The despatcher parachute (T100-A Thinback) was introduced into service to meet the requirements of personnel engaged in duties on the aircraft in the vicinity of the open ramp or doors, who are also required to move about the aircraft. It is a canopy-first deployment system that is operated manually by means of a ripcord.

The T100-A Thinback assembly:

a. pilot parachute;

b. canopy and suspension lines

c. risers and harness

d. a pack tray

e. a ripcord handle.

Pilot Parachute
A skyhook pilot parachute is attached to the apex of the canopy by a bridle line. The pilot parachute is fully enclosed by nylon mesh and has a helical spring inside, which forces it clear of the wearer's back once the ripcord pins have been withdrawn. The pilot parachute has two grommets sewn onto the crown so that when the pack is closed the closing loops pass through them, thus keeping the pilot parachute central.

Canopy
The T100 is a low porosity conical shaped canopy, constructed with orange and white ripstop nylon. It has a flat diameter of 7.9 metres and a flying diameter of 5.5 metres. The canopy is designed so that its flying diameter is 70 percent of its flat diameter. The canopy is constructed of 24 gores with four sections per gore and has a 25cm mesh net skirt around the base of the canopy extending down the suspension lines from the lower lateral band.

The canopy has a three-window, meshed modification that provides a forward speed of six knots (12kph). The steering toggles are located at the back of the rear set of the risers, where they are tacked down with two thickness of red cotton thread, for security on opening. The toggles run free on the suspension lines attached to gores 21 and 4.

Suspension Lines
There are 24 suspension lines of cordless braided nylon 5.24 metres in length from the riser connector links to the lower lateral band.

Risers and Harness
Risers - the risers are integral to the harness and no provision is made for canopy release devices (capewells) other than the wearer actually removing the harness.

Harness - the harness is constructed from nylon webbing. It is fitted to the wearer by means of three quick-eject snap hooks and V-rings.

Pack Tray
Pack tray - is made of nylon duck and has two side and end flaps that enclose the canopy and suspension lines. The top flap is fastened to the pack tray sides by eight press studs. The four envelope flaps are held in position in the centre of the pack tray by the closing loops and ripcord pins.

Ripcord Handle
Ripcord handle - is situated in the ripcord pocket that is sewn around the right hand side main suspension strap of the harness. The handle, when inserted in the pocket, is facing inboard. The ripcord is a two-pin wire type and is attached to a Butterfly handle.

Fitting the Parachute
The harness is adjustable in five places: the chest strap, two leg straps, and the two shoulder adjusters. The chest strap should be positioned at mid-chest level. The leg straps pass around each thigh and the adjustable V-ring connects to the snap on the front strap. Each leg strap should be adjusted up until firm but not uncomfortably tight. The two shoulder adjusters vary the length of the front straps. These are only used for large variations in the length of the trunk that cannot be taken up with adjustments to the leg strap length.

Excessively loose clothing may make it difficult to observe the harness fittings when donning and may obscure the ripcord handle during use. Care must be taken with the despatching as the ripcord handle, could be snagged, resulting in a floating ripcord or a deployed parachute.

T100 Activation and Deployment Sequence
On exiting the aircraft wearing the T100 paratroopers are to look for the handle, grasp and activate it once clear of the aircraft:

a. the pins withdraw from the cones;

b. the pack opening bands pull the four envelope flaps open;

c. the pilot parachute spring, packed under pressure, expands and presets the pilot parachute to the airflow;

d. as the paratrooper falls further, the bridle line deploys to full length and the pilot parachute lifts the apex of the canopy off the pack tray;

e. the paratrooper falls clear of the canopy;

f. the canopy begins to develop;

g. the suspension lines pull from the stows; and

h. the canopy fully develops.

Steering Toggles
On deployment, should the red thread holding the steering toggles in place break, the toggle could be up the suspension line out of reach. Should this occur the canopy can be steered by using the rear risers.

Despatcher Parachute T100 Thinback Assembly Specs

Pilot Parachute
Type SKYHOOK 10cm base. 15cm crown. 96.5cm length
attached to the canopy by a 1m bridle line

Canopy
a, Type 7.9 m Low Porosity conical nominal flying diameter 5.5m

b. Material 1.1 oz per sq yd (white and orange) ripstop nylon

c. Gores 24 with 4 sections per gore

d. Suspension Lines 24 (cordless braided nylon lines [249.4kgBS]) each
5.24m from lower lateral band to connector link

Risers and Harness
a. Material The harness is constructed from (2 494.8kg BS) nylon
webbing. The risers are integral to the harness.

b. Type Split saddle three-point suspension with quick-eject
snaps and V-rings

c. Hardware (1) Nicad plated steel (minimum BS 268kg)
Ripcord butterfly handle 7 x 7 strand steel wire (BS 420kg)

Pack Tray
a. Type 2 pin 4 flap manually activated ripcord

b. Material Nylon duck, 400 denier or 500 denier Cordura

Ripcord Handle
a. Type 2 pin

b. Handle Butterfly

c. Cable 7x7 wire (seven strand w/seven wires in each)

d. Tensile Strength 420kg BS

Characteristics
a. weight 7.25kg

b. rate of descent Below 7.6metres/second with a 90.7kg load


c. deployment Canopy first (less than three seconds from activation
to full deployment)

d. packed life 6 calendar months

e. serviceability Card Left hand side of harness (pocket)

TEST STANDARD

The Thinback Parachute Assemblies have been tested to the requirements of CASA CASR Part 21 Sub part 0 Emergency Parachutes.
To demonstrate compliance with CASR Part 21 Sub part 0, the United States Federal Aviation Administration, Technical Standard Order T.S.O - C23b was used as the specification.

Parachutes Australia holds both Certificates of Type Approval (CTA) issued by the Australian Department of Aviation and letters of TSO Authorisation from the United States FAA for the various component parts that make up the Thinback Parachute Assembly.

Thinback Emergency System.
The Thinback Parachute Assembly will meet the requirements for a 'Standard' category parachute provided the canopy fitted to the Thinback pack and harness has been certified to the standard type category.

Where a 'Low speed type' category parachute canopy is fitted to the Thinback pack and harness assembly, the resulting assembly must be identified as a Low Speed Parachute and is limited to use in airplanes under 150mph.

CONFIGURATIONS
The Thinback pack and harness assembly is manufactured in a range of configurations for various military and civil applications as follows:

T100 PARACHUTE, DESPATCHER, AUSTRALIAN ARMY, consisting of the following primary parts:

Despatcher Parachute T100-A

Thinback assembly

Activation and Deployment Sequence

Thinback Assembly material Specs

Test Standard

Configurations

Components and Materials

Operating Limitations

For more detailed information regarding the Thinback/Slimpack Emergency System please refer to the Thinback/Slimpack Manual .

Download/View Thinback Manual
in .pdf format.