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The image is extracted from this video (at 3m40s, when taking off)enter image description here

I circled in purple the strange pattern formed by few black straight lines. I'm quite puzzled as I have no idea of what it is or what purpose it can serve.

EDIT: I would like to sum up the ideas in comments as there is interesting guess and discussions in the comments. It is a strange device which can be:

  • a kind of gauge usefull as the windscreen seems to be a completely new one and the aircraft presented is one of the test aircraft
  • part of some windscreen heating device
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    $\begingroup$ looks like electric windscreen heat to me, but I'll defer to someone with specific systems knowledge of this airplane. $\endgroup$ – casey Aug 25 '15 at 13:46
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    $\begingroup$ @ManuH It doesn't need to cover more area. I don't know the a350 but it is almost identical to other screen heaters I've seen. Those things get really hot, they will burn you hand, and the windscreen only needs to be a little above freezing. $\endgroup$ – Simon Aug 25 '15 at 17:58
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    $\begingroup$ @Simon Ah, so you don't need to be an SR-71 pilot to be able to warm your lunch on the windshield! (As long as you choose the right part of it.) $\endgroup$ – David Richerby Aug 25 '15 at 19:15
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    $\begingroup$ Darn, I was really hoping it was the cockpit glass detonation cord for the A350 ejection seat. :-) $\endgroup$ – RoboKaren Aug 26 '15 at 3:07
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    $\begingroup$ @casey I agree with you. They are not heating elements as some others have suggested, but rather an electrical bus which provides electricity to a conductive windshield which heats the entire thing. I'm not familiar with the specific aircraft, but there are three sets, which probably are for something like high, low, and emergency settings for the windshield heat. $\endgroup$ – Lnafziger Aug 27 '15 at 3:17
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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:

enter image description here

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 the WHC.

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:

enter image description here

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