Thunderbirds and Altimeters

"Dudley Henriques" wrote:

[snipped for brevity]

There's something about this report some of us don't quite get, and it
concerns the zero set on the altimeters. The TB fly a zero set altimeter for
a show. It's not only basic for low altitude acro work, but it's specified
in the regulations for the Thunderbird mission and procedures

What puzzles me isn't whether or not he zeroed the altimeter prior to
launch or was attempting to convert AGL elevations to MSL altitudes,
but rather why he failed to recognize via outside visual cues that he
was simply too low to the ground to even THINK about initiating a
Split-S maneuver.

Clearly, he knew that something was wrong early on since he reportedly
exerted "maximum back stick pressure and rolled slightly left to
ensure the aircraft would impact away from the crowd should he
have to eject." Despite his exceedingly close proximity to the ground
the fact that he managed to eject successfully is another indication
that he realized quite early on that he done screwed up!

If you look at the cockpit video it's obvious that his head is tilted
way back watching the horizon while he was inverted prior to initating
the Split-S. My primary question is why he didn't abort the Split-S
and simply continue the roll at the top of the maneuver and perform
an Immelmann instead of pressing on with the Split-S?

"Mike Marron" wrote in message
...
"Dudley Henriques" wrote:

[snipped for brevity]

There's something about this report some of us don't quite get, and it
concerns the zero set on the altimeters. The TB fly a zero set altimeter
for
a show. It's not only basic for low altitude acro work, but it's
specified
in the regulations for the Thunderbird mission and procedures

What puzzles me isn't whether or not he zeroed the altimeter prior to
launch or was attempting to convert AGL elevations to MSL altitudes,
but rather why he failed to recognize via outside visual cues that he
was simply too low to the ground to even THINK about initiating a
Split-S maneuver.

Clearly, he knew that something was wrong early on since he reportedly
exerted "maximum back stick pressure and rolled slightly left to
ensure the aircraft would impact away from the crowd should he
have to eject." Despite his exceedingly close proximity to the ground
the fact that he managed to eject successfully is another indication
that he realized quite early on that he done screwed up!

If you look at the cockpit video it's obvious that his head is tilted
way back watching the horizon while he was inverted prior to initating
the Split-S. My primary question is why he didn't abort the Split-S
and simply continue the roll at the top of the maneuver and perform
an Immelmann instead of pressing on with the Split-S?

This is our observation exactly! Pilots who survive low altitude demo work
are NOT one cue pilots, but respond to multiple cues, many peripheral. All
of us discussing this back channel are in complete agreement with your
observation about visual cues.
The g line required to put the Viper in reverse at 1600 was higher than that
which would have been normal. This should have been a physical cue. The
horizon is different at 1600 than at 2500. This is a visual cue.
The inverted ground area showing past the canopy bow edge is wider (more
detailed ground area meets the eye) at 1600 than at 2500. This is a
peripheral visual cue.
The inverted pull is escapable in roll until just before exact vertical. The
shortest way out using roll must allow for snatch factor and roll rate and
this occurs in an airplane with the Viper's roll capability in this maneuver
profile at just before 90 degrees nose down. From then on it's a straight
pull commit. The Viper can be flown into a pitch rate defeat on the limiter
and that's where he put it apparently. I make it a dead airplane from 90
degrees nose down in the pull and a dead pilot except for the seat
capability.
The altimeter reference however, remains a puzzle for us.
Dudley

"Mike Marron" wrote

My primary question is why he didn't abort the Split-S
and simply continue the roll at the top of the maneuver and perform
an Immelmann instead of pressing on with the Split-S?

He would have had to buy the first round at the club for missing the
maneuver, and everyone would have bought him a round if he somehow
pulled it out of his ***. Ah well, no one went to the club that day...

Video?? There's video and I missed it??? Drat! Anybody have a link to it?
Please? )
Steve R.


"Mike Marron" wrote in message
...
If you look at the cockpit video it's obvious that his head is tilted
way back watching the horizon while he was inverted prior to initating
the Split-S. My primary question is why he didn't abort the Split-S
and simply continue the roll at the top of the maneuver and perform
an Immelmann instead of pressing on with the Split-S?

"Steve R." wrote:
"Mike Marron" wrote:

If you look at the cockpit video it's obvious that his head is tilted
way back watching the horizon while he was inverted prior to initating
the Split-S. My primary question is why he didn't abort the Split-S
and simply continue the roll at the top of the maneuver and perform
an Immelmann instead of pressing on with the Split-S?

Video?? There's video and I missed it??? Drat! Anybody have a link to it?
Please? )
Steve R.

Subject: Thunderbird pilot found at fault in Mountain Home AFB crash
Newsgroups: rec.aviation.military
Date: 2004-01-25 22:59:09 PST

http://www.avweb.com/eletter/archive...ll.html#186582

Ummm.... nevermind. I saw the link later while i was reading a different
thread. Thanks though! )
Steve R.


"Mike Marron" wrote in message
...
"Dudley Henriques" wrote:

[snipped for brevity]

There's something about this report some of us don't quite get, and it
concerns the zero set on the altimeters. The TB fly a zero set altimeter
for
a show. It's not only basic for low altitude acro work, but it's
specified
in the regulations for the Thunderbird mission and procedures

What puzzles me isn't whether or not he zeroed the altimeter prior to
launch or was attempting to convert AGL elevations to MSL altitudes,
but rather why he failed to recognize via outside visual cues that he
was simply too low to the ground to even THINK about initiating a
Split-S maneuver.

Clearly, he knew that something was wrong early on since he reportedly
exerted "maximum back stick pressure and rolled slightly left to
ensure the aircraft would impact away from the crowd should he
have to eject." Despite his exceedingly close proximity to the ground
the fact that he managed to eject successfully is another indication
that he realized quite early on that he done screwed up!

If you look at the cockpit video it's obvious that his head is tilted
way back watching the horizon while he was inverted prior to initating
the Split-S. My primary question is why he didn't abort the Split-S
and simply continue the roll at the top of the maneuver and perform
an Immelmann instead of pressing on with the Split-S?