P.Bowers Curtiss Aircraft 1907-1947 (Putnam)
The NC Boats (Model 12)
The famous NC flying-boats were the result of a design co-operation between the US Navy and Curtiss, hence the designation NC. As the JN designation became Jenny, so the NC became Nancy but while that term was used in contemporary times, it soon died; the fame of the NC series rests on the accomplishments of a single example, the NC-4, the first aeroplane to fly across the Atlantic ocean.
The concept of the NC boats originated with Rear Admiral David W. Taylor, Chief of the Navy's Bureau of Construction and Repair, who was concerned about aeroplanes en route to France by ship being lost to German submarines. He thought that aeroplanes should be developed that could fly across and be ready for duty on arrival. Navy engineers led by Commanders G. Conrad Westervelt and Jerome Hunsaker began design studies in September 1917.
As the only experienced builder of large flying-boats in America, Glenn Curtiss was called to Washington for consultation. He returned to Buffalo and was back in a few days with two versions of a short-hull flying-boat with a wingspan of 140 ft (42,67 m). One had five of the Navy's new 360 hp Liberty engines and the other had three. The short hull was primarily a weight-saving device; Curtiss had previous experience with the type on the earliest flying-boats and the BT of 1916. Curtiss's original designation for the design was TH-1, for Taylor-Hunsaker.
Taylor's group chose the three-engined design and Commander Holden C. Richardson was called in to do the detail design of the hull. Curtiss was to design the wings, empennage, and other details, finally receiving a contract for this work on 24 November. In December, it was decided to give Curtiss a contract to build four of the new flying-boats. Later, the new Naval Aircraft Factory was ordered to build six more.
No official designation for the new type existed at the time. Suggestions to call it DWT for Admiral Taylor were vetoed and Curtiss's TH-1 was not adopted because the Navy felt that it was primarily a Navy, not a Curtiss, project. The final NC for Navy-Curtiss was a logical compromise.
Virtual flying ships, the NCs followed the Naval custom of numbering the individual ships within a class. The assigned designations of NC-1 to NC-4 were not separate model numbers; they were individual aeroplane numbers for NC-class aeroplanes. Like series-built ships, the NCs showed individual differences as a result of construction experience and different approaches to design problems, particularly powerplant arrangement. Two official variations of the NC designation appeared in 1919: NC-T - a configuration using four tandem-pair engines in two nacelles, applied only to NC-2, and NC-TA - four-engined aircraft configured in the modified form of NC-1 and equipped for the transatlantic flight of May 1919.
Under the revised Naval designation system of 1923, all the NCs became P2N-1 for the Navy's second palrol design, at least on paper. The original designations remained in common use.
With the Buffalo plant expanding for large-scale production, Curtiss's design work on the experimental NCs got low priority from the new management. Not until the project was transferred to the new Experimental plant at Garden City did work really get under way although construction of NC-1 had started in Buffalo in December 1917.
The existing Curtiss Garden City plant was too small for such an enormous construction job, so the Navy built a greatly enlarged shop area there. It also built a new hangar capable of housing two assembled NCs at the Rockaway Naval Air Station, 20 miles (32 km) from Garden City. The NCs were first assembled at the factory, then dismantled, trucked to Rockaway, and reassembled for flight there.
Curtiss also had a manpower problem. All available skilled help was already employed in other aircraft plants in the New York area, so most of the actual construction of the NCs was farmed out to established boat builders and woodworking firms in the New England area. After the first four NCs were completed, Peter Jannsen, the Garden City shop manager, was hired by the Navy to supervise construction of the final six at the Naval Aircraft Factory. Average cost of the NC boats, less GFE, was $125,000.
The war ended soon after completion of NC-1 and the requirement for transatlantic delivery vanished. For a while, it looked as if the remaining NCs would be cancelled. However, with other nations preparing to go after the renewed Daily Mail prize for the first transatlantic flight, the Navy decided to be the first to make the crossing - not for the money but for the prestige of the US Navy. The project received official status on 4 February, 1919.
Briefly, the plan was to use NC-1, 3 and 4, collectively known as Seaplane Division One, departing from Rockaway for Trepassy Bay, Newfoundland, 950 miles (1,529 km) away, in May. From there, there was a nonstop flight of 1,381 miles (2.222 km) to Horta in the Azores, a short 169-mile (272 km) hop to Ponta Delgada, then a 925-mile (1,489 km) leg to Lisbon and a 500-mile (805 km) leg lo Plymouth.
Commissioning ceremonies were held at Rockaway on 3 May, and the three departed for Trepassy on 8 May, with departure for the Azores scheduled for 16 May. A string of Navy ships was stationed along the route to provide radio communication and necessary emergency assistance. Due mainly to the problems of navigating in fog, only NC-4 completed the record 3,925-mile (6,317 km) trip, reaching Plymouth on 31 May.
NC-1 - The NC-1 (serial A2291) was a tractor three-engined aircraft powered with the 360 hp low-compression Navy version of the Liberty. Each engine was in an individual nacelle and all were at the same level and in line with each other longitudinally. Pilot and co-pilot were in a cockpit in the centre engine nacelle and a gunner was located in a nest on the upper wing above the centre engine. Other gun stations were in the extreme bow and near the rear of the hull.
The NC-1 had the only Curtiss-built hull; the wings, with the now-traditional RAF 6 aerofoil, were built by the Locke Body Company of New York City, a builder of car bodies. The first flight, with Commander Richardson as pilot, was made on 4 October, 1918. On 27 November, NC-1 carried a record load of 50 passengers and crew plus one stowaway.
Test results showed that the three-engined NC-1 could not lift enough fuel for the transatlantic flight, so an extra engine was added. This was accomplished by raising the centre nacelle and modifying it to accommodate two engines in tandem. To prevent tail-heaviness from the new rear engine, the centre forward engine was moved ahead of the unchanged side engines. The pilots were relocated from the nacelle to a conventional side-by-side cockpit in the forward hull.
On the transatlantic flight, NC-1 alighted at sea short of the Azores; the crew was taken aboard a ship and the flying-boat was sunk.
NC-2 - As launched on 3 February, 1919, NC-2 (serial A2292) was a three-engined aircraft differing from NC-1 in having the centre engine installed as a pusher. The pilots rode in the front of the centre nacelle. With no centre tractor propeller between them, the side nacelles were closer together than on NC-1. This fact complicated the subsequent conversion to four engines - the revised NC-1 arrangement could not be used without the major structural work of moving the side nacelles further outboard. The problem was solved by arranging the engines in two tandem pairs in the side nacelles, hence the NC-T designation. The pilots remained briefly in the now engineless centre nacelle, which was later removed in favour of a conventional cockpit in the hull. The hull was built by Lawley & Sons, boat builders of Boston. The NC-2 was wrecked when blown ashore in a storm and parts were used on the other three NCs.
NC-3 - The construction of NC-3 (serial A2293) was far enough behind NC-1 to benefit from its test and modification programme. As launched and flown on 23 April, it duplicated the four-engined NC-1 pattern and was the first NC-TA built as such. Like NC-2, NC-3's hull was built by Lawley. NC-3 was chosen by Commander John H. Towers, commander of the flight, to be his flagship. It made a precautionary alighting at sea some 200 miles (322 km) short of the Azores. Unable to take-off again, it taxied to Horta.
NC-4 - The NC-4 (serial A2294), with hull built by the Herrescholl Company of Bristol, Rhode Island, duplicated NC-3 and was launched on 30 April. Under the command of Lt-Commander A. C. Read, it departed with the others for Trepassy, but was forced down by engine trouble and taxied 60 miles (96 km) to the Naval Air Station at Chatham, Mass. Following an engine change, it arrived at Trepassy on 10 May.
After an uneventful flight of 19 hr 23 min, NC-4 reached Horta on 17 May. It then made the short flight to Ponta Delgada to wait for word from the missing NC-1 and NC-3. It arrived in Lisbon on 27 May and reached Plymouth on 31 May after an emergency stop at Mondego in Portugal, just north of Lisbon and an overnight stop at Ferrol in Spain, due to the delay.
The hull of NC-4 was put on display in the Smithsonian Institution. In 1969 the entire machine was rebuilt for outdoor display in Washington on the 50th anniversary of the flight. It is now to be seen fully assembled in the Naval Aviation Museum at Pensacola, Florida.
Long-range flying-boat. Five crew. Three 400 hp Liberty 12A (NC-2), four 400 hp Liberty 12A (NC-4).
Span 126 ft (38,4 m); length 68 ft 3 in (20,8 m) NC-2, 68 ft 2 in (20,77 m) NC-4; height 24 ft 5 in (7,44 m); wing area 2,441 sq ft (226,76 sq m).
Empty weight 14,100 lb (6,396 kg) NC-2, 16,000 lb (7,257 kg) NC-4; gross weight 23,000 lb (10,433 kg) NC-2, 28,000 lb (12,700 kg) NC-4.
Maximum speed 85 mph (136,79 km/h); climb in 10 min - 2,200 ft (670 m) NC-2, 2,000 ft (610 m) NC-4; service ceiling 4,500 ft (1,372 m) NC-2, 2,500 ft (762 m) NC-4; endurance 14,8 hr at cruising speed.
G.Swanborough, P.Bowers United States Navy Aircraft Since 1911 (Putnam)
Navy/Curtiss NC Boats
The Navy/Curtiss boats which were to achieve undying fame as the first to complete a crossing of the Atlantic by air (albeit in stages) owed their origin to the successful German U-boat campaign of 1917. As British and American shipping losses mounted drastically, the call went out for more patrol aircraft to provide an umbrella over the Atlantic. Since many of the flying-boats then serving with the Royal Navy were built in America, that source was appealed to. In response to the urgency of the situation, the US Navy Department drew up plans in September 1917, for a new flying-boat to carry the war to the U-boat. The essential requirement was that this boat should be able to fly across the Atlantic-since shipping space was at a minimum-and be able to take on a U-boat immediately upon arrival.
Such a machine would need an endurance of 15-20 hours, which in turn meant that it would have to be very large, necessarily multi-engined, and of sufficiently rugged construction to be able to endure forced landings at sea. Alone among American manufacturers, Curtiss had the large aircraft experience and the shop facilities that would allow it to build such a mammoth. In reply to the Navy's detailed proposal for a transatlantic flying-boat using a unique new Navy hull design, Curtiss quickly produced plans for a suitable three-engine 28,000 lb biplane. The principal point of departure from traditional design was the Navy's new hull. While using the established Curtiss laminated wood veneer construction, it was very short - only 45 ft - with the tail surfaces carried clear of the water on a superstructure of spruce struts. This arrangement minimized hull weight and gave, as required, an uninterrupted field of fire straight to the rear for machine gunners in the rear of the hull. Because of the joint design effort involved, the new boats were designated NCs for Navy and Curtiss. The first four, built by Curtiss at its experimental plant in Garden City, New York, and assembled at the Naval Air Station at nearby Rockaway, were given the separate designations of NC-1 through NC-4, a departure from established model designation procedure. The NC-1, which first flew on October 4, 1918 had all three Liberty engines installed as tractors, with the pilot and co-pilot located in the centre nacelle behind the engine. A ladder was provided for the pilots and other crew members to move about in flight. On November 25, the NC-1 carried 51 persons aloft to establish a new world's record for passengers carried.
Testing proved that three engines were inadequate for the transatlantic mission, so the remaining aircraft were redesigned for four. NC-2, which first flew on April 12, 1919, was completed with two tandem pairs, with the pilots in a third nacelle between the engine pairs. NC-3, which flew on April 23rd, and NC-4 reverted to the three tractor engine arrangement of NC-1 but added the fourth engine as a pusher in the middle nacelle. The pilots were removed to the hull ahead of the wing on NC-3 and NC-4 and NC-1 was modified to the same pattern.
Although the NC boats were not completed in time to see war service, it was decided to fly them across the Atlantic anyhow, as a race was developing between England and America for the honour of being the first across by air. In preparation for this mission, the NCs were redesignated NC-TA, for Transatlantic. Only three gathered at Trepassy Bay, Newfoundland, for the May 16, 1919, start. The engine arrangement of NC-2 had been declared unsatisfactory for the mission, and NC-2's wings were removed and installed on NC-1 to replace the originals which had been damaged in a storm. Under the command of Cdr (later Admiral) John H. Towers, Naval Aviator No.3, the three boats took off on the 1,400-mile flight to the Azores. NC-4 achieved it by air, and later completed the voyage, reaching Plymouth on May 31 via Lisbon. NC-1 and NC-3 were both forced down at sea short of the Azores. NC-1 sank after the crew was rescued by a ship, but NC-3, with Towers aboard, managed to taxi the remaining 200 miles to the Azores.
Six additional boats, NC-5 through NC-10, were built after the war at the Naval Aircraft Factory, with NC-5 and NC-6 in trimotor configuration having the centre engine installed as a pusher. The others were four-engined in the NC-3/4 pattern. After the adoption of the new designating system in 1922, the surviving NC boats were redesignated P2N for the second Navy-designed patrol model, but the term was not actually applied. Following the transatlantic flight, NC-4 made a publicity tour of eastern and southern coastal cities and flew up the Mississippi river to St Louis before being handed over to the Smithsonian Institution.
TECHNICAL DATA (NC-TA)
Manufacturer: Curtiss Aeroplane and Motor Company, Garden City, LI, NY, and Naval Aircraft Factory, Philadelphia, Pennsylvania.
Type: Long-range patrol flying-boat.
Accommodation: Two pilots; navigator/nose gunner; radio operator, two flight engineers.
Power plant: Four 400 hp Liberty 12s.
Dimensions: Span, 126 ft; length, 68 ft 3 in; height, 24 ft 6 in; wing area, 2,380 sq ft.
Weights: Empty, 15,874 lb; gross, 26,386 lb.
Performance: Max speed, 85 mph; initial climb, 1,050 ft in 5 min; service ceiling, 4,500 ft; range, 1,470 st miles.
Armament: Machine guns in bow and rear hull cockpits.
NC-1/4: A2291-A2294. NC-5/10: A5632-A5635; A5885; A5886.
Jane's All The World Aircraft 1919
SERVICE FLYING BOATS OF THE U.S.N.F.C
Type NC.1. F.5L. H.16. HS.2L.
Span, OVERALL 126ft. 103ft.9in. 95ft. 74ft.
(38.43 m.) (31.92 m.) (29 m.) (22.60. m.)
Length, overall 68ft.2 1/2in. 49ft 3 1/2in. 48ft. 1 1/2in. 38 ft. 6 in.
(20.75 m.) (15.00 m.) (14.00 m.) (11.75 in.)
Height, overall 24ft 6in 18 ft. 9 in. 17 ft. 8in. 14 ft. 7 in.
(7.47 m.) (5.78 in.) (5.40 m.) (3.45 m.)
Chord 12ft. 8 ft. 7ft. 3/4in. 6ft. 3in.
(3.66 m.) (2.44 m.) (2.15 m.) (1.91 in.)
Wing area 2,380 sq. ft. 1.397 sq.ft. 1,164 sq. ft. 803 sq. ft.
(2,114.2sq m.) (125.7sq. m) (104.8 sq. m.) (72.3 sq. m.)
H.P. 1,200 800 800 400
Engines 3 Liberty 12 2 Liberty 12 2 Liberty 12 1 Liberty 12
Airscrews 3 Tractors. 2 Tractors 2 Tractors 1 Pusher
fully loaded 22,000 lbs. 13.000 lbs. 10.900 lbs. 6,432 lbs.
(9.900 kgs.) (5.850 kgs) (4.900 kgs.) (2.894 kgs.)
Useful load 7,750 lbs. 4,750 lbs. 3,500 lbs. 2,132 lbs.
(3.490 kgs.) (2.140 kgs.) (1,575 kgs.) (960 kgs.)
High speed 81 m.p.h.* 87 m.p.h. 95 m.p.h. 91 m.p.h.
(129.6 km.p.h.) (139 km.p.h.) (152 km.p.h.) (145.6 km.p.h.)
Low speed 61 m.p.h.* 57 m.p.h 56 m.p.h. 55 m.p.h.
(97.6 km.p.h) (91 km.p.h.) (90 km.p.h.) (88 km.p.h.)
Initial climb 1,050 ft. 2,625 ft. 3,000 ft. 2,500-3.000 ft.
320 m. (800 m.) (915 m.) (760-915 m.)
in 5 mins. in 10 mins. in 10 mins. in 10 mins.
Full speed endurance.
13 hours 10 hours.
Armament 8 M.G. 1 Q.F., 4 M.G. 6 M.G. 1 M.G.
2-500 lb., or
4-230 lb. bombs
Complement 5 5 4 3
Builder Curtiss Naval Aircraft Curtiss Standard
* Carrying a load of 21,560 lbs. (9,700 kgs)
Flight, May 15, 1919.
THE U.S. NAVY FLYING-BOAT, N.C. 1
THE machines representing America (non-competitive) in the Atlantic flight are the U.S. Navy flying-boats of the N.C. (Navy Curtiss) type, built by the Curtiss Engineering Corporation, to the designs supplied by the Bureau of Construction and Repair of the Navy Department. Three of these machines N.C.-1, N.C.-2 and N.C.-3 are, we believe, all of similar type, whilst the fourth machine, N.C.-4, differs in having four engines instead of three. The following illustrations and description of the original N.C.-1 type flying-boat should, therefore, be of general interest just now, this particular type differing from the Atlantic machines only in a few modifications rendered necessary by the requirements for the long-distance flight. Certain alterations in the arrangement of the engines have, we understand, been made in one or more of the Atlantic machines, such as the location of two screws as tractors and the third as a pusher.
As will be seen the N.C.-1 is a flying-boat of the short-hull type, with the tail planes carried from the hull and top main planes by means of outriggers. The hull is 44 ft. 8 3/4 ins. overall length, with a maximum beam across the side-fins of about 10 ft. It has a single step 27 ft. 8 3/4 ins. from the nose, and a V bottom. The main planes are built up in seven sections, three (two outer extensions and one centre section) in the top, and four (two outer extensions and two centre sections) in the bottom. The spans of the outer sections are 44 ft. 4 ins. and 35 ft. 4 ins. for the top and bottom planes respectively. The top plane centre section is 25 ft. 4 in. span, and each lower plane centre section mounted on either side of the hull is 10 ft. 8 in. span. The outer extensions of the lower plane have a 3 deg. dihedral, all other plane sections being "flat." The angle of incidence is 3 deg. top and bottom. Midway between the top and bottom planes are located the three engine nacelles, each supported by two pairs of interplane struts. The central nacelle, which is larger than the other two, contains the pilot's cockpit and control. Each of the outer engine nacelles are situated 11 ft. from the centre of the machine, and two pairs of interplane struts, located respectively 26 ft. 11 in. and 41 ft. 6 in. from the centre separate the top and bottom planes of the outer extensions. The overhang of the top plane is 15 ft. 6 in., and that of the lower plane 6 ft. 6 in. Balanced ailerons are fitted to the top planes only. Cockpits for the crew are provided in the nose and the centre of the hull.
The tail is of the biplane type, carried on three hollow spruce outriggers, braced by wire cable and struts. There are three rudders mounted between the tail planes, one of which, in the centre, is balanced, and the other two being hinged to vertical panels at each outer extremity of the tail. One-piece balanced elevators are fitted to both top and bottom tail planes. The gap of the tail is 9 ft. 3 in., and the overall span of the upper and lower planes is 37 ft. 11 in. and 26 ft., respectively.
The engines are of the Liberty, low compression, Navy type, developing about 350 h.p. each. The gross weight of this particular type of machine is 21,560 lb., the useful load being 7,750 lb. The speed range is about 81 to 61 m.p.h., and climb 2,000 ft. in 10 min. It was one of these machines that, in November last, carried 45 passengers in addition to a crew of five at Rockaway, N.Y., and also flew from New York to Washington with a crew of five and ten passengers.
Flight, June 5, 1919.
THE TRANSATLANTIC FLIGHT
IN our last issue we were able to record briefly the arrival of the N.C. 4 at Lisbon, and on Saturday last she arrived at Plymouth and was given a real British welcome. She left Lisbon on May 30 at 5.29 a.m. Greenwich time, but had to ome down at the Mondego River at 7 a.m. owing to trouble with one of the engines. At 1.38 p.m. a re-start was made, and Ferrol, 340 miles from Lisbon, was reached at 4.47 p.m.; it was then decided to stay for the night. At 6.27 the next morning, although the weather was thick and squally, Commander Read resolved to go on and Ferrol was left at 6.27 a.m. Only two destroyers were sighted, and at 11 o'clock the machine was over Brest, and met a head wind across the Channel. Plymouth was sighted at twelve minutes past one, and the N.C. 4 missed the three F. 2A flying-boats which had been sent out by the R.A.F. to meet them. The N.C. 4 crossed the breakwater at an altitude of about 15,000 ft., circled round Drake's Island, made a spiral descent opposite the Citadel, and settled on the water at 1.26 p.m., being greeted by a storm of cheering and the sounding of every siren and whistle within range. As soon as the machine was moored the officers and crew of the N.C. 4 were taken off by an American pinnace to the U.S. flagship Rochester, where they met Rear-Admiral Plunkett of the U.S. Navy, and the officers and crews of the N.C. 1 and N.C. 3, and a number of British Naval and Air Force officers. They were welcomed to England by the Mayor and Corporation of Plymouth; later in the afternoon, when they went ashore, they were led in procession to the Grand Hotel, where Admiral Cecil Thursby welcomed the men of the N.C. 4 on behalf of the Navy, and Col. Shepherd on behalf of the Air Force.
The King, immediately he heard of the N.C. 4's arrival, sent an Equerry to the United States Ambassador to ask him to convey His Majesty's hearty congratulations to Commander Read and his companions, and to the United States Navy on the accomplishment of the flight.
Besides Commander Read, the men on board the N.C. 4 were: Lieut. E. F. Stone (pilot), Lieut. Walter Hinton, U.S.N. (pilot), Ensign H. C. Rodd (wireless operator), Lieut. J. L. Breese, U.S.N. Reserve Force; and Chief Mechanics' Mate E. S. Rhoads, U.S.N.
On Sunday afternoon Commander Read and the other officers and men of the N.C. 4 came to London, and although very few people knew they were arriving, a large crowd quickly gathered at Paddington Station, and gave them a most rousing reception. Mr. Hawker being the first to greet Commander Read when he stepped from the train. The crowd insisted on chairing Commander Read and Mr. Hawker, and then they were taken from the station to the Royal Aero Club, afterwards proceeding to Hendon as explained elsewhere.
At Lisbon the aviators were decorated by the Portuguese Minister of Marine with the Grand Cross of the Order of the Tower and Sword.