pyrotechnics should be handled with care.  Rough handling may cause immediate functioning of the item, or it may damage the item so that it will not function properly at the desired time.  Much of the pyrotechnic material is more sensitive than other types of ammunition.

Pyrotechnics should be stowed in the boxes or watertight containers in which they are shipped, whenever possible.  They must not be stowed with other types of ammunition.

Pyrotechnics should never be stowed where the direct rays of the sun can strike them.  They should be protected against excessive and variable temperatures.  If possible, the stowage space should be kept at a temperature below 100 degrees Fahrenheit, and must be kept dry and ventilated.




Disposition

 When directed by the Bureau of Ordnance, pyrotechnics may be disposed of by dumping overboard or burning.  Dumping is preferred, and must be done ten miles off shore and in water at least 100 fathoms deep.  Certain items must always be dumped, while other items may be either dumped or burned.

Methods of projection

Aircraft pyrotechnics

1. Pyrotechnic Pistol AN-M8:  This pistol is used on aircraft with the Mount M1 and fires through an opening, in the fuselage.  It can also be detached from its mount and fired by hand.  It is generally used for signalling from aircraft in flight, to troops on the ground or to other aircraft.

2. Hand Projectors Mk 3 and Mk 4:  These projectors are fired by holding the barrel in one hand and pulling back on the firing pin handle with the other.  They are used to fire Very's Signal Light Mk 2.

3. Signal Pistol M5:  This is a single-action, single-loading pistol that fires the Very's Signal Light Mk 2.

4. Very Pistol M5:  This is a single-action, single-loading pistol that fires the Very's Signal Light Mk 2.  It is not procured by the Navy.

5. Pyrotechnic Discharger AN-M5:  This is a double-action, multi-barrel (6) discharger used on aircraft when installation of pistols is not practicable.  It is used for the same purpose as the Pyrotechnic Pistol AN-M8.  It is not procured by the Navy.

6. Hand Pyrotechnic Projector M9:  This is a single-action, single-loaded projector which is fired by striking the firing pin with the hand or by striking the firing pin on the ground.  It is used for projecting signals from the ground to aircraft in flight.  It is not procured by the Navy.

7. Pyrotechnic Discharger M10:  This is a metal cylinder with a mushroom firing mechanism and a hinged locking stem.  It is used to fire the Red Star Signal M73.

Ground pyrotechnics

1. Ground Signal Projector M1A1:  This is a single-loaded manually operated projector used to fire the High-Bursting-Range Ground Signal M27

2. Ground Signal Projector M3:  This is a single-loaded, manually operated projector that is fired by holding the projector in the hand and striking the base on the ground.  It is used to fire Signals M17 through M22.

3. Ground Signal Projector M4:  This projector is similar to the M3 and is replacing it.

4. Grenade Launchers M1, M2, M7, and M8:  This type of launcher is an extension to the barrel of a rifle or carbine.  It is used to fire ground signal M17A1 through M22A1, M51A1, and M52A1.

  

5. Tree Suspension Device T1, For Smoke Grenade:  This is a cardboard attachment containing about ten feet of suspension cord.  It is attached to a standard smoke grenade that is launched from a carbine or rifle.  The device is used to cause grenades to become entangled in trees or foliage, to permit emission of smoke above dense forests and foliage where it is readily visible to air observers.

Ship and submarine pyrotechnics

1. Signal Projector Mk 1 and Mk 1 Mod 1:  This is a barrel, about 30 inches in length which fits into a tube mounted on a three-legged stand.  The firing pin is part of a metal disc which acts as a valve.  It is used to fire Ship's Emergency Identification Signals Mks 1, 2, 3, and 4.

2. Submarine Rocket Pistol:  This is a single-loaded, breech-loaded pistol used to fire pistol rocket signals.

3. Submarine Emergency Identification Signal Ejector:  This ejector is similar to a miniature torpedo-tube arrangement.  It is used to fire Submarine Emergency Identification Signals, Submarine Float Signal Mk 1, Mk 1 Mod 1, or Mk 2 Mod 0, and False Target Shell, Mk 1.

4. Other Projectors:  These include Hand Projectors Mk 2 and Mk 4, and pyrotechnic Pistol An-M8, which are described above under Aircraft Pyrotechnics.  There is also a High-Altitude Mortar Mk 20 being developed, to which official nomenclature is being assigned.

Next Time: Aircraft Pyrotechnics - Pistol and Hand-Size (Part 1)