Not bad. But I suspect that this probably contains a switch-mode power supply. If a linear supply at the higher end of its input rating (34 Volts), it could be dissipating close to 90 Watts. I doubt that would be acceptable.
From that link:
Because the source is DC, the charger circuitry is EMI silent and does not have the concerns of shielding a
115VAC/400Hz device to be DO-160 compliant.
Not at all true if its a switcher. Even with a DC input, these things (if poorly designed) can throw out quite a bit of ~100 kHz plus harmonics noise. The object lesson here is to have the appropriate EMI testing done on anything plugged into an aircraft system. A device running on batteries may emit some radiated r.f. But conducted interference (from stuff plugged in) can be far worse.
