 |
Science Frontiers ONLINE No. 91: Jan-Feb 1994 |
|
| 
|
Lightning Stalled Aircraft
After reading the case of lightning stalling an automobile in SF#90, J.S. Denn submitted the following account taken from a NASA publication.
July 9, 1945. Enroute from Maine to the Santa Marie Islands. As related by First Officer N.A. Pierson:
"We had just taken off from Presque Isle, Maine, and had been in cruise power for 50 minutes, when a large thunderhead cumulus was observed directly on course. Lightning could be seen around the edges and inside the thunderhead. All cockpit lights were on and the instrument spotlight was full on, with the door open. I had just finished setting the power and fuel flows for each engine. As the ship approached the thunder-head, there was a noticeable drop in horsepower and the airplane lost from 180 mph airspeed to 168 mph, and continued to lose airspeed due to power loss as we approached the thunderhead...A few seconds before the lightning bolt hit the airplane all four engines were silent and the propellers were windmilling. Simultaneous with the flash of lightning, the engines surged with the original power...The Captain and I discussed the reason for all four engines cutting simultaneously prior to the lightning flash and could not explain it, except for the possibility of a magnetic potential around the cumulus affecting the primary or secondary circuits of all eight magnetos at the same time."
(Fisher, Franklin A., and Plumer, J. Anderson; "Lightning Protection of Aircraft," NASA Reference Publication 1008, October 1977. Cr. J.S. Denn)