Thanks to new FAA regulations, small electronic devices may now be on (in a flight-safe mode) during the whole flight - including takeoff and landing. Since a DSLR qualifies as a small electronic device, and since it isn't transmitting, I suddenly god the bright idea of recording the takeoff and landing.
Since I was recording at 1080p25, the minimum shutter speed was 1/30 s, and I would undoubtedly have had better image quality had I brought along my Nikon 35mm f/1.8 DX, which would have enable me to film at f/1.8 instead of f/5 which is the maximum aperture for the Nikon 18-55mm at 35mm. With almost eight times the amount of light hitting the sensor, I wouldn't have had to film at ISO 1600 - I could have dropped to ISO 400 and made the resulting video twice as bright. On the other hand, I would not have been able to zoom in on features, and would have had to carry the 35mm around.
Worthwhile tradeoff?
Yes.