ADS-B Users Gather Round, As the Means They Are a Changing

Weather + Position + Attitude… Keeping it all in check with ADS-B.

SkyVision Xtreme Portable, in its Xth and final iteration, was a convenient, hard-shell black briefcase of spy grade avionics that could receive and display aviation traffic and weather. More than that, SkyVision Xtreme Portable was the first demonstrable product in a complicated scheme to force general aviation’s adoption of ADS-B. Released in 2013, though conceived in 2010, the portable device offered ADS-B In & Out with little to no burden of installation.

SkyVision Xtreme Portable
SkyVision Xtreme Portable ADS-B In & Out System

By FAA mandate, aircraft operators are now (by 2020) obligated to equip with ADS-B (Automatic Dependent Surveillance-Broadcast). Essentially, ADS-B is an upgrade to the commonplace transponder, or “squawk” box, that it now circumvents. SkyVision’s portable gave stealthy first adopters a means to participate in the scheme.

The SkyVision Xtreme Portable concept was simple: Allow pilots to bring their weather and traffic system to the airplane with them; and it worked. Others quickly followed with compact portable devices offering a subset of capabilities. NavWorx offered WxBox, a hot selling weather-only unit, and PADS-B, an “In & Out” device that included traffic and position reporting. Appareo released its Stratus line, while Garmin introduced its GDL receivers. Everyone suddenly wanted “In.”

NavWorx WxBox
WxBox ADS-B weather receiver from NavWorx.
NavWorx PADS-B
PADS-B from NavWorx, full ADS-B In & Out with a portable device.

A common refrain among pilots fortunate enough to fly with traffic warning systems is that they suddenly feel vulnerable in aircraft without them.

Dave Hirschman, AOPA Pilot, April 2013

SkyVision Xtreme Portable was revolutionary, taking full advantage of what ADS-B had to offer. First, it was a step up from old-school radar traffic devices. Satellite-derived ADS-B sees traffic all the way to the ground when radar cannot. The Xtreme system also included graphical weather display, GPS derived position information, and an attitude heading reference system. Most importantly, the Xtreme Portable provided full ADS-B In & Out capability, the latter a requirement of the FAA mandate. SkyVision Xtreme arrived well in advance of the pending FAA 2020 deadline, appealing to early adopters and stoking developers.

Inside the SkyVision Xtreme Portable was an ADS-B transceiver (UAT) from NavWorx. The briefcase was a self-contained, complete system and its only physical connection was a 12/24-Volt power plug. An internal battery supplied backup power. A pair of antennas tethered from the unit. On an iPad, or other tablet device, the data was displayed, transmitted via Wi-Fi. As aircraft came into view—before they could be seen through the windscreen—each was shown with distance, relative height, heading, speed, climb/descent trend, aircraft type and call sign (if available). The device was smart and advanced. It set a standard others would copy.

SkyVision Xtreme on iPad
SkyVision Xtreme traffic and weather displayed on an iPad.

How rapidly development occurs. Nearly every existing avionics manufacturer, and a surge of newcomers, produced, bought, or sought compatible products with the new ADS-B standard. The rush was on. With both open source content and competitive efforts at work, ADS-B adoption was indeed a race. Big investment, from players like Garmin, aimed to meddle with the standard. A chary FAA frequently conspired. Programmers and electronics entrepreneurs concocted ideas and seized opportunities. The community of aviators welcomed a supply of creative new products.

Today, the innovation continues. There’s Stratus 3, the nexus of the SkyVision concept several years into its product life cycle. It comes from marketeers of aircraft transponders, electronic flight bags, and an array of technology innovations. Simple to use, portable, free benefits (such as weather, traffic, GPS navigation), works on almost any device, and compatible with all the top apps, Stratus is now the commodity for ADS-B In, priced at around $700.

There’s also FlightBox, a palm-sized cuboid sprouting two antennas with, “All the features of the Stratus 2S at 1/4 the price.” It’s an open source artifact of ADS-B development. With electronics available off-the-shelf, its users are emphatically embracing it. In the spirit of SkyVision and NavWorx affordability, FlightBox represents a culmination of ADS-B In development, setting one back a mere $239.

There’s even a DIY option with Stratux, an open source software adaptation of ADS-B development that can be used with widely available component parts. For example, one can get a 3D printed enclosure, add the electronics, and drive it with Stratux. The software is free and public forums actively support it. Stratux is the bridge from the world experimental aircraft to commercial ADS-B development.

A commodity in situ, culmination at play, and more bridges still ahead, ADS-B technology will continue to advance. We are seeing a glimpse of this at uAvionix, a company that integrates ADS-B into wingtip nav lights/strobes and tail beacons. These ultracompact and simple to install turnkey solutions are just the beginning.

SkyBeacon from uAvionix has a street price of around $1,800; it is “Out” only, hence no need for a display, and requires a transponder. A typical ADS-B transponder runs $3,000. By contrast, the latest touchscreen navigator from Garmin costs five G and comes with lots of extras; for an additional $2,700 you get ADS-B.

What’s next? ADS-B microchips will one day be implanted under the aircraft skin. GPS will get “smart,” interrogating and resolving issues before pilots are even aware of the anomaly. Aircraft surveillance under ADS-B will continue to be pervasive for the sake of safety. The incentive of free weather and traffic will pale in comparison to the advantages of what future ADS-B, or perhaps its successor, will bring.

Note: The legacy SkyVision Xtreme is still available today with Skyvision Xtreme Moving Map Software employing the Stratux receiver and an 8-inch tablet display.

Bearhawk Aircraft News – Summer 2019

Bearhawk Aircraft manufactures high quality quick-build aircraft kits for the Bearhawk 4-Place, and the Bearhawk Patrol and LSA two-place tandem models. These aircraft have in common excellent utility and superb flying characteristics. Bearhawks are known for their short field capability, higher than expected cruise speeds, and very gentle slow speed manners.

Bearhawk Aircraft and the many builders and owners are excited to be once again participating in AirVenture Oshkosh—the world’s greatest aviation experience. For a glimpse of what you can expect to see, here’s what’s new at Bearhawk Aircraft:

Bearhawk 4-Place Skylight Option

We are changing the design of the ceiling of the 4-Place so it can either have a skylight or fabric with no modification. Should be well received. -Mark Goldberg, president of Bearhawk Aircraft

Bearhawk Sales and Support in Brazil

A new Brazilian distributor is taking possession of the first Bearhawk LSA kit to arrive in Brazil.

Bearhawk LSA Meets Canada’s Advanced Ultralight Category

In Canada they have a category of planes called Advanced Ultra-Light Aeroplane. Our LSA can live within that category.

Bearhawk Completed in 6½ Months

A Patrol flew in Virginia after only 6½ months of building time. Record time.

Read the full report here.

Revival of the First Liaison Aircraft Began Here

When the Alamo Liaison Group (ALG) was formed in 1981, by a group of San Antonio area aviators, its mission was to acquire and restore liaison aircraft flown by the U.S. military in World War II. These aircraft were to be kept in flying condition, following their recovery and reconstruction, for the purpose of honoring those who operated them and all who served.

Group picture of the ALG L-1 through L-6 collection. Photo by Roger L. Beery
Group picture of the ALG liaison aircraft, L-1 through L-6, collection. Photo by Roger L. Beery

Led by Hardy Cannon, a master mechanic, ALG completed in 1982 the restoration of a 1941 Stinson L-1, a 1941 Taylorcraft L-2, a 1942 Aeronca L-3, a 1942 Piper L-4, a 1942 Stinson L-5, and a 1942 Interstate L-6. This collection of “L-birds” (L for liaison) represented the introductory class in a progression of light aircraft used principally by the U.S. Army Air Forces. 1

The most substantial, and certainly exceptional, among these aircraft was the Stinson L-1 Vigilant. The L-1 derived from Stinson Aircraft Corporation’s civilian Model 74. It was identified by the military as O-49, originally among the class of observation aircraft (O for observation). In April 1942, the O-49 turned L-1 when the liaison designation ascended that of observation.

Alamo Liaison Squadron L-1 Restoration 1982
Alamo Liaison Group’s L-1 Restoration in 1982.

The L-1 was envisioned as a highly versatile air defense instrument. Its requisition came with a monumental list of specifications and capabilities. Its design engaged with every demand of a vigilant military. However, the grand concept proved itself overindulgent. Ground forces, the predominant operator of liaison aircraft, found the L-1 to be complex and costly.

The liaison aircraft function demanded simplicity. L-birds were tasked with flying from point to point, often on short hops. They gathered, delivered, and reported stores and information. From their manufacture to delivery in the field, to the verity of improvised maintenance and the absolute necessity of organic 2 pilot/crew operations, the L-1 was a bear when the Army needed a cub.

As the role played out, succeeding L-bird models would prove ideal to the task. They were smaller and lighter, yet delivered results with greater and weightier outcomes than the L-1. Demand for liaison aircraft engagement still outstretched the ability to supply them. Nevertheless, L-birds were produced by the tens of thousands.

The L-1 was superseded in procurement by vast numbers of the Piper L-4 (in addition to similar Aeronca and Taylorcraft models) and the later Stinson model L-5 Sentinel. Nearly 4,000 L-5 examples were produced. Peak production of the L-4 was one aircraft every 20 minutes with over 5,000 going to the military. Piper delivered over 19,000 of the L-4 / J-3 3 type between 1938 and 1947. The smaller L-birds earned the nicknames “Puddle-jumper,” “Grasshopper” and “Flying Jeep.”

The L-1 was by no means inferior. It was extremely well-conceived, well-built, well-equipped, and performed to the illustrative standard Fieseler Storch that spawned its creation. The L-1 served with U.S. and Allied forces beginning in 1941, and up to 1947 with the Royal Air Force. The proliferation of simplicity, and ubiquity, within the liaison function necessitated its demise. The L-1 was the largest L-bird used in World War II.

3-View diagrams showing relative sizes of the most popular L-birds of WWII.

The Stinson L-1 Vigilant was used throughout the world, seeing service in Europe, Africa, Asia, and Alaska. Its primary missions included running supplies, transporting key personnel, and medical evacuation. The L-1 was also used in diverse roles such as towing training gliders, spotting artillery, and special espionage flights. Some were modified to perform amphibious air ambulance missions.


The Stinson O-49 / L-1 was conceived in response to a 1938 U.S. Army Air Corps 4 competition for a two-seat light observation aircraft. When a German-manufactured Fieseler Storch was demonstrated at the Cleveland Air Races—a national air race competition taking place in the U.S. since 1920—the Air Corps revised its specifications in an attempt to match the performance of the impressive Storch.

Stinson Aircraft Corporation of Wayne, Michigan, won the $1.5 million contract with the O-49, beating eleven competitors. A second contract was later awarded to Stinson, by that time a division of Vultee Aircraft Corporation, for the O-49A which had a slightly longer fuselage and other equipment changes. In all, 324 iterations of the Stinson O-49 / L-1 were built.

The Stinson Model 74, on which the O-49 / L-1 was based, was a high-wing monoplane with a single radial engine. It incorporated pilot-operated slotted flaps for low speed and high lift performance. It was built with full-span automatic slats (manufactured by Handley Page of the U.K.) on the leading edge of its wings. Both design features improved the airplane’s angle of attack and stall speed.

The aircraft was built of steel tubing and fabric, with the fuselage forward of the wing covered in sheet metal. Control surfaces and the empennage were fabric-covered stainless steel. The Lycoming powerplant, capable of 295 hp, was hand-cranked inertia starting and fitted with a Hamilton Standard constant speed propeller. First flight of the Model V-74 / YO-49 designated prototype took place on July 15, 1940.

The Vigilant was capable of stopping in less than its own length, and could maintain stable flight at 31 miles per hour. Coming in at a steep angle, then leveling off, it could land at 10 miles per hour. Anecdotally, it was said to be capable of backwards flight in a strong headwind. While the lighter L-birds could achieve the same, such performance was stunning for the larger, heavier L-1.

Up to 17 L-1 and 96 L-1A aircraft were allocated to the British Royal Air Force under the Lend-Lease Act of 1941. 5 The RAF designated these aircraft the Vigilant Mk I and Vigilant Mk II respectively.

In Canada, General Harry Crerar, Commander of the First Canadian Army in Europe during World War II, maintained a Vigilant for personal use. George S. Patton was provided a Stinson O-49 and a personal Air Corps pilot in 1941, during his participation in the Louisiana Maneuvers. He also flew a privately owned Stinson 10A—a model that would later become the L-9. In October 1944 at Burtonwood, a former joint RAF/USAAF base in the U.K., two L-1C litter-equipped air evacuation models were modified by the installation of a rear seat in place of the litter and intended for General Dwight D. Eisenhower’s personal use. 6

The ALG Restoration

Throughout the years a number of L-birds have operated from Cannon Field, home to the now renamed Alamo Liaison Squadron (ALS). These aircraft included actual L-birds with military history and other modern constructions resembling warbirds. Among them, the L-1 was a rarity. Keeping it flying was an onerous task. Its restoration proved, above all, a treasure hunt for the one-of-a-kind systems, accessories and equipment that made it unique. Despite the L-1’s absence today, ALS is proud to claim its revival began here.

Thankfully, the restoration undertaken by ALG on L-1 serial number 41-18915 in its 41st year survived another 37 years. Its history traced, the airplane now resides at the Alaska Aviation Museum on Lake Hood Seaplane Base in Anchorage, Alaska.

This aircraft (s/n 41-18915) was first constructed in 1941 as an O-49A, a lengthened (by 13 inches) version of the original O-49. It was later configured as a model L-1F which incorporated amphibious pontoon floats (manufactured by Edo Aircraft Corporation) and an ambulance configuration. Only five such conversions were done. The plane was put into service with the U.S. Army Air Forces on December 22, 1941—two weeks after the Attack on Pearl Harbor.

After serving in several southern states, in military exercises and training, 41-18915 was shipped to Alaska for service with the 11th Air Force at Fairbanks and Anchorage in 1944. It was stationed in Nome, participating in search and rescue operations as part of the Lend-Lease Act. It likely also performed supply hops and special espionage missions behind Japanese lines for the 1st Air Commando during the 1944–1945 China and Burma campaigns. 7

Following WWII, 41-18915 was sold in 1946 by the War Assets Administration at its last base of operations in Alaska. It began use with the U.S. Fish and Wildlife Service and gained civilian registry as N704 operating in Anchorage, Alaska from 1947–1953.

As an L-1A (in parity with its O-49A military designation), 41-18915 was registered as N704E by Lawrence E. Flahart of Anchorage, Alaska on December 6, 1953 (until 1972). It was modified as a cabin airplane by replacing the “greenhouse” with a solid top. 8

L-1, N704E prior to restoration.
Stinson L-1, N704E, prior to restoration by ALG.

The “L-1F” floatplane was withdrawn from use between 1977 and 1981 by James Harrower of Anchorage, Alaska. It was subsequently bought by Bill Stratton and, with floats removed and wheels installed, flown to San Antonio, Texas on May 27, 1982. Stratton also purchased what existed of N1377B (an L-1 s/n 41-19015 later restored by James P. Harker of Blaine, Minnesota ) for spare parts.

San Antonio Express-News article by Joe Fohn, May 28, 1982: One of the group’s rarest acquisitions consists of a tangle of tubing wires and rotted canvas. Four known. It is an L-1, the largest liaison plane used and one of four known to exist anywhere. ALG members found it after it had lain for decades in the Alaskan wilderness. Within a year, Stratton said, they hope to have it flying alongside the other five planes. Stratton said the group wrote to Wright-Patterson Air Force Base’s Air Force Museum for a photograph of an L-1 to guide restoration. “The picture they sent us was our plane. It had the same tail number,” Stratton smiled.

The aircraft underwent restoration by ALG in 1982. “The big Stinson was taken down to the bare air frame and sandblasted to bare metal so every part could be inspected. Slowly, the reassembly began as each additional part was refinished and installed,” Vintage Airplane magazine February 1984. After a nearly six-year grounding, the L-1 was flying again, as a landplane, to airshows and events:

May 1983, at Randolph AFB, Texas. Photo by John Dienst.
May 1983, the newly restored L-1 at Randolph AFB, Texas. Photo by John Dienst.
At the Kerrville, Texas EAA Fly-In in September 1983 is the Stinson L-1.
Touching down at the Kerrville, Texas EAA Fly-In in September 1983 is the Stinson L-1. Photo by Chuck Larsen, Vintage Airplane magazine February 1984.
April 1984, at Corpus Christi Naval Air Station, Texas. Photo by John R. Kerr.
April 1984, the ALG’s L-1 at Corpus Christi Naval Air Station, Texas. Photo by John R. Kerr.
June 1984, at Confederate Air Force Airshow in Denton, Texas.
Stinson L-1 Vigilant at the Confederate Air Force Airshow in Denton, Texas, June 1984. (photos above and below)
Stinson L-1 Vigilant

Flying Times, a publication of Kelly Air Force Base, August 3, 1984: A ride in a vintage 1941 Vultee L-1 “Vigilant” liaison plane is not typical of a ride in other small aircraft… As he is cleared for take-off, Straw revs the already-deafening engine and works the exposed cables that operate the flaps. The L-1 leaves the ground at only 30 mph, and about 10 seconds later it has climbed to a respectable altitude. The aircraft soars high above San Antonio – all the while it feels like a strong wind could blow the light plane over… In an abrupt landing, the L-1 straightens out and slows to about 30 mph. Rubber kisses the pavement and the plane shudders and shakes to a halt.

Hill Country Recorder September 19, 1984, by Roger L. Berry: The ALG L-1 was the only restored plane of its type left in the world. The USAAF [U.S. Army Air Force] flew them in Burma (Air Commandos), Europe, Alaska, and Hawaii (several were destroyed by the Japanese in the Pearl Harbor Attack). This “one-of-a-kind” aircraft has been restored in the markings of Bellows Field, Hawaii, December 7, 1941. Alamo Liaison Group flies over Boerne during the Kendall County Fair Parade.

Stinson O-49 / L-1 at Bellows Field, Hawaii, 1941
A Stinson O-49 / L-1 at Bellows Field, Hawaii (1941). Photo courtesy of the State of Hawaii Department of Transportation Airport Division.
Second September 1984 edition of Trade-A-Plane shows the L-1 in formation flight among seven aircraft of ALG.
Second September 1984 edition of Trade-A-Plane: Flying Liaison Aircraft Museum, ‘The Alamo Liaison Group.’ Photo by Roger Berry (above and below).
ALG Flying Liaison Aircraft Collection
October 12, 1984, edition of Ft. Sam Houston News Leader (A Publication of The 502nd Air Base Wing – Joint Base San Antonio-Fort Sam Houston). L-1 performed in a Confederate Air Force Air Show on Oct. 4th.
Spectators view the [Stinson L-1] on display as part of the Confederate Air Force Air Show. Photo by Allen Goralewicz, Fort Sam Houston News Leader (502nd Air Base Wing, Joint Base San Antonio) Friday, October 12, 1984.
October 12, 1984, edition of Ft. Sam Houston News Leader (A Publication of The 502nd Air Base Wing – Joint Base San Antonio-Fort Sam Houston). L-1 performed in a Confederate Air Force Air Show on Oct. 4th.
A Stinson-Vultee “Vigilant” and Taylorcraft “Tee-Cart” fly over Fort Sam Houston during the Confederate Air Force Show Oct. 4. Photo by Allen Goralewicz, News Leader.
San Antonio Light newspaper, October 5, 1984.
San Antonio Light newspaper October 5, 1984: Winging their way. Single-engine L-bird liaison aircraft belonging to the Confederate Air Force cruise over Fort Sam Houston yesterday. Photo by Leonard Parness.
At the Ft. Sam event October 19, 1984. (newspaper unknown)
An L-1 Vigilant receives some attention at a recent CAF Airshow preview at Fort Sam Houston. San Antonio, Texas, Friday, October 19, 1984 (newspaper unknown). Photo by Charles Barksdale.
Photo taken at Fort Sam Houston, October 1984.
Photo taken at Fort Sam Houston, October 1984. ALG’s restored L-1 in background.

Dave Smith of the International Liaison Pilot and Aircraft Association, San Antonio, Texas, registered the aircraft (N704E) in April 1985 (until 1992).

September 1986, at Wings Over Houston, still “in the silver war games paint.”
September 1986, at Wings Over Houston, the L-1 is seen still “in the silver war games paint.”

Flying Magazine October 1987, by Gordon Baxter: The big L-1 almost seemed to hover at its touchdown speed of 30 knots, slower than all the other liaisons. Load hauling in the roomy cabin seemed to be limited only by what the landing gear could stand. The gear was a weak point in the design of the L-1, and with its greater weight the big monoplane did not hop and skip over ground irregularities as the lighter liaisons did, but collapsed its landing gear. First in use as a liaison, the L-1 stayed on the longest [in government service]. In the postwar years there was a rush for the surplus airplanes, then all but the Interstate and L-1 went back into long, happy lives.

Express-News October 18, 1987, by Nora Lopez: They were called called the “Jungle Angels” during World War II since they swooped down from the heavens bringing medical supplies and hope to the wounded… All six “L-birds” were on display Saturday… there was the Stinson L-1. [The event took place on Saturday the 17th. This was the Sunday edition. On the following Monday, the infamous “Black Monday” stock market crash occurred.]

The L-1 at Stinson Airfield in San Antonio, Texas, in 1991, while being recovered. Photo by John R. Kerr.
The L-1 at Stinson Airfield 9 in San Antonio, Texas, in 1991, while being recovered. Photo by John R. Kerr.
In 1991, the L-1 emerged from painting at Stinson Airfield with a new green camo paint scheme and its “Vigilant Virgin” nose art (a female figure seated on a white lion rug). Photo by Craig Parchman.
In 1991, the L-1 emerged from painting at Stinson Airfield with a new green camo paint scheme and its “Vigilant Virgin” nose art (a female figure seated on a white lion rug). Photo by Craig Parchman.

N1ZS (s/n 41-18915) was registered in April 1992 (until 1995) to Dave Smith of San Antonio, Texas.

In 1993, at EAA Oshkosh. Photo by Ken Videan.
In 1993, the L-1 at EAA Oshkosh. Photo by Ken Videan.
On October 9, 1993, at Confederate Air Force Air Show in Midland, Texas.
On October 9, 1993, the L-1 at Confederate Air Force Air Show in Midland, Texas.
In October 1993, at Stinson Airfield.
In October 1993, the L-1 at Stinson Airfield.
At EAA Oshkosh. Photo by Carl Schuppel, EAA Sport Aviation September, 1984.
The L-1 at EAA Oshkosh. Photo by Carl Schuppel, EAA Sport Aviation September, 1984. (above and below)
At EAA Oshkosh. Photo by Carl Schuppel, EAA Sport Aviation September, 1984.

Karl S. Johnstone of Anchorage, Alaska, registered N1ZS on June 26, 1998 (until 2002).

“The Alaska Aviation Museum purchased 41-18915 from Alaska Judge Karl Johnstone in 2001” (per museum facebook). “The aircraft was donated to the Museum by Karl S. Johnstone in 2002” (per museum website). “It is the sole survivor of approximately 400 L-1s manufactured during WWII” (per museum website). Alaska Aviation Heritage Museum in Anchorage-Lake Hood, Alaska, registered the aircraft on January 29, 2003.

On July 7, 2005, at Lake Hood Seaplane Base.
On July 7, 2005, the L-1 at Lake Hood Seaplane Base, Anchorage, Alaska.
On June 10, 2010, uncovered and with wings removed at Alaskan Aviation Heritage Museum.
On June 10, 2010, the L-1 uncovered and with wings removed at Alaskan Aviation Heritage Museum.

A second restoration of 41-18915 began in 2015, and was completed in summer 2016. The Alaska Aviation Museum opened the exhibit of its newly restored Stinson L-1 Vigilant on September 21, 2016.

The L-1 on display at the Alaska Aviation Museum. (above and below)


  1. The liaison class would continue to evolve into the 1960s. As warbirds go, the L-birds were generally smaller and often unarmed. They were optimized for specific tasks and all featured short takeoff and landing (STOL) capabilities. Other single-engine aircraft carrying the L-bird moniker include:

    • L-7 Universal/Monocoupe/Luscombe pre and post-WWII
    • L-8 Interstate Cadet model S-1A (L-6 was model S-1B1)
    • L-9 Stinson Voyager 3-seat, yet smaller than L-5
    • L-10 Ryan 3-seat, only one served
    • L-11 Bellanca 31-50 Senior Skyrocket, only one impressed
    • L-12 Stinson Reliant, two each of the SR.5A and SR.7B
    • L-13 Stinson-Vultee/Convair with folding wing
    • L-14 Piper J-5 Cruiser 3-seat
    • L-15 Boeing with its unique tailboom and dual downward-mounted stabilizers
    • L-16 Aeronca Champion/Champ with slightly better performance than the L-3 Chief
    • L-17 & L-22 North American/Ryan Navion & Super Navion
    • L-18 & L-21 Piper Super Cub, a higher performing L-4 Cub
    • L-19 Cessna Bird Dog, all-metal
    • L-20 de Havilland Canada Beaver 7-seat, similar in size to L-1 with higher payload
    • L-24 & L-28 Helio Courier 6-seat
    • L-60 Czechoslovakian Brigadýr 4-seat.

  2. Organic refers to the ground arms desire to have complete control of the use of their planes while being manned by personnel from the units they served and stationed as close to them as possible.
  3. Many J-3 models went to various War Training School operators.
  4. The U.S. Army Air Corps became the U.S. Army Air Forces on June 20, 1941.
  5. Lend-Lease was enacted to aid U.S. allies in the war against Germany, with the donation of nearly 9,000 combat aircraft flown from Great Falls, Montana to the Eastern Front via Canada, Alaska and Siberia.
  6. The Fighting Grasshoppers by Kenneth Wakefield, p. 36.
  7. World War II Journal #15: U.S. Warplanes by Ray Merriam, p.27.
  8. Ibid, World War II Journal, Merriam, p.27. Greenhouse refers to extended cabin windows both overhead and aft. This was done to improve visibility for the rear-seated occupant.
  9. Stinson Municipal Airport was established in 1915 when the Stinson family, three siblings Marjorie, Katherine and Eddie, initially leased the land from the City of San Antonio, Texas. Here, they created the Stinson School of Flying. The airport is now the second oldest general aviation airport in continuous operation in the U.S. In 1920, Eddie founded Stinson Aircraft Company in Dayton, Ohio.

L-bird Collection Complete

The world’s only flying collection of WWII liaison aircraft is once again whole following the acquisition of an Aeronca L-3 by Alamo Liaison Squadron.

Alamo Liaison Squadron (ALS) has completed its ensemble of L-birds with the recent acquisition of an Aeronca L-3 Defender. Based at Cannon Field in San Antonio, Texas—also known as Military City USA—ALS is home to the only collection of actively flying World War Two liaison aircraft, including L-2, L-3, L-4, L-5 and L-6 models.

Liaison aircraft of WWII, commonly referred to as L-birds, were slight in stature compared to other “warbirds,” yet they often performed critical duties on the battlefield. L-birds were called to action in artillery observation and reconnaissance; officer, parcel and message transport; among others, in support of frontline troops. While small in size, the accomplishments of L-birds were immense and the roles they played were as critical to the successes of Allied Forces as any mechanized means of combat.

ALS was formed in 1981 by Hardy Cannon, a master mechanic, and a group of San Antonio area aviators expressly for the purpose of acquiring and restoring WWII liaison aircraft. The following year, ALG had completed the restoration of six aircraft: a 1941 Stinson L-1, a 1941 Taylorcraft L-2, a 1942 Aeronca L-3B, a 1942 Piper L-4, a 1942 Stinson L-5, and a 1942 Interstate L-6.

The restored L-birds of ALS, at the time known as Alamo Liaison Group (ALG), were owned by both the organization and the individual members. In succeeding years, members have rotated in and out, and a variety of aircraft have called Cannon Field home. Presently, the group is proud to say the L-bird ensemble is whole again. One notable exception is the rare, and complex, L-1. The original L-1 restored by ALG is under new ownership. Early in WWII, larger L-1 series aircraft were replaced by the succeeding five L-bird models which served to define the liaison class in vast numbers.

1942 Aeronca L-3 / ­O-58B
1942 Aeronca L-3 / ­O-58B acquired by Alamo Liaison Squadron in 2019.

Brought to the attention of ALS by member Chris Hiatt, a self-proclaimed “Aeronca guy,” the L-3 was offered by Jim Bilyeu from whom Hiatt had previously purchased an Aeronca Chief 1. For many months Hiatt’s Chief served as a stand-in for an Aeronca L-3 in the ALS collection.

The newly acquired L-3 is five years the Chief’s senior. Built in 1942, it once had the military designation O-58B. This “observation” class of aircraft were redesignated liaison aircraft later that year, following the military’s adoption of new tactical guidelines for aerial reconnaissance. The B models in the O-58 series had their canopy modified and additional radio equipment installed. Some 875 examples of the O-58B / L-3B were constructed along with other variations bringing the total of Aeronca L-3 aircraft built to around 1,490.

Derived from the Aeronca Model 65 Defender—a high-wing tandem seat military trainer—the L-3 avails a long line of predecessors including pre-war Chief models. The L-3 could operate from small hastily-built flying fields. It was used mainly for training liaison pilots before they moved on to frontline aircraft like the Piper L-4 or the Stinson L-5. During World War II, the L-3 did see some action in artillery fire direction, courier service, and other frontline liaison activities.

Due to the company’s limited manufacturing capacity, the L-3 was produced in smaller quantities for the military than the roughly 20,000 L-4s Piper built. Nevertheless, the L-3 and the Aeronca family of aircraft are highly praised aircraft. They topped the list in a recent Sport Aviation magazine (Feb 2019) article, “10 Best Buys in Classic and Contemporary Aircraft,” by Budd Davisson:

Aeronca is a proud name that goes back to what could be considered the first light general aviation airplane, the Aeronca C-2/C-3 series. After World War II, [the company] produced one of the more iconic airplanes of the period, the 7-series Champ. Champs have always languished in the shadow of the iconic J-3 Cub. All things being equal, Champ prices still lag well behind the Cub… [despite] the design goal of Aeronca to produce an airplane that addressed every shortcoming of the Cub (it’s wider, you solo up front, excellent visibility, etc.).

Today’s Cubs, and the Champ’s offspring Citabria, have improved on these points, in addition to equipping with more horsepower and often sophisticated electronics. Nevertheless, the demand for true warbirds in their “vintage” state remains strong. There is a strong correlation between L-birds and the modern “taildragger.” Both perform equally well, on the remote battlefields of the past and the alluring backcountry of the present.

ALS’s newly acquired L-3, O­-58B s/n 2082, was described by its previous owner, Jim Bilyeu: “Thought some of your bunch would like a real WWII bird.” He added, “Contributing factors to offering her for sale are creaky bones and expanding waistline that make in/out access to the cockpit exceedingly difficult.

“The Army Air Corps original paper work seems to be there except for a DD 214 [Certificate of Release or Discharge from Active Duty issued by the United States Department of Defense]. Maybe because it went to the CAP [Civil Air Patrol], it wasn’t considered discharged.

“It is in civilian livery [tan and orange, as purchased], but fabric tests good and painting would be ok. For full effect, the greenhouse 2 could be reinstalled. I put the 85-­8 [85 hp Continental engine] (675 hrs since overhaul) from the 11CC [Aeronca Super Chief] on with Wagner STC [FAA Supplemental Type Certificate no. SA7NW]. It really perked the little bug up. Spins, steep banks, etc. are smooth. I have a friend who takes it up nearly every weekend. Flies an hour or so. Using 100LL and getting 4–5 [gal/]per hour.”

Following the L-3’s arrival at Cannon Field, ALS President and its ferry pilot, Gene Jensen informed, “We recently purchased an Aeronca L­-3B originally known as an O-­58B, more recently restored and hiding in civilian attire as an early model Champ. The aircraft is currently airworthy and made the trip from NW Dallas to Cannon Field in four hours flight time with a fuel stop in Cameron, TX. This aircraft is in original configuration which means that it does not have an electrical system and requires hand propping to start. Come see the new member of the ALG lineup and help with plans to return it to basic L-­3B paint scheme.”

The L-3 has been thoroughly inspected and confirmed to be in airworthy condition. It has subsequently been flown by various members of ALS. For its gentle and responsive handling characteristics, the L-3 is quickly becoming a favorite among members. Further review detected minor metal fatigue in the seat structure, and repairs were deemed necessary. In the process an adjustable seat was developed to allow for longer-legged pilots. Wear was also found, and addressed, in the exhaust system and carburetor.

1942 Aeronca O-58B

Other L-3 aircraft that have been based at Cannon include an Aeronca O-58B, c/n O-58B-1782, built in 1942, N52169, 236152. Nicknamed “Strafin,” this L-3 was formerly owned by late ALS member Henry B. Whitmore.

ALS seeks to perpetuate, in the memory and hearts of the American people, the spirit with which the liaison pilots, their crews and the airplanes served in the defense of not one, but many nations. To help punctuate these contributions, the ALS mission is to bring people together and thereby foster an interest in aviation and its history. Many of the organization’s activities offer an opportunity to increase awareness, bolster membership and grow support. In this way, veteran liaison pilots, along with those who built and supported the L-birds, can be remembered for their daring feats so often displayed yet seldom recorded.

As a 501c3 non-profit organization all funding is derived from member dues, reimbursement for flying expenses, and contributions. All member activities are performed on a volunteer basis, so all funding goes directly to support the aircraft and their upkeep. We encourage you to join ALS with an annual contribution, a one-time contribution, or donation. All enthusiasts are welcome to tour the facility at no cost. Demo flights can also be arranged.


  1. The Aeronca Chief was a family of high-winged light touring aircraft built in the U.S. from 1936 to 1949. Following some thorough maintenance and updating of his Chief, Hiatt has since accumulated 100 hours on the 2-seat taildragger, an Aeronca 11AC originally built in 1947, and based at Cannon Field.
  2. Greenhouse refers to an area of the fuselage covered with windows. In the case of L-birds, extended rear windows and an overhead window improved visibility for the rear seated passenger whose function was to observe ground activities and spot enemy pursuits in time for the pilot to take evasive maneuvers.

Timber Play Plane

Constructed primarily of common lumber, this Play Plane is perfect for your child’s play time in the garden, garage, patio and driveway, or on the hangar floor. Even the most modest of craftsmen can build one with this fully illustrated set of plans and descriptions (19 pages in all). Order your plans today at

DIY Play Plane Airplane, Pedal Plane, Child's Airplane, Young Pilot, Garden Driveway Garage Hangar Airplane
Timber Play Plane, a Young Pilot’s Airplane for the Driveway and Garden.

AERO Friedrichshafen 2019 – The Brightest in European Aviation

AERO Friedrichshafen Brings Out the Brightest in European Aviation, Published in InFlightUSA | May 2019 (pp 34/36).

Originally published in In Flight USA magazine… AERO 2019 delivered a consistently pleasing balance of trade fair, camaraderie, evolution, esprit de corps, solidarity, and fine cuisine. AERO lacks the enormity, the casual spectators and the frequently petulant weather of comparable U.S. shows; and that’s just fine with the vendors and shoppers it’s devised to draw.

Download the article PDF.

Bearhawk Print Ad – Kitplanes Magazine 2019

Beyond compare in Strength, Performance, & Safety
Beyond compare in Strength, Performance, & Safety

All airplanes are not created equal…

4-Place and 2-place tandem model Bearhawks deliver the best in strength and durability:

  • 100% Flush-head solid rivets on all 2024-T3 aluminum skin wings
  • 17% Stronger, utility category strength at full gross weight.

Unmatched in performance, nothing flies as fast, lands as slow, is tougher built:

  • Patrol touches down at 35 mph and cruises at 150+ mph
  • 4-Place has 1,350 lb useful load and outclimbs the competition.

Built-in safety margin is best in class, with more utility:

  • Riblett airfoils outperform in climb, speed and slow flight
  • Beefy 4130 steel frame provides a safe and roomy cabin.

Will the warbirds return to Friedrichshafen in 2019?

The carbon-composite SkyLeader UL-39 Albi two-seater, ultralight concept presented in 2017 was not seen in 2019. However, other aircraft were on display from its manufacturer Zall Jihlavan Airplanes of the Czech Republic.

SkyLeader UL-39 Albi from Zall Jihlavan Airplanes
SkyLeader 600 all metal 2-seater from Zall Jihlavan Airplanes.

The JH Aircraft Corsair is a replica of the legendary Vought F4U Corsair American fighter aircraft certified to LTF-L German civil airworthiness requirements and U.S. American FAR part 103 regulations. It returned in 2019 and is available in a ready-to-fly aircraft as well as kit form.

Corsair replica from JH Aircraft
Ultralight Corsair replica from JH Aircraft of Germany.

Marketed as “a fighter jet design in a luxurious form,” the desert camo plumed TL Ultralight Stream was seen again in 2019 suspended in its hangar/hall at Messe.

Desert cammo plumed TL Ultralight Stream
The TL Ultralight Stream from the Czech Republic.

The Stampe SV4-RS from Ultralight Concept in Belgium is a light-sport full scale replica of the 1930s Stampe-Vertongen SV4b. It returned in 2019 and is available ready-to-fly at under €100,000.

Ultralight Concept Stampe SV4-RS
Ultralight Concept Stampe SV4-RS replica.

While two examples of the T-131 PA Jungmann were present at Aero 2017, Air Res did not show in 2019. The T-131 is a stunning replica of the Bücker 131 offered by the flight school and maintenance operation of Air Res Aviation of Poland.

T-131 PA Jungmann from Air Res Aviation
T-131 PA Jungmann from Air Res Aviation in 2017.

The ChemTools T-28 Trojan seen in 2017 was scrubbed and the company branded Extra EA-330LT was on exhibit in its place in 2019.

ChemTools Extra EA-330LT
ChemTools of Germany’s Extra EA-330LT aerobatic and touring aircraft.

The Tomark Viper SD4 is an all-metal two-seater microlight/LSA aeroplane seen again at Aero 2019. The company is pitching the SD4 as a Primary Air Force trainer.

Tomark Viper SD-4
Tomark Viper SD4 from the Slovak Republic.

Blackshape, though neither vintage nor warbird, presented two exciting aircraft including the full carbon fiber framed high performance two-seater Prime alongside Gabriél. The latter, powered by Lycoming, was pitched as an airline trainer. According to Blackshape, “both aircraft have been inspired by cutting edge approaches in military training syllabuses.”

Blackshape Gabriél
Blackshape Gabriél and Blackshape Prime are built in Italy.

The Zeppelin is ever-present at Messe Friedrichshafen. This year the Europa Park logoed Zeppelin was tethered at the airfield. Based at Bodensee Airport adjacent Zeppelins are available for scenic flights of the area.

Europa Park Zeppelin
Europa Park Zeppelin at Bodensee Airport in Friedrichshafen.

Again, a newly manufactured Junkers F13 was present, this time on the aircraft’s 100th anniversary. It was the second in a contemporary minting of the Junkers F13 being built from original drawings. The F13 was developed in Germany at the end of World War I and first flew in 1919. Like other manufacturers of civil aircraft immediately after World War I, Junkers was faced with competition from the very large numbers of surplus warplanes and the F13 was the company’s answer.

Junkers F13
Junkers F13 newly manufactured aircraft from Junkers Flugzeugwerke in Switzerland.

A newcomer to Aero 2019 was the Bücker 133 Jungmeister, an advanced trainer of the Luftwaffe in the 1930s. This one is named for Liesel Bach, a German aerobatic pilot and flight instructor, and the first woman to fly over Mount Everest.

Bücker Jungmeister Liesel Bach
Bücker Jungmeister “Liesel Bach” at Aero 2019.

Inside the Dornier museum at Bodensee Airport one can learn about the Do-27. TQ Avionics, based in Germany, is well aware of the importance of this classic high-wing taildragger. Built for military use in a light utility role, it’s a heavy hauler, and compared to similar STOL-capable it’s a standout, which correspondingly reflects the diverse capabilities of TQ Avionics’ parent company, TQ Group. The company has recently purchased a Do-27, and while it will based in the U.S. one can expect to see it in many places including North American fly-ins and cameoing in international press.

Dornier Do 27
The Dornier Do 27 first flew in 1955 and was the first mass-produced aircraft in Germany after World War II.

In 1919, ground trials began for the Siemens-Schuckert R.VIII bomber. In 2017, Siemens brought the Magnus eFusion aircraft to Aero. The eFusion fully electric design was unfortunately lost in a test flight accident in June 2018. But at Aero 2019, the Magnus returned.

Magnus Fusion
The Magnus Fusion from Hungary.

Trig Avionics displayed a pair of Pitts S-1D Specials at Aero 2017. These aircraft have since been retired and their pilots have ventured into an organization called Ultimate Warbird Flights offering experiences in a variety of warbirds including Supermarine Spitfire, TF-51D Mustang, ME109 (Hispano Buchón) Hawker Fury, Hawker Hurricane Republic P-47D Thunderbolt, and North American T-28 Trojan.

A pair of Pitts S-1D Specials
A pair of Pitts S-1D Specials.

A newcomer to Aero 2019 was the ScaleWings Mustang. The company’s SW-51 Mustang replicates the historic North American P-51 Mustang in ultralight and experimental kit versions. It is produced in Poland and Germany.

ScaleWings SW-51 Mustang
The ScaleWings SW-51 Mustang 70% replica.

This Focke-Wulf 190 A 5 was spotted at Aero 2019.

Focke-Wulf 190 A 5
Focke-Wulf 190 A 5 at Aero 2019.

Tecnam brought its new P2002JF MkII CS-23 / FAR Part 23 certified fully IFR trainer in silver military camo.

P2002 Sierra MkII
The P2002JF Mark 2 from Tecnam of Italy.

Jets and helicopters were display by the German military at Aero 2019.

German Luftwaffe Tornado
German Air Force (Luftwaffe) Panavia Tornado multirole combat aircraft on static display.
German military helicopter
German Army (Deutsches Heer) Eurocopter EC135 T1 helicopter in the halls of Messe Friedrichshafen.

The stealthy looking Nexth aircraft from Aero & Tech of Italy will be German LTF-UL certified and constructed of faceted aluminum, titanium and carbon fiber components.

The stealthy Nexth
The stealthy Nexth from Aero & Tech of Italy at Aero Friedrichshafen.

© Mike Taylor. Contact for re-publication and hi-res images.