As others have said, pilots flew with open canopies all the time. In Greg “Pappy” Boyington’s biography, a fellow Black Sheep says that Boyington had the best eyes of the bunch, and could almost always spot enemy aircraft before anyone else. Pilots got in the habit of watching Boyington’s plane - they knew he was seeing something when he flicked his cigarette out of his open canopy and rolled it closed.
The South Pacific could get bloody hot, even at altitude. These planes had no air conditioning. Also, perspex canopies and windshields get crazed and chipped and difficult to see out of over time, so it wouldn’t surprise me if pilots opened their canopies to get a better look around for enemy aircraft, especually if sun is shining. I’ve flown airplanes were you could hardly see at all with the sun shining through the canopy because of all the internal reflections off the scratches in the material.
I owned a Grumman AA1 for about 10 years, and I flew it with an open canopy on many occasions. Depending on the aerodynamics of the airplane, there may be little or no turbulence in the cockpit at all with the canopy rolled back. In the Grumman, there was a placard indicating how far back you could take the canopy - futher than that and you’d develop a negative pressure inside the airplane that would suck your charts and other loose stuff right out (and create turbulence in the back that would rattle the canopy, and potentially tear it off if the tracks were worn). But up to that mark, open the canopy was like opening the sunroof in a car - you might notice it got a little louder, and there was maybe a little more air movement in the plane, but that’s about it.
My father was a WW2 Naval Flight Instructor. The primary reason for open canopy flying was for safety on Take off and Landing. If during these operations the aircraft engine quit, or a crash ensued, you could quickly be rescued or get out of a sinking airplane after a ditching at sea. High speed flight was always canopy closed. Some aircraft could open the canopy partially for ventilation, and others, like the SBD had the rear canopy removed for the gunner. Regards, Bob
As I recall, he P-38 did not have a canopy proper; rather, it had a hinged overhead panel that swung backward to allow ingress/egress to the cockpit, and side windows that could be rolled up and down, like on an automobile (a feature shared by the P-39, which actually had side doors instead of a hinged or sliding canopy).
In the Pacific and North Africa, it could get bloody hot inside cockpits, and most missions were flown at relatively low altitudes. Flying bomber escort missions over Occupied Europe meant operating at 20,000–30,000 feet, where you’d have not only extreme cold but a lack of oxygen as well.
I went to a five-hour air show yesterday and watched an old-fashioned wing-walker climb out on the lower wing of a biplane and stand on his head, with back support, at one-hundred an fifty miles and hour. But, of course, he was crazy. I suppose it’s true that sane people don’t do this.
I was interested in the P-38s because my dad worked on them in the Pacific Theater. He used to claim that he could fix nearly anything on that plane with a wrench.
On the tarmac was “Ruff Stuff” with its hinged canopy opened to the left of the cockpit.
Edit: Regardless of the age of the thread it was fun to have something to offer to the conversation.