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Friday, June 23, 2017

Final Fantasy - Quest for the Flying Car

There are two main schools of thought amongst airmen; those that a spouse to the belief that it is safer to stop before landing and those that prefer to land before stopping. The helicopter is one flying machine that conforms to the first school.

Helicopters have been around a long time. In fact, the first helicopter accepted as such was the Focke-
Wulf Fw 61, created in 1936. Sikorsky later mastered helicopters. The term “helicopter” comes from hélicoptère in French, after Gustave Ponton d’Amécourt coined it in 1861. He took it from the Greek helix. It didn’t take long for someone to imagine a car with a helicopter rotor above it.
The flying car animated picture above is a mashup of the following flying cars. 1917 Curtiss Autoplane 1937 Waterman Aerobile 1947 ConVairCar Model 118 1966 Aero-Car 1971 AVE Mizar 2009 Terrafugia Transition 2014 AeroMobil 3.0 2017 AeroMobil 4.0

The fixed wing aeroplane on the other hand usually lands before stopping and to do that safely requires large expansive surfaces such as airports to operate from. Airports are generally associated with large urban centers, served with all kinds of services such as car rental check out counters so, no need for a car that flies in this case. As an flyer myself I have the idea that the most useful form of flying car would be one that stops before landing such as a helicopter or auto-gyro that exhibits also, good driving characteristics with a ground range of about 200 miles. The flying feathers should be easily detachable and the drive-able module electric powered.  The transportation standards have become so extensive over the years for cars with requirements for crash worthy bumpers, airbags,  impact crash testing, roll over standards etc have made it impractical to develop a flying car that complies with airworthiness and roadworthiness standards simultaneously, witness the case where the selling price for the Aeromobile has risen from 200,000 dollars to 400,000 during its development phase.

In my opinion it would make more sense to design the road vehicle comply with standards as a three wheel motorcycle.

1917 Curtiss Autoplane

Glen Curtiss invented and built the first flying aerial limousine - the Curtiss "Autoplane." Curtiss "Autoplane" 1917 The Pan American Aeronautical Exposition of 1917, held in New York's gaudy Grand Central Palace exhibition hall, represented "the biggest and best display of airplanes, aeronautic motors and aerial accessories and supplies ever gotten together on this continent. It was one of the most interesting exhibits at the Exposition.

The Autoplane quickly picked up the nickname "aerial limousine" because the pilot sat at the steering wheel and the two passengers in seats behind him.

The body is a combination of the motor car and aircraft practice, and follows very closely the lines of a modern limousine or coupé car-body. It is constructed mainly of aluminum, the windows being of celluloid. Elaborate upholstery and tapestries are employed for the interior, which accommodates two passengers in the rear and a "chauffeur" forward. Right in front is a circular radiator, through which passes a starting handle for the engine, a Curtiss OX-5 100 h.p., which is located under the bonnet. From the engine, power is transmitted through a shaft, extending to the rear of the body, to the four-bladed propeller located at the top.

There is a pair of wheel fore and aft, mounted in a similar way as on the Curtiss tractor triplane. The axle of the front pair, however, follows motor car practice in that the wheels are pivoted and connected to the control so as to enable the machine to be steered on the ground.

The triplane wings are also similar to the triplane tractor, except that they are staggered and the lower plane is of shorter span. The wing section is "F-2" with an angle of incidence of 4º and a dihedral angle of 3º to the lower plane. The top plane is connected to a cabane mounted on the roof of the "car," whilst the center and lower planes are attached to the body itself. Covered-in K-shaped inter-plane struts separate the planes, and interconnected ailerons are fitted to top and center planes.

The tail is carried by a pair of horizontal tubular outriggers attached to the center plane. The tail surfaces consist of a rectangular horizontal stabilizer, divided elevators, rudder and triangular vertical fin. Mounted on the bonnet, just above the front wheels, is a small plane. The general dimensions are as follows: - Span (top and center) 40 ft. 6 ins., (bottom) 23 ft. 4 ins.; chord (top and center) 4 ft., (bottom) 3 ft. 6 ins., gap, 3 ft. 3 ins.; stagger, 11 ins.; overall length, 27 ft.; height 10 ft.; width of body, 3 ft. 6 ins.; speed range, 45-65 m.p.h.; useful load, 710 lbs.

Development of the Autoplane was superseded by the war effort when America entered World War 1 only 2 month after the unveiling.

1937 Waterman Aerobile

Waldo Waterman's first flying wing aircraft was the unofficially named Waterman Whatsit, a pusher configuration low swept-wing monoplane with fins near its wing tips. The Whatsit also featured a wing-mounted tricycle undercarriage and a trim foreplane. Powered by a 100 hp (75 kW) Kinner K-5 5-cylinder radial pusher engine, it first flew in 1932.] In May 1935 Waterman completed a submission to the government funded Vidal Safety Airplane competition. This was the Arrowplane, sometimes known as the W-4. This adopted a similar layout to the Whatsit but had a strut-braced high wing on a blunt-nosed, narrow fuselage pod with a tricycle undercarriage mounted under it. Its wings had wooden spars and metal ribs and were fabric covered, with triangular endplate fins carrying upright rudders. Its fuselage was steel framed and aluminium covered. It was powered by a 95 hp (71 kW) inverted inline 4-cylinder Menasco B-4 Pirate pusher engine mounted high in the rear of the fuselage. The Arrowplane was not intended for production or to be roadable, but its success in the Vidal competition encouraged Waterman to form the Waterman Arrowplane Co. in 1935 for production of a roadable version. The resulting Arrowbile, referred to by Waterman as the W-5, was similar both structurally and aerodynamically to the Arrowplane, though the fins differed in shape, with rounded leading edges and swept-back rudder hinges. For road use the wings and propeller could be quickly detached. The main other differences were in engine choice, the need to drive the wheels and to use conventional car floor-type controls on the road. The air-cooled Menasco was replaced by a water-cooled engine as used by most cars. Waterman modified a 6-cylinder upright, 100 hp (75 kW) Studebaker unit and placed it lower down in the pod, driving the propeller shaft at the top of the fuselage via six ganged V-belts with a 1.94:1 speed reduction. The radiator was in the forward fuselage, fed from a duct opening in the extreme upper nose. On the ground the engine drove the main wheels through a differential gear, as normal, and the car was steered by its nosewheel. The wheels were enclosed in fairings, initially as a road safety measure. Instead of removing the propeller for the road, it could be de-clutched to prevent it windmilling the engine at speed. The wheel in the two-seat cabin controlled the Arrowbile both on the road and in the air. Outer wing elevons moved together to alter pitch and differentially to bank. The rudders, interconnected with the elevons when the wheel was turned, moved only outwards, so in a turn only the inner rudder was used, both adjusting yaw as normal and assisting the elevon in depressing the inner wing tip. This system had been used on the Arrowplane as a safety feature to avoid the commonly fatal spin out of climb and turn from take-off accident but the raked rudder hinge of the Arrowbile provided the banking component even from a nose-down attitude. There were no conventional flaps or wing mounted airbrakes but the rudders could be operated as brakes by opening them outwards together with a control independent of the wheel. The cabin interior was designed to motor car standards, with easy access and a baggage space under the seats. The Arrowbile first flew on 21 February 1937, making it a close contemporary of the Gwinn Aircar, and a second prototype with a number of minor modifications followed. Studebaker were interested in the Arrowbile because of the use of their engine and ordered five. The third Arrowbile was the first of this order. However there was little market response and the line was halted in 1938, with no more production aircraft completed. The production aircraft had several changes, some of which aimed to emphasise the similarities with cars; there was a radiator grille with a single headlight centrally above it and also car type doors and petrol filler cap. The fourth Aerobile was completed as a conventional, non-roadable aircraft; Waterman initially retained the Studebaker engine but in 1941 replaced it with an air-cooled 120 hp (89 kW) Franklin. In 1943 he modified the wings with slotted flaps and later still replaced the braced wing with a cantilever one, using the wing from the unbuilt fifth aircraft. The last, sixth aircraft was not completed and flown until May 1957. It was a three-seat, roadable version powered by a water-cooled 120 hp (89 kW) Tucker-Franklin. This was cooled by radiators on each side of the engine, fed air by fuselage side scoops. In the absence of the forward radiator the nose was remodelled, becoming shorter and blunter. The fins were also altered so that the upper and lower leading edges met at an acute angle. At some point this particular Arrowbile was renamed the Aerobile, though it was not a name that Waterman used.

1966 ConVairCar Model 118

Consolidated Vultee Aircraft (later Convair) was seeking entry into the post-war aviation boom with a mainstream flying car. Theodore P. "Ted" Hall had studied the concept of a flying car before World War II, with Consolidated unsuccessfully proposing the idea for use in Commando type raids. Following the end of the War, Hall and Tommy Thompson designed and developed the Convair Model 116 Flying Car featured in Popular Mechanics magazine in 1946, which consisted of a two-seat car body, powered by a rear-mounted 26 hp (19 kW) engine, with detachable monoplane wings and tail, fitted with their own tractor configuration 90 hp (67 kW) Franklin 4A4 engine driving a two bladed wooden propeller. This flew on July 12, 1946, completing 66 test flights.Hall subsequently designed a more sophisticated development of the Model 116, with a more refined car body and a more powerful "flight" engine. A 25 hp (19 kW) Crosley engine was in the rear, powering the plastic-bodied 4-seat car and a 190 hp (142 kW) Lycoming O-435C was used for the powerplant of the aircraft. A lofty production target of 160,000 was planned, with a projected $1,500 price tag. Convair anticipated that the Model 118 would be purchased in large numbers to be rented at airports.Operational history[edit] Test pilot Reuben Snodgrass flew the prototype, registration No. NX90850, for the first time on November 15, 1947. On November 18, 1947, while on a one-hour demonstration flight, it made a low fuel forced landing near San Diego, California destroying the car body and damaging the wing. The pilot, who escaped with minor injuries, reportedly took off with little or no aviation fuel aboard. Although the fuel gauge he had visually checked during the pre-flight check indicated that the tank was full, it was the automobile's fuel gauge, not the aircraft's gauge. Using the same wing and another car body, the second prototype flew again on January 29, 1948 piloted by W.G. Griswold, but enthusiasm for the project waned and Convair cancelled the program. The rights reverted to Hall, who formed T.R Hall Engineering Corp., but the Model 118 in its new incarnation never achieved production status.

1971 AVE Mizar

The prototypes of the Mizar were made by mating the rear portion of a Cessna Skymaster to a Ford Pinto.The pod-and-twin-boom configuration of the Skymaster was a convenient starting point for a hybrid automobile/airplane. The passenger space and front engine of the Skymaster were removed, leaving an airframe ready to attach to a small car. AVE planned to have their own airframe purpose-built by a subcontractor for production models, rather than depending on Cessna for airframes. According to Peterson's Complete Ford Book, by mid-1973, two prototypes had been built and three more were under construction. One prototype was slated for static display at Galpin Ford, owned by AVE partner Bert Boeckmann of Sepulveda, California. The other prototype, fitted with a Teledyne Continental Motors 210 horsepower (160 kW) engine, was unveiled to the press on May 8, 1973. It then began a series of taxi tests at Van Nuys, California. AVE made special arrangements to do flight testing at the U.S. Navy's test facilities at Point Mugu, California. AVE stated that FAA certification flights were underway in mid-1973. The Mizar was intended to use both the aircraft engine and the car engine for takeoff. This would considerably shorten the takeoff roll. Once in the air, the car engine would be turned off. Upon landing, the four-wheel braking would stop the craft in 525 feet (160 m) or less. On the ground, telescoping wing supports would be extended and the airframe would be tied down like any other aircraft. The Pinto could be quickly unbolted from the airframe and driven away. Production was scheduled to begin in 1974. AVE had stated that prices would range from US$18,300 to US$29,000. On a test flight from Camarillo Airport in California on August 26, 1973, according to test pilot Charles "Red" Janisse, the right wing strut base mounting attachment failed soon after takeoff. Because turning the aircraft would put too much stress on the unsupported wing, Janisse put the aircraft down in a bean field. After the roadway was closed to traffic, Janisse drove the otherwise undamaged aircraft back to the airport. On September 11, 1973, during a test flight at Camarillo, the right wing strut again detached from the Pinto. With Janisse not available for this test flight, Mizar creator Smolinski was at the controls. Although some reports say the Pinto separated from the airframe, an air traffic controller, watching through binoculars, said the right wing folded. According to Janisse, the wing folded because the pilot tried to turn the aircraft when the wing strut support failed. Smolinski and the Vice President of AVE, Harold Blake, were killed in the resulting fiery crash. Even though the Pinto was a light car, the total aircraft without passengers or fuel was already slightly over the certified gross weight of a Skymaster. However, in addition to poor design and loose parts, the National Transportation Safety Board reported that bad welds were partly responsible for the crash, with the right wing strut attachment failing at a body panel of the Pinto.

2009 Terrafugia

The experimental Transition Proof of Concept's first flight in March 2009 was successful and took place at Plattsburgh International Airport in upstate New York using U.S. Federal Aviation Administration (FAA) tail number N302TF. First customer delivery, as of March 2009, was originally planned to take approximately 18 months and occur in 2011. On July 1, 2010 it was announced that the Terrafugia Transition had been granted an exemption from the FAA concerning its Maximum Takeoff Weight (MTOW) allowing the Transition to be certified with a take-off weight up to 1,430 pounds (650 kg); the limit matches the MTOW for amphibious light-sport aircraft. The extra 110 pounds (50 kg) granted by the exemption provides more weight allowance for the mandatory road safety features such as airbags and bumpers. Oshkosh July 2008, Proof of Concept Oshkosh July 2011, Production Prototype The proposed design of the production version was made public at AirVenture Oshkosh on July 26, 2010. Aerodynamic changes revealed included a new, optimized airfoil, Hoerner wingtips, and removal of the canard after it was found to have an adverse aerodynamic interaction with the front wheel suspension struts; furthermore, the multipurpose passenger vehicle classification from the NHTSA removed the requirement for a full width bumper that had inspired the original canard design. On November 16, 2010 the U.S. National Highway Traffic Safety Administration (NHTSA) published Terrafugia's petition for a temporary, three-year hardship exemption from four FMVSS standards in the Transition. Terrafugia requested to use lighter weight motorcycle tires instead of RV tires, polycarbonate for the windshield and side windows, basic airbags instead of advanced, dual stage airbags and to not include an electronic stability control system. The NHTSA granted all of the requested exemptions on June 29, 2011, but limited the stability control and airbag exemptions to one year. In June 2011, a delay was announced and Terrafugia's CEO estimated that about another 18 months would be required before first customer delivery in "late 2012", but this was not achieved. December 2011 saw the base price increased to US$279,000 from an initial price of US$194,000. After undergoing drive tests and high-speed taxi tests, the production prototype completed its first flight on March 23, 2012 at the same airport in Plattsburgh, New York that was used for the Proof of Concept's flight testing. The production prototype then made its auto show debut at the 2012 New York International Auto Show in April 2012. In June 2012, Terrafugia announced that the Transition had completed the first of six phases of flight testing. By July, the second phase of testing was underway, expanding the performance envelope in the sky and continuing drive testing on the ground. In January 2013, development continued and the company announced that it might be necessary to construct a third, completely new prototype, due to the large number of modifications required. The modifications to date are said to appear to have improved the previous handling characteristics. By March 2014, the design of the third, updated prototype had progressed to finalization of the major structural members and a statement to investors said that it would be used in final compliance testing for certification before the first customer delivery which was then estimated to take at least another 18 months and occur "in 2015". By April 2014, 12 two-person test flights had taken place; this was the first time that anyone other than Terrafugia's chief test pilot had flown the Transition.As of 22 August 2014, first customer delivery was hoped for in about 18 months "in the second quarter of 2016." In December 2014 the company asked the FAA to allow the Transition to be operated at a gross weight of 1,800 lb (816 kg) instead of the light-sport aircraft maximum weight of 1,320 lb (599 kg) and have a stall speed of 54 kn (100 km/h; 62 mph) instead of the category maximum of 45 kn (83 km/h; 52 mph). The company indicated that the increases were required to allow inclusion of structures to meet FMVSS ground operation safety regulations. The company had previously been granted an increase in gross weight of 110 lb (50 kg) and another LSA aircraft, the ICON A5, was granted a 250 lb (113 kg) exemption to meet FAA spin resistance requirements; this new application would increase the Transition's allowed weight by a total of 480 lb (218 kg) or 36%. During consultations the request for the weight increase was supported by the General Aviation Manufacturers Association, the Experimental Aircraft Association, the Aircraft Owners and Pilots Association and the Light Aircraft Manufacturers Association. Only a few individuals expressed opposition to the request. The exemption was granted by the FAA on 19 June 2016.In April 2015 the company announced that parts were being built for the third version of the aircraft, and that current planning estimated the first customer delivery after roughly two years. Terrafugia COO/VP of Engineering Kevin Colburn also stated that the company has changed the price estimate from $279K to between $300K and $400K.  In November 2015, the company announced that the third version of the Transition was being tested with a Rotax 912is engine, rather than the Rotax 912ULS that the second prototype had flown with. As of April, 2017, the company's website says "Today, Terrafugia is finalizing production vehicle design and compliance testing in preparation for vehicle deliveries within the next three years."

2014 Aeromobile 3

AeroMobil, a Slovakian company, plans to start selling its creation, the AeroMobil 3.0, in 2017. The company claims on its site that the vehicle "transforms in seconds from an automobile to an airplane" by using "existing infrastructure created for automobiles and planes." The vehicle is gas-powered and has wings that fold, which allows it to be parked like a car, though it is nearly 20 feet long. The company's web site features a video where the AeroMobil 3.0 drives out of a hangar and goes down a highway, sharing the road with regular cars until it arrives at an airstrip. The car then unfolds its wings and takes off from a stretch of grass, rather than a paved tarmac, and flies through the air like any other small airplane. AeroMobil spokesman Stefan Vadocz said his company hasn't nailed down an exact price because it's not ready yet. "The prototype is a work in progress," he said in an email. But he said to expect the price to be several hundreds of thousands of euros, somewhere in between a sports car and a light sports aircraft. Related: Challenger Hellcat production suspended The vehicle seats two people -- the pilot and a passenger - and its single propeller is located to the rear of the plane. The company said the car's top speed on the road is at least 99 mph and while flying is at least 124 mph. It can fly for 435 miles before running out of gas.

Wednesday, June 21, 2017

Cheerson CX 20 Temporally Grounded by Mission Planner Accident

After many sessions with Mission Planner we were left with a drone that couldn't fly.
Someone suggested I needed to calibrate my transmitter.
  1. Drone weighted down during the throttle calibration process; no fear of a flyaway with that hunk of rusty tube threaded through the landing skids.
Calibration of the throttle completed and the rotors now throttle up normally but after the session we check and find that throttle calibration may be required at the beginning of each flight now. 

CX20 not lifting off Posted by Rob Nielsen on February 20, 2015 at 2:15pm in QuadcoptersView Discussions I just got my CX20 yesterday, I have been reading up on all the details and quirks so I was ready for it's arrival. I did a complete inspection of the interior components (ensuring I had disconnected the magnetometer in the mast). Everything is secure and in it's proper position. all solder connections seem sound. APM and GPS are in place and secure (they are mounting the GPS on the opposite side from the USB now). I reassembled everything and reconnected the Mag. Checked the propellers for balance. By this tiem the stock battery on the stock charger was completely charged. I updated the firmware and made sure it knew where home is in the Mission Planner software, as well as did a full calibration of accelerometers, Mag and transmitter. Propellers on their proper arms. All set to go. Ok time to fly. I take the unit outside. connect the battery, switch on the TX. The system binds as it should. Everything seems good. I have a solid green (Sats visible). I unlock the motors and try to take off. the moment the throttle leaves the full off position, the motors kick in at moderate revs, not enough for liftoff but flattening the grass. The unit leans forward so i pull back on the cyclic (right stick) to compensate. As i rev to max throttle, there is not difference in the RPM of the motors. At 0 throttle it is off, at 1% and up it is at a fast idle, not enough to take off. If i move the cyclic, i can rock it side to side and front to back, but it doesn't have the power to liftoff. similar to and ICE with the choke applied. I have gone through every permutation of the calibration routines from the incorrect factory ones to the ones used by people who fly this unit successfully many times over. I tried the all at once ESC calibration but this seems to not be the APM that works with that method. The only thing I can think of is doing a manual 'one at a time' ESC calibration but at this moment I am waiting for word back from the supplier. I have been waiting for a while for this to show up and now I am waiting with the thing right in front of me. it's pretty frustrating as you can imagine. Great weather and I can't fly it. FPV and telemetry gear on the way for it. ARG! If anyone has some good suggestions, i am VERY eager to try them. Flying the little Walkera and the Syma is getting old.

Suffice to say that I have been having this very same problem and I could not have explained it any better myself. It has been a very frustrating series of experiences that I have been having ever since I became risky soul  by updating firmware for my drone using the Mission Planner Graphic User Interface (GUI). Those sessions left my Cheerson CX 20 with Throttle settings of 80 when the default value should be 1000, rendering it incapable of flight. Several flip-overs later the USB port has been damaged will no longer talk to my computer so you can imagine how excited I was to discover this YouTube video which carefully explained how to re-calibrate the drones throttles using only the controller (transmitter). In my case I didn't even have to remove the blades; I simply slipped a heavy length of steel through the landing skids and carried out the procedure exactly as explained in the video.


The problem still persists, I have tried everything I can think of. I have downloaded the factory settings, firmware and computer drivers but am reluctant to do it since the instruction video is in Chinese.


One more thing to try before I bite the bullet.

Lasse Lundberg says on February 26, 2015 at 3:05pm your esc's are probably not calibrated, I go into mission planner, in the full list there is a setting that says esc calibrate and you can choose to enter calibration on the next reboot....so I set that, write parameter, disconnect, unhook battery, take props off, move throttle on transmistter to max but keep it off, hook up battery to copter and quickly turn on transmitter. mine will beeb a few extra times than it normally does, i then lower throttle to minimum. disarm, unplug quad, and turn of tx....turn everything back on and see if the motors spin up like they are supposed to, then mount props and see if it will fly?
The answer of course it would not.

Here is another |Guy who claims he has the answer.........maybe it's worth a try.

Reinstalling Factory Parameters on the Cheerson CX-20/Quanum Nova By: Joey Mirabelli You disconnected while calibrating in Mission Planner and now your CX-20/Nova is stuck like this?

Follow this tutorial to solve the above problem or to just restore to factory settings

STEP 1: Download this file and save it somewhere that is easy to access, like the desktop. We will be loading this into the quadcopter shortly.

In case this link disappears sometime I have the file saved in the cloud for downloading here

STEP 2: Plug a Mini USB (OR power up the telemetry) into the belly where it says "USB" and then plug in the battery.

STEP 3: Plug the other end of the USB into the computer and start up Mission Planner.

STEP 4: Click the connect button on the top right and allow it to connect.

STEP 5: Locate the CONFIG/TUNING tab at the top and then click "Full Parameter List" on the left.

STEP 6: Click "Load from file" on the top right and select the file we downloaded at the beginning of the tutorial.

STEP 7: Select "Write Params" and wait 20 seconds. Then click the disconnect button at the top right of Mission Planner. The quad is likely still beeping at this point.

STEP 8: Once you've clicked "Disconnect" and have waited a few seconds, unplug the USB from the computer, unplug the battery from the quadcopter, then unplug the USB from the quadcopter itself.

STEP 9: Plug the battery back into the quadcopter to confirm that the consant beeping has stopped. DO NOT GO AND FLY YET.

STEP 10: Now you must go through the calibration wizard. This is a crucial step.

Mission Planning in my opinion is a complete disaster. I now wish that I had never heard of the program.....I should have left well enough alone and stuck with the factory settings. 

Mission Planner behaves differently each time I use it; sometimes it will connect and other times it will not, no matter how many times I try. The screens are nothing like what others tell you, for example I could never find options like  "Full Parameter List" or "Load from file" no matter how many times or versions of the program that I tried.

The last time I used Mission Planner these were the two setup pages that were displayed:

 If I were a conspiracy plan believer I might say that this would be a clever plot to render millions of camera drones useless and grounded forever: simply make the default maximum throttle parameter 200 (in my case 80) when it would normally be 1000 and none of them would ever fly again.

The key to fixing the throttle problem is found in this video.

Link to video showing how to back up and install firmware using Mission Planner

Complete guide to CX 20 Calibration and Binding:

Perhaps I was a little harsh with my comments on Mission Planner, I can now find the options mentioned above after discovering the Layout Button which when pressed uncovered the Basic/Advanced option.

Screen shot of Mission Planner screen that shows where options to list all parameters shows up.
THR_MAX at the bottom of the list of parameters was changed from the default of 80 to 1000.
THR_MIN was changed from 250 to 0.

These parameters were written to the drone and arming was tested but failed to unlock the motors.
At this frustrating point it was time for a break to and wait for further inspiration.
I remembered the Arming Check; a series of check boxes requiring a tick to include a particular arming condition. Maybe this is why the drone isn't arming? When I got around to looking for it, it wasn't showing up any more. Perhaps we have to go back to Basic option before the check boxes will show up?
Changing the Advanced Layout back to Basic and re-clicking the CONFIGTUNNG icon Standard Params the page we are looking for suddenly appears. Then we notice that the All box has been selected, which confirms our suspicion on why our drone is not arming. After on-checking the All box and writing the parameters we are anxious to see if the drone will arm and........Surprise surprise! the drone immediately arms and the motors unlock on command.
  The motors respond with full range throttle as they did when it was new. Now we are anxious to put it back together and see how it will fly.


Finally a taste of success after being grounded for over a year; downloading and installing factory parameters proved to be the key to success.

In Conclusion: I now think the flawed parameter files found in Mission Planner are not the result of some conspiracy, but rather the work of a few malicious individuals (who else would create files where maximum throttle is of a lower value than minimum throttle) hoping to lure as many drone newbies into loading their tainted parameter files and sit back and watch the havoc created; in much the same way that hackers operate. Everyone using Mission Planner to update their drone's behavior should be aware that tainted files exist and exercise extreme caution when attempting to load a new parameter file.


Saturday, June 3, 2017

Vought V-173 “Flying Pancake”

Weird But Worked! Vought V-173 “Flying Pancake” Flying Pancake

The Vought V-173 “Flying Pancake” was an American experimental test aircraft designed by Charles H. Zimmerman and was built as part of the Vought XF5U “Flying Flapjack” World War II United States Navy fighter aircraft program. Both the V-173 and the XF5U featured an rather unorthodox “all-wing” design consisting of flat, somewhat disk-shaped bodies (hence the name) serving as the lifting surface. Two piston engines buried in the body drove propellers located on the leading edge at the wing tips.
The original prototype, designated the V-173, was built of wood and canvas and featured a conventional, fully symmetrical aerofoil section. Designed as a “proof-of-concept” prototype, the initial configuration V-173 was built as a lightweight test model powered by two 80 hp Continental A-80 engines turning F4U Corsair propellers.
These were later replaced by a pair of specially modified 16 ft 6 in three-bladed units. A tall, fixed main undercarriage combined with a small tailwheel gave the aircraft a 22° “nose-high” angle.

Ground testing of the V-173, c. 1942
Ground testing of the V-173, c. 1942

The disc wing design featured a low aspect ratio that overcame the built-in disadvantages of induced drag created at the wingtips with the large propellers actively cancelling the drag-causing tip vortices.
The propellers were arranged to rotate in the opposite direction to the tip vortices, allowing the aircraft to fly with a much smaller wing area. The small wing provided high maneuverability with greater structural strength.
In January 1942, the Bureau of Aeronautics requested a proposal for two prototype aircraft of an experimental version of the V-173, known as the VS-135.
The development version, the Vought XF5U-1, was a larger aircraft with all-metal construction and was almost five times heavier than the first prototype.

Diagram of the complicated powertrain

The first flight of the V-173 was on 23 November 1942 with Vought Chief Test Pilot Boone Guyton at the controls. The aircraft’s most significant problem concerned its complicated gearbox that routed power from the engines to its two long propeller shafts.
The gearbox produced unacceptable amounts of vibration in ground testing, delaying the aircraft’s first test flight for months.

Edited NACA image of of a Vought V-173 ("Flying Flapjack") undergoing testing in a wind tunnel.
NACA image of a Vought V-173 (“Flying Flapjack”) undergoing testing in a wind tunnel.

Flight testing of the V-173 went on through 1942 and 1943 with 190 flights, resulting in reports of UFOs from surprised Connecticut locals.

Maiden flight, 1942

Charles Lindbergh piloted the V-173 during this time and found it surprisingly easy to handle and exhibiting impressive low-speed capabilities.
On one occasion, the V-173 was forced to make an emergency landing on a beach. As the pilot made his final approach, he noticed two bathers directly in his path. The pilot locked the aircraft’s brakes on landing, causing the aircraft to flip over onto its back.
Remarkably, the airframe proved so strong that neither the plane nor the pilot sustained any significant damage.

V-173 upside down on the beach

The developmental V-173 made its last flight 31 March 1947. In 131.8 hours of flying over 190 flights, Zimmerman’s theory of a near-vertical takeoff- and landing-capable fighter had been proven.
The V-173 is now part of the Smithsonian collection at the Paul E. Garber Preservation, Restoration, and Storage Facility in Silver Hill, Maryland.
It was restored at the Vought Aircraft plant in Grand Prairie, Texas, as of April 2012 it is on loan to the Frontiers of Flight Museum in Dallas, Texas.

Sunday, May 28, 2017

Bras d'Or The Little Ship that Flew

Bras d'Or was named in honor of Bras d'Or Lake on Nova Scotia's Cape Breton Island, where inventor Alexander Graham Bell performed hydrofoil experiments in the early 20th century near his estate and new laboratory at Beinn Bhreagh, setting the world watercraft speed record in the process. In 1909 the lake was also the historic site of the first flight of an aircraft in Canada and the British Commonwealth; the airplane, named the Silver Dart, was built by the Aerial Experiment Association under Dr. Bell's tutelage. The lake's name was thus fitting for a hydrofoil vessel which could 'fly' above an ocean's surface. 

HMCS Bras d'Or (FHE 400) hydrofoil served in the Canadian Forces from 1968 to 1971. During sea trials in 1969, the vessel exceeded 63 knots (117 km/h; 72 mph), making her the fastest unarmed warship in the world. The vessel was originally built from 1960 to 1967 for the Royal Canadian Navy, as a project for the testing of anti-submarine warfare technology on an ocean-going hydrofoil.


Specifications: [2] 
Name: Bras d'Or Type: FHE Fast Hydrofoil Escort Class: Bras d'Or 
Displacement: 180 tons
Length: 46 metres - 151 feet 
Width: 6.4 metres - 21 feet 
Draught: 7 metres - 23 feet 
Propulsion: 2 Pratt and Whitney FT4A turbines 
Speed: Turbines - 22,000 shp - 63+ knots; 
Diesel - 2000 hp - 15 knots 
Crew: 4 Officers, 25 men 
Weapons: None fitted 
Pendant/Hull Number: 400 
Builder: Marine Industries Ltd., (MIL), Sorel Quebec 

Ordered: DeHavilland of Canada was given a contract in 1960 to design and build the Bras d'Or hydrofoil ship. 
Laid Down: Hull construction of the FHE-400 commenced in 1964.
Launched: On July 23, 1968 Bras d’Or was towed on the slave dock from the Naval Dockyard to the Halifax Shipyard for launching. 
Commissioned: 19 July 1968 
Paid Off: 1 May 1972 
De-Commissioned: The Bras d'Or was de-commissioned on 02 November 1971. Changes in Canada's defense priorities and cost overruns were the reasons for the project's cancellation.
Scrapped: Project canceled in 1972 by the Liberal Government of Pierre Elliott Trudeau, with most of the valuable components sold by Crown Assets or scrapped. 
Current Location: Musee maritime du Quebec at L'Islet, Quebec. 

A combined Anglo-Canadian study (RCN and British Admiralty) into the use of hydrofoils for anti-submarine work and coastal patrol craft began post Second World War. 

This led to a 17-tonne prototype, the R-103, built by Saunders-Roe in the UK, and sea-trials were conducted in Canada.  
The primary contractor was de Havilland Canada, an aircraft company. The Principal Naval Overseer was Commander Donald Clark, CD, RCN, who initiated the project on completion and launch of HMCS Nipigon in 1964. The hull was built upside down out of aluminum and rotated on 22 January 1966 when it was complete. The foil system was constructed from maraging steel. Bras d'Or flew on a set of surface-piercing foils in a canard configuration with a small foil forward and a larger load-bearing foil aft. 

The foils were made of maraging steel coated in neoprene to prevent corrosion. However, the neoprene coating did not work adequately and the foils still suffered from a form of stress corrosion. 

Diamond-shaped front foil The main foils featured several parts: two anhedral foils, two anhedral tips, two dihedral foils, and a center high-speed foil. The steerable front foil featured two anhedral sections and two dihedral sections with a strut down the middle, resulting in a diamond shape.
The surface-piercing foil system of this hydrofoil is very evident from the photo. The main foil carries about 90% of the lift, whereas the small bow foil carries the remaining 10%. The latter is steerable and acts like a rudder for both foil-borne and hull-borne operations. It can also be adjusted in rake, enabling the best angle-of-attack to be selected for foil-borne or hull-borne operation under whatever load or sea conditions that may exist. As in many hydrofoil designs, the different power levels involved in hull-borne and high-speed foil-borne operations dictate separate propulsion systems. 

The accompanying illustration shows the layout of BRAS D'OR's propulsion system. For the lower-power, long endurance hull-borne system, fuel weight is a critical factor which made the selection of a high speed diesel engine a logical one. A Paxman 16 YJCM diesel rated at 2,000 hp drove two three-bladed propellers on pods mounted on the main anhedral foils. These 7-foot diameter, fully-reversible, controllable-pitch propellers were 30 feet apart in the lateral direction which provided excellent maneuverability at low speed through differential pitch control. 

Foil-borne power was provided by a FT4A-2 gas turbine developing 25,500 horsepower (19.0 MW) at 21,500 rpm through General Electric gearboxes to a pair of three-bladed super-cavitating propellers. Hull-borne propulsion was driven by a Paxman Ventura 16YJCM sixteen-cylinder diesel engine to a pair of variable-pitch propellers. Auxiliary power and electrical power while foil-borne was provided by an ST6A-53 gas turbine powering an auxiliary gearbox. Both of the P and W turbines were built by United Aircraft of Canada. There was also a Garrett GTCP85-291 gas turbine for essential ship electrical requirements in emergencies.The foil-borne propulsion system consisted of a Pratt and Whitney FT4A-2 gas turbine engine, rated at 22,000 hp, driving two fixed-pitch, three-bladed propellers 4 feet in diameter.

The hull was made of welded aluminium and was built upside down. It was righted on January 22 1966 and the superstructure and systems were added at that time. The ship's hydrofoils were constructed of welded 250 ksi marging steel. The main foils were a hollow structure consisting of a 3-D truss-work of span-wise running members, thus forming a closed multi cell bending structure. There were no ribs per-se, except the two end ribs that contained the machined integral connecting lugs. 

DeHavilland subcontracted fabrication of the hull and installation of ship systems to Marine Industries Ltd. in Sorel, Quebec. Hull construction of BRAS D'OR commenced in 1964, but during construction, on 5 November 1966, there was a disastrous fire in the main machinery space which almost caused termination of the program. A de Havilland employee was in the main engine room with the ST6 running when a hydraulic fluid leak ignited on a hot joint in the ST6's exhaust stack, resulting in a flash fire. The technician responsible for the fire-suppression system rescued the employee, but as a result did not have time to activate the fire-suppression system. The fire was put out one and a half hours later by the Sorel fire department. This fire delayed the ship's launch to 12 July 1968 and cost $5.7 million. 

In spite of the delays and cost increase, however, the ship, designated FHE-400 and named BRAS D'OR, was completed in 1967.   A variety of teething problem interfered with the progress of BRAS D'OR's trials. These involved the hull-borne transmission system, the bow foil pivot bearing, the foil-tip and steering actuators, the electrical system, and the hydraulic pumps. 

None of these proved to be insurmountable problems however, and steady progress was made in overcoming them. In July 1969, BRAS D'OR was docked to repair persistent foil-system leaks, and a large crack was discovered in the lower surface of the center main foil. When the neoprene coating was removed, an extensive network of cracks was found, some at least entering into the spar and rib members of the sub-structure. A replacement foil element was constructed, but later, it too developed severe cracking.   


The ship's helmsman had to be qualified as both a sea pilot and an aircraft pilot. Bras d'Or had two propulsion systems; one for foil-borne operation and one for hull-borne operation, which included four engines. 

Bras d'Or arrived in Halifax, Nova Scotia on 1 July 1968 to begin a long series of trials. From September of 1968 until July 1971, when the trials terminated, the ship logged 648 hours, 552 hull-borne, and 96 hours foil-borne. The most operationally representative trial was a 2,500 mile voyage to Hamilton, Bermuda, and Norfolk, Virginia, in June 1971. The biggest disappointment, albeit from a scientific point of view (but not the sailor's aboard), was that the amount of significant rough-water data collected was regrettably small. At no time during the trip were limiting rough-water conditions experienced, either hull-borne or foil-borne. 

This was not to say that BRAS D'OR did not encounter rough water! According to Michael Eames, who describes highlights of these trials in his paper cited, HMCS FRASIER, a 3,000-ton frigate sailing in company during a rough water trial sent a signal as follows: "Weather conditions were considered most unpleasant, heavy seas and 15-20 ft swell, wind gusting to 60 knots, ship spraying overall with upper deck (of FRASIER) out of bounds most of the time. BRAS D'OR appeared to possess enviable sea-keeping qualities. She was remarkably stable with a noticeable absence of roll and pitch, and apparently no lack of maneuverability. The almost complete absence of spray over the fo'c's'le and bridge was very impressive." 

Foil-borne, BRAS D'OR exceeded her calm-water design speed, achieving 63 knots at full load in 3 to 4 foot waves. Sea trials included a comprehensive set of sea-keeping and motions data, all of which prompted the Canadians to conclude that BRAS D'OR showed its performance to be quite a remarkable surface-piercing hydrofoil ship. 

The Bras d'Or first flew on 9 April 1969 near Chebucto Head off the entrance to Halifax Harbor. The vessel exhibited extraordinary stability in rough weather, frequently more stable at 40 knots (70 km/h; 50 mph) than a conventional ship at 18 knots (33 km/h; 21 mph). Bras d'Or exceeded 63 knots (117 km/h; 72 mph) on trials, quite possibly making her the fastest warship ever built. It was however, never fitted with equipment for warfare (no weapons or weapon systems) and the title now lies with the Norwegian Skjold-class corvettes that do 60 knots (110 km/h; 70 mph), fully equipped. 

Cancellation of the Bras d'Or's trials came on 2 November 1971 by Minister of National Defense Donald S. MacDonald, attributing it to a change in defense priority (from anti-submarine warfare to sovereignty protection). The ship was laid up for five years, then the program was completely cancelled by Liberal Government under Pierre Elliott Trudeau, with most of the valuable components were either sold by Crown Assets or scrapped. 

My Personal Recollections of Canadian Hydrofoils:
The Bras D'Or (FHE 400) was not the first hydrofoil that I had worked on. In 1962 while employed  as a  newly graduated mechanical engineer at Fairy Aviation  in Eastern Passage Nova Scotia working under Benny Walworth, I was given several assignments on the R-103. Those mainly had to do with developing a system for handling towed underwater bodies to house listening devices for detecting enemy submarines.

The R-103 pictures below are credited to David Mills.
She was:
Laid down and Launched: 22 May 1957;
Commissioned: 26 Jun 1957; 
Renamed: Baddeck 1962; 
Paid off: 1973; 
Final Fate: stored Museum ship at the Canada Science and Technology Museum in Ottawa.

Experience gained with this experimental craft resulted in the selection of foil configuration used for Bras d'Or.[2].  Bras d'Or 2 was the fourth vessel to bear that name.

 Bras d'Or finally flying level and roaring westwards along the Menai Strait

 Bras d'Or 'flying' back towards Beaumaris past the old Bishop's Palace where my father lodged around 1945. He told me that he stored his New Imperial TT Replica motor cycle in pieces in the tower. When he rebuilt it he had to wheel it down the spiral stairs and out through the lounge one night to avoid the landlady finding out he had kept it there.

R-103 renamed Baddeck at Halifax prior to being transfered to Ottawa.

 Saunders-Roe R-103 (BADDECK) was retired in 1970 and spent the intervening years sitting in her cradle near the Fleet Diving Unit, Atlantic, on CFB Shearwater waterfront. Her fate then was uncertain, but is now stored in the Museum of Science, Ottawa awaiting conservation. The foils and central propeller skeg have been removed and are safely in storage. Unfortunately both Rolls Royce Griffon engines have long since been removed.

It has been a long time (more than 50 years) since I moved from Fairy Aviation in Eastern Passage (Shearwater) to work on the FHE 400 as a new DeHavilland employee. Much of that is now a distant memory, but some of it is as vivid as if it was yesterday. 

I well remember being at my workstation with one half scale drawings of the main center foil and main dihedral foils spread out on the worktable. My job as a stress engineer was to determine the strength and safety factories for these components. We were all well aware that the foils were to be manufactured of "a Space Age Alloy" maraging steel; a then fairly new product of the steel industry, mainly intended for high temperature applications. 

The allowable stress for that material is 250,000 pounds per square inch but after applying every factor we could imagine, we were not able to predict internal stresses greater 35,000 psi. In other words, the foils could have been made of any aircraft grade steel or for that matter aircraft grade aluminium alloy.

I recall at the time participating in discussions around the water fountain which suggested that the maraging steel was proving difficult to machine and weld. Given the projects time constraints a steep learning curve in its fabrication techniques was anticipated.

About this time I was transferred out of the project to the DC-9 which was ramping up a few yards away on the other side of the divider that separated working groups, in that sprawling old building that was built in the war years to house Victory Aircraft, as part of Canada's aircraft production effort. 

While my first hand involvement with the hydrofoil project had ended I still got to learn news from my near by friends still engaged with the engineering effort. I learned of the disastrous fire caused by a simple hydraulic fluid leak (fire resistant fluid would have eliminated the problem). The fire came close to completely destroying the prototype at the ship yards in Sorel I also heard of the silver lining story; how that fire afforded the designers an opportunity to discover and remedy some potential short coming in the hull, in the area of torsional stiffness. 

The stiffness calculations had assumed the hull as a closed structure, where in reality it had a significant length where the deck was interrupted by a large cutout which was incapable of carrying the shear loads. 

I also heard stories of the monster cracks that were discovered in the center foils which ultimately were attributed to the lack of stress relief of the welded structure, its exposure to sea water and the choice of maraging type 250 ksi steel, no cracks were ever found in structural elements fabricated in the lower 200 ksi strength material [ref 1].

Even today there is still a great deal of confusion in my mind about what vessel people are referring to when they use the name Bras d'OR, as I am now discovering there is a long line of small craft that have been given that name.

1. Bras d'Or Bell's hydrofoil of 1909

2. PT-3 built in the US under the Lend-Lease Program

3. R-103 built in the UK by Saunders as a joint British/Canadian experimental effort

4 FHE-400 designed and built in Canada for the Canadian Navy

The hull and foils of Bres d'Or was saved and donated to the Musée Maritime du Québec atL'Islet-sur-Mer, Quebec where it remains on display to this day.[3]
Canada's once proud hydrofoil ship underway

Ref 1 HMCS BRAS D’OR - The Ship That Flew
by Tom Bennett

Ref 2 FHE 400 - HMCS Bras D'Or Canada's Military Hydrofoil, 6th December 2012