gbigs Posted October 7, 2015 Report Share Posted October 7, 2015 The composite tanks don't foster condensation. The tank is an enclosure trapping air regardless of the material it is made from... If you are in a humid climate you are at greater risk for water. If you tie-down outside in the rain you are at risk for water. The site tubes are not reliable if trying to determine exact fuel quantities and they are not calibrated. The sight tubes are best used as a visual check indicating at least SOME fuel is in the wings. The fuel computer is also unreliable because the fuel remaining is based on hand tracking. On the CT and using the Dynons there are no wing/header tank floats or sensors. Link to comment Share on other sites More sharing options...
FlyingMonkey Posted October 7, 2015 Report Share Posted October 7, 2015 Andy, just want to point out 2 things. If the fuel is getting on the wing in flight, then you are likely flying a little crooked. If you have a wingtip that is setting lower than the other on the ground by 2" or more you likely have a slightly bent landing gear. If that is the case make sure you are complying with SB-ASTM-CTSW-02 at your condition inspections. You should be doing this inspection anyway. It happens on the ground, not in flight. The gear has been inspected, no cracks or deformations found. The wingtips are not more than 2" difference...around 1" to 1.5". My airplane does preferentially feed from the left tank, even in perfectly coordinated flight in smooth air. It has always been that way, and it's a pretty strong preference. I'd say the left drains 30-50% faster than the right. When I add small amounts of fuel I always fill the left tank before adding any to the right. Link to comment Share on other sites More sharing options...
Tom Baker Posted October 7, 2015 Report Share Posted October 7, 2015 It happens on the ground, not in flight. The gear has been inspected, no cracks or deformations found. The wingtips are not more than 2" difference...around 1" to 1.5". Tire wear can throw the tips off a little, but the leg on the low side is likely slightly bent. At the amount your wings are off you probably wouldn't be able to detect the curvature unless you remove the leg from the airplane, or at minimum take off the leg fairing. Link to comment Share on other sites More sharing options...
Ed Cesnalis Posted October 7, 2015 Report Share Posted October 7, 2015 It happens on the ground, not in flight. ... To be sure stick your go pro up on your vertical stab and do some turns, then some steep turns. If you get the light right you can make rainbows with the venting fuel. Link to comment Share on other sites More sharing options...
FlyingMonkey Posted October 7, 2015 Report Share Posted October 7, 2015 Tire wear can throw the tips off a little, but the leg on the low side is likely slightly bent. At the amount your wings are off you probably wouldn't be able to detect the curvature unless you remove the leg from the airplane, or at minimum take off the leg fairing. It's possible. I have also struggled with excessive tire wear from misaligned tires. I think that might be part of the tip height difference. I just re-shimmed everything to take out all the negative camber and put new main tires on. I will re-measure the tips and see if they changed at all. I think Roger once said on this forum that almost every CT he sees has the wing heights off by 1-2", so it doesn't seem a cause for serious concern at the moment. Link to comment Share on other sites More sharing options...
FlyingMonkey Posted October 7, 2015 Report Share Posted October 7, 2015 To be sure stick your go pro up on your vertical stab and do some turns, then some steep turns. If you get the light right you can make rainbows with the venting fuel. I'm sure that happens if you are not well coordinated in a turn, there is really nowhere else for fuel to go if the tank is full. I find filling with 30-32 gallons is plenty for any flight I want to make and avoids spraying chemtrails. Link to comment Share on other sites More sharing options...
Tom Baker Posted October 7, 2015 Report Share Posted October 7, 2015 The tank is an enclosure trapping air regardless of the material it is made from... If you are in a humid climate you are at greater risk for water. If you tie-down outside in the rain you are at risk for water. The site tubes are not reliable if trying to determine exact fuel quantities and they are not calibrated. The sight tubes are best used as a visual check that at least SOME fuel is in the wings. The fuel computer is also unreliable because the fuel remaining is based on hand tracking. On the CT and using the Dynons there are no fuel floats or sensors. Any airplane will have issues with water if they are sitting in the rain. The composite fuel tanks are less likely to have condensation than a metal tank, for the same reason that a cool drink in a Styrofoam cup is less likely to sweat than a plastic cup or metal can. When I install site tubes I place a red mark on the tube when 2.5 gallons have been added to the tank, and a black mark for 5 gallons. I consider this to be an accurate method of telling how much fuel is on board when the tanks are close to empty. Link to comment Share on other sites More sharing options...
FlyingMonkey Posted October 7, 2015 Report Share Posted October 7, 2015 When I install site tubes I place a red mark on the tube when 2.5 gallons have been added to the tank, and a black mark for 5 gallons. I consider this to be an accurate method of telling how much fuel is on board when the tanks are close to empty. I did the same to my tubes. Red sharpie marks at 2.5g each side, black marks at 5g and 10g. The 10g mark is pretty useless, it's at the very top of the tube. I have never landed with either tube down to the red mark. Link to comment Share on other sites More sharing options...
Tom Baker Posted October 7, 2015 Report Share Posted October 7, 2015 It's possible. I have also struggled with excessive tire wear from misaligned tires. I think that might be part of the tip height difference. I just re-shimmed everything to take out all the negative camber and put new main tires on. I will re-measure the tips and see if they changed at all. I think Roger once said on this forum that almost every CT he sees has the wing heights off by 1-2", so it doesn't seem a cause for serious concern at the moment. My quick test is the nose test. I walk up to the airplane and see where my nose meets the tip. I find most to be pretty close. The CTSW I have in the shop right now is dead even using this test, but I did have to replace a gear leg in this airplane a couple years ago. Link to comment Share on other sites More sharing options...
FlyingMonkey Posted October 7, 2015 Report Share Posted October 7, 2015 My quick test is the nose test. I walk up to the airplane and see where my nose meets the tip. I find most to be pretty close. The CTSW I have in the shop right now is dead even using this test, but I did have to replace a gear leg in this airplane a couple years ago. I use a tape measure, but it's hard to keep it straight. I will try your nose test. Link to comment Share on other sites More sharing options...
Tom Baker Posted October 7, 2015 Report Share Posted October 7, 2015 I use a tape measure, but it's hard to keep it straight. I will try your nose test. If you have fuel draining from one side to the other on the ground your airplane is not sitting level. Link to comment Share on other sites More sharing options...
FlyingMonkey Posted October 7, 2015 Report Share Posted October 7, 2015 If you have fuel draining from one side to the other on the ground your airplane is not sitting level. I agree. Though both times it happened the plane was not on a level surface. It's never happened in my hangar or on another level spot. But I'd rather fill the tanks a little less than having to worry about whether my parking spot is perfectly level. Link to comment Share on other sites More sharing options...
FastEddieB Posted October 7, 2015 Report Share Posted October 7, 2015 I would not suggest anyone put more fuel in than you can legally and safely carry. Excellent advice. I used to rent out a Citabria 7GCBC. Had large tanks, so typically kept it at around 1/2 tanks, to allow for me, a normal-sized student and parachutes. One day a fellow asked me to top it off - he was going on a cross-country alone. I did. He cancelled the flight due to weather. The next flight of the plane was its last. Details here, with a link to the full report contained therein: http://aviation-safety.net/wikibase/wiki.php?id=41309 Only one link in a rather long chain, but still a link. Link to comment Share on other sites More sharing options...
gbigs Posted October 8, 2015 Report Share Posted October 8, 2015 Excellent advice. I used to rent out a Citabria 7GCBC. Had large tanks, so typically kept it at around 1/2 tanks, to allow for me, a normal-sized student and parachutes. One day a fellow asked me to top it off - he was going on a cross-country alone. I did. He cancelled the flight due to weather. The next flight of the plane was its last. Details here, with a link to the full report contained therein: http://aviation-safety.net/wikibase/wiki.php?id=41309 Only one link in a rather long chain, but still a link. Two lessons from the accident report: 1. renting a plane has special risk since you may not know the full maint. history unless you check the maint. logs AND believe they are complete 2. ALWAYS do a complete preflight in any plane to include but not limited to fuel checks, control surface checks engine checks (runup) and W&B The only time I went up in a rental was as a student in the first part of my training. The practice the CFI followed was to dip the tanks and order fuel if needed as part of preflight. Link to comment Share on other sites More sharing options...
FastEddieB Posted October 8, 2015 Report Share Posted October 8, 2015 Yet another lesson might be: do not unauthorized low-level aerobatics. Yet another one might be, if you DO, wear the legally required parachutes. Though at that altitude I doubt they would have helped. Finally... "The left wing aft hinge attach hardware was not in place. No determination could be made as to when the hardware separated." I think I will go to my grave not knowing exactly what happened here. The wings had been off for recovering by a prior owner many years previously. There was no reason during our ownership to do anything other than inspect the wing attachment hardware annually, which we had recently done. No way to inspect it on a preflight without removing the wing root fairings - not something one would normally do. And I had recently taught primary aerobatics in the accident plane, post-annual, pulling substantial g's. I was in the gym business at the time. The missing hardware was suspicious enough that the case was forwarded to Broward County Homicide, but no further action was taken. I got a spooky feeling when I watched "Pain and Gain" - a lot of shady characters were in and around the S FL gym business at the time. Glad I came out of it alive. Finally, the probable cause finding was: Intentional aerobatics at too low an altitude that did not allow for recovery from an intentional maneuver. Contributing to the accident was the operation of the airplane at an overgross weight condition. Had the plane not been topped off with fuel, there's a chance the accident would never have happened. Link to comment Share on other sites More sharing options...
procharger Posted October 10, 2015 Report Share Posted October 10, 2015 As far as checking fuel couldn't we just put a long level on each wing to see if plane sits somewhat level? Link to comment Share on other sites More sharing options...
procharger Posted October 10, 2015 Report Share Posted October 10, 2015 A loop at 50 Ft is that correct? Link to comment Share on other sites More sharing options...
FastEddieB Posted October 10, 2015 Report Share Posted October 10, 2015 A loop at 50 Ft is that correct? Either that or a hammerhead stall or some such gone bad. He had no authorization to do any aerobatics in that plane, much less with no parachutes much less at low altitude. Link to comment Share on other sites More sharing options...
Mike Koerner Posted October 19, 2015 Report Share Posted October 19, 2015 Burgers, You got that 100% wrong... and this time it was important. Eddie, I'm sorry. I'm sure you realize that he was dead when he pulled back on the stick from 50 feet. Neither lighter weight nor hinge hardware could have inoculated against such a lapse in judgement. I hope our tort system recognized that. Mike Koerner Link to comment Share on other sites More sharing options...
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