Originally Posted by
PineappleFrenzy
I too heard nothing notable in the video shot from the south. The video with the audible pop was taken from the north side of the runway (left side of runway, from A/C perspective). At the nine second mark, an audible pop or crack is evident. Attached is a screenshot of the waveform. The pop occurs at 09.24 seconds, after which the recording device's automatic gain control (volume limiter) compensates for the noise (the waveform shrinks instantaneously, and gradually grows again for a half second or so). Something loud definitely occurred at around 09.24 seconds. Below the waveform image is a spectrograph of a three second portion of the audio (8.00 to 11.00 seconds). That image shows two anomalies: one, just before the 1 second mark, and another at about the 1.2-1.3 second mark (8.9 and 9.2-3 seconds according to the video timecode). Upon listening, I could detect no audible anomaly before the 9 second mark. So the spectrograph doesn't tell the whole story I'm afraid.
Waveform of audible anomaly detected in video of Kamloops CT-114 crash.
Spectrograph of audible anomaly detected in video of Kamloops CT-114 crash. Covers a three second portion of the video's audio track (8.00 - 11.00 seconds).
That video came out in the first hour after the crash. I think you can only hear the pop in the Cory Pelton video, the one in which the aircraft pass abeam in the air. I'd seen a bird cross during the takeoff roll and I played it back to listen for a bird strike. When you're looking for the unusual, it does stand out, and is immediately before the zoom starts. To me, it sounded like it might be a vehicle door closing. I asked Cory iif it could have been a car door and he said no. He said everybody was already out of their vehicles and waiting to watch the takeoff at the time. He saw no birds before or after. Thanks for the audio work.