Examples of quotes from debriefs with test site crews after a day of flying CNS tests and the corresponding topic category.
CNS 1 Information: Availability
18 I was watching on one USS, we had multiple USSs today executing
different lost-link things. I couldn’t tell when that happened at all, and I was kind of isolated, looking at when XXX’s stuff would go lost link, I’d have to listen on the radio to figure out when that even happened. So, there’s no information provided right now across USSs and, if we were operating in adjacent air spaces, it would be very valuable I think to share in some information.
Information meets user: Information desired or wanted
16 It should also broadcast the last known heading, altitude, and airspeed so you can take a guess that it is going in that direction and that is a place to avoid.
Operator experience:
Situation Awareness
12 You really only have to know – even if someone else is even having
trouble, you shouldn’t have to know about it unless it’s putting them in danger or affecting your airspace or where you’re operating.
Method: Procedures for flight/event
5 If you still have one link and are in control of your vehicle, and you’re going to stay in your own space, I don’t care, really. Someone cares, but it’s not me if I’m trying to operation my own mission and you’re not coming into my space.
Automation: Design of system
20 We were able to have a flight window open, execute the flight, and be
midway through the flight before the XX USS figured out that is what we are doing. And then the XX USS closed ours and we had no indication for why it closed. (This was during the first flight of CNS3 three minutes into the flight).
Concept: Privacy/ sharing
8 I’m comfortable with the notion of, if you lose one link, and your
secondary link doesn’t impair your mission at all, doesn’t put any other aircraft in harm’s way, and you’re confident in the robust, that it’s not going to impact anybody, I don’t know if you have to share that.
CNS 2 Information:
Reliability/ accuracy of information
11 … but the fact that the degraded GPS is difficult to get, should give him some, uh, mean doesn't provide certainty, but it should certainly give [NASA] some additional comfort in [the] CNS work that it's...not that you can't jam or anything, but GPS is a highly available and, and uh, is very reliable, you know, so much so that even putting a shroud around the antenna was not creating difficulty.
Information meets user: Accuracy of information
2 It's also important for a troubleshooting perspective to see if the number of satellites and the reported HDOP are incongruent. Like if I have high HDOP but I have 16 satellites, there may be something else going on.
Operator experience:
Situation Awareness
2 So in the event that I lose GPS, I have a general idea of where the aircraft is. Even though I may, it may take me a second to figure out what
orientation I'm in, uh, and I can take over the flight by a manual control and return it back to my position or if I feel that I am not comfortable with that, then I can actually have it lands where it is.
Method: Procedures for flight/event
4 … procedures that, that sometimes it's not clear why things are working
and why things aren't and we just have to, you know, reset them a number of times and, and everything... And eventually, eventually got it. Um, but you know, we're, we're learning …
Automation: Degradation
10 The biggest problem/fear is RF interferences that changes the flight pattern of the aircraft, could be GPS signal interference, C2 band interference, backup RC band interference, or overload on the onboard RF circuits.
CNS 3 Information: Usefulness of information
7 But the thing is that the interface doesn’t tell us why. It actually grays that button out with the alert icon in it. If it closes and tells us specifically why it closed you because of time conflict or altitude conflict, otherwise we are taking another shot in the dark.
Information meets user: Confidence in information
1 That’s probably my biggest concern of stuff we could be flying around –
power lines or large metal structures (inaudible) interference and you start kind of seeing it dance around up there. That makes me more nervous than if my video goes out or something like that.
Operator
experience: Lack of awareness
1 But for us we didn’t have any explanation in the USS interface for why it
got closed. They had to go on the back end and figure out why.
Method: Procedures for flight/event
4 So I was piloting the aircraft and basically just looking, watching the aircraft, I wasn’t paying a lot of attention to the ground control station. I had XX watching that for me and just kinda trusted him to tell me if anything was out of the ordinary or if everything was working like it was supposed to. I mean, it works fine for us because I can just keep my eyes on the aircraft and do it that way.
Automation: Functions
12 So, from the moment we send time and receive acknowledgment that loop
should be less than 3 seconds. If it exceeds that then there is something wrong there.
Concept: Design of system
2 Another USS was on our LUN, …. Multiple USS’s can be on that, but, we
just saw another USS that came onto our LUN that was pushing our band data, and it turned out it was rejecting your plan.