Pyrotechnical thrustor PL 81


In flight vibratory analysis of aircraft structures , carried out by means of impulse excitation applied through thrustors , offers positive advantages compared with other processes :
         * Reduced testing time
         * Small size
         * Simple application

The PL 81 thrustor is a new model of simple design and of reliable and reproductible operation, allowing the synchronization of several thrustors controlled simultaneously.

It is composed of a rectangular bar made of a block of hollowed-out aluminium , equipped at one end with the firing relay (black powder plus firing tube) , and at the other end with the ejection nozzle for the gases , mounted perpendicular to the top face , including its security device.

The principal charge consists of propergol strips whose lenght and thickness are calculated to suit the desired force and combustion time.

The thrust time curve is similar to a "square wave" impulse.

The PL 81 thrustor meets the standard operating specifications and the particular ambient conditions for in-flight tests (temperature vibration , shock , pressure , etc...).


  PL 81 I PL 81 II
Conventional thrust

600 N

200 N


0.5 g black powder
8 g propergol
0.25 black powder
3 g propergol
Conventional combustion time, depending on the thickness of the propergol strips

Type D 12 ms
Type C 18 ms
Type B 22 ms
Type A 26 ms

Dispersion over firing period

4 ms

Frequency range depending on the thickness of the propergol strips

Type D 30 - 70 Hz
Type C 20 - 50 Hz
Type B 10 - 40 Hz
Type A   5 - 30 Hz

Ohmic resistance

2 0,4 Ohm

Minimum operating intensity

0.35 A

Recommended ignition intensity

> 2.5 A

Safety and measurement intensity

< 0.05 A


200 grams

125 grams

Overall dimensions (mm)
(delivered with cable 50 cm)

137 x 23 x 25

78 x 23 x 25

Fixing points

4 holes M4 diameter, hole spacings
114 mm x 20 mm

4 holes M4 diameter, hole spacings
60 x 20 mm

Operating and storage temperature

From - 40 C to + 70 C

Flash point

140 C

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