All Notes (23)
Fin not working while drifting and post-recovery. That puts fin failure around when stuck under ledge. This was less than 24 hours from initial leak detection.
Fin was reading 0.0 but would not move and was taken out of service.
RU25d was rescued by Nicole and co. via zodiac just a couple minutes ago!
After getting stuck under a ledge and/or iceberg, blowing its weight and
drifting for the last 2 days towards islands and water too shallow for
the ship, it is now safely onboard the zodiac.
Nice work Nicole and Osc!
26 degree upslope did this glider in 11 rise, 23 run
glider hit bottom, got stuck surface behavior kicked in. won't retry yo's. yo behavior looks like its trying to take control but cant/doesnt. So it continues to climb. Eventually aborts and weight drop
Glider got stuck on bottom and shot its weight. Bottom angle from altimeter data was 30 degrees. We were inflecting 30 m off bottom.
Of course the sea mount can't rise forever but eventually 30 and 26 have colliding paths.
New protocol needed for Antarctic gliders, maybe steeper climb angles.
ru25 drifting since weight likely gone and fin is no longer working. Not sure if fin not working is related to being stuck or not or if digifin leak got bad enough. Fin stuck at ~0 and wont move without the following:
49653 51 DRIVER_WARNING:digifin:-1:digifin_v2_ctrl() Digifin movement
Digifin busy too long!!!
Double digifin leakdetect abort. Grabbed MLG for second abort. Around 380 m digifin ld dropped from 1022 to 475 instantly. It held there and cleared by the time it got to surface.
Lowered threshold to 250.
Fixed depth to 400 m max.
25 and 26 have pitch oddities and some warnings... should check post-deployment
tbdlist changed to every other yo to save time on surface during run into Rothera.
CTD I think is SN 194, should verify via u4stalk. I think the checkout sheet had it wrong as 196
Aft: 5 * (6x3); 1 * (5x3)
Pitch: 4 * (6x3); 2 * (5x3)
--> 69 strings
69 * 5.5 Ah = 380 AH * .985 (SD) * .95 (1st falloff) =
!!! 355 total AH !!!!
Voltage dropping to about 8.5 - 9 V on pumps. Abort was for glider abandoning the climb, appears to have gotten stuck on the ascent on bottom? and then the 2nd pump caused an abort.
Abort segment was ru25d-2017-355-3-129 (0129.0129)
Downloaded the MBD and MLG from the segment.
Lowered abort threshold to 8.5 V
Lowered speeds of glider to -230/+170 cc
Pump oddities building looks like some slosh, should get pump serviced after this prob needs new valve since rest was serviced.
u_reqd_depth_at_surface 4.5 (via script)
bpump to 310 on climbs
shallower route than I thought, treble yo's and 6 hour no comms
Looked at old plot. Bpump switching on next surfacing. Full throw dive, 330 climb
bpump back to -345 cc on dive
Also slowing dive down a bit. -330 bpump.
600 m ok; Not reaching 750 yet, but going for full depth yo on next surfacing. No comms triggered last surfacing; picked up new surfac this time so good to go. Single yo for now; will switch to doubles in shallower water.
3.5 hr nocomms on next surfacing to account for full depth
500 m ok; stepping down to 750.
tbd knocked back from 12 to 16 second sampling; matches 26, but may need to be further decimated.
Deployed by Schuyler Nardelli & crew off Palmer Station. Mechanics look fine, but no altimetry yet; stepping down gently to test. If ok, off to Rothera.
Database configuration incorrect.
After leak in Antarctica entire glider was sent to Webb on 4/30/10. Webb is going to investigate CTD leak as well as retrofit the glider with new pump and digifin. All repairs should be covered under warranty.