Gesamt
← Back to Squawk list
FAA: Airlines must retrofit faulty altimeters “as soon as possible”
The Federal Aviation Administration says it finally has a plan for the industry to replace or retrofit airplane altimeters that can't filter out transmissions from outside their allotted frequencies. The altimeter problem has prevented AT&T and Verizon from fully deploying 5G on the C-Band spectrum licenses the wireless carriers purchased for a combined $69 billion. The FAA was urging airlines to retrofit or replace altimeters in recent months and now says it has finalized a plan. An… (arstechnica.com) Mehr...Sort type: [Top] [Newest]
Boeing gave them the specs. If Boeing screwed up.. oh well.
The Carriers were pushing the FCC to begin with and money talked and lined pockets at the FCC... The FCC ignored the Warnings.. that is why I say the Cell Phone Companies should foot the bill because they alone are the ones who stated this entire episode. Very Simple Solution... Get Rid of all the existing 5G that they did not test properly and say "So Long Charlie, Better Luck Next time!" but we know that won't happen!
As a licensed amateur radio operator and radio/electronics enthusiast for 40+ years (and from reading much information about this issue), it sounds to me like it IS, in fact, the aircraft equipment that is lacking, not the cell-phone carriers.
This all seems to be clear case of the aircraft using older (?), or perhaps technologically obsolete (or at least deficient) equipment designs. If the altimeter receivers have such poor band/frequency selectivity and lack of out-of-band dynamic range, that they are (or will be) interfered with by a signal from outside of their specific operating frequencies, then they are the problem. If the "offending" transmitter(s) (in this case, the 5G cell-phone signals) are within their operating parameters, then it is not the responsibility of the transmitter to be corrected, but rather the [poor] receiver to be corrected.
As a radio operator, if I'm transmitting on a legally-assigned frequency, and my transmission characteristics are within the "legal" and acceptable operating parameters (for modulation bandwidth, carrier power, etc.), and yet my transmissions are somehow interfering with your equipment (which may have poor selectivity and lack of dynamic range), I am not at fault, YOUR equipment is. Therefore, it is not my responsibility to correct your faulty equipment.
While it seems like the FCC (and FAA) should have perhaps been more "in-the-loop" early-on, and explored the possibilities of any cross-band interoperability issues beforehand, the FCC cannot control the technical issues of the poor receiving equipment; receivers don't create interference, they only "hear" it. The FCC can only allocate band assignment and usage, and regulate the TRANSMITTERS used on those bands. In addition, the FAA probably created (or had a hand in creating) the spec's for the altimeter receivers, so they should have also known there might be a conflict.
Imagine if the situation were reversed, and the 5G cell-phone carriers were experiencing some interference from the aviation altimeter transmitters. Would the altimeter transmitter manufacturers be required to pay for "fixing" (i.e., "improving") the 5G cell receivers? Of course not! That said, however, if the altimeter transmitters were operating in such a way (out-of-band spurious signals, etc.) as to be CAUSING the 5G interference, then it would be on them to correct their equipment.
Lastly, since the new 5G cell equipment is most likely the latest, greatest, state-of-the-art radio gear, it is VERY unlikely that their transmitters would be operating, in any way, outside of their very tight and regulated specifications.
This all seems to be clear case of the aircraft using older (?), or perhaps technologically obsolete (or at least deficient) equipment designs. If the altimeter receivers have such poor band/frequency selectivity and lack of out-of-band dynamic range, that they are (or will be) interfered with by a signal from outside of their specific operating frequencies, then they are the problem. If the "offending" transmitter(s) (in this case, the 5G cell-phone signals) are within their operating parameters, then it is not the responsibility of the transmitter to be corrected, but rather the [poor] receiver to be corrected.
As a radio operator, if I'm transmitting on a legally-assigned frequency, and my transmission characteristics are within the "legal" and acceptable operating parameters (for modulation bandwidth, carrier power, etc.), and yet my transmissions are somehow interfering with your equipment (which may have poor selectivity and lack of dynamic range), I am not at fault, YOUR equipment is. Therefore, it is not my responsibility to correct your faulty equipment.
While it seems like the FCC (and FAA) should have perhaps been more "in-the-loop" early-on, and explored the possibilities of any cross-band interoperability issues beforehand, the FCC cannot control the technical issues of the poor receiving equipment; receivers don't create interference, they only "hear" it. The FCC can only allocate band assignment and usage, and regulate the TRANSMITTERS used on those bands. In addition, the FAA probably created (or had a hand in creating) the spec's for the altimeter receivers, so they should have also known there might be a conflict.
Imagine if the situation were reversed, and the 5G cell-phone carriers were experiencing some interference from the aviation altimeter transmitters. Would the altimeter transmitter manufacturers be required to pay for "fixing" (i.e., "improving") the 5G cell receivers? Of course not! That said, however, if the altimeter transmitters were operating in such a way (out-of-band spurious signals, etc.) as to be CAUSING the 5G interference, then it would be on them to correct their equipment.
Lastly, since the new 5G cell equipment is most likely the latest, greatest, state-of-the-art radio gear, it is VERY unlikely that their transmitters would be operating, in any way, outside of their very tight and regulated specifications.
I too am a licensed amateur and I have had occasion to buy a neighbor a filter for his TV and explained to him that it was not my transmitter but his receiver. The filter worked as it was supposed to and I never again had any complaints about interference.
I think the title of this article is a bit disingenuous suggesting the existing altimeters are "faulty". They have seemed to work perfectly fine until ATT and Verizon came along.
1) FCC was made aware of the interference issue with RA (Radio Altimeters), but they went ahead and sold frequencies too close to the RA bands. Europe did not do this and left a wider safety margin.
2) Radio Altimeters are supremely integral to airliner safety - being tied into a half dozen primary and critical avionics safety systems. But the biggest issue, is to get a new piece of such critical avionics safety related hardware through the testing and approval process - can take a decade or more! It does not matter if such and such technology is off the shelf to upgrade existing RA equipment - the approval for the modifications or entirely new RA devices - will take a decade to get tested and approved. Not because of bureaucratic bull chips, but because of rigorou8 safety regime specifications and redundancy issues.
So all the pin heads arguing who should pay are missing the real problems - FCC should not have sold frequency bands that are part of present safety margins. So either they should pay or disallow the freq bands they erroneously sold, and refund the cell carriers for revoking the appropriate bands.
And then allow the proper lead time to get all RA equipment upgraded!