My opinions only, no facts here:
Unfortunately, the purported 9-11 cell phone calls from various doomed aircraft in the U.S. 2001 terror incident turned the issue of cell phone performance at altitude into a political argument, to this day.
I read a scientific article that explained succinctly why there are essentially no sustained communications between a cell phone in a plane at more than 8000 feet above ground level and and ground-based towers. Interesting, but according to summitpost.org, cell phones work for at least some distance above 14,200 feet on Mount McKinley in Alaska. Of course, service will be unreliable there because cell towers are very scarce in the wilderness. In 2007, a climber at the top of Mount Everest (29,000 feet) successfully sent a cell phone text message through the tower at Rongbuk, China (16,000 feet). Can you make a sustained cell-phone connection with a tower from altitude differentials far greater than 14,000 feet? Probably not, for reasons explained below. But can a cell tower acquire your position (handshake/ping) when you are far more than 14,000 feet above the tower? In some cases, yes.
Regarding cell phone calls from aircraft, there is nothing magically-wrong about being at 35,000 feet, as long as the cell tower is no more than 22 to 45 miles away from you (the useful ranges of towers vary by configuration and design), and the tower is not directly under your position or is its dish tilted too-steeply downwards. At high altitude, you always have line-of-sight with towers, which is the ideal situation for maximum range communication. But I have learned from pilot reports on the internet that cell phones only occasionally make contact with a tower when the plane is at 35,000 to 39,000 feet. So, what is the problem? The problem is not that your high altitude is magically preventing all contact with the tower. The problem is actually threefold:
1) from the airplane you can typically detect many towers at the same time. This wreaks havoc, hogs the system, and leads to dropped calls.
2) you are changing position at a speed of hundreds of miles per hour. New towers are constantly detectable, magnifying the problem described above.
3) if the tower dishes are tilted towards earth, your signal at great altitude may be weak to non-existent.
The claim that the First Officer's cell phone (on MH 370) connected with a tower conveniently supports the westward turn and track of the plane, and also supports that the plane deliberately moved to lower altitudes (14,000 feet or lower, based upon my above information). Interestingly, ground witnesses generally report that the plane was lower than normal and noisier than usual. But none of this changes my previously-posted opinions by one whit: if the First Officer's cell phone could contact/ping a tower, so could any other active cell phone/device on the plane. The passengers and crew did not have to be conscious- their devices would not stop working from a lack of oxygen- their devices only had to be left on by mistake or on purpose.
Sleuth On!
but I wonder if it's possible if the current plotted handshakes on the 7th arc could be mirrored or opposite. Visually speaking the current handshake points are on the East side of a circle and I'm wondering if the points could be on the west side (yes, it's a stretch I know :what
