Flags flown on or flown from aircraft

"Aerial flags" towed by helicopters (url followed by quote):

Wieland Helicopters provides information on flags flown from aircraft:

Wieland helicopters can tow a range of aerial flags and flying banners to meet any aerial advertising or marketing requirement. Our helicopters conduct the majority of banner towing services throughout Australia, using a specialised overland system which ensures we can fly your advertising banners anywhere at any time as required.

Several examples are given.
Jan Mertens, 27 July 2008

[Editor's Note: The term for this instance of f an aerial flag as given in the Dictionary of Vexillology is "Flying Line".]

This came up before, as the Royal Navy does the same thing, with flags.
Colin Dobson, 27 July 2008

The Australian flag (for which official specs exist) has been modified by adding a triangular piece of cloth to the fly. as is apparently the case for the other items as well. This was doubtlessly done for technical reasons, but - apart from size and usage - there is the physical difference. In other words, no rectangles.

On another point, it is not as if a pilot sticks a tiny flag through the window after landing or as if a flag carried on the aircraft helps identify it - aren't the above flags or flag-like objects sui generis.
Jan Mertens, 28 July 2008

Years ago, at some party, (so I have no references for this of any sort) I was talking to somebody about airplane cockpit windows that open. It appears that when the increasing speed of passenger aircraft was making windows that open impractical, one of the primary complaints from pilots was that this meant that they'd no longer be able to open the window to fly their flag after landing. So it appears that pilots used to do this routinely at one point.
Jon Radel, 28 July 2008

The practice continues for some aircraft flying VIPs.

Papal plane on arrival in Sydney

images located by Ralph Kelly, 31 July 2008
Source: Yahoo photos (link no longer active) from Associated Press
resized by António Martins-Tuválkin, 31 July 2008

Pope Benedict XVI recently visited Sydney for World Youth Day. and photos show the papal plane departing Rome airport and flying the Vatican and Italian flags from the cockpit. The original image came from Yahoo Photos sourced from AP Photo; by Palinio Lepri on July 12, 2008. When the plane landed in Sydney, the Vatican flag was moved to the right side of the plane (from the observer's perspective) and the Australian flag was used on the left side.
Ralph Kelly, 29 July 2008

Both show the Vatican flag and the host country’s hoisted on poles outside the cockpit windows of the visiting aircraft — Italy in the first case, and Australia in the second.

However while the Vatican flag is at starboard and the Italian flag at port side in , in the Vatican flag is at port side and the Australian flag is at starboard. I’m almost sure that both photos were properly oriented (i.e. none was flipped or mirrored vertically), which can be confirmed by looking at non some reversible elements visible on the full images (mostly lettering).
António Martins-Tuválkin, 12 August 2008