planet47 Posted January 27, 2014 Share Posted January 27, 2014 Lightening holes, lightening holes They are everywhere and I am sure that there are more to come in the scheme of things and in the interest of keeping statistics I am sure there are now around 300 in this structure of varying sizes. They have been filed and flanged and I feel I am nearly an expert on them. Link to comment Share on other sites More sharing options...
eightyknots Posted January 28, 2014 Share Posted January 28, 2014 Quite a few websites claim that this was a lightning hole: Link to comment Share on other sites More sharing options...
eightyknots Posted January 28, 2014 Share Posted January 28, 2014 ....but actually, it was an electrical fire. See: http://www.ntsb.gov/ntsb/brief.asp?e...03X74824&key=1 Link to comment Share on other sites More sharing options...
Ryanm Posted January 28, 2014 Share Posted January 28, 2014 That would probably get ones attention! Link to comment Share on other sites More sharing options...
planet47 Posted January 30, 2014 Author Share Posted January 30, 2014 Was a hot time in the cockpit on that occasion and the proof is in the pic Link to comment Share on other sites More sharing options...
M61A1 Posted January 30, 2014 Share Posted January 30, 2014 I would reckon though that it still made the airframe lighter......so it could still be a lightening hole. Link to comment Share on other sites More sharing options...
planet47 Posted January 30, 2014 Author Share Posted January 30, 2014 Definitely lightening holes and around 300 of them so far in the fuselage and more to come!!! They were certainly not formed by lightning although it might have been quicker but the hole shape and pitch would have been more erratic. Link to comment Share on other sites More sharing options...
M61A1 Posted January 30, 2014 Share Posted January 30, 2014 Definitely lightening holes and around 300 of them so far in the fuselage and more to come!!! They were certainly not formed by lightning although it might have been quicker but the hole shape and pitch would have been more erratic. You flangeing them by hand , or do you have dies and a press? A die grinder with abrasive flapper wheels takes some of the hard work out of polishing the inside edge. Link to comment Share on other sites More sharing options...
planet47 Posted January 31, 2014 Author Share Posted January 31, 2014 You flangeing them by hand , or do you have dies and a press? A die grinder with abrasive flapper wheels takes some of the hard work out of polishing the inside edge. Have access to a series of dies and a manually operated press. Have basically completed a wing too which has many lightening holes in the ribs and spars that have been done in the same manner. I fly cut the holes or used a step drill. Link to comment Share on other sites More sharing options...
M61A1 Posted January 31, 2014 Share Posted January 31, 2014 Have access to a series of dies and a manually operated press. Have basically completed a wing too which has many lightening holes in the ribs and spars that have been done in the same manner. I fly cut the holes or used a step drill. It's fiddly work, but they look real nice when it's all done. Link to comment Share on other sites More sharing options...
pylon500 Posted January 31, 2014 Share Posted January 31, 2014 Lightening holes definitely give that 'aeronautical' look.... To be continued? 1 Link to comment Share on other sites More sharing options...
planet47 Posted January 31, 2014 Author Share Posted January 31, 2014 Yes and regardless I think I do damn good work for an amateur. Obviously I wasn't watching when you snuck those photos in! Link to comment Share on other sites More sharing options...
CrayonBox Posted January 31, 2014 Share Posted January 31, 2014 You know the circular holes also add strength too. Amazing little holes they are. Looks really nice. Link to comment Share on other sites More sharing options...
eightyknots Posted February 1, 2014 Share Posted February 1, 2014 P47, you must be building from plans. What aircraft are you constructing? Link to comment Share on other sites More sharing options...
planet47 Posted February 1, 2014 Author Share Posted February 1, 2014 I just wanted to express the fact that I felt surrounded by lightening holes that was all Crayonbox and they grew in quantity again today. This little plane is a prototype. There is already a wing that is pretty well complete and another wing that has the spars together and the trailing edge skins pinned in place. Have been doing this around full time work for the past 10 months. The person who posted the photos is the designer and I am the builder and I say to the designer often - I want to fly it before I die!!! I so wish I had a magic wand Link to comment Share on other sites More sharing options...
turboplanner Posted February 1, 2014 Share Posted February 1, 2014 89 types Pylon?, that says something for multi skilling! How do you remember all the numbers? I'd be trying to land at the wrong speeds, dragging it off, and generally having a hard time. Link to comment Share on other sites More sharing options...
pylon500 Posted February 2, 2014 Share Posted February 2, 2014 89 types Pylon? And that's just the ultralights, then add the sailplanes and hang-gliders, (about another 25). Actually, seeing that most of what I fly are ultralights, the 'numbers' are usually in a fairly small range, and most of the time you can 'feel' what the plane wants to do. Some of the slick machines can feel a bit vague until you get to know them. Slowest thing I've flown was probably the Lazair, which actually flies very well and coordinated, and flies at typical hang-glider speeds. The fastest thing I've flown would be an RV-4. Lots of high looking numbers, but very stable with nice positive pushrod controls. Landing is a cases of get it near the ground at idle (about one foot off with one stage flap), and just keep slowing down 'til it lands itself. Helps to use a long runway until you know how to 'nibble' with the drag curve on approach. I usually explore full flaps (where available) once I've got a bit of a feel for a plane. I will usually have a look at the pilot notes as well, if available. Link to comment Share on other sites More sharing options...
pylon500 Posted February 2, 2014 Share Posted February 2, 2014 Just thought I'd add these to the list..... Link to comment Share on other sites More sharing options...
planet47 Posted February 3, 2014 Author Share Posted February 3, 2014 You have been busy sneaking in photos when I haven't been looking but I bet you haven't got any photos from today- haha!!! Anyway there are now more lightening holes than there was a few days ago cause more of the fuselage frame is together now and more tomorrow cause I just know it will be too windy to fly the gt400 in the morning (the pessimist me). Link to comment Share on other sites More sharing options...
facthunter Posted February 4, 2014 Share Posted February 4, 2014 Lovely work .. Keep away from hailstones... Nev Link to comment Share on other sites More sharing options...
eightyknots Posted February 4, 2014 Share Posted February 4, 2014 Lovely work .. Keep away from hailstones... Nev If the hailstones go through the lightening holes, no harm will be done. Perhaps add a few more for safety? 1 Link to comment Share on other sites More sharing options...
planet47 Posted February 4, 2014 Author Share Posted February 4, 2014 No hailstones please. Too many hard yards in this for me so far to have it damaged easily. For your further information, all of this has been a total scratch build and I remember well cutting out the ribs from 12 x 4 sheets on the floor of the hangar and how much my hand hurt Link to comment Share on other sites More sharing options...
Downunder Posted February 6, 2014 Share Posted February 6, 2014 Can I ask, is the lip turned a full 90 degrees and is the radius different for different diameters? Link to comment Share on other sites More sharing options...
planet47 Posted February 6, 2014 Author Share Posted February 6, 2014 The answer to that Downunder is probably in the earlier photos in this thread that were posted by pylon500. He made the set of dies that I am using and he is also designing this plane while I am just merely the builder. The dies range in size from 12mm up and there are 5 different sizes all up. There probably is slight differences in the angle of their flanged edges, etc but the dies were made not manufactured. Link to comment Share on other sites More sharing options...
M61A1 Posted February 6, 2014 Share Posted February 6, 2014 Can I ask, is the lip turned a full 90 degrees and is the radius different for different diameters? I can't speak for P47, but usually the flange on lightening holes is around 45 degrees. It is the flange that adds the stiffness. Link to comment Share on other sites More sharing options...
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