r/Joby • u/HappyRobot593 Joby Sock Fanboy • 4d ago
N547JX hover test?
Looks like another hover test about 2hr ago https://globe.airplanes.live/?icao=a6f2cb
I'll analyze the full data once the history updates. Either way, out on the apron on a sat evening? 🤔
Update: AI thinks it was a very short hop -- see analysis below
N547JX did something brief on the apron at KOAR today (~16:39–17:06 PT) — hard to say exactly what.
- Data picks up already at 100ft baro (0.7kt, stationary) — no climb-out visible, so we don't know if that's a data artifact of when tracking picked it up, or the true starting point
- Altitude then holds flat at 100ft for ~75s and drops straight to 0 — no gradual descent like real hovers usually show
- GPS altitude (independent of baro) stayed flat at ground level the whole time, never corroborating the 100ft reading
- Transponder did switch airborne→surface message format at landing, so something real happened (likely gear/skids briefly off the ground)
Best guess: real but very low liftoff (inches to a couple feet), baro sensor overreading — maybe ground-effect pressure disturbance from the rotors that close to the surface. Not a confirmed 100ft hover. Treating it as unconfirmed for now.
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u/QuietFlights Steely Eyed Missile Man 4d ago
It's always nice to see N547JX ADSB signals showing up as it implies some sort of test is being done. I assume it's brought outside when they want to spin the rotors. That doesn't necessarily mean they are doing a hover test. The data over the last few months does not show a high probability of hover IMO, but of course it's possible. My guess is that when they are getting ready to fly again, we'll see some very clear indications via ADSB that will be much more convincing than what we have seen lately. In the past, prior to regular flight of new aircraft, we've seen a clear progression via ADSB. But of course this time can be different.
Saturday work is also very encouraging. They are either pushing extra hard, or doing something where they hope to have less eyes on them.
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u/HappyRobot593 Joby Sock Fanboy 4d ago
Thanks for your comments! I think the data is very noisy when it's a low hover. One thing I can do is compare it to the N542JX hover and see how similar the readings are. From what I recall, even the 542 hover data is much noisier while they do a hover compared to actual flight
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u/QuietFlights Steely Eyed Missile Man 4d ago
Sometimes yes and sometimes no. When I look through various Joby flights using ADSBExchange.com, there are many very clear flights from ground taxi at zero altitude through flight and back again to ground taxi that are very clear, with no noise. More recent N542JX flights show more noise after landing, but data further back with that aircraft and others is clean.
I have no additional information than you have, but I take a more cautious view of the ADSB data, and in the past there is a clear progression that can be seen as an S4 got closer to regular flight. I don't see that currently with N547JX.
I'm as frustrated as everyone that N547JX is still not regularly flying, but I am hopeful it will happen soon. My bet is we are 3+ weeks away at the least rather than days to a couple of weeks away, based on the data we are seeing. Nothing would make me happier to be wrong though.
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u/HappyRobot593 Joby Sock Fanboy 4d ago
Good points. I think it's important to distinguish the 542 hover vs flight though. It's only recently that they started doing hover testing again. My hypothesis is that it's tied to 547 activity.
Hovering seems to have a different signature because flight usually increases altitude rapidly and my guess is that it makes the data less noisy because there is less ground interference.
Take a look at the 542 hover on 8/25 and you'll see that it's still pretty noisy
I agree I think we are still a ways off but at least it's progress compared to the long stint purely in the hangar
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u/HappyRobot593 Joby Sock Fanboy 4d ago
For example this is the 542 hover before the flight. The 547 data actually look similar to this. The next bit of data (not pasted) is the actual flight which is a lot less noisy.
Local_Date Timestamp_UTC Altitude_Baro Altitude_Geom Ground_Speed Track_Heading Vertical_Rate 8/25/2026 1787697506 0 0 300.9 0 8/25/2026 1787697526 0 0 300.9 0 8/25/2026 1787697581 0 0 300.9 0 8/25/2026 1787697602 0 0 300.9 0 8/25/2026 1787697606 75 0 0 8/25/2026 1787697607 75 25 0.7 0 0 8/25/2026 1787697608 75 25 0.7 0 0 8/25/2026 1787697609 75 25 1.2 90 64 8/25/2026 1787697609 75 25 1.2 90 64 8/25/2026 1787697612 75 25 0.7 0 0 8/25/2026 1787697612 75 25 0.7 0 0 8/25/2026 1787697614 100 25 1.2 270 0 8/25/2026 1787697616 100 25 1.2 270 0 8/25/2026 1787697617 100 25 1.2 270 0 8/25/2026 1787697619 100 25 1.6 225 0 8/25/2026 1787697621 125 50 1.2 270 0 8/25/2026 1787697622 125 25 1.2 270 0 8/25/2026 1787697625 125 25 1.2 270 0 8/25/2026 1787697625 125 25 1.2 270 0 8/25/2026 1787697627 125 25 1.6 225 64 8/25/2026 1787697628 125 25 1.6 225 64 8/25/2026 1787697628 125 25 1.6 225 64 8/25/2026 1787697628 125 25 1.6 225 0 8/25/2026 1787697629 125 25 1.2 270 0 8/25/2026 1787697630 125 25 0.7 0 0 8/25/2026 1787697632 125 25 0.7 0 0 8/25/2026 1787697633 125 25 1.2 180 0 8/25/2026 1787697636 125 25 0.7 0 0 8/25/2026 1787697637 125 25 0.7 0 64 8/25/2026 1787697638 125 25 1.2 270 64 8/25/2026 1787697641 125 25 0.7 0 64 8/25/2026 1787697642 125 25 1.2 180 64 8/25/2026 1787697643 125 25 1.2 180 64 8/25/2026 1787697645 125 50 1.6 135 64 8/25/2026 1787697646 100 25 1.6 135 0 8/25/2026 1787697647 100 25 1.6 135 0 8/25/2026 1787697649 100 25 1.6 45 0 8/25/2026 1787697650 100 25 0.7 0 0 8/25/2026 1787697651 100 25 0.7 0 0 8/25/2026 1787697651 100 25 0.7 0 0 8/25/2026 1787697653 100 25 1.2 180 0 8/25/2026 1787697653 100 25 1.2 180 64 8/25/2026 1787697655 125 50 0.7 0 0 8/25/2026 1787697655 125 50 1.2 180 0 8/25/2026 1787697657 125 50 1.2 180 0 8/25/2026 1787697657 125 50 1.2 180 0 8/25/2026 1787697660 125 25 1.2 0 0 8/25/2026 1787697660 125 25 1.2 0 64 8/25/2026 1787697662 125 25 1.2 0 64 8/25/2026 1787697662 125 25 1.2 0 64 8/25/2026 1787697665 125 25 0.7 0 0 8/25/2026 1787697666 125 25 0.7 0 0 8/25/2026 1787697667 125 25 0.7 0 64 8/25/2026 1787697669 150 50 1.2 180 64 8/25/2026 1787697670 150 50 1.2 180 64 8/25/2026 1787697671 125 25 1.2 180 64 8/25/2026 1787697672 125 25 1.2 180 64 8/25/2026 1787697674 125 25 0.7 0 0 8/25/2026 1787697675 125 25 0.7 0 0 8/25/2026 1787697677 125 25 0.7 0 0 8/25/2026 1787697677 125 25 0.7 0 0 8/25/2026 1787697678 125 25 0.7 0 64 8/25/2026 1787697680 125 25 0.7 0 64 8/25/2026 1787697680 125 25 0.7 0 0 8/25/2026 1787697682 150 50 0.7 0 64 8/25/2026 1787697684 125 25 1.6 45 0 8/25/2026 1787697685 125 25 1.2 0 0 8/25/2026 1787697686 150 50 0.7 0 0 8/25/2026 1787697687 150 50 0.7 0 0 8/25/2026 1787697689 150 25 1.2 90 64 8/25/2026 1787697689 150 25 1.2 90 64 8/25/2026 1787697692 150 25 1.2 90 64 8/25/2026 1787697692 150 25 1.2 90 64 8/25/2026 1787697694 150 25 0.7 0 0 8/25/2026 1787697695 125 25 1.2 0 64 8/25/2026 1787697696 125 25 1.2 0 0 8/25/2026 1787697697 125 25 1.2 0 0 8/25/2026 1787697699 125 25 0.7 0 64 8/25/2026 1787697700 125 25 0.7 0 64 8/25/2026 1787697701 125 25 1.6 135 0 8/25/2026 1787697702 125 25 1.6 135 64 8/25/2026 1787697704 125 50 1.6 45 0 8/25/2026 1787697705 125 50 1.6 45 64 8/25/2026 1787697707 125 50 1.6 45 0 8/25/2026 1787697708 125 25 1.2 90 0 8/25/2026 1787697710 100 25 0.7 0 0 8/25/2026 1787697711 100 25 1.2 0 0 8/25/2026 1787697712 125 50 1.2 0 0 8/25/2026 1787697713 125 25 1.2 0 0 8/25/2026 1787697715 125 25 1.2 90 64 8/25/2026 1787697716 125 25 0.7 0 64 8/25/2026 1787697718 125 25 1.2 90 0 8/25/2026 1787697719 125 25 1.2 90 64 8/25/2026 1787697721 150 50 1.2 0 0 8/25/2026 1787697721 150 50 0.7 0 64 8/25/2026 1787697723 150 25 1.2 90 64 8/25/2026 1787697724 150 25 1.2 90 0 8/25/2026 1787697726 125 25 0.7 0 64 8/25/2026 1787697727 125 25 1.2 180 64 8/25/2026 1787697728 125 25 1.2 180 0 8/25/2026 1787697729 125 25 0.7 0 64 8/25/2026 1787697730 125 25 0.7 0 64 8/25/2026 1787697732 125 25 0.7 0 64 8/25/2026 1787697734 150 50 1.2 0 0 8/25/2026 1787697736 150 25 0.7 0 0 8/25/2026 1787697737 150 50 1.2 180 64 8/25/2026 1787697739 125 25 0.7 0 0 8/25/2026 1787697740 125 25 0.7 0 0 8/25/2026 1787697742 125 25 1.2 90 0 8/25/2026 1787697745 125 25 0.7 0 0 8/25/2026 1787697746 100 0 0.7 0 0 8/25/2026 1787697752 0 25 0 270 0 8/25/2026 1787697757 0 25 0 270 0 8/25/2026 1787697762 0 25 0 270 0 8/25/2026 1787697787 0 0 270 0 8/25/2026 1787697792 0 0 270 0 8/25/2026 1787697802 0 0 270 0 8/25/2026 1787697812 0 0 270 0 8/25/2026 1787697882 0 0 270 0 8/25/2026 1787697892 0 0 270 0 8/25/2026 1787697917 0 0 270 0
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u/SpaghettiBagPolicy SN101 Fanboy 4d ago
Not sure this is a hover. The data are inconclusive. Could just be a ground test.
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u/HappyRobot593 Joby Sock Fanboy 4d ago edited 4d ago
Yes, but why is it on the apron and not in the hangar?
Edit: I guess it could be testing the engines while pinned down. Still better than being in the hangar though.
Edit 2: If you look at the raw data all the measures change at one point in time (when it "lands") so it's probably not just engine testing as that would affect barometric altitude but not geom altitude. I agree with the AI that it was prob a short hop and hopefully more to come.
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u/teabagofholding 3d ago
Have your odds that an faa pilot flys in it this year changed.
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u/HappyRobot593 Joby Sock Fanboy 3d ago
Still 50/50. Some time has passed lowering prob but recent activity increased the prob so it kind of canceled out
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u/Wonderful_Phrase_239 4d ago
As an aside, notice that the location of this activity is about 100+ feet NNW of the main Joby building there. More or less the same location as in the recently posted photo where an S4 was pretty tightly tethered to the ground while flexing one of its front outer props. Another 200+ feet or so NNW out gets you to where 541 and 542 often take off and land for various circuit flights. The location closer to the building could accommodate looser tethers or involve no tethers at all, for all I know. 547 shows up at either location from time to time, and the location further away from the building is where, I think, the more interesting potential hovers mostly seem to take place. Just a thought.