STARCS Motorized Sting Arm 

STARCS designed and built the Motorized Sting Arm to be able to perform store release testing in our transonic wind tunnel T1500. However, the rig is mobile and can also be used in, for example, our low speed wind tunnel LT1 for purposes like measurement of
pressure in highly complex movement patterns and with high positioning accuracy. The rig control software has been developed in LabVIEW. The control system can be programmed to perform any required trajectory.

Store Release Simulation
When used as a store release rig, the rig is mounted to the sting pod and thus always has the same static angle of attack as the parent aircraft. The store separation rig corrects for deflections in both the parent aircraft and the separated store in real time. Measures have been taken to avoid collision between the parent aircraft and the store. When the store position in relation to the parent aircraft is calculated, the deflection in both the sting and balance of the parent aircraft as well as the deflection in the trajectory rig and its balance is considered.
Although the store is positioned close to the parent aircraft at the start of the trajectory it should not come in contact with the aircraft model, which could occur especially at high angles of attack due to model vibrations. If the store anyway comes in contact with the parent aircraft the control system will immediately detected this and withdraw the store. Data acquisition is continuous while the store performs a linear motion either in the x-direction of the aircraft (missile release) or the vertical direction of the wind tunnel (bomb release).

Technical Specification
The rig has six degrees of freedom and has been designed with a new working principle consisting of 1 translation and 5 rotations. It consists of one linear bearing and five rotating joints of which two are inclined 13° to the axial direction.
The axial stroke length of the two-sting rig is 750 mm and the maximum radius from the straight line is 350 mm with the store parallel with the sting pod.

Coordinates Travel Range Max. Speeds Verified Accuracy
x -125–625 100 mm/s 0.1 mm
y -99–601 mm 40 mm/s 0.3 mm
z -220–530 mm 40 mm/s 0.3 mm
q ±17.6° 5 °/s 0.05°
s ±17.6° 5 °/s 0.05°
j ±90° 10 °/s 0.1°

Design loads referred to the store balance:
Normal force:

300 N

Pitching moment:

10 Nm

Axial force:

50 N

Yawing moment:

10 Nm

Side force:

300 N

Rolling moment:

3 Nm


Main Features

STARCS Motorized Sting Arm is primarily intended for store release simulation but can also serve as a very flexible and accurate probe holder for pressure or flow field measurement. The rig is extremely rigid and can perform any trajectory even under extreme loads thanks to advanced deflection compensation.

Related Information

Inlet Aerodynamics

STARCS has a unique capacity of high flow rate air suction which can be used for simulation of air inlet specific phenomena.

T1500 - Transonic Wind Tunnel

T1500 is suited both for testing of high speed air- and spacecraft testing.
LT1 - STARCS Low Speed Wind Tunnel
STARCS low speed wind tunnel is a multipurpose aerodynamic wind tunnel, capable of testing not only all sorts of aircraft models but also almost any type of transportation, large buildings and wind turbines.