4 ms·

Pilot here. Generally speaking, FAA regs allow owners to update GPS databases (14 CFR 43.3 [0]) if we're provided with the means to do so. However, this method

by peckrob 10y ago

Pilot here. Generally speaking, FAA regs allow owners to update GPS databases (14 CFR 43.3 [0]) if we're provided with the means to do so. However, this method of doing it may be legally questionable. The crux of the matter is this regulation (14 CFR 43.3(k)): > (2) The pilot must comply with the certificate holder's procedures or the manufacturer's instructions. > (3) The holder of operating certificates must make available written procedures consistent with manufacturer's instructions to the pilot that describe how to Basically, while as an engineer I can appreciate the technical cleverness of this, I would definitely talk to an aviation lawyer first before trying this myself. [0] http://www.ecfr.gov/cgi-bin/text-idx?rgn=div5&view=text&node=14:1.0.1.3.21&idno=14#se14.1.43_13 http://www.ecfr.gov/cgi-bin/text-idx?rgn=div5&view=text&node... [1] http://aviation.stackexchange.com/a/1300 http://aviation.stackexchange.com/a/1300

cnvogel 10y ago
Interestingly, by 14 CFR 43.3(k) even the "official" method described in the article is noncompliant, as the device is removed from the aircraft, and put into a docking-station at home, loaded via RS232. I also understand the need to follow procedures, even if there are cases in which they are clearly nonsensical or obviously without influence on air safety -- just because it's not guaranteed that everything that seems to have no influence on safety actually does have no influence on safety. But: I had seen photographs of an old floppy drive in a B737 (I think) which was used to load updates to the FMS. Then there's a version with USB. Both storage devices could be inserted into a PC, with junk stored on them, or swapped with a completely unrelated disk/usb-stick. Inadvertently, or even with malicious intent. So the risk of arbitrary data on the floppy drive must have been mitigated (by signing the FMS updates, checksums, ...) and considered acceptable during the design of the system. The same, I think, should hold true for the memory card in the article: If traditionally these cards had been shipped around by postal mail, I'll claim that the possibility of damage which isn't visually apparent must have been taken into account, and a procedure been put into place, such as a CRC check to be performed after the swap, or a self-test after every turn-on of the unit. Afterwards, the card should be considered "good", independent of the method by which the data was loaded. Does that make sense, or am I overseeing something obviously here?
- peckrob 10y ago
  > Interestingly, by 14 CFR 43.3(k) even the "official" method described in the article is noncompliant, as the device is removed from the aircraft, and put into a docking-station at home, loaded via RS232. It's not noncompliant, it just means that owner maintenance on this GPS isn't possible and has to be done by a specialist. A general rule I go by is if something needs to come out of the panel, it needs a mechanic or avionics tech to do. This unit is from 1996. IIRC we weren't allowed to do our own updates until 2012 or so. So it's not surprising that owner maintenance may not be legally possible on it. I can pretty easily construct a scenario where doing something like this gets you in trouble. Chances are nothing will happen but it's all about your risk tolerance. Mine is pretty low.
  - matheweis 10y ago
    He has added an interesting disclaimer "Please note: I am in no way saying that you can, should, or are allowed to fly with a card updated in this way (even though the bits in it are identical). I am not claiming that I plan to or am flying with such a card. All experimentation was performed on a card and a GPS that is not used for IFR flight." Also author appears to have commented on this thread with a similar disclaimer. Very neat hack, but yea, walking a very fine line with the relevant aviation authority :(

by peckrob 10y ago

cnvogel 10y ago

Interestingly, by 14 CFR 43.3(k) even the "official" method described in the article is noncompliant, as the device is removed from the aircraft, and put into a docking-station at home, loaded via RS232. I also understand the need to follow procedures, even if there are cases in which they are clearly nonsensical or obviously without influence on air safety -- just because it's not guaranteed that everything that seems to have no influence on safety actually does have no influence on safety. But: I had seen photographs of an old floppy drive in a B737 (I think) which was used to load updates to the FMS. Then there's a version with USB. Both storage devices could be inserted into a PC, with junk stored on them, or swapped with a completely unrelated disk/usb-stick. Inadvertently, or even with malicious intent. So the risk of arbitrary data on the floppy drive must have been mitigated (by signing the FMS updates, checksums, ...) and considered acceptable during the design of the system. The same, I think, should hold true for the memory card in the article: If traditionally these cards had been shipped around by postal mail, I'll claim that the possibility of damage which isn't visually apparent must have been taken into account, and a procedure been put into place, such as a CRC check to be performed after the swap, or a self-test after every turn-on of the unit. Afterwards, the card should be considered "good", independent of the method by which the data was loaded. Does that make sense, or am I overseeing something obviously here?

peckrob 10y ago
> Interestingly, by 14 CFR 43.3(k) even the "official" method described in the article is noncompliant, as the device is removed from the aircraft, and put into a docking-station at home, loaded via RS232. It's not noncompliant, it just means that owner maintenance on this GPS isn't possible and has to be done by a specialist. A general rule I go by is if something needs to come out of the panel, it needs a mechanic or avionics tech to do. This unit is from 1996. IIRC we weren't allowed to do our own updates until 2012 or so. So it's not surprising that owner maintenance may not be legally possible on it. I can pretty easily construct a scenario where doing something like this gets you in trouble. Chances are nothing will happen but it's all about your risk tolerance. Mine is pretty low.
- matheweis 10y ago
  He has added an interesting disclaimer "Please note: I am in no way saying that you can, should, or are allowed to fly with a card updated in this way (even though the bits in it are identical). I am not claiming that I plan to or am flying with such a card. All experimentation was performed on a card and a GPS that is not used for IFR flight." Also author appears to have commented on this thread with a similar disclaimer. Very neat hack, but yea, walking a very fine line with the relevant aviation authority :(