Well, for those of you following what I've been learning about the Mountain
Home Viper crash, here's the latest update.
I just received an e-mail from a friend.....an ex Thunderbird lead. He tells
me that his team used the MSL settings for their shows and NOT the zero set
altimeter. He also supplied a very accurate set of figures that would
indicate the present team is also using MSL settings locally. I was under
the impression that the team was using a zero set altimeter and this might
not be true. I'm awaiting confirmation on this now. There seems to be a bit
of confusion between teams on the zero set issue, and it will be interesting
to see if it has indeed changed from team to team.
In a letter from a recent team member and Viper driver in answer to my
question about the zero set, he replied,

"However, to answer your question.....Zero altimeter. Indeed, it's in the
regulation".

Now one of the ex team leads has replied that he used the MSL settings. It's
still a puzzle, but I'm working on it!!! :-))
Anyway, here's the math for the Mountain Home accident.

From the ex-team leader;
"What appears to have happened in this case is that the pilot forgot where
he was, so to speak. The pilot shoots for 2500' AGL minimum to commence the
split "S." Mt. Home being at 2996' MSL, 3000' (rounded) + 2500' AGL (Target
alt) = 5500' on the Altimeter to commence the maneuver.
"The accident report said he was only at 1670' AGL instead of 2500. So, if
you add 1670' to 2996' you get 4666ft indicated when he rolled inverted.
Subtract 2500' from that and you get 2166', which is, if I recall, the
approximate Field elevation of Indian Springs, where the team practices.
The 800' too low differential was more than even the mighty F-16 could
accommodate".

It's getting clearer by the minute!!!
Dudley Henriques
International Fighter Pilots Fellowship
Commercial Pilot/ CFI Retired
For personal email, please replace
the z's with e's.
dhenriquesATzarthlinkDOTnzt