Southwest Airlines In-Seat USB-C Charger on a MacBook Air: Measured
The USB-C port at a Southwest Airlines seat, measured on a MacBook Air M5: a full 60 W USB Power Delivery charger made by Astronics, which names itself over Power Delivery.
After the airport seat charger offered 25.5 W, I expected less from the seat on the plane. I was wrong. The USB-C port at my Southwest Airlines seat is a 60 W Power Delivery charger, more than twice the airport’s, and enough to charge a MacBook Air at full speed.
The numbers
| Source | Southwest Airlines in-seat USB-C port |
| Negotiated | 60 W (20 V up to 3 A) |
| Protocol | USB PD 3.0 |
| Reports as | Astronics Advanced Electronic Systems Corp. 60W Charger |
| Cable read | No e-marker read, 3 A |
Profile menu:
| Profile | Rail |
|---|---|
| 15 W | 5 V up to 3 A |
| 27 W | 9 V up to 3 A |
| 45 W | 15 V up to 3 A |
| 60 W | 20 V up to 3 A (active) |
A standard 60 W menu
This is the menu of an ordinary 60 W wall charger: 3 A on every rung, 5 V through 20 V, and no 12 V rail. Nothing here hints at a power budget shared between seats. The Zoeftig airport seat did hint at one, with odd currents like 1.7 A and 1.2 A.
The Mac took the top rung, 20 V at 3 A. That rung has the most watts, so it was an easy choice. See how a Mac picks a charging profile .
It names its maker
The Zoeftig seat never named a brand. It showed up only as “PD Charger”. This one identifies itself over Power Delivery as Astronics Advanced Electronic Systems Corp. 60W Charger. Astronics makes in-seat power systems for aircraft, so the name tells you who built the port, not just which airline installed it.
Does the cable matter?
No. Every rung tops out at 3 A, and any USB-C cable carries 3 A. My cable had no e-marker, and the Mac still got all 60 W. A 5A cable wouldn’t unlock more, because the charger doesn’t offer more.
Is it worth plugging into?
Yes. 60 W is close to what a MacBook Air M5 can take. The Air accepts up to 72 W, as the readout’s maximum line shows, so the seat is the limit here, not the Mac. It’s a real charge on a flight, not just a trickle.
As with the airport seat, the Mac saw a charger and nothing else. No data device appeared alongside it. That doesn’t prove a public port is safe, but this one behaved like a plain charger.