When loading the sondes before the flight today, I noticed there’s a significant difference in the texture of the tubes. Some of them are very smooth and polished, others are pretty rough. I have a log of which ones are smoother and which ones are rougher, to see if there’s any correlation to sondes ejecting cleanly.

During the flight, there were two sondes that failed while loading. They got stuck on the safety gate valve lip, so had to be pulled out. I talked to Dean, and only the Global Hawk version of AVAPS has a button to restart the sounding if this happens, so the only way to remedy this is to take the sonde out and put it into the launcher bin to be re-loaded. One of the sondes I pulled out fine and launched. The second sonde when I tried to pull it out of the launcher I popped the parachute instead.

On Sonde 21 (ID 183640239) the parachute popped in the launch tube. So there is no actual launch on this sounding. When I tried to launch the sonde nothing happened, so I went back and pulled it out. I’m not sure if the parachute popped prematurely or if it only happened at launch. Either way it stayed firmly in the launch tube even when the gate was open, and did not slide out at all. By the time I got the sonde out and another sonde loaded, it was time for the next drop anyway.

On the last sonde (190520083) the sonde appeared to die at launch. This may be the first failure we’ve seen due to the PTU module shorting out the pins. With the schedule so far, I haven’t been able to apply tape to any sondes. Now that it’s been an issue, I’ll see if there’s time to at least fix some of them tomorrow morning. Otherwise, Saturday’s maintenance day will probably be spent getting some sondes fixed. Back to back flights don’t allow much time to make changes between flights. We’re not allowed to bring the sondes out of the airport, so that means we can only mess with them on maintenance days.

4 Comments

  1. Jacquelyn Witte

    Hi Mack

    Raw data from RF07 are missing in the /net/ftp and /scr/tmp directories.

  2. Mack Goodstein AUTHOR

    Yeah, it seems that the NAS is still broken. I’m going to have to manually upload those files for now.

  3. Jacquelyn Witte

    Good to know! Thank you Mack.

  4. Holger Voemel

    Another idea for our launcher problems could be ice building up between the ejection gate vale and the end of the short tube going out of the aircraft. Each time we launch a sonde, we blow relatively moist air over a very cold piece of metal. Water vapor will condense and may slowly build up an ice layer in corners, where the crazy air flow cannot get rid of it. When the ejection gate valve opens the sondes may get stuck there. By the time you land all water is gone and everything is fine again. Can you discuss that with the mechanics to see, if that seems possible to them and if they have an idea how to reduce it? This may explain, why we did fine in CSET and Socrates, but seem to be suffering now.

       Could it be possible that ice even builds up on the inside of the ejection gate valve? That would give water vapor more time to condense and to form ice, if it is cold enough on that side of the valve.