I did a quick pressure check on the attach system and there does appear to
be a leak. I’ll track it down later today and report back.
Bill
On Thu, Oct 21, 2021 at 8:12 AM William Claybaugh <wclaybaugh2@xxxxxxxxx>
wrote:
Rick, Troy:
There is a well known wind shear about 100-120 feet up at the MTA.
Apparently due to winds from the dry lake separating from the terrain as
they reach the top of the rise where the MTA is located.
However, that shear only occurs on windy days and pitches rockets on the
down range direction.
This pitch was in the opposite direction on a windless day.
After sleeping on it I’m increasingly thinking that Troy may be right:
venting of the pneumatic system could cause that sort of pitch change.
I’ll pressurize that system today and see if it leaks.
Bill
On Wed, Oct 20, 2021 at 8:37 PM Rick Maschek <dmarc-noreply@xxxxxxxxxxxxx>
wrote:
I have no idea 'why' but every year at 'HPR' events, I'll see a few solid
propellant rockets leave the rail straight and fast and about 50 to 100
feet above the launch rail take a quick change in direction and then again
proceed in a straight line nominal flight. I'll try to find some videos of
this phenomenon.
Rick
From: William Claybaugh <wclaybaugh2@xxxxxxxxx>
Date: Wed, 20 Oct 2021 15:04:27 -0600
Subject: [AR] Re: Test Launch
Looking at two videos I see the turn starting around 100-120 feet (based
on
the known 24 foot length of the launch tower). I counted 14 frames to
complete the turn. Given the trajectory, this implies the video was shot
at
60 frames/second and the turn took place in 0.25 seconds. (At Mach
0.38....)
The vehicle is flying straight and true up to the start of the turn, which
makes a stuck belly band questionable: why didn't it turn as soon as it
left the launcher if a belly band was adding drag to one side?
Conversely,
why did it stop turning if not because a stuck belly band coming off?
Similarly, if the sudden turn was due to an internal failure leading to an
off-axis mass asymmetry, why did it straighten out and fly true on the new
heading?
And then there is the telemetry LOS occurring at about the same altitude
as
the turn and the subsequent finding that the antenna had snapped off at
the
base. For now, I am tentatively assuming that was an effect of the sudden
very sharp turn but I'm open to other suggestions.
All thoughts are welcome....
Bill