Originally Posted by
On-MarkBob
Indeed, Flash2001,
Also when the concept of power outlets was introduced, mobile pone chargers and the like had barely been invented. As technology improves, more airlines will require this stuff and aircraft will be fitted with suitable outlets I'm sure. Let us not forget that the manufacturers know their aircraft far better than we do and if they tell us we can't use the current type of outlet for reasons they were not intended for, then we should take the responsible attitude and do as we are told by them, and if we can't do that we are in the wrong industry.
My advice to all is before you plug any commercial bit of equipment into any aircraft in any way, go and discuss the matter with your Chief Technical Captain. He will have access to the engineering manager and the aircraft manufacturer and will be able to, thus, get an answer of yes or no.
Is there an 'approved use' list for either type of cockpit ac outlets, either 400Hz or 60Hz?
The manufactures/airline customers must have had something in mind when they were added.
Even the touted 28V dc to USB charger (BTW does look like a useful device, especially for small aircraft) is not 'certified' for cockpit use, from their data sheet:
The conclusion of all test show EMI levels well
within the standards necessary for flight deck use. The following test results
are provided as reference for maintenance engineering groups to coordinate
with their own independent EFB system tests.
In other words a system approach is needed to ensure compatibility and safety for cockpit use.
Under seat outlets in the cabin are intended for use with arbitrary devices up to a certain power level so the 'plug ... in any way' comment is a bit too broad a statement.
Agency certifications (EMI/UL/din/whatever) rely mainly on testing over specified ranges, not design review (although there is some).
With the exception of some Apple chargers that are tested at 400Hz most certs will typically be for 100-240V 50/60Hz so use of chargers on 400Hz is outside the certified range, even though they will work just fine.
One last comment is that much of the discussion centered on questioning unsupported claims such 400Hz power reducing battery life and similar, not legality which is a different thing altogether.
There is a lot of misinformation around, not that anyone would rely on a rumor web site to bless a cockpit system.