On June 12, 2025, one of the worst aviation accidents took place in Ahmedabad, India, where seconds after being airborne, the AI 171, a Boeing B787-B8 Dreamliner aircraft crashed into a building. All 241 passengers died in the crash except for one passenger who miraculously walked away from the burning debris. 

As fate would have it, a teenager casually recorded a video of the AI 171 gliding down at a rather low altitude, little knowing that it was headed for a deadly crash. From this casual video, or more precisely the AI 171's audio record, spectrograms were derived. From side- by- side comparison of spectrograms showing engine orders of a reference Dreamliner aircraft and the AI 171, I've been able to detect the latter's engines failing during the glide. The video below gives a full narration of the process and findings.

On July 12, 2025, the Ministry of Civil Aviation, Govt. of India, released a preliminary report on crash of the AI 171. Investigation was done by the Aircraft Accident Investigation Bureau (AAIB). According to the report, the left and right fuel control switches were both recorded as having transitioned from Run to Cutoff, within a time interval of just 1 sec. 

Through qualitative reasoning founded on mechanics, snap- thru instability and participation of a 'Bounce' mode of the switch head, I've almost certainly established that the transition was caused under adverse vibration arising from engines thrust larger than derated. The video below is a narration of the reasoning, conclusions and recommendations.

On Apr 10, 2025, a Bell 206L-4 Longranger helicopter broke up over the Hudson river, NY, in its very last minute of flight. This was another bad accident, fatal to all five passengers and the lone pilot. 

Using video and acoustic data extracted from a publicly available footage of the accident, I could identify that a very sharp yaw of nearly 90 deg occurred in just 0.4 secs. Complementing this yaw, an acoustic data scalogram reveals a pair of distinct high frequency 'bangs', each lasting a few milliseconds during this brief interval of 0.4 secs. These bangs, in 1500- 3000 Hz, are characteristic of structural failures in the tailboom.

For full details of the above analyses and results, below is a link to my video.

Scalograms are to signal processing as microscopes are to a laboratory. In this second video on the Bell 206L-4 breakup, scalograms show the tail rotor blade passing frequency of 85 Hz 'climbing' to the next order of 170 Hz, in just milliseconds. This near- instantaneous climb would be expected in the event of a rotor seizure, from a jammed transmission as was reasoned in my last video on this incident.

The video here explains!