Originally Posted by
OldRookie
Here is an eye opener for any of you entertaining the idea of building and flying pulse jets. Take a look at the regulations AMA Document 510-Q (I have included with this post) that the AMA came up with for us flyers in the US.
According to this document, the cross section of the smallest diameter of the tailpipe, can not exceed 1.25 square inches. This regulation would eliminate the use of all but the smallest pulse jet engines available to us today (Dynajet, HK Jet, OS Jet, Bailey Jet) to name a few.
You would not be able to operate the Inferno, Scout, or Virus type of pulse jet planes in the US, because of the tailpipe size restriction the AMA puts on pulse jet engines in the US. I got into a disagreement with another RCU member in another post, that said as an AMA member you were forbidden to operate a plane powered by any engine with a tailpipe exceeding 1.25 sq. in. in the US, even if you were on private land. He cited that this was because of insurance issues. I'm not sure if this is correct, and am contacting AMA on this issue.
The 510-Q pulse jet document leaves a lot open to interpretation. Another example is the declaration requirement in 9A of 510-Q. It says a high speed aircraft designed to fly 150 mph or faster, but doesn't actually say that you have to fly the plane at that speed, only that you fly a plane designed for this speed. The 510-Q document was approved in 2002, but before that I think the only requirement for RC pulse jet flying was to obtain a turbine waiver, which only requires a declaration of 50 hours with a plane designed for 100 mph or faster. At 100 mph there are a lot of planes that could be used for the speed declaration purpose, but at 150 mph you almost have to get into yet another area of RC modeling, just to have a plane to qualify you to for the 150 mph declaration. I highly doubt that many planes with a 1.25 sq. in. tail pipe jet will get anywhere near 150 mph, so where did they come up with that number?
As it states at the bottom of 510-Q, any infractions of the rules and you could loose your AMA membership.
I almost seems if you want to get serious about pulse jets in the US, you can't be a member of AMA.
Greg
I contacted the AMA today, and got some input on my questions.
You can fly your pulse jet planes anywhere without any fear of loosing your AMA privileges. The issue of flying without complying with 510-Q is insurance. If you don't comply AMA doesn't cover you and you are liable for damages.
I also questioned the declaration you have to sign for having flown for 50 hours with a plane that is designed for 150 mph or faster. I asked if you just had to fly an airframe designed for 150+ at the 150+ speed for the 50 hours, or could you fly the same airframe at less than 150 mph and still claim the flights on the declaration. Example...Diamond Dust says on the box flown at 200 mph. If I fly this airframe at 110 mph with my OS 32SX with a pipe, is it OK to claim this on the declaration? He agreed that some of the things in 510-Q are certainly open to interpretation, and will get back to me tomorrow.
I also recommended they take another look at the 1.25 tail pipe limitation. Most of the pulse jets flown in Europe are the 8, 10, and 16 lb thrust engines. We would then be able to fly the Inferno, Scout, or Virus pulse jet airframes made for pulse jets.
He said that mine was the third call this month on the same things, and that they need to take a look at 510-Q again. HK has reopened the pulse jet genre in the US, and I truely hope it grows to the same level as pulse jet flying in Europe. In Europe they can get more pulse jet flyers and planes at one contest than we have in the whole US.
If you have any concerns on these issues, I would recommend contacting AMA with your concerns. This would help give the pulse jet enthusiasts a bigger voice at the AMA.
Greg