In this paper we present the effects of Wi-Fi interference on a Wireless Sensor Network (WSN) in an aircraft. We use Time-Slotted Channel Hopping (IEEE 802.15.4e) as Link layer in the WSN network. We conduct measurements in an environment realistically representing an aircraft cabin. We provide the resulting application failure and packet drop rates with and without interference, for an exemplary deadline critical application. In order to outline the importance of hopping against interference in a controlled environment, we compare the results of individual channels, full channel hopping and clear channel hopping, where the TSCH only hops over channels free from WiFi interference. Results open further discussions for more sophisticated Link layer implementations resulting in increased reliability such as optimization of frequency allocation depending on the application deadline.