iPhone blamed for flight malfunction
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iPhone blamed for flight malfunction
from The Australian, 16 May 2013
Wonder why this has taken two years to be published?
Anyone know any specifics about the case?
A passenger using an iPhone mid-flight allegedly caused a compass malfunction on a US plane that sent it several kilometres off course.
Business site Bloomberg reports that the compass came good at the same time a flight attendant asked the passenger in row 9 to switch off their smartphone.
Bloomberg reports that despite recent calls for rules to be relaxed surrounding switching off phone functionality in-flight, airlines have logged dozens of cases where passenger electronics were believed to have interfered with navigation systems.
The incident is understood to have taken place in 2011.
The website AppleInsider said that modern wireless interference is believed to be associated with cellular radios in phones.
"That's why airlines that use the iPad as an electronic flight bag do not use cellular-capable versions of Apple's touchscreen tablet," AppleInsider said.
Business site Bloomberg reports that the compass came good at the same time a flight attendant asked the passenger in row 9 to switch off their smartphone.
Bloomberg reports that despite recent calls for rules to be relaxed surrounding switching off phone functionality in-flight, airlines have logged dozens of cases where passenger electronics were believed to have interfered with navigation systems.
The incident is understood to have taken place in 2011.
The website AppleInsider said that modern wireless interference is believed to be associated with cellular radios in phones.
"That's why airlines that use the iPad as an electronic flight bag do not use cellular-capable versions of Apple's touchscreen tablet," AppleInsider said.
Anyone know any specifics about the case?
Last edited by VH-Cheer Up; 16th May 2013 at 06:13.
Anyone know any specifics about the case?
"After departing, climbing through 9,000 FT we received an EFIS COMP MON caution message. Flight Manual directs pilots to slew compass to reliable side. It was apparent neither side was correct with the Captain's, magnetic compass, and First Officer's headings all different. We were cleared direct to a fix. Multiple attempts were made to match the headings with only temporary results. The Captain elected to hand fly while the headings mismatched. While the FMS was taking us in a direct line, with the wind shift while hand flying the aircraft ended up 4 miles south of the original "direct to" course. ATC called and asked if we were going direct, I told them we are having heading problems and asked how our heading looked. He told us 10 right and direct when able. On this trip we flew this same aircraft for 9 legs and did not have this problem on any other flight. In the past I have had similar events with speculation that cell phones left on may contribute to the heading problems. I made a PA asking our passengers to check their cell phones and make sure that they are off. Short of flying with both headings in DG we attempted to slew the compasses together again, and the EFIS COMP MON was cleared with no further messages. Our Flight Attendant called and asked if that had helped, I said yes, what did you do? He stated he walked through the cabin and spoke to each of the 12 passengers. A passenger in Row 9 had an iPhone in the standby mode, not airplane mode or off. He showed the passenger how to turn the phone off fully. The flight continued to destination with no further problems.
In my opinion and past experience the cell phone being on and trying to reconnect to towers on the ground, along with the location of row 9 to the instrumentation in the wing caused our heading to wander. The timing of the cell phone being turned off coincided with the moment where our heading problem was solved. Eight other flights in the same aircraft in two days span completed without a similar event."
In my opinion and past experience the cell phone being on and trying to reconnect to towers on the ground, along with the location of row 9 to the instrumentation in the wing caused our heading to wander. The timing of the cell phone being turned off coincided with the moment where our heading problem was solved. Eight other flights in the same aircraft in two days span completed without a similar event."
This isn't very scientific, is it ?. I find it hard to believe that a
phone in standby mode could affect what is after all a magnetic sensor.
Avionics kit is stringently tested for rf susceptability and sensitive
signal cables are screened. The only way that there could possibly be an
effect is via rf into one of the antennas, but a phone on standby and
not transmitting ?. Convenient to blame the device, when it could be for
any number of other reasons.
A bit more scientific study might not be such a bad idea, with various
phones and devices, under all operating conditions...
phone in standby mode could affect what is after all a magnetic sensor.
Avionics kit is stringently tested for rf susceptability and sensitive
signal cables are screened. The only way that there could possibly be an
effect is via rf into one of the antennas, but a phone on standby and
not transmitting ?. Convenient to blame the device, when it could be for
any number of other reasons.
A bit more scientific study might not be such a bad idea, with various
phones and devices, under all operating conditions...
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Well actually a phone in standby is still on and has it's aerials active. Standby in an iPhone sense is the same as "locked". Airplane mode disables the antenna and turning if off obviously means nothing happens, but a phone in standby is still turned on with an active cellular connection (or at least hunting for one at that height).
find it hard to believe that a phone in standby mode
"My device comes on really quick from Standby" is a misnomer. All that is happening is that the screen is being turned on.
You've got to "slew the compass" in a CRJ? Ark version 2?
Agree with Tumtiddle.
From my knowledge of cellular comms, the phone is constantly in rf contact with towers, both sending and receiving data when the phone is locked, because there are two channels that the phone communicates on - one where you speak to your end party, and one where the 'background' comms work to connect calls, ensure tower linking, handshaking etc.....
Only when the phone is in Flight Mode, or Off, is when all communications are disabled i.e. no wifi, data, voice etc....
From my knowledge of cellular comms, the phone is constantly in rf contact with towers, both sending and receiving data when the phone is locked, because there are two channels that the phone communicates on - one where you speak to your end party, and one where the 'background' comms work to connect calls, ensure tower linking, handshaking etc.....
Only when the phone is in Flight Mode, or Off, is when all communications are disabled i.e. no wifi, data, voice etc....
Have great difficulty believing the phone was the cause in an RF immune airliner.
The numbers of them that get left on either in pockets, hand luggage or hold luggage, this would be happening all the time.
The numbers of them that get left on either in pockets, hand luggage or hold luggage, this would be happening all the time.
Well why don't they do a proper test and send up a CRJ with cell phones on only in row 9. They can repeatly switch the phone on and off and see if the problem is consistent. Sounds like a job for 'myth busters'
Don't forget the potatos for the RFI test:
Boeing Potato Wi-Fi: Engineers Using Spuds To Improve In-Air Internet Signal Strength
Boeing Potato Wi-Fi: Engineers Using Spuds To Improve In-Air Internet Signal Strength
Well why don't they do a proper test and send up a CRJ with cell phones on only in row 9. They can repeatly switch the phone on and off and see if the problem is consistent. Sounds like a job for 'myth busters'
They found that on the aeroplanes they tried mobile phones on, they could not find any interference.
However, they also built their own simulated light aircraft cockpit with the usual array of instruments. At first they used regular unshielded wire and when they used a mobile phone near the instruments, they found a heck of a lot of interference going on. They then swapped all the wire over to the shielded type used in aircraft and found that the interference disappeared.
I've mentioned all this before several times here and it's been ignored every time. Hopefully this time someone will take notice and remember - My point being that unless you can guarantee that 100% of the wiring in 100% of the aircraft is 100% shielded, then there is a real chance of mobile phone interference.
Last edited by 18-Wheeler; 14th Jun 2013 at 00:36. Reason: too many zeros
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Yes, I flew a Sikorsky helicopter where the aft baggage bay smoke detector would be activated by any mobile phone left switched on, as it "polled" between cells during the flight. There was no fire extinguisher fitted in the aft baggage bay so the only safe response was to land asap and investigate. Not easy if you were IMC, or at night, especially over the sea. I used to explain to passengers the importance of switching off their phones, emphasising the exact reason for the requirement. They got the message (but obviously not by phone).
I've been in the front of an a320 family aircraft on a turnaround when the phone rang. The side window was open.
As it rang, GPS PRIMARY LOST flashed up on my ND and the ND slewed off to one side (was on 10mm range at the time). I finished the call and all went back to normal.
The other ND didn't change.
As it rang, GPS PRIMARY LOST flashed up on my ND and the ND slewed off to one side (was on 10mm range at the time). I finished the call and all went back to normal.
The other ND didn't change.
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It's already been proven that cars with Onstar can be hacked to slam the brakes, accelerate, and that the Airbus family has ground control over rides in case of hijacking or pilot incapacitation.
It's not new news that there is only so many frequency bands that electronics work on, that any phone can be hacked to transmit or a ground signal can transmit to an airliner the code necessary to screw things up on the deck.
It might have been what happened on 447.
The answer is simple, if you hire pilots that are competent, that you can trust, then you don't have to rely on gear that can be compromised so easily.
It's not new news that there is only so many frequency bands that electronics work on, that any phone can be hacked to transmit or a ground signal can transmit to an airliner the code necessary to screw things up on the deck.
It might have been what happened on 447.
The answer is simple, if you hire pilots that are competent, that you can trust, then you don't have to rely on gear that can be compromised so easily.
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I have lost nav in a B727 twice when both units failed. I was able to continue but on a MIA to CUN flight had no long range Nav. When the passengers deplaned and baggage was unloaded everything worked perfectly again. It could have been an FM radio in baggage that turned on with an alarm or a cell phone.
I worked on business radio systems before flying full time and had some interesting situations, one when a weather receiver was jamming one of our companies radios in their office on a UHF frequency. I tuned to our frequency and drove the jeep around with a scope tuned to that frequency and it peaked out passing a business trailer. I stopped and verified their receiver was sending harmonics out of the antenna of their receive only unit and causing the problem. Also at KSNA we had a constant problem of clearance delivery having a loud squeal when they were reading clearances. I took a portable radio tuned to the frequency and it was our Aircal high speed printer in ops sending out the signal. We dealt with these interference problems a lot and they sometimes are not very straight forward solutions. Now with GPS and being familiar with your wet compass it shouldn't cause much of a problem if you can think outside the box a little.
I worked on business radio systems before flying full time and had some interesting situations, one when a weather receiver was jamming one of our companies radios in their office on a UHF frequency. I tuned to our frequency and drove the jeep around with a scope tuned to that frequency and it peaked out passing a business trailer. I stopped and verified their receiver was sending harmonics out of the antenna of their receive only unit and causing the problem. Also at KSNA we had a constant problem of clearance delivery having a loud squeal when they were reading clearances. I took a portable radio tuned to the frequency and it was our Aircal high speed printer in ops sending out the signal. We dealt with these interference problems a lot and they sometimes are not very straight forward solutions. Now with GPS and being familiar with your wet compass it shouldn't cause much of a problem if you can think outside the box a little.
13 years ago I had an old PC. Whenever I did insert column in excel, my clock radio used to buzz for a split second. Down the hall, three rooms away.
No other computer function was noted to cause the same effect.
No other computer function was noted to cause the same effect.
Well why don't they do a proper test and send up a CRJ with cell phones on only in row 9. They can repeatedly switch the phone on and off and see if the problem is consistent.
What's not a good idea is dismissing the possibility, outright.
Interference can be tricky to reproduce, sometimes. For example, the shielded wiring may have its shield grounding point(s) going intermittent. On the ground, all is fine; once in the air, with the wing bending up a bit, the wiring shifts and not so RF-proof anymore.
Once in the signal wires, RF can "mutate" through a variety of mechanisms down to the interference frequency. Even somewhat oxidized connectors are known to make a poor rectifier. Show me a schematic and we can start hunting for potential mixing hazards.
Anyhow, the sporadic nature of the reports of this sort, that I've come through over the years, makes me think that the problem could involve aircraft maintenance state/assembly quality, not just the design.
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The United Kingdom CAA in October 2002 conducted a series of laboratory tests which exposed general aviation avionic equipment to simulated cellphone transmissions. A VHF radio, a VOR/ILS receiver with HSI and secondary indicators, and a remote gyro compass system were used. At high signal levels, similar to that attainable from a cellphone 30 cm from the equipment or its wiring, anomalies were produced on all equipment readings except the glide slope indication. These tests confirmed onboard cellphones as an interference source, and endorsed current legislation restricting their use on aircraft.
Unfortunately, I don't have the UK CAA report. That reference is from this 2011 NZ accident report:
Piper PA 31-350 Navajo Chieftain ZK-NCA, controlled flight into terrain, near Christchurch Aerodrome, 6 June 2003*
Aviation Reports - Aviation Reports
Although I still think it likely that the crash was nothing to do with anomalies and everything to do with the fact that the pilot was using the phone on approach.
* No points for guessing why I'm looking at this crash
Last edited by akaSylvia; 14th Jun 2013 at 08:58.