Sleep mode and airline travel

Is a laptop in sleep mode a threat to the functioning of the aircraft?
Hobo wrote on :

hello,

Whenever I fly the stewardesses warn the passengers to turn off all electronic equipment before takeoff and landing. I usually have my ibook in sleep mode under the seat in front of me when these announcements are made. Is a laptop in sleep mode a threat to the functioning of the aircraft?

TIA

Jerry Kindall replied on :

In article noemail-07DFD2.00144101092003@redacted.invalid, Hobo noemail@redacted.invalid wrote:

Whenever I fly the stewardesses warn the passengers to turn off all electronic equipment before takeoff and landing. I usually have my ibook in sleep mode under the seat in front of me when these announcements are made. Is a laptop in sleep mode a threat to the functioning of the aircraft?

A laptop in full operational mode is in fact no threat to the functioning of the aircraft except, possibly, if wireless networking is active. You probably already have it turned off, though, because there's nothing to connect to on the plane anyway and thus no reason to waste the battery. A laptop in sleep mode would be even less of a threat, except it is not possible for something to be less of a threat than no threat at all.

That doesn't mean they won't make you turn it off. You are required by law to obey instructions given by thei arcraft flight crew. So if you are ever told to turn off your sleeping laptop by a flight attendant, then turn it off.

That said, you will never be told to turn off a sleeping laptop if it is properly stowed. It is far more of a danger as a projectile than as a source of RF interference, and the flight crew is rightly more concerned with making sure it doesn't go hurtling through the air if the plane hits a rough patch.

Simon Slavin replied on :

In article noemail-07DFD2.00144101092003@redacted.invalid, Hobo noemail@redacted.invalid wrote:

Whenever I fly the stewardesses warn the passengers to turn off all electronic equipment before takeoff and landing. I usually have my ibook in sleep mode under the seat in front of me when these announcements are made. Is a laptop in sleep mode a threat to the functioning of the aircraft?

No. In sleep mode the laptop is doing almost nothing more than it is when it's off.

However, if you have an Airport card in that iBook then you must take measures to ensure it's not working /all the time during the flight/, not just during take-off and landing. I don't know enough about BlueTooth to know if the same measures are necessary.

Dale J. Stephenson replied on :

slavins@redacted.invalid@redacted.invalid (Simon Slavin) writes: [...]

No. In sleep mode the laptop is doing almost nothing more than it is when it's off.

However, if you have an Airport card in that iBook then you must take measures to ensure it's not working /all the time during the flight/, not just during take-off and landing. I don't know enough about BlueTooth to know if the same measures are necessary.

What do you know about Airport card that makes turning it off necessary? I turn off my airport (when I remember) to help the battery last longer. If airlines thought wireless cards posed a safety risk at cruising, they'd take some measure to stop it, even if it were nothing more than the same instructions they give for cellphones.

Simon Slavin replied on :

In article m3bru1igw0.fsf@redacted.invalid, dalestephenson@redacted.invalid (Dale J. Stephenson) wrote:

slavins@redacted.invalid@redacted.invalid (Simon Slavin) writes: [...]

However, if you have an Airport card in that iBook then you must take measures to ensure it's not working /all the time during the flight/, not just during take-off and landing.

What do you know about Airport card that makes turning it off necessary?

Hmm, yes. I think I overstated. I've never heard an announcement which told me not to generate a wireless signal while the plane was in flight. You're right.