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  1. 7Aug19
    RF01

    Flight tech: Kyle

    Takeoff: 12:24
    Landing: 17:44

    During initial startup, had to recycle LWOO 2D probe for proper end diode voltages.

    12:32 RWO DSM reboot. Unknown reason.

    During initial accent. Straightened out some headset issues.

    Lost VCSEL dew point at 12:40. ACGAIN never at zero. Rebooted at 13:01. Possibly iced over. Did not see RICE go off but lots of 2D and CDP concentrations at that time. VCSEL dew point back at 13:04.

    We went through some clouds with moisture at approx 12:42ish which lasted about 5 to 6 minutes. Sharp decline in ADIFR around 12:44. NAN at 12:53. Most likely frozen. QCR had issues at this time and appears to have recovered around 12:54. QCTF was affected as well and recovered around 13:21. All this started at approx 28000 feet with temps around -25c.

    Lost satcom at 13:31. Came back 13:34.

    RICE should have reacted during that accent. Rebooted RWO at 14:03 with the hopes that RICE would get fixed but no success. I suspect a cabling issue.

    ADIFR came back at 16:00.

  2. Noise I gather?  Spowart back in the day had us increase the wire AWG size on the grounds. 

  3. Unknown User (abailey)

    Many of the instruments seemed to "hiccup" around 13:00, through what appears a first pass through a very cold big cloud. Can the field crew confirm? The biggest problem from the perspective of winds is that we lost ADIFR for about 3 hours! As a result, we have no estimates of vertical wind during this period (both variables WIY and WIC are affected). Around 16:00, ADIFR appeared to recover, and the WIY estimate of winds looks good thereafter.

    I'm trying to understand, why was ADIFR affected so much longer than any of the other measurements?

    Is there water residue in the drainage lines? It would be good to check the radome before RF02.

    Is the science crew targeting cloud passes early in the flight on purpose? Or are these simply unavoidable? 

  4. To comment on your post Adriana, no, science crew was not interested in the cloud pass.  This is an example of a project when we go high and stay high while passing through enough moisture to fill the ADIFR and QCR radome holes.  This is not ideal unfortunately.  If we had done a low dip enough to melt the ice, this would have been cleared.  Sometimes enough sunshine will eventually clear the ice which was this case.  We plan on blowing out the radome holes for this particular issue.  

  5. Unknown User (abailey)

    Okay, great! Jorgen mentioned that this happened in DEEPWAVE and that blowing out the lines was key. I didn't realize that. Thanks for being on top of it!

  6. Unknown User (abailey)

    A heads up to anyone monitoring winds in upcoming flights: WIC and soon WIY will be both coded so that they use a constant "backup" ATTACK value if there are missing data. So you may not see a radome blockage by looking at vertical winds or the ATTACK variable. Try looking at ADIFR and BDIFR directly, since these are the actual pressure differences measured across the radome. QCR is also obviously a good indicator but it is a little less critical, because we use QCF for the dynamic pressure in all our wind calculations.