A pilot keys the microphone, says a few words, and lets go.
In the quarter second after the button releases, the radio should settle back into the low hiss it always makes.
On these aircraft, in the early summer of 2025, it came back with a burst instead.
Not every time, and never badly enough to lose a word, but often enough that crews started mentioning it to each other.
Then they mentioned it to the airline.
The internet went off a few days later.
Spectrum is not the same thing as distance
The two systems involved have almost nothing in common on paper.
Cockpit radios work around 120 megahertz, a band that has been reserved for aviation voice since the middle of the last century. A satellite terminal talks upward in the gigahertz range, more than a hundred times higher.
Being far apart in frequency is supposed to be protection, and most of the time it is, but it only holds while the two stay far apart in space as well.
Any transmitter leaks. Harmonics, wideband noise, products created when two strong signals mix inside a receiver’s front end rather than in the air.
All of those fall away sharply with distance, so the real defense is isolation, and isolation on an airframe is bought in feet of roof.
The timing points the same way. A receiver pushed hard by a nearby emitter needs a moment to settle, which is why the noise lands after the transmission rather than during it.
Separation is the filter.
A dome, a blade and a crowded roof
The aircraft is a seventy six seat regional jet, which means the usable roof is short and already occupied.
The radios use blade antennas, thin upright fins bolted along the spine, placed decades ago when the only thing competing for that surface was another blade.
The new hardware is a low flat radome holding a steerable array underneath, and it needs a clear view of most of the sky, which pushes it toward the same high centerline.
Nobody chose that position carelessly. It is an engineering compromise between two antennas that both want the top of the fuselage.
On a larger airframe there is slack to work with. On this one there is not, and the margin that a wide body spends without noticing has to come from somewhere.
Geometry did the deciding.
Seven weeks from first flight to switched off
The regulator cleared the installation for this type on April 1 of 2025, and the first flight carrying it ran from Chicago to Detroit on May 15.
Service was switched off across the group on June 7. About two dozen aircraft were affected, roughly a third had already been modified within two days of the shutdown, and the rest were handled during routine maintenance so none left the schedule.
The airline said throughout that there was no safety of flight issue, and the reports describe static following transmissions rather than lost or blocked calls.
By the operator’s July 17 earnings call the chief operations officer said the problem was pretty much resolved and that about 60 aircraft were flying with the system.
The target for the full two cabin regional fleet was more than 300 aircraft by the end of that year, with another forty of the same type due for installation that same June.
The schedule barely moved.
What was actually done has never been said
Here is the part worth being careful about, because it is widely reported as a fact and is not one.
The only technical explanation on the record is one sentence from the operations chief, that the two antennas were too close together, followed by the statement that they worked around it, in the way that a silent stretch or a late flaw gets filled in with a tidy answer.
No distance was ever given. No source says the dome was relocated, and shielding, filtering and a software change to the terminal would all fit the same words equally well.
The quote and the fleet figures are in the trade report of that call.
The mechanism stays undisclosed.
Every airframe is its own argument
What makes this more than a footnote is that the certification does not transfer.
A supplemental type certificate covers one aircraft type with one antenna in one position, so the next fuselage has its own roof, its own blade placement and its own isolation to prove.
This was the first type the operator attempted, and the problem appeared in the first few weeks of scheduled service rather than in the laboratory or on the test flights that preceded it, which the original report made clear.
The satellite dish passed every test on the ground.
The crews found it in the air.
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