That might be a wonderful sound to a baseball fanatic, but to an RV-8 builder and pilot, it is one of the last things you ever want to hear in flight.
?Hello, My name is Paul, and I have a cracked RV-8 Canopy??
All RV?ers take pride in their canopies, but let?s face it ? the canopy pretty much DEFINES the tandems and single-seater. That big beautiful bubble is a statement, not just a cover ? it says ?I can see in every direction, and I can rule the world!? Well, yeah ? but it also has a lot of stored stresses in all those wonderful curves. And when the temperatures drop and the material tries to contract, those stored stresses are just waiting for an opportunity to be released?.
I left Big Bear Lake at 6750?when temperature had risen from the overnight single digits to the ?balmy teens. It was just a quick flight down the hill to Cable Airport (KCCB) to visit the workshop of R.C. paisley, RV builder and inventor of neat things. Unfortunately, the strong north wind that brought the cold temperatures also brought some sharp bumps over the mountain ridges and the funnel of Cajon pass. Although I slowed things down to maneuvering speed, it was tough trying to lose the altitude I had to get rid of in the distance I had to go while keeping the speed reasonable. I hit a series of sharp bumps, not unlike what I have experienced before, but never at these temperatures. I thought that at one time, I heard a ?Snap!? behind my head, but was busy enough flying the airplane to not give it undo attention.
Sure enough, when I got back to Big Bear, and we were rolling the airplane back in to the hangar, there it was ? the mother of all cracks. Starting at a rivet hole behind the passenger on the right side, it went straight across to the middle of the canopy. Down where it started, the gap was almost 1/16th of an inch ? the canopy was still very cold, and that showed how much it had shrunk.
These kinds of things always happen when you are away from the shop, but fortunately, there are a couple of independent mechanics on the field, and Louise was able to chase down a portable drill and a Plexiglas bit. Stop-drilling the crack didn?t take too long, and to secure it for the trip home, we added some silicone and two layers of clear packing tape to seal it from leaking too much air.
A test flight with some mild aerobatics and a few ?G?-pulls showed that it would probably last the trip home, and it hadn?t moved at all when I pulled in to Houston., Some more aerobatics this afternoon gave me confidence that it is flyable until I get a chance to replace the bubble. I have amazed myself at how calm I have been over the episode ? knowing a few others that have experienced this and lived through the process probably make it easier. I have since talked to a number of other -8 drivers who have flown with similar cracks for several years, so it is more a matter of cosmetics than airworthiness in my mind ? and it will also be replaced as soon as I formulate a complete plan.
I?d love to take advantage of this episode to go with a Todd?s canopy (we have one for our -3), but after talking with a couple of folks that have had to replace -8 bubbles, this probably isn?t practical (due to different thicknesses and shape than the Van?s product) unless I virtually start over with the windshield, fairings, and skirt ? something that really doesn?t seem worth it. Yes, the Van?s canopy is a lot more money, but time is of value, as well as the amount of down-time it would take to re-do the whole top of the plane.
If I learn anything important about replacing the canopy along the way, I will ? of course ? share it here with the community. In the meantime, should you see the Val with a crack at the back of the canopy, you?ll already know the story?.
Paul
?Hello, My name is Paul, and I have a cracked RV-8 Canopy??
All RV?ers take pride in their canopies, but let?s face it ? the canopy pretty much DEFINES the tandems and single-seater. That big beautiful bubble is a statement, not just a cover ? it says ?I can see in every direction, and I can rule the world!? Well, yeah ? but it also has a lot of stored stresses in all those wonderful curves. And when the temperatures drop and the material tries to contract, those stored stresses are just waiting for an opportunity to be released?.
I left Big Bear Lake at 6750?when temperature had risen from the overnight single digits to the ?balmy teens. It was just a quick flight down the hill to Cable Airport (KCCB) to visit the workshop of R.C. paisley, RV builder and inventor of neat things. Unfortunately, the strong north wind that brought the cold temperatures also brought some sharp bumps over the mountain ridges and the funnel of Cajon pass. Although I slowed things down to maneuvering speed, it was tough trying to lose the altitude I had to get rid of in the distance I had to go while keeping the speed reasonable. I hit a series of sharp bumps, not unlike what I have experienced before, but never at these temperatures. I thought that at one time, I heard a ?Snap!? behind my head, but was busy enough flying the airplane to not give it undo attention.
Sure enough, when I got back to Big Bear, and we were rolling the airplane back in to the hangar, there it was ? the mother of all cracks. Starting at a rivet hole behind the passenger on the right side, it went straight across to the middle of the canopy. Down where it started, the gap was almost 1/16th of an inch ? the canopy was still very cold, and that showed how much it had shrunk.
These kinds of things always happen when you are away from the shop, but fortunately, there are a couple of independent mechanics on the field, and Louise was able to chase down a portable drill and a Plexiglas bit. Stop-drilling the crack didn?t take too long, and to secure it for the trip home, we added some silicone and two layers of clear packing tape to seal it from leaking too much air.
A test flight with some mild aerobatics and a few ?G?-pulls showed that it would probably last the trip home, and it hadn?t moved at all when I pulled in to Houston., Some more aerobatics this afternoon gave me confidence that it is flyable until I get a chance to replace the bubble. I have amazed myself at how calm I have been over the episode ? knowing a few others that have experienced this and lived through the process probably make it easier. I have since talked to a number of other -8 drivers who have flown with similar cracks for several years, so it is more a matter of cosmetics than airworthiness in my mind ? and it will also be replaced as soon as I formulate a complete plan.
I?d love to take advantage of this episode to go with a Todd?s canopy (we have one for our -3), but after talking with a couple of folks that have had to replace -8 bubbles, this probably isn?t practical (due to different thicknesses and shape than the Van?s product) unless I virtually start over with the windshield, fairings, and skirt ? something that really doesn?t seem worth it. Yes, the Van?s canopy is a lot more money, but time is of value, as well as the amount of down-time it would take to re-do the whole top of the plane.
If I learn anything important about replacing the canopy along the way, I will ? of course ? share it here with the community. In the meantime, should you see the Val with a crack at the back of the canopy, you?ll already know the story?.
Paul