The B Flight contingent of Team ONSPEED spent last week modifying the Jurassic RV-4 with new AOA systems and a calibrated test boom. No way a washed up, unfrozen caveman stick monkey could handle a j-o-b like that—way too much smoke potential. Time to fly south to Naked Lady Ranch Airpark (yup, it was fun to say that on the radio) to Lenny’s place.
Lenny is an outstanding electrical engineer and software guru. He’s also a consummate craftsman, pilot, and host. His RV-10 is gorgeous. He can fabricate anything. His hands move so fast when he’s wiring, they blur. And he has a spare room and most excellent espresso machine.
The ADS-B mandate allowed Mr. Procrastination to negotiate with CINCHOUSE (Commander and Chief, House) for some new Garmin kit, presuming I put in a new driveway and painted the house. A new Garmin GNX-375 arrived with a beautiful, Stein-crafted harness to hold all of the magic smoke. Once Lenny used small words to explain what “unswitched” audio input was, I also learned that we’d need some of those. Who knew? A call to nearby Sarasota Avionics solved that problem in the form of a Garmin GTR-200 radio.
To kill some time whilst we waited for the new radio, we (see what I did there?) fabricated one of the new AOA systems. Based on Dr. Dave Roger’s work, this system is entirely self-contained and mounts on a wing inspection plate. It replaces the pitot heat controller and allows the wiring to be used for power and pumping EFIS data into the SD card on the AOA computer. This system uses a wind tunnel and flight-tested algorithm to measure absolute angle of attack.
Day 2. Most of the new wires in the airplane are hanging outside of the airplane. Lenny was crafting schematics as we went, which was good, because the stick monkey was pretty sure the wires should be inside the airplane.
Day 3. Upward canted radios in the -4 in front of the stick really helps with limited panel space. All of the new Garmin gear talks via Bluetooth, so the 660 portable and iPad are “up front” controllers for the GNX. Perfect for a single-seat, single radio stick monkey. The radio stack was a challenge, since we had to get the angle right for mounting the racks. The console isn’t a square box--no stinking right angles! Ouch.
Day 4. The Jurassic RV-4 may be the only one flying with manual flaps and a flap position sensor—the AOA computers have to know where the flaps are. It took most of the day to figure out that all we needed was an adel clamp, FAA-approved coat hanger and a couple of nut plates. Had we read Ray Allen’s instructions; we would have reached this conclusion much sooner.
Day 5. I figured I better bolt all of this up, since I’m sure at some point some of it will be coming out for maintenance or modification. Talk about negative progress! 0100 Smoke test. Success…except the GNX isn’t talking to the auto-pilot…check Stein’s schematic. Check Garmin pubs, whoops, no install manual available. Plan B, look through GNX set-up menu to see how you can configure serial ports. Ouch. Serial wire is hooked up to the wrong port on the GNX to interface with the TruTrak. Engineering in progress.
Day 6. Take it out. Swap wire. Put it back in. Auto-pilot is now happy. Due to Lenny’s high-speed hands and my previous steep learning curve, it only took until lunch to pull this off. Six days in and NOW we can get to the meat of the mission: getting the new AOA systems installed. First, modify Lenny’s CNC machined mounts for the calibrated test boom to fit the RV-4 airfoil shape.
The boom is a “ground truth” reference that is used for flight test. It measures alpha (AOA), beta (yaw) and airspeed very accurately. It transmits wirelessly to the cockpit at 20 Hz and weighs less than 1 lb. Boom data is recorded in our primary AOA computer along with data from the Dynon EFIS.
Install the “Gen 2” ONSPEED computer. Make sure all of the test systems talk to each other and an accurate GPS time hack running everywhere at 50 Hz.
Day 7. FCF (functional check flight). It works, mostly. Generate some AOA calibration data for the engineers. Land in time to duck a massive south Florida T-storm and call it a day. Stash the airplane and start gonking (that’s a technical term for doing whatever it is that engineers do) data to develop initial calibration for the primary ONSPEED box using Dr. Roger’s technique.
Day 8. Go home. Say “Naked Lady Ranch” on the new radio again. Stop for gas and a butt break in Ocala after an ADS-B certification run in the Orlando Class B. The magic words were “ADS-B certification” and before you know it, ATC is giving me 360’s, box patterns around Disney World, climbs and descents and helping to monitor the 30-minute minutes in rule airspace. The FAA datalink god is now happy with the Jurassic RV-4.
Stick monkey screws up hot start and shears bendix during gas and go. What are the odds a local shop with a sense of humor has a long-nose SkyTech on the shelf to replace the old Lamar paperweight? 100%. Quick tow to the maintenance hangar, fab a new starter cable. She’s due for a 50 hour and the cowling’s off; so, buy oil, filter and oil analysis kit and have at it. A young, local pilot stops by. I inquire as to whether he knows how to service a set of spark plugs. Now we’ve got six hands turning wrenches. Ably assisted by a retired Navy master chief, the stick monkey breaks the airplane at 1005 local and is pushing it out of the shop at 1220 local to RTB with a new starter and 50-hour inspection signed off. Always better to be lucky than good. Took less time than swapping a sheared starter shaft on a J-79...
Tyndall TRACON is down, so all of the MOAs are cold—more good luck with a nice short cut. Land, fuel, beer at home plate. Wow—thank you Mr. Iszak for a great week of the holy schnikes edition of RVation!
All that AOA gear? Accurate AOA information helps me to fly my airplane to the edge of the envelope, optimize performance, manage energy and maintain aircraft control. The tone lets me keep my eyes out of the cockpit. We recently completed some engine failure on takeoff testing. Our test was a 250’ AGL engine failure, followed by 3 seconds of non-action to simulate “oh ****” time and turn back to the runway for landing. The following short video explains the test parameters and shows the AOA tone in action. Please keep in mind, I’m not advocating for any specific technique under these circumstances other than to maintain aircraft control all the way to the crash, where ever that may be. Also keep in mind that the minimum altitude to turn back is highly pilot, aircraft and flight condition dependent and requires flight test to determine. I’m only posting this to demonstrate some of the utility of being able to listen to your angle of attack during an engine failure scenario that requires maximum performance maneuvering. I realize that the “zero thrust” setting I’m flying may, in fact be producing residual thrust and I have the added advantage of knowing what’s going to occur. Real-life reaction time may be longer than 3 seconds.
https://youtu.be/U1T-ePy9e94
We’ll be doing a couple of forums on ONSPEED AOA at OSH and will have a small booth in the innovation pavilion (IC-29) to share lessons learned and technical information (we are a non-profit, open source organization). Our AOA forums will be Monday, 22 July 1300-1415 in Workshop Classroom B and Friday, 26 July 1430-1545 at Forum Stage 1. During the AOA forums, we’ll talk about what “ONSPEED” AOA is and how it’s applied during flight. We are also working on F-18 inspired DIY HUD and will be conducting a forum on that project on Thursday, 25 July 0830-945 at Forum Stage 3. Here's a vid of the HUD running at 5x speed: https://youtu.be/x0rPdBmn_wY
We look forward to meeting anyone that wants to talk AOA, Heads Up Displays, system integration, energy management, RV’s or just share a beer and spend some quality time shooting down watches. If you are interested in our work, there is more information available at our website at FlyONSPEED.org; and Dr. Dave Roger’s work is available at nar-associates.com.
Thanks, Lenny for an epic week!
Cheers,
Vac
Lenny is an outstanding electrical engineer and software guru. He’s also a consummate craftsman, pilot, and host. His RV-10 is gorgeous. He can fabricate anything. His hands move so fast when he’s wiring, they blur. And he has a spare room and most excellent espresso machine.
The ADS-B mandate allowed Mr. Procrastination to negotiate with CINCHOUSE (Commander and Chief, House) for some new Garmin kit, presuming I put in a new driveway and painted the house. A new Garmin GNX-375 arrived with a beautiful, Stein-crafted harness to hold all of the magic smoke. Once Lenny used small words to explain what “unswitched” audio input was, I also learned that we’d need some of those. Who knew? A call to nearby Sarasota Avionics solved that problem in the form of a Garmin GTR-200 radio.
To kill some time whilst we waited for the new radio, we (see what I did there?) fabricated one of the new AOA systems. Based on Dr. Dave Roger’s work, this system is entirely self-contained and mounts on a wing inspection plate. It replaces the pitot heat controller and allows the wiring to be used for power and pumping EFIS data into the SD card on the AOA computer. This system uses a wind tunnel and flight-tested algorithm to measure absolute angle of attack.
Day 2. Most of the new wires in the airplane are hanging outside of the airplane. Lenny was crafting schematics as we went, which was good, because the stick monkey was pretty sure the wires should be inside the airplane.
Day 3. Upward canted radios in the -4 in front of the stick really helps with limited panel space. All of the new Garmin gear talks via Bluetooth, so the 660 portable and iPad are “up front” controllers for the GNX. Perfect for a single-seat, single radio stick monkey. The radio stack was a challenge, since we had to get the angle right for mounting the racks. The console isn’t a square box--no stinking right angles! Ouch.
Day 4. The Jurassic RV-4 may be the only one flying with manual flaps and a flap position sensor—the AOA computers have to know where the flaps are. It took most of the day to figure out that all we needed was an adel clamp, FAA-approved coat hanger and a couple of nut plates. Had we read Ray Allen’s instructions; we would have reached this conclusion much sooner.
Day 5. I figured I better bolt all of this up, since I’m sure at some point some of it will be coming out for maintenance or modification. Talk about negative progress! 0100 Smoke test. Success…except the GNX isn’t talking to the auto-pilot…check Stein’s schematic. Check Garmin pubs, whoops, no install manual available. Plan B, look through GNX set-up menu to see how you can configure serial ports. Ouch. Serial wire is hooked up to the wrong port on the GNX to interface with the TruTrak. Engineering in progress.
Day 6. Take it out. Swap wire. Put it back in. Auto-pilot is now happy. Due to Lenny’s high-speed hands and my previous steep learning curve, it only took until lunch to pull this off. Six days in and NOW we can get to the meat of the mission: getting the new AOA systems installed. First, modify Lenny’s CNC machined mounts for the calibrated test boom to fit the RV-4 airfoil shape.
The boom is a “ground truth” reference that is used for flight test. It measures alpha (AOA), beta (yaw) and airspeed very accurately. It transmits wirelessly to the cockpit at 20 Hz and weighs less than 1 lb. Boom data is recorded in our primary AOA computer along with data from the Dynon EFIS.
Install the “Gen 2” ONSPEED computer. Make sure all of the test systems talk to each other and an accurate GPS time hack running everywhere at 50 Hz.
Day 7. FCF (functional check flight). It works, mostly. Generate some AOA calibration data for the engineers. Land in time to duck a massive south Florida T-storm and call it a day. Stash the airplane and start gonking (that’s a technical term for doing whatever it is that engineers do) data to develop initial calibration for the primary ONSPEED box using Dr. Roger’s technique.
Day 8. Go home. Say “Naked Lady Ranch” on the new radio again. Stop for gas and a butt break in Ocala after an ADS-B certification run in the Orlando Class B. The magic words were “ADS-B certification” and before you know it, ATC is giving me 360’s, box patterns around Disney World, climbs and descents and helping to monitor the 30-minute minutes in rule airspace. The FAA datalink god is now happy with the Jurassic RV-4.
Stick monkey screws up hot start and shears bendix during gas and go. What are the odds a local shop with a sense of humor has a long-nose SkyTech on the shelf to replace the old Lamar paperweight? 100%. Quick tow to the maintenance hangar, fab a new starter cable. She’s due for a 50 hour and the cowling’s off; so, buy oil, filter and oil analysis kit and have at it. A young, local pilot stops by. I inquire as to whether he knows how to service a set of spark plugs. Now we’ve got six hands turning wrenches. Ably assisted by a retired Navy master chief, the stick monkey breaks the airplane at 1005 local and is pushing it out of the shop at 1220 local to RTB with a new starter and 50-hour inspection signed off. Always better to be lucky than good. Took less time than swapping a sheared starter shaft on a J-79...
Tyndall TRACON is down, so all of the MOAs are cold—more good luck with a nice short cut. Land, fuel, beer at home plate. Wow—thank you Mr. Iszak for a great week of the holy schnikes edition of RVation!
All that AOA gear? Accurate AOA information helps me to fly my airplane to the edge of the envelope, optimize performance, manage energy and maintain aircraft control. The tone lets me keep my eyes out of the cockpit. We recently completed some engine failure on takeoff testing. Our test was a 250’ AGL engine failure, followed by 3 seconds of non-action to simulate “oh ****” time and turn back to the runway for landing. The following short video explains the test parameters and shows the AOA tone in action. Please keep in mind, I’m not advocating for any specific technique under these circumstances other than to maintain aircraft control all the way to the crash, where ever that may be. Also keep in mind that the minimum altitude to turn back is highly pilot, aircraft and flight condition dependent and requires flight test to determine. I’m only posting this to demonstrate some of the utility of being able to listen to your angle of attack during an engine failure scenario that requires maximum performance maneuvering. I realize that the “zero thrust” setting I’m flying may, in fact be producing residual thrust and I have the added advantage of knowing what’s going to occur. Real-life reaction time may be longer than 3 seconds.
https://youtu.be/U1T-ePy9e94
We’ll be doing a couple of forums on ONSPEED AOA at OSH and will have a small booth in the innovation pavilion (IC-29) to share lessons learned and technical information (we are a non-profit, open source organization). Our AOA forums will be Monday, 22 July 1300-1415 in Workshop Classroom B and Friday, 26 July 1430-1545 at Forum Stage 1. During the AOA forums, we’ll talk about what “ONSPEED” AOA is and how it’s applied during flight. We are also working on F-18 inspired DIY HUD and will be conducting a forum on that project on Thursday, 25 July 0830-945 at Forum Stage 3. Here's a vid of the HUD running at 5x speed: https://youtu.be/x0rPdBmn_wY
We look forward to meeting anyone that wants to talk AOA, Heads Up Displays, system integration, energy management, RV’s or just share a beer and spend some quality time shooting down watches. If you are interested in our work, there is more information available at our website at FlyONSPEED.org; and Dr. Dave Roger’s work is available at nar-associates.com.
Thanks, Lenny for an epic week!
Cheers,
Vac
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