MH370 speculation sparked by debris found on Indian Ocean island

a reply to: TamtammyMacx

I can tell you definitively; they won't work. Certainly not at the location where they were when the events apparently started to unfold. I've been all over that area in the S. China Sea (on the water) and there's no cellular coverage. Well, I should probably clarify this; I've been all over that area in the late 90's and there was no coverage.

a reply to: Flyingclaydisk thank you for replying.. I don't want to get annoying

i meant it from the time you board the plane till they order you to turn of all your devices

I found a comment from elsewhere something in those lines

- pulling all passengers carrier records would clearly show timings of their cell disconnect. Mass disconnect in a short period (eg boarding) would elude to a jammer. A more staggered disconnects would be more realistic of passengers manually switching off their phones. And at what point did the last passenger's phone log off, and where was the associated cell tower?

I know myself and my dad and mom
before all the peopme get settled is a boing it takes forever. myself and them and everyone has a phone laptop or blackberry and you know there are always those guys that the staff hast to ask numerous times to switch that stuff off specially business class parents with kids at home or contacting people u are meating

It was 1am but still
I send heaps of stuff to friends just before take off mum always sends at text to buckle up or they call me once they sit down to pray they don't crush they fly heaps especially dad

originally posted by: Layaly
I send heaps of stuff to friends just before take off mum always sends at text to buckle up

Those are private communications between you and your mum which the public can't access.

So why would you expect us to be able to access the private communications between the MH370 passengers and their friends/families?

www.cnn.com...

"Each mobile operator will have its own guidelines for the duration of metadata storage and would not normally be made public for obvious national security and law enforcement reasons."

If investigators listened to private messages of mom telling her daughter to buckle up, they're not under any obligation to, and they are likely prohibited from, making such conversations public. Your curiosity is no reason to release that information, and I'm not sure why you're so curious to listen to moms telling their daughters to buckle up and have a safe trip, etc.

a reply to: Arbitrageur

like u said.. I am curious
these days airliners have also on board wifi entertainment

9/11 passanger made phone calls

so I am just asking how that works

or not just mobile but those in build seat phones

a reply to: Layaly

I assume you are referring to the (3) calls made from AA77 which crashed into the Pentagon.

This was a little bit of a unique case, but equally an excellent example of some of the points I made earlier. AA77 flew at very low altitudes for quite a while before the crash. This enabled the calls to be made when ordinarily they would be impossible. The 1st call, the 'May call' (made at 0912L) was placed by flight attendant Renee May to her mother. The call lasted 2 minutes. The 2nd (2) calls, the 'Olson calls' were made by passenger Barbara Olson at 0916L and at 0922L. The first of these two calls was cut short after one minute, and the second was cut short after 4 minutes. Both of these cut offs were likely due to loss of cell coverage even at low altitude. AA77 impacted the Pentagon at 0937L just 15 minutes later. Numerous witnesses on the ground reported AA77 passing very low overhead before the crash.

So, yes, some calls are possible under certain circumstances, but even in this instance there were coverage issues. Commercial airliners rarely travel any distance at very low altitudes. As a pilot, altitude is your friend, but more importantly regulations and economics drive getting to cruise altitude as quickly as possible. In this respect the flight of AA77 was different and unique making limited cellular phone comms possible. MH370 was neither low nor over a populated area (it was over water) when the initial events unfolded, so there's a big difference.

Regarding the use of in-seat phones; first off they are rather conspicuous, a bad guy could easily see a passenger attempting to use one. Second, they aren't particularly easy to use (i.e. swipe your credit card, wait, place the call, wait, etc.) And further, not all aircraft are equipped with them. I don't know if MH370 was equipped accordingly. Many long range over water aircraft are not so equipped because they are essentially useless (and one more thing to maintain). In fact, many airlines have phased them out completely because they are expensive and no one uses them, so it's just something else to break. Their main use was as toys for children who are notoriously hard on objects such as these. Once broken they leave a an unsightly blight in the seat-back which makes for bad publicity and image for the airline. Image is very important, especially in aviation, hence their removal from many aircraft.

Your questions are good ones, but I believe there are satisfactory explanations for both scenarios in the case of MH370.

One other data point; many people have questioned why passengers aboard MH370 still had working voice mail after the incident (as if their phone was still on). There is an easy explanation for this. In the early years of cell phones if the cell phone was out of range callers would hear something to the effect of "the phone you have called is outside the coverage area, please try again later". For cell phone companies this message was kind of bad publicity telegraphing coverage gaps in their system, so they moved away from this. In it's place they have centrally hosted the customers voice mailbox on equipment which is at a fixed location (i.e. in a central office like facility). Consequently, anyone who calls a out of range cell phone will be vectored immediately to the cell phone's voice mailbox account to leave a message. The cell phone it self could be simply out of range, or it could be smashed into tiny pieces at the bottom of an ocean and it would make no difference...the call would still go to voice mail. So there's definitely no conspiracy here.

One last comment about cellular phone technology. This gets into a little bit of physics, but it's probably worth mentioning. Often RF signals are simplistically described like light radiating from a light bulb. With modern antenna design this description isn't entirely accurate. Because the RF energy is finite it is important to focus this energy where it can best be utilized otherwise some of the total signal strength is wasted. Consequently, cellular companies use antennas which focus the signal in what are known as "lobes" which are essentially parallel to the surface of the ground. They do this to optimize their coverage area for each tower. Antenna designs essentially flatten these lobes out as much as possible across the surface to accomplish this. Imagine looking at the beam of a flashlight from the side; as you narrow the beam height you increase the effective distance of the beam. The total amount of light (energy) being emitted is the same, but the effective range is increased (at the expense of coverage above and below the beam).

Now imagine a 360 degree flashlight using this same principle (using multiple antennas), the coverage radius would be wide if you looked at it from overhead, but if you looked from the side the beam would be very narrow vertically. Because the vast majority of cellular customers are to the "side" of a tower site (rather than above or below) this explains why the companies focus their broadcast transmissions in this way.

This (hopefully) explains why cellular phones are of little or no use aboard aircraft (MH370 in particular).

a reply to: Layaly

Not all aircraft have wifi, and many that do you have to pay to use. It's far more common than it was but several systems are still in testing and are being evaluated.

a reply to: Flyingclaydisk

wow thank you so so much .. you just reminded me how my real dad used to explain these type of things to me.. makes perfect sense now.. the second reply wows me even more it shows just how cleaver humans are is crazy is totally mind blowing

a reply to: Flyingclaydisk

thank you so much as well .. even that you both can fly a plane and you are chatting here with me just like that whilst i am bragging to my friends here that i’ve just talked to two pilots about mh370 !!! how awesome is that !

I flew home to Perth (Australia) from Thailand this weekend just gone and you don't have to turn your phone off any longer. In fact, it was the same for 2014 as well when I did a similar trip. They just ask that all devices be switched to the Aircraft flight mode setting OR off. I forgot to do even that. Most people switch to the aircraft setting and don't turn their phone off anymore and haven't for years. Even my phone in 2010 had flight mode setting.

a reply to: Layaly