Tony’s Scrapbook; Boeing 247 Transport

Passengers waiting to board the Boeing 247

The Boeing 247 revolutionized civilian air travel through high speed, passenger comfort, and futuristic designs not seen by the previous airliners, virtually rendering them obsolete in a single day. Some examples of earlier airlines consisted of the Ford Tri-motor “Tin Goose,” the Fokker F-10 Super Trimotor, and the Curtiss Condor biplane. These airliners were usually underpowered for their size with open engines and large fixed landing gear resulting in a large drag coefficient and overall poor performance with long flight times between destinations.

Newspaper clipping from Tony’s scrapbook dated January 1933

The first flight of the Boeing 247 happened on February 8, 1933, and enters into service with United Air Lines on March 30, 1933, launching United well above the competition. The Eastern division of United received the first delivery in April. By the end of September, the entire fleet is in service operating in all of the United Air Lines territories. The 247 sets the trend for future airlines with United on top and momentarily deems all other current airliners out-of-date for about a year until the Douglas DC-2 entered the market on May 11, 1934, for TWA.

United ordered sixty planes in 1932 after seeing a final version model with the first batch of fifteen airplanes entering production by mid-1932. Boeing built much of the 247’s components in secrecy because United Air Lines didn’t want the other airlines knowing of their intent on the future of airline travel.

Boeing 247

Prototyping of the 247 began in 1930 and evolved from a combination of Boeing’s previous single-engine high-performance mail plane, the Model 200 “Monomail,” and it’s twin-engine military bomber, the Model 246/Y1b-9A.

Boeing “Monomail”

On May 6, 1930, the Boeing “Monomail” completes a successful test flight powered by a fully cowled Pratt & Whitney “Hornet” B radial engine rated at 575 hp with a maximum cruising speed of 140 mph at sea level. This new all-metal airplane has a cantilever low-wing design with retractable landing gear and three mail compartments totaling 220 cubic feet.

Boeing Y1B-9. (U.S. Air Force photo)

The United States Army Air Corps (USAAC) ordered five Boeing YB-9 bombers for assessment and tested it against other competitors’ aircraft, all competing for a new military contract. Boeing produces the YB-9 as an upgraded model based on their earlier experimental designs, the 214 and 215 models. Powered by two Pratt & Whitney 600 hp “Hornet” engines, this cantilever low-wing monoplane with retractable landing gear can carry five crew members, two machine guns and has an external explosive payload limit of 2200 pounds.

Martin B-10

As impressive as the Boeing YB-9 is, it has its limitations, especially without any internal bomb bay. The Martin B-10 bomber is a better fit, and the Glenn L. Martin Company of Baltimore, Maryland, wins the contract.

Boeing YB-9 (courtesy Ray Crupi)

Boeing retains the cantilever low-wing twin-engine monoplane construction of the YB-9 in designing the 247 but completely redesigns the fuselage for passenger transport. Designers add seating for ten passengers and a flight crew of three, including the pilot, a co-pilot, and a flight attendant. The wing spars of the internally braced cantilever wings became a tripping hazard where passengers had to step over them to traverse the cabin forward and aft.

Pratt & Whitney R-1340 Wasp
Pratt & Whitney R-1340 “Wasp” engine (courtesy Insomnia Cured Here)

The Boeing 247 is the first airline with twin direct-drive supercharged Pratt & Whitney S1D1 “Wasp” engines rated at 550 hp at 5000 ft spinning three-bladed fixed pitch propellers and has a top speed of 180 mph. The retractable landing gear attaches under each engine mount and folds into each wing’s leading edge engine nacelles. The all-metal construction of the 247 proves durability, safety, and efficiency, which reduces the previous transcontinental flight between New York and San Francisco by seven hours, with only seven stops in less than twenty hours. United Air Lines revenue increases dramatically because of their fast and dependable schedules, passenger comfort, and aggressive advertising campaign, earning the title “Three-Mile-A-Minute-Transport.”

Boeing 247
Boeing 247 (courtesy planephotoman)

Boeing soon discovered that replacing the fixed-pitch propellers with variable-pitch props improved performance and added 10mph to the already impressive cruising speeds. The demand is high for the Seattle Washington Boeing Airplane Company, a division of the United Aircraft & Transport Corporation, to produce sixty aircraft on time. Boeing soon increases its workforce to thirteen hundred workers and sublets work to Stearman Aircraft in Wichita, Kansas, another division of United, to assemble the landing gears, tail wheel assembly, and various small packs for the 247.

Interior seating of the Boeing 247

The 247’s semi-monocoque fuselage’s main cabin has five seats on each side and seating for the flight attendant located towards the aisle’s end at the plane’s rear. The 20′ x 6′ high cabin features separate heating and air vents for each passenger, reclining seats, dome and reading lights, and convenient ashtrays. Gray-green fabric adorns the interior walls, covering insulation layers and soundproofing, making for a pleasant flight with complimenting green whipcord patterned fabric upholstered seats.

A businessman prepares to climb three portable steps to board the 10-passenger Boeing 247 operated by Varney Air Lines, part of the United system in the 1930s. A flight attendant stands at the ready. Once aboard the airliner, they will have to step over the wing spars to reach the front of the cabin. (Frederick A. Johnsen collection)

A right-side main entry door, aft of the right wing’s trailing edge, allows access to the welcoming cabin by traversing a few steps on a short rolling ladder. Once inside, one must carefully step over the interior wing spars that intersected the floor while proceeding towards the passenger cabin’s front. The wing spar is an inconvenience, but the passengers soon accept it as visual reassurance of the strength and engineering behind the new 247 design. On the left side, a small lavatory and stewardess pantry that can serve light meals during the flight sits across from the rear main entry door. A tail section cargo bay is easily accessible through a door to the left of the main entrance with a maximum capacity of 65 cu ft. A second 60 cu ft cargo area is located behind the aircraft’s nose but can only be accessed externally.

Notice the forward slanting windscreen on this early 247

The forward-slanting windscreen quickly identifies the cockpit of the early 247’s as opposed to the later models with backward slanting windshields, but I’ll cover those other models later. All cockpits have dual controls, sliding side windows, two-way radios, state of the art navigational instruments, night-flying equipment, and a radiophone in the nose compartment’s upper area.

1933 Boeing 247

The stub wing is an integral part of the fuselage that firmly supports the massive landing gear, engine mounts, and nacelles. Fuel tanks also reside in the wing stub, one on each side with an additional 70-gallon reserve in the right tank. The smooth metal skin consists of anodized aluminum sheeting riveted to internal framing, resulting in a grayish exterior color often left unpainted. The all-metal tail section uses a similar cantilever design where internal bracing strengthens the horizontal stabilizer, but later models switch to fabric-covered rudders and elevators to reduce weight.

Boeing 247-D at the Smithsonian Institution National Air and Space Museum. Photo by Eric Long. Photo taken on March 19, 2018.

Newly designed “trim tabs” added to the ailerons’ trailing edges, elevator, and rudder allow the pilot to trim the aircraft during flight. Offset hinges installed on both the rudder and elevator provide additional aid to the pilot by reducing the amount of force needed at the control wheel to steer such a large airplane with substantial control surfaces.

Boeing 247 9444
Boeing 247 (courtesy Del Hoffman)

This impressive aircraft measures 51′ 4″ in length and has a height of 12′ 6″ with a 74′ wingspan. It has an empty weight of 8370 pounds with a useful load of 4280 pounds, bringing the maximum gross value to 12,650 lbs. The top speed is 182 mph at 5000 ft, but a comfortable cruising speed of 161 mph at the same altitude is ideal. Climbing to 8000 ft is achieved 10 minutes after takeoff, with the initial rate of climb decreasing from 1070 ft after the first minute to 830 ft at 5000 ft. The maximum fuel capacity is 265 gallons when the tanks are filled to the caps when needed but usually run below that level resulting in 203 gallons per flight. Cruising range is about 600 miles when the pilot can manage the fuel-hungry “Wasp” engines to sip just 30 gallons each per hour.

Boeing sees room for improvements in powering the 247 and is confident that the airframe is structurally sound to handle larger engines. After discussions with Pratt & Whitney, the two reach an agreement that Boeing will modify the 247 as a test plane for their new “Twin Wasp Junior” engines currently in development and used exclusively as an executive transport for the officers of the United Aircraft & Transport Corporation. The 247-A is born.

Pratt & Whitney R-1535-96 Twin Wasp Junior
Pratt & Whitney “Twin Wasp Junior” engine (courtesy Daniel Berek)

On September 14, 1933, Bernard “Benny” Whelan piloted the newly designed 247-A airliner’s first flight. “It’s a delight to fly with the increased power,” Benny remarked after landing and is impressed with the redesigned engine nacelles and broadened shrouds that now cover the more in-depth double row engines. He also enjoys seeing the new plush interior, now with spacious seating for six passengers, and still retains the rear lavatory and small kitchenette. Larger fuel tanks increase the capacity to 356 gallons extending the cruising range to about 1000 miles and reduce the number of stops on longer flights. The Pratt & Whitney SGR-1535 “Twin Wasp Junior” engine is rated at 625 hp at 2400 rpm at 7000 ft.

Engine testing continued with the installation of Pratt & Whitney’s newest development, the S1A1G engine rated at 660 hp at 2400 rpm at 7000 ft. This upgrade added 695 lbs to the total gross weight while retaining the same performance level as the previous SGR-1535 engine. Only one 247-A is produced for the sole purpose of testing and logged more than 3000 hours of flight time from 1933 to 1942 from its hanger based in Hartford, Connecticut. In 1947 the 247-A was scrapped but not before an accident-free career spanning 14 years, including two mercy flights saving both people’s lives and valuable data collected during those flight years.

The 247-A “Special” variant of the 247-A features higher torque engines, the Pratt & Whitney SA7G rated at 655 hp, increasing the gross weight to 13,650 lbs. That’s a 1000 pound increase from the original 247s gross weight of 12,650 lbs! This new 247-A “Special” also tests previous engines used in the 247-A, the 625 hp SRG-1535, and the 660 hp S1A1G with different passenger configurations leading up to the 247-D.

The 247-D is the last variation of the easily adaptable 247 in Boeing’s goal to stay competitive and easily identified by its backward sloping windshield. New supercharged Pratt & Whitney 550 hp S1H1-G “Wasp” engines fit in larger, more streamlined nacelles with close-fitting NACA cowls that reduce drag and increase speed. The 3:2 geared prop shaft spins the Hamilton-Standard “Controllable Pitch” propellers for better thrust, replacing the direct-drive fixed pitched props of the earlier 247s. The 247-D can carry ten passengers with up to 750 lbs of baggage and a flight crew of three, retaining the original configuration of the previous 247s but with an increased payload weight. Improvements to the cabin provide passenger comfort and convenience while the pilot enjoys an increase in performance and updated controls, making it easier to fly. Plus, the revised instrument panel, including an optional Sperry autopilot and Goodyear deicer boots on all leading edges. The aircraft can maintain the “Three-Miles-A-Minute” status at 3/4 throttle compared to the first 247s needing full throttle to achieve the same results due to the reduced drag and larger engines.

NC13369 - BOEING 247   Washington
Boeing 247-D (courtesy Vin LK)

Pratt & Whitney S1H1-G “Wasp” engines are rated at 550 hp at 2200 rpm at 8000 ft, increasing the service ceiling from 4500 ft to 11,500 ft with one engine out under full payload compared to the earlier S1D1 engines. Gross weight remains consistent at 13,650 lbs, but the maximum speed increases to 202 mph at 8000 ft with a cruising speed at 3/4 throttle of 184 mph at the same altitude. The climb rate in the first minute is 1150 ft at sea level and can reach 11,000 ft in ten minutes with a service ceiling of 25,400 ft. Cruising range reduces to 800 miles due to the smaller fuel tanks needed to offset the extra weight of 10 passengers and their luggage, burning 66 gallons of fuel per hour at cruising speed. The redesigned all-metal tail group features additional internal strengthening under the aluminum skin and improved control surfaces. Fabric-covered rudder and elevator installed with offset hinges replace the metal cover units to reduce weight and lighten the force at the pilot’s control wheel.

247-D “Adaptable Annie” and Paul Garber

On October 20, 1934, Roscoe Turner and Clyde Edward Pangborn entered a modified 247-D “Adaptable Annie” into the MacRobertson Centenary Air Race celebrating Melbourne, Australia’s 100th anniversary. This aircraft had additional fuel tanks installed into the fuselage and upgraded navigational equipment for the grueling 18,000-kilometer trip.

The flight path traversed over three continents, nineteen countries, and seven seas with five stops in Baghdad, Allahabad, Singapore, Darwin, and Charleville starting from Mildenhall, England, and finishing in Melbourne, Australia. The race has two divisions, speed, and handicap with no limitation on the aircraft, engines, or flight crew size. Turner and Pangborn finish the race in 92 hours and 55 minutes, coming in third behind a Douglas DC-2 entered by KLM piloted by the flight crew K.D. Parmentier, J.J. Moll, B. Prins, C. Van Brugge, and carrying three passengers. The DC-2 finished the race in 90 hours and 13 minutes and won the handicap division. This race showcased the strength and durability of stressed metal airplanes and that air travel over long distances is possible, making international air transport a safe alternative.

CF-JRQ (Chevron Standard)
Boeing 247-D Chevron Standard Limited (courtesy Reinhard Zinabold)

In Seattle, Washington, the Boeing factory builds thirteen new 247-Ds while the United Air Lines Overhaul Base in Cheyenne, Wyoming, converts existing 247s in their service fleet. By 1937, the 247-D finds itself becoming obsolete through fierce competition and new advances in aviation development, especially in the Douglas DC series of airliners. United decides to lease or sell most of its service fleet of 247-Ds to smaller airline companies who are more than happy to acquire them. In 1942, 27 are called into duty by the USAAF and rebranded as the C-73 for military use. By 1944, undamaged deactivated planes return to their former owners or lent to foreign countries temporarily and eventually return to the U.S.

Boeing C-73, at Hammer Fld
Boeing C-73 at Hammer Field (courtesy SDASM Archives)

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Tony’s Scrapbook; Northrop Delta

Northrop XB-35 (courtesy Northrop)

John Knudsen Northrop, aka “Jack” Northrop, doesn’t need an introduction, and I have fond memories of the first time seeing his XB-35 flying wing on the cover of an old magazine that my father had been reading the night before. I must have been five or six at the time, and that single image still has lasting impressions for me to this day. I’ve always know Northrop’s involvement with military aircraft, but never seemed interested or paid much attention to his past or previous designs. Because I found the XB-35 so fascinating, I never gave it much thought about the career path that this legendary man had taken in creating an array of distinguishing aircraft.

In the above news clipping dated January 1933 by my father, a Northrop Delta illustrates the future sixteen-hour coast-to-coast schedules for TWA’s passenger transport with a delivery date of March 1 of fifteen aircraft. The Delta can carry eight passengers and 1,000 pounds of freight at 187 mph, as stated above and powered by a 700 hp Wright engine. These details seem vague to me, and I thought a thorough investigation of the Northrop Delta is necessary.

Jack Northrop (courtsey Northrop Grumman Corp.)

The Northrop Delta came about from the partnership of Jack Northrop and his good friend Donald Douglas of the Douglas Aircraft Corporation. Douglas hired Northrop in 1923 to design the fuel tanks for the Douglas World Cruiser. Their relationship was complicated, and Northrop decided to part ways in 1926 to further expand his career. Northrop left on good terms when he accepted a position as chief engineer with Lockheed Aircraft Company. Shortly after being hired, Northrop began to work on a new project, the Lockheed Vega. On July 4, 1927, the Vega test flight was such a massive success that it created an instant backlog of orders. Every pilot wanted a Vega, and many set new records that Lockheed advertised the slogan “It Takes a Lockheed to Beat a Lockheed.”

Lockheed Vega (courtesy

Even though Northrop was ecstatic with the Vega’s performance and worldwide acceptance, he knows the future of aviation lies within all-metal construction, making the wooden airframes obsolete. Northrop decides to leave Lockheed on June 28, 1928, to form the Avion Corporation, where he can work on new commercial aircraft designs using his new all-metal stressed-skin construction. He developed and built his first flying wing, the Avion Experimental No. 1, unveiling it in 1929. Northrop’s new “multi-spar” wing construction is revolutionary to future aircraft construction where multiple full-length span-wise stiffeners, or shear webs, replaced the traditional wing spars attached directly to the fuselage for structural support. I’ll cover a bit more on his multi-cellular wing construction in a few paragraphs, but let’s continue with the timeline.

Northrop “Experimental No. 1” Tractor (NX216H) (courtesy Northrop)

On January 1, 1930, Northrop sold his Avion Corporation to William Boeing’s company, the United Aircraft & Transport Corporation, establishing the Northrop Aircraft Corporation. Northrop then turned his attention to designing and building a new commercial aircraft, the low wing Alpha featuring his metal stressed skin technique. The highly polished aluminum skin gleamed in the sunlight, and Northrop was proud of his newly designed aircraft! He always felt that his most significant contribution to aviation technology was his new structural innovation, the stressed skin construction. Northrop often quoted, “As far as the structure is concerned, that which was developed into the Alpha was really the pioneer for every airplane in the sky today.

Northrop Alpha (courtesy

The Northrop Alpha is an all-metal six-passenger cabin low wing monoplane powered by a Pratt & Whitney Wasp radial engine rated at 425 hp. The pilot is seated slightly above the passenger cabin in an open cockpit located towards the aircraft’s aft section. The Alpha is the first commercial aircraft to use deicer boots on the leading edges, allowing day or night operations in all weather conditions combined with the state of the art radio navigation equipment. On April 20, 1931, TWA started their coast to coast service with the Alpha on a flight from San Francisco, California, to New York, New York, in just over 23 hours with 13 stops. The Alpha was a great success, and a total of 17 were built, with TWA operating 14 planes.

In September 1931, the Northrop Aircraft Corporation merged with Stearman Aircraft in Wichita, Kansas, due to the Great Depression’s collapsed economy to economize the company. Northrop isn’t happy with the merger and decides to form a new company, vowing not to leave California. He has three people agreeing to stay with him, Walter J. Cerny, Kenneth Jay, and Don Berlin, but he still requires the financial support of his good friend Donald Douglas.

DC-1 (courtesy

Douglas thought very highly of Northrop’s designs, especially his new “stressed skin construction,” which he thought would be perfect for the D.C. airliners. As a result of their conversations, the two men formed the Northrop Corporation based in Inglewood, California, as a Douglas subsidiary on January 1, 1932.

To help me better understand Northrop’s multi-cellular wing construction, I found a quote in the document 3-22(a-b) 3-22-b: Engineering Department, Douglas Aircraft Co. “Development of the Douglas Transport,” Technical Data Report SW-157A, ca. 1933-34, Folder AD-761184-05, Aircraft Technical Files, National Air & Space Museum, Washington, D.C., as stated;

Multi-cellular wing construction of the Northrup YB-35 in 1946 (courtesy Northrup)

In determining the wing construction of the early Douglas machines single, two, three and multi spar designs were considered as well as shell type and multi-cellular designs. After a thorough investigation of all types the Northrop multi-cellular wing construction was finally decided upon. This type of structure consists of a flat skin reinforced by numerous longitudinals and ribs. The bending is taken by the combination of flat skin and full length [longitudinal] stringers. Three main flat [vertical] sheets or ‘webs’ carry the shear loads. Torsion and indirect stress are carried by the skin with frequent ribs preserving the contour and dividing the structure up into a number of small rigid boxes or cells. Since the major loads are carried in the outer surface of the wing as well as in the in the internal structure, an inspection of the exterior gives a ready indication of the structural condition. The unit stresses in the material are low and therefore the deflections are at a minimum giving a maximum in rigidity. This construction has proven to be a happy medium of those considered since it combines practically all of the advantages of each; namely, very small unsupported areas, extreme lightness for its strength and rigidity; also ease of construction, inspection, maintenance and repair.

Donald Douglas (courtesy Douglas Aircraft Company)

Initially, the Northrop Corporation’s main focus was to serve as an experimental and research department for Douglas but soon began to produce aircraft when output capacities exceeded Douglas’s production limitations. Looking to fill the request of a fast cargo mail plane over long distances for the airlines and an aircraft capable of experimental over-weather or high altitude flights with deicing technology, Northrop designed and built the Gamma, an upgraded version of his successful Alpha aircraft. A 710 hp nine-cylinder Wright “Cyclone” radial engine, SR-1820-F3, provides the power for a cruising speed of 215 mph at 7000 ft with a service ceiling 20,000 ft. The pilot’s cockpit retains the original location, aft of the wing’s trailing edge, but features an enclosed sliding canopy that offers an unobstructed view of the 47′ 10″ cantilever wingspan. The front of the large round fuselage has two cargo bays with a total capacity of 1300 lbs, placing the entire payload weight over the center section of the wing. Gross weight is 7350 lbs with a range up to 1700 miles at 40 gallons per hour supplied by the 334-gallon fuel system. The fuselage has an overall length of 31′ 2″ and is 9′ in height.

Northrop Gamma 2B “Polar Star” in 1935 (source and author unknown)

Production started in 1932, and the first Gamma off the assemble line, the Northrop Gamma 2B Polar Star, went to Lincoln Ellsworth on November 29, 1932, to be shipped to the Ross Sea for the start of his 1934 Antarctica expedition. Northrop produces a total of 61 Gammas through 1937, with 49 sold to the Chinese.

Northrop Gamma 2A “Texaco Sky Chief” in July 1933 (courtesy Elwood W. Mason)

Frank Hawks of the Texas Oil Company purchased the second Gamma, a Northrop Gamma 2A Texaco Sky Chief, and set a record flight on June 2, 1933, from Los Angeles, California to New York, New York in 13 hours, 26 minutes, and 15 seconds.

Northrop Gamma 2-D (courtesy Patrick Rodwell)

TWA received their Gamma 2-D for the transport of mail and cargo, and on May 13, 1934, Jack Frye set a new cross-country record for transport planes leaving Los Angeles, California, and arriving in Newark, New Jersey in 11 hours and 31 minutes.

Northrop Delta Type 1A (courtesy SDASM Archives)

While in the middle of the Gammas production, Northrop added the newly designed Delta passenger transport to the assembly line to start production in 1933 at the new plant in El Segundo, California. The prototype, Type 1A, successfully flew in May of the same year, and Northrop received an order from TWA for 15 planes. Taken from the proven and popular Gamma design, the Delta retains the same airframe and powerplant but relocates the cockpit to the airplane’s front. The widened semi-monocoque fuselage can accommodate up to eight passengers, plus the pilot seated slightly above the passenger level in an enclosed cockpit. An optional configuration of two pilots with six passengers and cargo arrangements are also available. The Delta Type 1A receives certification to carry six passengers after a few months of testing. On a lease, TWA receives delivery on August 4, 1933, for preliminary trails to transport mail between Los Angeles, California, and Kansas City, Missouri. Unfortunately, on November 10, 1933, the plane develops an engine fire in flight near Albuquerque, New Mexico causing the pilot Harlan Hull to eject from the aircraft. He survives by parachuting safely to the ground, but the airplane is a total loss. TWA decides to cancel its order due to the recent flight problems and a rumored amendment to the Air Commerce Act of 1926 taking effect in October 1934, banning the Delta from being operated by U.S. airlines. More on that later.

Northrop Delta Type 1B (source and author unknown)

The second Delta, Type 1B, is purchased by the Mexican subsidiary Aerovias of Pan American Airways in August 1933 for the Los Angeles-Mexico City flight route. In May 1934, another engine fire destroyed this second Delta, but fortunately, no one is injured. I looked into the possibility of a common issue with the engine, but the Type 1B used a different powerplant, a 660 hp Pratt & Whitney Hornet T2D-1 engine, so that doesn’t seem to be a common cause. Unless there was some defect in the fuel delivery system, I’m not an A&P mechanic, and your guess is as good as mine. Some articles state that the aircraft crashed due to an engine fire while in service on a flight to Mexico City, but I cannot confirm this statement. Most accident reports say there was an engine fire without any injuries, but it’s unclear if it was on the ground or in flight.

Northrop Delta Type 1C (courtesy

The last Delta to be sold to an airline is the Type 1C and was purchased by AB Aerotransport in Sweden in April 1934, and given the name “Halland.” Only one of the Type 1C model is built and featured the optional Pratt & Whitney T1D-1 engine rated at 700 hp. This aircraft had a long service life without mechanical issues, as the previous models, operating on the Gothenburg-Copenhagen-Malmo and Malmo-Copenhagen-Hanover flight routes. “Halland” ceased its airline service in May 1937 and was later purchased by a private citizen.

These first three Delta models had a single-seat cockpit with a sliding canopy and operated with a two-bladed propeller. Later, the new Delta models switched to a three-bladed propeller and reconfigured the cockpit to allow room for a pilot and co-pilot. Northrop produces 32 Deltas, but the majority are sold outside the U.S. or to the private market.

The initial plan to sell the Deltas as single-engine airliners capable of carrying medium loads on the U.S. trunk airline routes came to an abrupt halt when an amendment to the Air Commerce Act of 1926 regarding airline safety requirements take effect on October 1, 1934. The revision requires all airlines operating on the trunk routes to use multi-engine aircraft at night or over rough terrain, instantly banning the Delta from any airline.

The new provisions included the requirement for airline pilots to use multi-engine aircraft capable of operating with one engine not functioning when flying at night or over terrain not readily permitting emergency landings. Instrument or blind flying was permitted only for multi-engine airliners equipped with two-way radio.

Canadian Vickers Northrop Delta (courtesy RCAF)

Northrop, discouraged with the new amendment, turns his attention to the mounting military aircraft contracts and finds the short-lived Delta project a much-needed break from the nuisance that the Delta was creating. He did continue to produce the Delta 1-D, already in the assembly line before the new amendment, but reconfigured the cabin for the limited private sector sales and selling the remaining inventory to other countries unaffected by the amendment. In August 1936, Canadian Vickers Ltd purchased the last Delta produced by Northrop as part of assembled patterns and built 19 additional aircraft under license in their factory until October 1940. Canada initially selected the Delta as a photographic survey aircraft. Still, in August 1939, with the approaching Second World War, the Deltas are converted to coastal patrol planes fitted with floats to carry out long anti-submarine missions. After only two months of use, the ocean environment proved to be too damaging to the Deltas from the large ocean swells and corrosion caused by the salty water, the military quickly returned them to land use.

Northrop Delta 1-D “The Richfield Eagle” (courtesy SDASM Archives)

Now on to the private market. Northrop offered the optional “Executive Model” for the Delta 1-D, which included custom seating for 5 to 7 people and focused the advertising towards professional sports athletes and businessmen. A Wright “Cyclone” radial engine, SR-1820-F2, produced 735 hp at 2100 rpm at 4000 ft giving the Delta 1-D similar performance as the Gamma perfect for long country flights. The maximum speed is 219 mph at 6300 ft with a cruising speed of 200 mph at 8000 ft at 3/4 throttle. Six fuel tanks located in the center section of the wing carry a total fuel capacity of 328 gallons providing a range between 1100 and 1500 nautical miles at 3/4 throttle depending on the headwind or tailwind. The climb rate is 1200 ft/min at sea level with a service ceiling of 20,000 ft. Northrop offered a Wright SR-1820-F52 engine as an option rated at 775 hp at 2100 rpm at 5800 ft for those interested in a little more performance. Now that should get your blood pumping!

Northrop Delta 1-D (courtesy Jacob Zilber)

A spacious cabin measuring 58 inches wide is heavily sound-proof with a left side entry door and customizable in either the “Club” or “Executive” packages. Both versions are incredibly lavish, featuring overstuffed chairs, a divan with storage underneath, a bathroom, and a 25 cubic foot baggage compartment behind the tail section’s cabin. The “Club” upgrade reduced the seating for 4 or 5 people. It included a refined interior, some upholstered in red and tan leather, a complete lavatory, a Sperry autopilot, and extra instruments. Standard equipment for either package includes; a Hamilton-Standard controllable propeller, an electric starter, a generator, an Exide battery, an oil-cooling radiator, navigational lights, landing lights, parachute flares, a fire extinguisher, a Western Electric radio, window curtains, and a full set of airline-type instruments. The base price started at USD 37,500 with standard equipment in 1934, which roughly equates to USD 727,500 in this writing, 2020.

Some of the “Delta Executive” owners include; Powell Crosley Jr., Hal Roach, Richfield Oil, Stewart Pulitzer, Earl P. Haliburton, and Wilbur May, to name a few. I recognize Powell Crosley Jr. for his invention and manufacturing of the 1921 Crosley Harko tubless crystal radio and Hal Roach, Laurel and Hardy’s comedy producer. These are extraordinary men, including Jack Northrop, and these talented individuals’ success always inspires me.

Tony’s Scrapbook; Burnelli CB-16

Tony had many scrapbooks, but his favorite is the one he started around 1930 using his father’s hardcover book “The Home” that he glued newspaper and magazine articles into that he found meaningful about aviation. Little did he know, or maybe he did, that he was preserving aviation history so the stories would always be shared and never forgotten! Before my father covered these pages with articles, this book outlined many home plans that you could browse with full descriptions and basic floor plans detailing the layouts. Towards the back, there is an order form to purchase complete plans and specifications for any of the model homes illustrated in this book. The price range is between $5 and $40 and includes an estimate of cost and materials list. I understand that my father’s parents didn’t have a lot of money during his childhood. They immigrated to Jamestown, New York, from Italy in the spring of 1920 when he was eight years old. He learned to utilize anything available by re purposing or upcycling, and this scrapbook is just one example he used throughout his life. He did this with aircraft hangers too, but I’ll save those stories for another time. The back cover is missing with some pages torn and discolored, but it’s in reasonably good condition for being around ninety years old!

I’ve been going through my father’s scrapbook and found a loose page that he saved from one of his “The AOPA Pilot” magazines. At first, I thought he kept it for the advertising for the new Narco Mark VI 190 channel crystal controlled VOR/LOC. I didn’t find a date, but it is page 105 and 106 from that unknown issue. When flipping this page over, I realized it was an article about Vincent Burnelli and his revolutionary CB-16 multiengine plane. Granted, it is only part of the article, but there is enough information about his CB-16 that I find him extraordinarily fascinating and yearning for more! I hope you enjoy this story as much as I did while researching and writing about this revolutionary aeronautical engineer, Vincent J. Burnelli.

Vincent Burnelli designed and built his first successful airplane, the Burnelli-Carisi Biplane, with his friend John Carisi at Maspeth, a borough of Queens in New York, in 1915 under the Burnelli Aircraft Company. The above photo shows the open cockpit “pusher” biplane at Hempstead Plains Aviation Field located east-southeast of Mineola, Long Island, New York. This field was renamed Roosevelt Field in 1919 in honor of President Roosevelt’s son, Quentin, who died during air combat in World War I. It didn’t take long for the two men to make money with their new biplane, and it was a great way to fund future projects. “We used it for barnstorming,” Mr. Burnelli explained. “You could make $500 to $1,000 in those days working a fair, and that was big money.” Vincent designed a night fighter a few years later with hopes of using it as a combat plane in World War I, but things didn’t work out, and he eventually sold the airplane to the New York Police Department for their aerial operation.

Lawson Airliner, 1919 (photo courtesy George Hardie)

At the end of World War I, Alfred Lawson, founder of the Lawson Aircraft Company, hired Vincent Burnelli as an aeronautical engineer and six engineering specialists to work on a new project idea of a sizable commercial aircraft to transport passengers regularly between major cities. Work began in March 1919, and within five months, the team built the first multi-engine passenger aircraft ever produced in the United States, the Lawson C-2 biplane “House on Wings.” This large aircraft features a 91-foot wingspan, is 48 feet long with a gross weight of 12,000 pounds. Powered by two 400-hp 12-cylinder Liberty engines mounted between the wings on each side of the fuselage developed a cruising speed of 110 mph with a range of more than 400 miles. Landing on two tandem wheeled landing gears mounted to the bottom wing inline with lower engine bracing gave maximum support, and a large tail skid supported the rear. Laminated wood bulkheads replaced the traditional interior wire and bracing commonly used on large bombers to allow passengers to walk freely through the streetcar style fuselage. Seating accommodates 18 passengers with eight additional folding seats when needed. For the first time, an enclosed cockpit design keeps the flight crew warm and dry by adding a roof and a Flexiglass front panel with a small sliding window on the co-pilot’s side. All previous airplanes in this era use the conventional open cockpit design. “Lawson Air Line” adorned each side of the fuselage in large letters.

Lawson C-2, Alfred Lawson, second from the left (photo courtesy PoorOldSpike)

On August 27, 1919, Alfred Lawson, “Captain in Command” along with his flight crew Charles Cox “Steersman,” Vincent Burnelli, Carl Schory “Engine Mechanic,” and Andrew Surini “Mechanic” departed the New Butler flying field in Wisconson headed to Ashburn Field in Chicago. Initially, the flight crew thought they were on a second test flight, but Lawson had other plans. Shortly after takeoff, Lawson ordered Cox to follow the shoreline of Lake Michigan south towards Chicago. “For one thing,” Burnelli later recalled, “we had planned on having several test flights; you just don’t build a plane from scratch in six months without encountering a bug here and there. For another, none of us had brought even so much as a toothbrush. Actually, however, we were all too excited and enthused to really care much where we went, although I doubt if I could say the same for our creditors in Milwaukee.” And so it begins, Alfred Lawson’s planned demonstration tour of the first airliner covering two thousand miles in over two months and ending on November 15, returning to the New Butler flying field. Shortly after this flight, Mr. Burnelli left Lawson Aircraft Company to pursue other avenues in his ever-challenging quest of designing and building the perfect aircraft.

The Lawson C-2 visited Bolling Air Force Base in September 1919, on its way from New York to San Francisco. (photo courtesy of U.S. Air Force)

1919 was a pivotal year for Mr. Burnelli when he changed his design approach from the conventional fuselage to his new airfoil-shaped fuselage stemming from his disappointment after his involvement and flight experiences with the Lawson C-2 biplane. The plane looked to him as a streetcar with wings. “The air is the roadbed of an airplane,” he said, “and I decided I’d leave streetcars on the ground from then on.” Being extremely fascinated with the flying wing and its efficiency, Mr. Burnelli started working on various transport designs of his “lifting body” wing type fuselages with twin tails or a tail-mounted on booms at the rear of the aircraft. He felt that these new fuselages could contribute about 40 percent of the lifting surface during flight and would be much safer in a stall or engine failure event. Not too mention the reduced structural loads on the wings, especially where the engines are mounted, and reduce the mortality rate in a crash due to the more robust flat rectangular shape of his fuselage. Mr. Burnelli’s design also places the engines well in front of the passenger compartment to help absorb the shock of a crash and locates the propellers away from the passengers. Another advantage is the flight crew’s partial access to the engines during the flight from inside the cabin.

(photo courtesy of

In 1920, Mr. Burnelli moved from Lincoln, Nebraska, back to Long Island, New York, after a brief career opportunity at the Nebraska Aircraft Company when he left Lawson. Again, he struggles with other people’s concepts and designs and decides it’s time to start working on building his perfect aircraft. Once settled back in New York, he partnered with T.T. Remington to initially form the Airliner Engineering Corporation, but later merged as the Remington-Burnelli Aircraft Corporation in the same year. There he could focus on building a large transport aircraft using his new lifting fuselage design. With little time to waste, he finishes the RB-1 biplane in 1921 with a successful maiden flight at Curtiss Field in Garden City, Long Island, New York, in June that same year. The slab-sided airfoil-shaped fuselage of the RB-1 has a cabin width of 14 feet and can carry a maximum of 32 passengers. A luxurious, spacious lounge divides the middle section. Comfortable chairs are positioned beside the windows on each side of the cabin for a breathtaking view. There are two entrance doors on each side of the fuselage with access towards the rear just behind the wings. A vestibule separates the passenger compartment from the baggage and express compartment located in the fuselage tail section for easy access. Twin 550 horsepower Galloway Atlantic engines mounted in the nose powered this large airplane with partial interior access panels for in-flight service if needed. Two open-air cockpits sit on top of the fuselage and provide a 360-degree field of view for the pilot and co-pilot. Throughout the remainder of the year and into 1922, Mr. Burnelli promoted his RB-1 through promotional advertising and scenic rides. The “Flying Festival” at the Curtis Field, where he stored the aircraft, was a popular event with a high turnout.

Burnelli RB-2, (photo courtesy kitchener.load)

An upgraded RB-1, the RB-2 Freighter was built in 1923 with improved control surfaces, twin 650 horsepower Galloway Atlantic engines provided more power, and corrugated metal construction replaces the fabric skin. It was the most significant transport aircraft ever built with an unladen weight of 5 tons and a gross vehicle weight of just under 9 tons! The passenger cabin could accommodate 25 people with standing headroom or converted to transport 6000 pounds of cargo with a flight crew of 3, the pilot, co-pilot, and mechanic.

Burnelli RB-2 w/Hudson Essex Logo (P Matt via Avn Heritage)

With no potential sales and difficulty in marketing, his business partner T.T. Remington departed the company in 1924. During the same year, Mr. Burnelli partners with Thomas Garvin to form the Garvin-Burnelli Aircraft Corporation. The new partnership focuses on promoting the RB-2 rather than building a new aircraft. In 1925 the RB-2 carried a Hudson Essex automobile built inside the cabin on an aerial sales tour flown at Mitchel Field, Long Island, New York. The passenger cabin also featured a fully equipped office and could carry eight passengers. Even with so much exposure, the RB-2 was slow, and Mr. Burnelli couldn’t generate interest for future investors or the financing that he desperately needed to finance production.

A few years have passed with no new interest in the RB-2, Mr. Burnelli is hired by banker and Skylines Incorporated president Paul B. Chapman in 1928 to build the CB-16 under contract on a progress payment basis for a total of $230,000 including design, engineering, and shop costs. He received the purchase order in May 1928, rented space and tools at the Aeromarine plant in Keyport, New Jersey, and completed the aircraft in December. The CB-16 was Mr. Burnelli’s first monoplane, single-wing, executive transporter with all-metal construction and retractable landing gear to reduce drag. It was accessible during flight for minor service or emergency release. The open cockpit design remains from the RB-2, but the CB-16 is the first multiengine aircraft capable of single-engine level flight in the event of an engine failure. A new twin-boom tail design is incorporated to correct stability issues encountered by the RB-2.

The CB-16 has a wingspan of 90 feet, a length of 56 feet, is 12 feet 6 inches in height, and has an empty weight of 11,400 pounds. The gross weight is 17,400 pounds, and two 625 horsepower Curtiss Conqueror engines supply the power with a cursing speed of 140 mph. The climb rate is 800 fpm, 300 fpm with a single-engine, and a ceiling of 20,000 feet. The cruising range is 12 hours, with a landing speed of 62 mph. For night flying, an ample center searchlight illuminates the pilot’s surroundings. With a spacious cabin measuring 12 feet by 18 feet, there is plenty of space for a large central lounge, ten swivel chairs, and soundproof luxurious tapestry and upholstery to finish the decor. An advanced air pressurization system maintains cabin ventilation and heating control while the unique washroom facility features running water. The stainless steel kitchenette has a hot plate and refrigerator with a radio in the center compartment.

A barge moves the unassembled pieces of the CB-16 to Newark Airport, which was still in construction at the time, to an available two-way cinder runway. The CB-16 is the first new design to be tested at the newly constructed airport, which officially opened on October 1, 1928, as the first major airport in the metropolitan area. With the assembly completed in December, a scheduled test flight occurs on a cold morning during Christmas week. Lieutenant Leigh Wade of Army ’round the world flight fame was at the controls with Jimmy Doolittle from Mitchel Field as a test collaborator. On that morning, Mr. Doolittle offered a parachute to Lt Wade. Still, he did not use it and instead brought along an assistant to operate the emergency release lever for the landing gear if they ran into trouble. Lt Wade landed after a successful 40-minute test flight and was eager to start performance tests the following day. Mr. Chapman chartered a bus on Christmas Eve to bring his friends to see his unique airplane, and Lt Wade offered to take anyone interested in a ride around the Statue of Liberty. When the aircraft landed, a line started to form for additional flights, and Lt Wade kept flying until dusk for four scenic flights carrying over a total of 50 passengers on this extraordinary holiday. In 1929, the CB-16 crashed during a test flight resulting from a maintenance error where the aileron cables malfunctioned. Thankfully, the pilot, Lt George Pond, and his co-pilot survived the crash, and it is a testament of how safe Burnelli’s fuselage designs are.

(photo courtesy

Mr. Burnelli designed and built many more unique airplanes, the UB-20, the GX-3, and the CBY-3, to name just a few. He continued to promote his airfoil-shaped fuselage designs throughout his life but could never sell his ideas for mass production. He is a true pioneer in aviation history, and some people consider him a revolutionary genius. I hope you enjoyed my post on the CB-16, and I encourage you to research the life of Vincent Burnelli and his innovative lifting designed fuselages. You won’t be disappointed, and maybe I’ll find a few more clippings in my father’s scrapbook on him to share with you.

Burnelli CBY-3 Loadmaster restored (photo courtesy NEAM)

Vincent J. Burnelli passed away at age 69 on June 22, 1964 (as reported by The New York Times on June 23, 1964, page 33).