Short answer: These are the three temperature sensors to control the temperature of the heating film used for anti icing and defogging of the windscreen panels. Three sensors are already used on the A330 and A340.
From A-350 Technical Training Manual:
Windows Anti Icing/Defogging Function, Description and Interfaces
The windows anti icing/defogging system is divided into two
sub-systems (F/O and CAPT). Each sub-system is comprised of one
windshield, one FWD lateral window, one AFT lateral window and a
Window Heat Computer (WHC). [...]
The anti icing and defogging function of the cockpit
windshields is ensured by the heating of one resistive/heating ﬁlm. Each
windshield's resistive heating ﬁlm is powered by 230 VAC, provided by
There are three temperature sensors near the heating ﬁlm that
continually send information to the WHC for the heating regulation and
the overheat protection functions. [...]
The WHC regulates the temperature of the cockpit windows (35 degrees C
- 42 degrees C) based on the temperature value it receives from one of the three temperature sensors. The other two temperature sensors are
in standby mode. [...]
If the temperature of the cockpit windows reaches a specific
temperature level (+60 degrees C), the WHC will stop supplying the
specific window. [...] For each window, the WHC uses temperature
values from the three temperature sensors to detect an overheat.
The WHCs interface and exchange data via CRDCs with the
AFDX network.The two WHCs are located in the cockpit: WHC1 is located
next to the fourth occupant console behind the Captain. WHC2 is
located next to the coat stowage behind the First Ofﬁcer.
The strips visible on the image are likely the temperature sensors usually built-in the glass panels, albeit there are some differences for this flight test aircraft:
- They are larger than usual.
- As commented they may be sticked on the glass instead of being built-in.
- These sensors are usually resistive RTD. It seems here they are capacitive since the two electrodes in each pair are not connected together (1)(2).
This setting might be specific for flight test purposes. Someone may bring additional elements.
1: This would indicate more a fog sensor than a temperature sensor.
2: Another explanation is that the resistive patch has been removed, leaving only the electrodes.
An unlikely alternative is that we are viewing strain gauges to measure the windscreen panels distortion.
Similar sensors on a Pilatus PC12-NG: