FlyerTalk Forums - View Single Post - ATA tries to arrest you for using your iPhone in "Airplane Mode"
Old Oct 10, 2007, 11:04 pm
  #13  
eoinnz
 
Join Date: Dec 2006
Posts: 1,114
Jim Irving is a colleague who flies B737 aircraft for a major US carrier.

One day departing Portland Oregon we noted that the FMC [Flight Management Computer] Map display showed a disagreement with the "raw data" VOR position. Our training is such that we would normally immediately switch over to "raw data" and assume the FMC was in error.

We would have done that except that it was a beautifully clear day and I looked out the window and was able to determine that the FMC seemed to be right on. I called back to the cabin and asked the flight attendants to check for someone using a cell phone or computer. A few minutes later they called back to say that a man had been using his cell phone and it was now off. Strangely (?) our VOR and FMC map now agreed.

Later in the flight the flight attendants called back and said that they had caught the man using his cell phone again but this time we had not noticed any problems, perhaps because we were in cruise far from the ground and not paying as much attention.


Another pilot's account:

In our company we recently had a Localizer deviation (out of tolerances) on a B737-200 related to a GSM (mobile phone) being operated by a passenger (who was disregarding our company regulations). When requested by the cabin crew to switch off his GSM, localizer indications became normal. Is this scientific proof? Certainly not, but good enough for me as a captain to insist that all the electronic toys, computers, mobile phones, etc., are OFF during critical phases of flight. [...]

I had fuel indications on the FMC going crazy on board the B737, that returned to normal when all electronic stuff in the back was switched off. I suspect a "Gameboy" electronic game device to have interfered, but this is no more than a guess. No, I did not ask to switch the toy back on again and investigate more in depth as I was responsible for the safety of 140 passengers and this would have been extremely irresponsible! This is not a situation in which to do such testing! This [ever-present responsibility accounts for why] there is no "proof" of the relationship.

I also recall experiencing *impossible* mode annunciations on the FMA (flight mode annunciator) on B737. Having both the autothrottle AND the pitch channel of the autopilot trying to maintain speed (both in MCP SPD mode) for example, not programmed by the pilot (you cannot program that). After an expensive in-depth troubleshooting session by our maintenance department, the incompatible mode annunciations were traced to a ... faulty cockpit window heat wiring. This caused electronic interference with the auto flight system.

Here are some more incidents:

June 07, 1997. B737-300: *Verify position* was indicated on the CDU. Both IRS and radio position were correct, the FMC position was not. The difference rapidly increased to 8 nautical miles. After switching a GSM in the cabin from STBY to OFF, the FMC updated normally. FMC was correct for the remainder of the flight and on the return flight.

April 30, 1997. B737-400: During level cruise, the AP pitched up and down with ROC/ROD of 400 fpm indicated. Other AP was selected: no change. Cabin was checked for PC's and other electronic devices: nothing was found. Requested passengers to verify that their mobile phone (GSM) was switched OFF. Soon
after this request all pitch oscillations stopped.

[There was one incident reported with a] B737-200. During approach to MAN (Manchester International, UK), the LOC for landing runway 24 oscillated and centered with the aircraft not on track (but offset), confirmed visually. Ground equipment was monitored and working normally. When a GSM in the cabin was switched off, all indications became correct.

More examples, taken directly from NASA's ASRS:

In October of 1998, a Boeing 757, flying from Seattle to Covington/Cincinnati, experienced loss of all three of its autopilot systems. Flight attendants checked for a passenger using a portable electronic device and discovered a man wearing headphones, which were part of a hearing aid. The passenger was allowed to continue using the device, but was moved forward several rows. The autopilot system then regained full operational capabilities and was later checked by maintenance, with no problems being found.

In March of 1997, a Cessna 340/A pilot experienced erroneous readings when attempting to determine his location because of a passenger using a cellular phone. After the passenger turned off the phone, the pilot was able to locate his position and continue on with no problems.

In January of 1997, a regional jet was flying from Salt Lake City to Eugene. The flight crew received three separate warning messages stating that there were disagreements between the captain’s and the first officer’s instruments. The three warnings were for discrepancies in heading, airspeed, and altitude indicators. After flight attendants checked the cabin for passengers using portable electronic devices and had the devices turned off, all problems ceased.

In August 1995, an aircraft making its approach to George Bush Intercontinental Airport in Houston was advised that it was 4 miles off course. Because the course director indicators had been scalloping left and right of center, the captain ordered the flight attendant to check the cabin for any passengers using a portable electronic device. Within 15 seconds, problems with the course director indicators disappeared. The captain later learned that a passenger had been using a portable computer.

In May of 1995, the electric compass indicators of the first officer of a Boeing 737 gave erratic readings. After a sweep of the cabin was made for portable electronic devices, which resulted in flight attendants asking a passenger to turn off a compact disc player, the first officer’s instruments returned to normal working order.

Shortly after takeoff from Baltimore, in April 1994, an aircraft was advised by ground control that it was 10 miles off course, though the plane’s instruments indicated nothing abnormal. It was found that a passenger in first class was using a portable computer. After the computer was turned off, navigation instruments returned to normal.

In February 1994, a turboprop aircraft flying government officials from Lake Havasu, AZ to Yuma, AZ experienced trouble with its navigational radios. Ground control showed that the airplane was off course and gave corrections. However, the plane’s navigation system had been checked earlier in the month and was said to have zero error. After the flight, the pilot learned that at least one passenger was using a cellular phone while the plane was in the air.

In August 1992, a turbojet aircraft was notified three times, by two different control towers, that it looked to be off course. All instruments in the cockpit were showing the plane’s position to be correct. Flight attendants searched for portable electronic devices and found a tape machine and a hand-held video game unit in use. The devices were turned off and there were no other navigational discrepancies during the flight.

In September of 1990, a plane travelling from Boston to Youngstown/Warren, OH was advised it was off course and was issued a new heading. The plane’s navigational instruments showed it to be on course. After checking the cabin for portable electronic devices, the lead flight attendant informed the captain that 23 passengers were using AM/FM cassette players and one passenger was using a personal computer. The passengers were asked to turn off the devices and the flight proceeded without further incident.

Here is a link for more reading on the topic: http://www.rvs.uni-bielefeld.de/publ...ports/EMI.html

The above post was taken from airliners.net
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