Bill,
Looking at one of Ed’s frame grabs, it looks like the airframe is not entirely
straight at that moment (of the turn). That could be an optical illusion of the
different colour sections though as the bend seems to occur where the shades
transition?
Troy
From: arocket-bounce@xxxxxxxxxxxxx [mailto:arocket-bounce@xxxxxxxxxxxxx] On ;
Behalf Of William Claybaugh
Sent: Thursday, 21 October 2021 8:04 AM
To: arocket@xxxxxxxxxxxxx
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
On Tue, Oct 19, 2021 at 6:13 AM William Claybaugh <wclaybaugh2@xxxxxxxxx
<mailto:wclaybaugh2@xxxxxxxxx> > wrote:
Troy:
Antenna was mounted vertically and internally.
Bill
On Mon, Oct 18, 2021 at 8:03 PM Troy Prideaux <troy@xxxxxxxxxxxxxxxxxxxxx
<mailto:troy@xxxxxxxxxxxxxxxxxxxxx> > wrote:
Yeah, you’re most likely correct Ken. We mount all our antennas internally, so
it that didn’t occur to me, but Bill might be constrained to mount his
externally with a metal airframe or surrounding structure.
Troy
From: arocket-bounce@xxxxxxxxxxxxx <mailto:arocket-bounce@xxxxxxxxxxxxx>
[mailto:arocket-bounce@xxxxxxxxxxxxx ;<mailto:arocket-bounce@xxxxxxxxxxxxx> ] On
Behalf Of roxanna Mason
Sent: Tuesday, 19 October 2021 12:31 PM
To: arocket@xxxxxxxxxxxxx <mailto:arocket@xxxxxxxxxxxxx>
Subject: [AR] Re: Test Launch
Sounds like damage from the launcher,
Ken
On Mon, Oct 18, 2021 at 6:15 PM Troy Prideaux <troy@xxxxxxxxxxxxxxxxxxxxx
<mailto:troy@xxxxxxxxxxxxxxxxxxxxx> > wrote:
Bill,
Any ideas why the antenna snapped off? Was it in the same area at the chute and
shock cords? Any photos to share?
Troy
From: arocket-bounce@xxxxxxxxxxxxx <mailto:arocket-bounce@xxxxxxxxxxxxx>
[mailto:arocket-bounce@xxxxxxxxxxxxx ;<mailto:arocket-bounce@xxxxxxxxxxxxx> ] On
Behalf Of William Claybaugh
Sent: Tuesday, 19 October 2021 11:32 AM
To: arocket@xxxxxxxxxxxxx <mailto:arocket@xxxxxxxxxxxxx>
Subject: [AR] Test Launch
Launched a 6” rocket at the MTA this weekend.
The rocket part worked fine: clean ignition, full 8 second burn. Bellybands
worked and separated as planned.
The payload had multiple failures: telemetry stopped at 119 feet and 425 ft/
sec when the antenna snapped off at the base. About the same time the payload
separated from the rocket. (The two may well be related.) Payload was
recovered and I will download the data for review when I get home.
The bellybands were pretty chewed up by the ride up the rail. The fins clearly
tore into the bottom band on ignition (bands were 0.020” 2024-T3). A redesign
with stronger bands appears a good idea.
Bill