|Re: Ode to the calculators I have used...and the 41C|
Message #7 Posted by Geoff Quickfall on 27 June 2011, 12:52 p.m.,
in response to message #5 by Joerg Woerner
A few points on these.
- Shielding is wonderful until you drop your item.
- RF is not a problem unless you are sitting by the antenna.
- Aircraft navigation can be affected depending on the phase of
flight, stength of electronic, lack of sheilding and position
relative to the aircraft antenna.
- Some electronic use prohibition was probably revenue generated
later in time but originally was prohibited for reason.
- Ipad use not approved yet!
Sheilding on older equipment was lacking or shifted or just plain useless. Note, the FAA and IATA/ICAO are reactionary, they respond to problems, develop strategies and implement them. They are slow to remove archaic rules. Lawyers and liability and laziness and all that. It is easier to ban all electronics during phase of flight then to make a list of approved electronics. The reason are money and time.
That LLOYDS 333 will completely jam a SW and AM radio when within 2 feet of a radio antenna. Fortunately for the cockpit, the F/O and Capt radio nav equipment antennas are located over and under the passenger cabin. Also all equipment on the flight deck is sheilded for obvious reasons. Conversely, antennas are not sheilded for obvious reasons!
Phase of flight usually depends on radio navigation and hence the antennas. That is why there is a prohibition in the cabin of transmitting devices today during takeoff and landing. High use of VHF and LW radio navigation systems of both ground and aircraft systems are used during takeoff and landing. In cruise GPS is used (different frequencies less liable to interference by RF and different attenna location).
When phones were installed at the seats (ten years ago) they generated revenue. So the ban on cell phones for all phases of flight became a revenue thing, in part. They also had a dedicated antenna which was directional, located away from aircraft navigation antennas and again, a different frequency to aircraft navigation and communication systems.
The FAA has not approved the battery system on the IPads and as it is new tech they have not yet tested it for use in the cockpit. They are in the process now so technically the IPad is ok but the battery is not (oxymoron?). Of course it can be stated that the public has been testing this battery for years. And guess what! Computers have caught fire in the cabin. Computers placed on pillows on the lap, plugging venting cooling fans and boom! Bad lithium ion battery batch and boom! Some rechargeable lithium based flashlights are banned from the cockpit. Happened to a fight I was on to Beijing from Vancouver. Got to tell you, at 39000 feet over the Pacific 5 hours from anywhere and the smell of smoke in the cockpit! NOT FUN. Think Swissair.
Back to the IPAD, it can be used at your discretion. This implies a liability aspect that has not been investigated by the FAA (USA). Some airlines are using it for manuals such as the Flight Operations manual, Aircraft Operating manuals and etc. The exception are Jeps which are not approved for the IPad at the at the tier one Airline level (Alaska Airlines being one but not for Jeps). They are also only used for specific phases of flight.
IPads are certainly the future for Jeps, the current problem is the only update available is manually loading the system. The FOM must be updated to include a revision provision for IPads as approved for the airline by the FAA. That has yet to be done. It is co-ordinated between individual airlines creating procedures that insure the Jeps are updated in a timely manner and that the procedure is then examined and approved by the FAA.
I have seen my radio nav go nuts, autopilot was not on at the time. I was climbing out of LAX to YVR (1992) going through 20,000 feet when the radio nav (VOR) started wildley fluctuating. If the auto pilot had been on the aircraft would have started a series of rapid banking (25'). After running an experiment in business class; asking everyone to turn off their computers and games. I had them turn them on one at a time. We got to a kid who had a portable nintendo hand held. He happened to be sitting right below the physical location of the #1VOR antenna. Everything went wonky (technical term) again. Business class electronic equipment was suspect as the antenna for the #1VOR is located on the ceiling right above the second row of seats.
Like any rule, law or etc the precept is based on a combination of known evidence, actual affect, probable affect, worst case scenario and etc. The rules usually apply to worst case scenarios; every one switches on the cell phone at the same time...
I still think, electronics near antennas should have a phase of flight restriction. The cost and time required to test ALL electronics on the market today is prohibitive.
As far as electronics go, during takeoff, climb, descent and landing (the so called critical phases of flight) electronics in the cockpit: NO WAY! In the cabin also NO WAY! There are still to many older electronics, older aircraft and still a reliance on radio navigation and therefore antennas.
Of course an argument can be made to retrofit all older aircraft and redesign new aircraft to allow hand held nintendos and etc. But that is a cost OR how about a phase of flight prohibition.
My airline allows cell phones on ground and during taxi. They do not in the air, of course, being me, I have tested them in the air. My analog worked perfectly as it did not due to software, limit the transmit to one tower at a time. My blackberry does lock on to one tower at a time. Because of this and at 450 KTS it has about 5 seconds of useful broadcast, just enough to tell you it has disconnected.
We were testing phones as means of communication in the event of a loss of all radios, electrics. Call ATC directly and collect the pax cell phones. Worked in the analog days and early digital (2002) but not any more.
HP 71B sitting on the lap Joerg, not the flight computer! And no where near an antenna. Also the wiring is shielded in the cockpit for radio aids similar to the cable tv cable and all equipment in the cockpit is sheilded. It is the passenger cabin antenna locations that are the problem.
OR it is all a conspiracy along with chem trails ;-)
Edited: 27 June 2011, 10:09 p.m. after one or more responses were posted