Originally Posted by
cncpc
I did an analysis of the critical heights in the Corey Pelton video. Altitude at top and altitude at eject. The methodology was to stop the video, take a screen capture. Put it into Photoshop.
The wingspan of the Tutor is 36 feet, and the length 32 feet. At the top, the wing is almost or is vertical. In the eject, the aircraft is almost vertical when the second eject still has smoke coming from the seat. Photoshop can measure in pixels. I measured the wing span in pixels, and calculated the number of pixels that represent a foot in that view. Same with the aircraft length. Less than two pixels, but appropriately different in the two shots. Then measure pixels from aircraft to ground.
The resultant calculation indicates 720 AGL for the almost knife edge part, and 280 for both seats out. I'm a little surprised at the 720, not the 280. Maybe a little more energy at the beginning of the problem? Not full power loss immediately. More speed at the start of the zoom. Ask to the guys that know.
Heres another way of looking at it:
A reasonable estimate of speed is , say, 120 knots based on the Jet Provost, a jet trainer not dissimilar to the Snowbird in terms of weight, thrust and performance.
The Jet was almost vertical at the time of ejections, so the ROD was about 200 FEET. feet per. second.
Ejections were close to 2 seconds before, not more than 3, before impact. I have no stopwatch handy but that seems reasonable watching the video.
Realistically that means ejection occurred at about 600 feet, perhaps lower, with a ROD of about 12000 fpm, Whichever way you look at this it was way outside the seat’s capability using the MB rule of thumb and that is no criticism of the Weber seat.