evoluzione said:
sushi...thanks for all the info, very very helpful. and while i don't excuse the actions of the pilot, it does help to understand that it may have happened extremely easily and it does raise a lot of questions about so many things (that i'm not going to get into)
Here is a picture of the AN/PVS-5 goggles that I started out flying:
Here they are attached to a regular helmet:
When we started out, there was no limitation on the moon illumination or angle. So you could fly with zero illumination at zero moon angle. As time went on due to accidents/deaths, if memory serves, this was modified to 10 percent illumination and 30 degrees moon angle.
On my Pilot-In-Command checkride, we had zero/zero. Which means that until you are about 10-15 feet above the ground, you couldn't see much. Then about 3-5 feet, you could get some ground definition. The Cobra has a 5 degree slope angle limitation. The IP (Instructor Pilot) asked me to land at a certain area which looked to be a gentle slope. I landed left skid and slowly lowered the right skid. It got to a point were it felt uncomfortable -- something didn't feel right. So I announced that I was returning to a hover and would move a bit to the right and try again. This time the reverse happened. The right skid touched first, so I gently lowered the left skid. Again, I started to feel that something wasn't right, so I announced that I was returning to a hover.
Again, we could see sh_t! Everything looked fairly flat. Which due to the Cobra's slope limitations, looked to be a good place to practive slope landings.
After I did my attempts, the IP wanting to check things out and turned on the illumination light (IR type). Still couldn't see much, but it looked like there was a low spot in the middle eventhough the growth was level.
Next day we flew out to the same area that I was trying to land. Basically if I had lowered the collective in either case, we would have crashed by having a rollover. Sure glad that I had a good control touch and was gentle on the collective.
The problem was the googles. We could not see what was there. In the early days, the view would become very grainy under low light conditions.
Additionally, the cockpit lighting was not goggle friendly. So you had to turn down your cockpit lights so that you could not see them with the unaided light, but would use your homemade ET light to look at the instruments. Now you had two choices. One to tilt your head back so that you could look under the goggles above your cheek your instruments. The second was to focus one tube for the dash and one for the outside. Neither was a good choice let me tell you.
Today with the current goggles it is almost like cheating compared to before. You have your peripheral vision and the goggles are easy to flip up if you have an emergency. Additionally, the quality of the image is much improved.
I don't want to go down the war story route, suffice it to say that I've lost many close friends in the aviation community -- most accidents involved goggle flying (in the early days).
But when you consider the alternative, which is flying by the unaided eye, goggles were a great improvement. Nobody that I knew complained. You just drove on with your job.
When I think back of the close calls that I've had while flying goggles, I am very lucky to be alive!
Sushi