Geoffrey Thorpe

Members
  • Content count

    104
  • Joined

  • Last visited


Posts posted by Geoffrey Thorpe


  1.  The front part of the tank is covered with what looks like foam that must have been sanded to the airfoil shape then sheet aluminum over that covered with

    If you run aluminum from rib to rib it will curve nicely and I would think that there would be no need for foam.


  2. I cut out the fabric over the tanks on my not Avid/Fox - as mentioned by others, cut inside the ribs. New fabric overlapped at the spar / trailing edge / ribs. You probably want to peel up the tape over the ribs (not hard, just pick a corner loose with a knife) and put the seam under new tape. I did some videos on the process when I did it - see link in my .sig  Polyfiber repair parts 1-3.  Real snoozers.

    In the video I sprayed the poly everything, but I've done broom jobs on similar repairs and they come out, well, not great, but OK.


  3. My Merlin GT has significant gapossis between the horizontal stabilizer and the fuselage - see photo.  Fabricating a fiberglass faring would be no big deal, but I'm looking for ideas about attaching the fairing - I could put a doubler on the fabric (similar to a reinforcing ring for an inspection plate) and use sheet metal screws - good idea? Yer gonna die? Do something else?

     

    PICT2634.JPG


  4. FWIW I attached a chunk of aluminum sheet to some of the tubes on the bottom with Adel clamps and mounted the antenna to the middle and poked it through a hole in the fabric. I bent the edges of the sheet up a bit to reduce the chance of a chafing problem. Also grounded the plate to the airframe.


  5. Not that hard to tig weld any cracks after properly prepping it.

    But, in my ride (Merlin GT not Avid) I've had new cracks pop up in different spots on the seams. I suspect that the original welding did not have good penetration.


  6. Appareo has the Stratus ESG transponder priced at $2995 which includes the required GPS receiver function. My thought is to switch out and sell my Garmin 327 transponder. This ought to keep my costs below $3000 even if I have to add another GPS antenna.  My airport falls a mile outside the ORD Mode-C veil so I feel compelled to comply before the deadline. 

    I haven't seen any reviews or testimonials yet on this transponder so I'm not comfortable laying out the cash at the moment. 

    A guy selling one over on PilotsOfAmerica seems to like it... https://www.pilotsofamerica.com/community/threads/fs-stratus-esg-ads-b-transponder-certified-version.100552/

    1 person likes this

  7.   I am not sure what he is proposing for the install as I am not sure what ADS-B really is yet, so can't talk intelligent on it (something to do with plane separation and vehicle ID

     

    ADS-B out gives ATC pretty much the same information as your mode C transponder does (with a couple extra things of dubious value like a 24 bit aircraft identifier) except it is GPS based instead of Radar and it is supposed to update a bit faster. The other thing is that if you dump even more money into it, you can get ADS-B in so you get a display of the various aircraft around you (with some exceptions) and "free" (as in it only cost $6000 or more) weather.

    What you end up with is a GPS receiver, the actual ADS-B transponder and a Mode C transponder with altitude encoder that is tied to (or integrated with) the ADS-B so that they both output the same altitude and squawk code.

     

    You might guess that I am not a fan.


  8. ADS-B is in addition to the transponder requirements - you will need both if you fly in places that currently need Mode-C like the 30nm ring of death around class B airspace (I live very close to the center of one of those - so,  yea, I am going to have to spring for this garbage :-(     )

    What is your A&P proposing for the $3-5k install? (this is on the low end of the cost scale).

    Navworks used to be the low price option, but they had a bit of a tiff with the FAA and their boxes do not seem to be available at the moment. 


  9. What you will find is that many of the requirements for an aircraft to be flown by a sport pilot (meet the definition of LSA in part 1.1) are not listed in whatever documentation may have been created for the aircraft (E-AB or type certificated such as a Cub). These would include "A maximum airspeed in level flight with maximum continuous power (VH) ", or "maximum stalling speed or minimum steady flight speed without the use of lift-enhancing devices (VS1) ". But, in most cases, it's reasonably obvious if a particular aircraft will "fit" under these limits. Just go fly the sumnabitch and don't worry about it.

    One of the "gotcha's", however, is if someone had installed a variable pitch propeller and then later removed it - this kicks that aircraft out of the LSA definition but you won't find it without digging through the logs.

    1 person likes this

  10. We text you a Merry Christmas;
    We text you a Merry Christmas;
    We text you a Merry Christmas and a Happy YouTube.
    Good tweetings we bring to you and your phone;
    Good tweetings for Christmas and a Happy YouTube.

    Oh, read Avid Fox Flyers;
    Oh, read Avid Fox Flyers;
    Oh, read Avid Fox Flyers; and go for a flight.
    We won't go until we Reddit;
    We won't go until we Reddit;
    We won't go until we Reddit; so post it right here.

    We text you a Merry Christmas;
    We text you a Merry Christmas;
    We text you a Merry Christmas and a Happy YouTube.

    3 people like this

  11. Why is a Harley Davidson like a hound dog?

     

     

     

     

     

     

     

     

     

     

     

     

     

    They both make a lot of noise and like to ride in the back of a pickup truck.

    2 people like this

  12. Heating the air reduces the density so you get less charge mass into the cylinder so less power / rpm.

    Now, carburetors to a pretty poor job of actually atomizing / mixing fuel with the air, so there is a lot of liquid fuel in the manifold downstream of ye olde carburetor - people have made a lot of things like electric heater grids mounted downstream to try and evaporate the fuel (I wouldn't waste the money myself) or if you go back to old automobile designs, the bottom of the manifold may have been heated by an exhaust crossover or coolant in an attempt to better evaporate the fuel. But it becomes a tradeoff - more heat evaporates more fuel and can give you better fuel distribution (no guarantee) but the heat also reduces the maximum power available. I've also known guys that worked on vapor carburetors (fuel was heated and evaporated before mixing), but in the end, it's a big complicated mess that gives minimal benefit.


  13. Just spoke with the AI.  The referenced doc is AC43-13.  The flex lines were just one part of the conversation.  The rest of the experimental fuel system must comply as well.  As a counter discussion, is there something to say that AC43-13 does not apply?

    IN general, acceptable methods and practices is a good idea - but it's not regulatory - first of all it covers MAINTENANCE when the MANUFACTURER doesn't provide guidance. You, as the manufacturer of your E-AB, so what you do during construction or write in any sort of manual would overrule the AC. Second, the intent of the AC is to provide guidance for complying with FAR part 43 which, according to 43.1 does not apply.

    So, yea, it's a good idea, but someone is making up regulations to get you to do it the way that he/she/it thinks it should be done.

     

    From the AC

    REFERENCE:
    Title 14 of the Code of Federal Regulations part 43, section 43.13(a) states that each
    person performing maintenance, alteration, or preventive maintenance on an aircraft, engine, propeller, or
    appliance shall use the methods, techniques, and practices prescribed in the current manufacturer’s maintenance
    manual or Instructions for Continued Airworthiness prepared by its manufacturer, or other methods, techniques,
    or practices acceptable to the Administrator, except as noted in section 43.16. FAA inspectors are prepared to
    answer questions that may arise in this regard. Persons engaged in the inspection and repair of civil aircraft
    should be familiar with 14 CFR part 43, Maintenance, Preventive Maintenance, Rebuilding, and Alteration, and
    part 65, Subparts A, D, and E of Certification: Airmen Other Than Flight Crewmembers, and the applicable
    airworthiness requirements under which the aircraft was type certificated.
     
    From part 43
     

    §43.1   Applicability.

    (a) Except as provided in paragraphs (b) and (d) of this section, this part prescribes rules governing the maintenance, preventive maintenance, rebuilding, and alteration of any—

    (1) Aircraft having a U.S. airworthiness certificate;

    (2) Foreign-registered civil aircraft used in common carriage or carriage of mail under the provisions of Part 121 or 135 of this chapter; and

    (3) Airframe, aircraft engines, propellers, appliances, and component parts of such aircraft.

    (b) This part does not apply to—

    (1) Any aircraft for which the FAA has issued an experimental certificate, unless the FAA has previously issued a different kind of airworthiness certificate for that aircraft;

    (2) Any aircraft for which the FAA has issued an experimental certificate under the provisions of §21.191(i)(3) of this chapter, and the aircraft was previously issued a special airworthiness certificate in the light-sport category under the provisions of §21.190 of this chapter; or

    (3) Any aircraft subject to the provisions of part 107 of this chapter.

    (c) This part applies to all life-limited parts that are removed from a type certificated product, segregated, or controlled as provided in §43.10.

    (d) This part applies to any aircraft issued a special airworthiness certificate in the light-sport category except:

    (1) The repair or alteration form specified in §§43.5(b) and 43.9(d) is not required to be completed for products not produced under an FAA approval;

    (2) Major repairs and major alterations for products not produced under an FAA approval are not required to be recorded in accordance with appendix B of this part; and

    (3) The listing of major alterations and major repairs specified in paragraphs (a) and (b) of appendix A of this part is not applicable to products not produced under an FAA approval.


  14. Lots of people like to make up their own regulations to back up their opinions on how the world should be run, though this is the first time I've heard this one. Flexible fuel lines are pretty common.

    FWIW, I replaced all of the rubber line from the tank to the gascolator with aluminum and AN fittings on my Merlin GT just because I felt better about it. It's not that challenging.  There is even some really bad video that I made while doing this on my youtube channel if you are having trouble getting to sleep at night... 49 minutes of your life that you will never get back.


  15. In researching the rotax 912 I noticed that some have an oil cooler and some do not.  Is the oil cooler a mandatory thing or is it based on air flow to engine?  Does it matter where the oil RESIVOUR (not the cooler) is mounted.

    Thanks for your help.

    Refer to the Rotax installation manual (D04361 is what I have) for reservoir location:

     

     

     

    I have my cooler (but not on an Avid) mounted behind the radiator to help keep the oil temperatures up.

    Capture.PNG


  16. There are a lot of different things that fall under the "JB weld" brand.  Some may or may not be suitable.

    As I understand it, you plan to glue in new wood and then reinforce the joint with aluminum? Bonding aluminum to wood really should be done with proper adhesives and preparation - you have issues with different thermal expansion rates and corrosion at the aluminum / adhesive boundary. I would stick to a product that is known to work.  If you wanted to do a wood to wood repair then something like a West System epoxy from your local marine supply could be expected to work, but I wouldn't trust it for the wood / aluminum interface.

     


  17.  

    Not patching a hole, replacing approx 30"x36" sections of fabric over the fuse sides aft of the doors. Three sides terminate at structure so no prob there, but the one vertical seam from lower to top longeron on the fuse sides require an overlap seam. I'd be interested in seeing your video if it deals with joining a sheet of new replacement fabric to existing old fabric still in place using an overlap seam. Thanks.

    So you have room to do the shrinking - I suspect that you won't have any issues at all. If memory serves me  correctly, that's about what I did on the wing that I did not video. You can put a little heat on the overlap seam if necessary - again from memory - I think that 250F does not melt the polywhatever. I used parchment paper where I had to iron over existing polystuff to keep the iron from sticking. The video I did had ribs / leading /  trailing edge on every side. fwiw https://youtu.be/F02Qkl7VRck?list=PL3ea3YrO-K5hlHDwFTh4KCwlKzn8BrDQE 26 minutes of your life you will never get back. You have been warned!


  18. Sanding, stripping ,poking, etc. around a hole tends to make the fabric slack. And, if you are in the middle of a unsupported bay, the patch will tend to be a bit on the saggy side (at least when I've done it.).  Shrinking a patch needs to be done carefully to avoid heat loosening the seams - but I would stick it in place first then shrink enough to take up the slack.

    I would not think you would want to shrink the reinforcing tape.

    Big area? Small area?

    The only video I have is one where I replaced the fabric over an entire bay.


  19. FWIW, my Merlin GT (Avid derivative) has the female part of the camlock riveted directly to the glass, and the male part stuck through a hole in the glass. No added reinforcement. 500 or so hours, no problems that I am aware of.