A380 Landing Short on Pax Video?
Join Date: Dec 2000
Location: Horsham, England, UK. ---o--O--o---
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The delay is due to the distance from the main gear to the camera in the tail! The gear arrives at the touch down point before the tail arrives over the same point.
Delay is inherent in digital video. If activate the camera on my smartphone and wave my hand in front of the lens, I can easily get the hand on the screen moving in the opposite direction from the object itself. That's only a fraction of a second, but it's not hard to believe that IFE equipment (and whatever else may between the camera and the screen) introduces more complexity and more delay. The delay might also vary depending on the demand on the processor(s) at any given time.
Delay as an explanation for this video? I call bull. Videos of the view from the tail camera of a landing A380 are available all over the internet.
There was one doing the rounds years ago when they were a novelty, showing in daylight what appeared to be a A380 touching down on the piano keys. However if you watched spoilers there was no movement until several seconds later demostrating where the touchdown was on the video.
The 380 spoiler rise is quite slow, and does not happen straight away. In at least one of the videos that was doing the rounds the spoilers were fully extended when the nose went past the PAPI.
The 380 spoiler rise is quite slow, and does not happen straight away. In at least one of the videos that was doing the rounds the spoilers were fully extended when the nose went past the PAPI.
Join Date: Sep 2008
Location: Bratislava, Slovakia
Age: 47
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I don't really care either way, but if the video feed is digital (and it most likely is) there MUST be a delay due to the digital compression and decompression of the video feed from the cameras. Given that these are non-essential, entertainment cameras (I assume) the priority would not even be on making this delay as short as possible, so you can be sure there is one. Another delay is added due to the IP network infrastructure feeding the displays around the plane (again, non-essential, entertainment). Switching/routing gear can and will add non-negligible delay. Also, I assume each display is basically its own computer with an operating system and layers of object programming, again, creating little delay. The TFT displays themselves have a relatively big delay (compared to CRT/plasma they are at least 4000x slower). So, from a technical point of view, the delay is there and has to be there. It may not add up to be seconds, but half a sec to a second is totally normal.
