Airspeed v Ground Speed
Discussion
I'm sure the physics makes sense but this is mad to watch 
https://x.com/OnDisasters/status/19487806594151346...
https://x.com/OnDisasters/status/19487806594151346...
Years ago we had a microlight (a mighty Thruster TST) which would do about 50mph flat out. A few times we found ourselves hovering or even with a negative ground speed!
A strong head or tail wind will not change the rate of climb (i.e. fpm), but will change the climb angle. There is something not right about that video as the Airbus is barely climbing either. Any context?
A strong head or tail wind will not change the rate of climb (i.e. fpm), but will change the climb angle. There is something not right about that video as the Airbus is barely climbing either. Any context?
I suspect that video has been tweaked, not exactly a tricky edit.
Makes no sense to get airborne then not climb as thats not how it would work, also a good trick to be able to get airborne then suddenly have sustained wind with the perfect direction and speed to achieve zero groundspeed and zero drift.
Makes no sense to get airborne then not climb as thats not how it would work, also a good trick to be able to get airborne then suddenly have sustained wind with the perfect direction and speed to achieve zero groundspeed and zero drift.
That's at the Farnborough Airshow. I can tell because:
A. Its raining.
B. I worked there (RAE Farnborough) for ten years and that's 'A Shed' in the background, in front of which the Red Arrows would usually park.
C. (Edit) A quick Google says its the 1994 show.
This A330 will be with the absolute safe minimum of fuel in it, probably only two crew and nothing in the hold. As such its stalling speed will be very low, allowing the pilots to demonstrate the aircraft's low speed handling. Also bear in mind that at high angles of attack, the engines' thrust contributes to the lift. It was probably very windy as well, so the aircraft has sufficient airspeed although its ground speed is low. The final factor is the sheer length of the A330. Because it takes longer to cover its own length, it appears slower.
On the subject of airspeed/groundspeed, a few days ago one of my model clubmates let me fly his radio controlled Hobbyking Paramotor. This thing flies slow slowly, that the only way I could get it back upwind in the breeze we had, was to fly it a few inches above the top of the long grass, right at the bottom of the wind gradient, so it could actually make headway.
A. Its raining.
B. I worked there (RAE Farnborough) for ten years and that's 'A Shed' in the background, in front of which the Red Arrows would usually park.
C. (Edit) A quick Google says its the 1994 show.
This A330 will be with the absolute safe minimum of fuel in it, probably only two crew and nothing in the hold. As such its stalling speed will be very low, allowing the pilots to demonstrate the aircraft's low speed handling. Also bear in mind that at high angles of attack, the engines' thrust contributes to the lift. It was probably very windy as well, so the aircraft has sufficient airspeed although its ground speed is low. The final factor is the sheer length of the A330. Because it takes longer to cover its own length, it appears slower.
On the subject of airspeed/groundspeed, a few days ago one of my model clubmates let me fly his radio controlled Hobbyking Paramotor. This thing flies slow slowly, that the only way I could get it back upwind in the breeze we had, was to fly it a few inches above the top of the long grass, right at the bottom of the wind gradient, so it could actually make headway.
Edited by GliderRider on Sunday 27th July 10:57
b
hstewie said:
hstewie said: So I'm confused now.
Have I been rinsed by some dodgy edited footage?
It depends what you thought you were seeing. If you thought it was an airliner in normal service, then yes. If you thought it was the manufacturer's flight test crew demonstrating the limits of the flight envelope in a very lightly loaded aircraft at a show in a 20 knot headwind, then no. Have I been rinsed by some dodgy edited footage?
I don't think the video has been slowed down. They were flying it slowly all week and it was very impressive.
GliderRider said:
It depends what you thought you were seeing. If you thought it was an airliner in normal service, then yes. If you thought it was the manufacturer's flight test crew demonstrating the limits of the flight envelope in a very lightly loaded aircraft at a show in a 20 knot headwind, then no.
I don't think the video has been slowed down. They were flying it slowly all week and it was very impressive.
Whatever it was didn't look doctored but also looked very unnerving and unnatural.I don't think the video has been slowed down. They were flying it slowly all week and it was very impressive.
So either I've been rinsed or I didn't know an airplane that size could do that in any configuration
GliderRider said:
bhstewie said:
hstewie said: So I'm confused now.
Have I been rinsed by some dodgy edited footage?
It depends what you thought you were seeing. If you thought it was an airliner in normal service, then yes. If you thought it was the manufacturer's flight test crew demonstrating the limits of the flight envelope in a very lightly loaded aircraft at a show in a 20 knot headwind, then no. Have I been rinsed by some dodgy edited footage?
I don't think the video has been slowed down. They were flying it slowly all week and it was very impressive.
https://m.youtube.com/watch?v=Q0K41K5vQSs&t=34...
(5m15s if it doesn't carry the timestamp).
None of them are quite impressive as the 'hover' in the video you posted, but they do show the effect of a big aircraft against a grey sky that make it seem to be travelling much more slowly than it is.
'Your' video looks like it was taken on a much windier day, so perhaps a stronger headwind, a bolder crew and a lighter load all combined to make the A330 'hover'.
Thank you that's fascinating.
I know physics applies but that just looks freaky though as you say not quite to the same extent as the shorter clip does.
At least I know I've not been done by an edited video.
I'm just trying to think how I'd feel if I was a passenger looking down and the ground wasn't moving
I know physics applies but that just looks freaky though as you say not quite to the same extent as the shorter clip does.
At least I know I've not been done by an edited video.
I'm just trying to think how I'd feel if I was a passenger looking down and the ground wasn't moving
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