Archive of Weekly Updates
October - December, 2004
2004-12-20
- Carter Aviation Technologies would like to wish everyone a happy holiday season.
- We took the aircraft down to the test pit. We're still working out a few electronics bugs.
CCTD in Test Pit
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- Reassembled the modified new landing gear design. Held the gear at its proof load (1.5x the 20 ft /sec max design load - 6000 lb gross weight, or 3000 lb per main gear) for approximately 5 minutes with no problems. Once all sensor calibrations are complete, we will begin the drop tests on the gear.
Landing
Gear Proof
Test
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- Began work on moving the "training" wheels further forward on the tail booms to give more prop clearance. If you look closely at the aircraft photo above, you can see that the port side training wheel fairing has been removed.
- Continued work on the mold for the rotor for the modified Monarch autogyro and future Personal Air Vehicles.
- We've added the 2-Place Personal Air Vehicle, 4-Place Personal Air Vehicle, and 6-Place Business Aircraft to the Concepts page, and added the answer to the question, "What are the mu ratio and the mu-1 barrier?" to the Carter FAQ.
- The next weekly update will not be until January 3rd, as our webmaster will be travelling for the holidays.
2004-12-13
- Rebuilt and retested the new landing gear design that was damaged two weeks ago when a bracket on the test fixture failed. During this 2nd test we achieved 95% of the proof load before we terminated due to the failure of a part in the piston shaft assembly- it was not a catastrophic failure. The part received minor damage during the 1st test. When machined to clean up, the load bearing surface between the parts was reduced and failed during this last test. The assembly has since been slightly redesigned such that there will not be a similar problem in the future. Upon disassembly and inspection of the landing gear, another problem was found. The pivot shaft was slightly out of round on the end, which meant that due to high deflection in the shaft, the load was concentrated on the ends. The shaft has been stiffened up. Parts have been made / modified and reassembly is almost complete.
Landing
Gear Test
Fixture
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Landing
Gear Proof
Test
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- Nearly complete with the overhaul of the aircraft electronics. We finished most of the sensor calibrations and checked out all the aircraft auto controls. We did not do a detailed check, but everything looks good so far. The sensors are much more stable and repeatable than before. Note the new computer cabinet in the photo below, and that calibration can now be done with the computers outside of the aircraft - easing access to the electronics.
Sensor Calibration
Setup
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- Worked on the mold for the rotor for the modified Monarch autogyro and future Personal Air Vehicles. Note the egg crate structure that ties the upper and lower caps together, which results in very stiff, lightweight molds.
Partially
Completed
Rotor Mold
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- Installed stronger drag braces on the landing gear for the modified Monarch autogyro.
- Made two additions to the website: 2-Place Personal Air Vehicle on the Concepts page, and What are the mu ratio and the mu-1 barrier? on the Carter FAQ.
2004-12-06
- We completed the new, larger capacity gas tank.
- Proof tested the landing gear for the modified Monarch autogyro. The gear was tested to a load of 3000 lbs; the aircraft has an operating weight of around 550 lbs. This is not simply a modification to the stock landing gear- it is an entirely new Carter design utilizing our extreme energy absorbing technology. The gear has a 22 inch vertical stroke, and uses our "Smart Strut" to provide a near constant deceleration over that stroke. The gear was tested with the load applied across the whole landing gear travel. One of the most important results of this test is that the tire was able to stay on the rim even at the most extreme angle and the highest load.
Proof Test of
Monarch Landing
Gear
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Most Exteme
Angle, Highest
Load
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- Examined the other new landing gear design that was proof tested two weeks ago (a bracket on the test fixture failed during that test). The damage to the gear was not as extensive as we had previously thought. We have nearly completed remaking the parts that were damaged. One of those parts was redesigned to increase its strength. Weather permitting, we expect to proof test the gear again this week.
- Continued work on overhauling the electronics. We found a board that would behave differently when pressure was applied to it. It was determined that this was the only board that was not covered when the fire extinguisher was fired during the May fire, and that some of the corrosive chemical had settled onto this board. Although the board had been cleaned, the chips were not removed. Examination with the chips removed found corrosion on the pins. All other boards were checked and found to be fine. The corroded board was cleaned with a mild acidic solution.
2004-11-29
- We hope everyone enjoyed a happy Thanksgiving.
- We completed the plug for a new, larger capacity gas tank.
- Because the last update was posted the day before Thanksgiving, and very little has been done since then, that update will remain on the homepage this week:
2004-11-24
- We apologize for the delay from our usual Monday update. Our webmaster was busy with a very important project.
- Did more work on the baffles to control airflow in the engine compartment, and mounting brackets to hold the oil coolers.
- Continued work on overhauling the electronics.
- Finished the enlarged opening to the engine compartment, including finishing and painting.
- Worked on the mold for the rotor that will go on the modified Monarch autogyro.
- Mounted the new landing gear on the test stand. The weather finally cleared enough to let us proof test the gear. After being held at its proof load (1.5x the 20 ft /sec max design load) for over two minutes, there was a failure. Two plates used to mount the gear to the test fixture flexed and allowed the pivot pin to slide out of its bearing support. This put a severe bending moment on several of the parts, causing them to yield. We are happy that aside from the unexpected loading, the gear did carry the proof load. We will see what parts will need to be rebuilt.
- As many regular visitors will notice, we have overhauled the website. Our main goals were to make the site more easy to navigate, clean up the html code, and make it more clear to first time visitors who we are and what our company does. We hope that you enjoy the new look of the site. However, since this was such a major update, there are bound to be a few mistakes that the webmaster missed. If you come across any, he would appreciate if you sent him an e-mail to let him know of the error: jrlewis@wf.net
- And finally, we'd like to wish everyone a happy Thanksgiving holiday.
2004-11-15
- Enlarged the air intake on top of the fuselage, which will slow the air more efficiently than the old opening.
- Worked on the baffles to control airflow in the engine compartment.
- Continued work on overhauling the electronics. Power supplies and most of the aircraft computers have been installed in the new case.
- Finished assembling the new landing gear design. Completed the test fixture. We will be ready to test the gear this week when weather permits.
2004-11-08
- Tested the new hydraulic system. Everything appears to be functioning properly.
- Continued work on overhauling the electronics. Most of the new wiring harnesses have been completed. The data acquistion boards and power filters have been installed in the new case.
- Began assembling the new landing gear design. Did some work on the test fixture to test that landing gear.
- Worked on the plug for the rotor that will go on the modified Monarch autogyro.
- To clear up a misunderstanding regarding Larry Neal's "G-Force" landing gear vs. Carter "Smart Struts," we have published a clarification on this site: Clarification of G-Force Landing Gear vs. Smart Struts.
2004-11-01
- Installed all major mechanical components in the aircraft, including the engine, drive shaft, prerotator, and the new rotor-driven hydraulic system. The hydraulic system still needs to be tested, and there are still a few small projects such as purging air from lines and checking fluid levels, but everything else mechanical on the aircraft is completed.
- Began an overhaul of the electronics. The several computers currently used for data acquisition and our automated controls will all be housed in one metal case, consolidating the electronics in one area, shielding the computers from stray RF, and in general simplifying their installation. Many wiring harnesses will have to be modified or replaced to accomodate this change.
- Installed several baffles in the aircraft to control airflow through the engine compartment.
- Verified that all sensors currently in the aircraft are functioning. The sensors still need to be calibrated.
2004-10-25
- Test fit the drive shaft in the engine compartment. Modified the engine mounting brackets (the rubber took a set from the heat of the in-flight fire in May).
- Installed two electrical air pumps to replace the mechanical pumps that were used previously.
- Worked on the new rotor-driven hydraulic pump. The hydraulic system will now use hydraulic fluid with a rotor-driven pump, instead of the engine oil system with an engine-driven boost pump used before. Using hydraulic fluid will greatly reduce viscosity change with temperature, and using a rotor-driven pump will ensure that the aircraft always has adequate hydraulic pressure, even with the engine at idle during landing, or in emergencies when the engine quits running.
- Installed strain gauges on the cyclic pitch links. These new strain gauges give a much higher resolution than the previous gauges.
- Several months ago, Carter purchased a Monarch autogyro from Larry Neal. The Monarch is a very good design, and we felt that it would be a good platform to modify to demonstrate some of our patented technologies, and to give us an aircraft that we could take to airshows when we were unable to take the original CarterCopter. We have already designed a new landing gear and rotor for the aircraft, and plan on designing a new propeller. The landing gear will absorb a 1200 fpm impact with no damage to the aircraft. The rotor will have a mechanical prerotator and pitch change mechanism, allowing jump takeoffs. It is being designed such that the molds will be able to be used to make rotors from 20' diameter up to 34' diameter, for a range of sizes of autogyros and gyroplanes. Parts have already been made for the landing gear and rotor head. The plug for the rotor is nearly completed.
EAA article about "Mini-CCTD"
Larry Neal's Butterfly and Monarch Website
- Carter is looking to hire an electronics technician/engineer. If you are interested, take a look at the job description.
2004-10-18
- We completed prop testing on Monday. We ran the prop to a maximum speed of 2467 rpm (5550 engine rpm) for a tip speed of Mach 0.96, with a total of 27 1/2 minutes at or above 2350 rpm (5300 engine rpm). We have not yet tweaked the prop to determine the most efficient pitch vs. rpm settings (we will do that once it is installed on the aircraft with the spinner), but performance is very good- 1900 lbs of static thrust at 391 HP and 2222 rpm. The spinner passed its testing on Wednesday, so now we're ready to put the aircraft back together.
- Removed the engine from the test stand and temporarily installed it back in the aircraft, to verify fit of several new parts that are being designed.
- Installed a new, higher shutter speed tail camera. Installed a display in the cockpit to allow the pilots to see the video from the tail camera in flight.
- Completed installation of the new fire detection system.
- Installed the Crossbow yaw/pitch/roll sensor as part of the Army contract.
- Continued work on the landing gear test stand to test the new landing gear design.
- Carter is looking to hire an electronics technician/engineer. If you are interested, take a look at the job description.
2004-10-11
- UPDATE 2004-10-11 We completed prop testing today. We ran the prop to a maximum speed of 2467 rpm (5550 engine rpm) for a tip speed of Mach 0.96, with a total of 27 1/2 minutes at or above 2350 rpm (5300 engine rpm). We have not yet tweaked the prop to determine the most efficient pitch vs. rpm settings (we will do that once it is installed on the aircraft), but performance is very good- 1900 lbs of static thrust at 391 HP and 2222 rpm. We will begin testing the spinner tomorrow, and once spinner testing is done, we will be ready to put the aircraft back together.
- Completed the new scimitar propeller, and began testing. A small crack appeared in the spar, running parallel to the carbon strands about 1/16 inch deep. We were running at 5300 engine rpm when the crack appeared. It's possible that the crack is due to some strands not being wet out properly with resin. Since this is the first time we've seen a crack in the spar in the 8 years that we've been testing propellers, and since none of the strands appear to be broken, we've decided to continue testing this propeller, while keeping a close eye on the spar. If there are any other problems with this propeller, we'd like to find them now before building a new one. In the meantime, we will start on a new spar that we will use to test various wrapping methods to keep a similar failure from happening in the future. Once we have successfully completed testing the current prop, we will build a new one using the best wrapping method on the spar, as determined by our tests. (Note that during these prop tests, we are taking the propeller to rpms and twists 1.25 times greater than what the prop will experience in operation.)
- Continued work on the landing gear test stand to test the new landing gear design.
- Carter is looking to hire an electronics technician/engineer. If you are interested, take a look at the job description.
2004-10-04
- Worked on the new scimitar propeller. Completed the remaining leading edge spar. Performed the main bonding of one blade. Main bonding of the other blade was started today.
Scimitar Prop- One
Blade Bonded, One
Blade Being Bonded
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- Began modifying aircraft electronics to incorporate the new sensors received as part of the Army contract.
- Continued work on the landing gear test stand to test the new landing gear design.
- Carter is looking to hire an electronics technician/engineer. If you are interested, take a look at the job description.
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