W.Green, G.Swanborough The Complete Book of Fighters

ORDNANCE ENGINEERING (ORENCO) TYPE D USA

Towards the end of 1918, the Ordnance Engineering Corporation offered a new single-seat fighter designed around the 300 hp Hispano-Suiza H eight-cylinder water-cooled engine, the Type D, receiving an order for four aircraft. A two-bay equi-span staggered biplane of wooden construction with an armament of two 0.3-in (7,62-mm) guns, the first Type D was completed in January 1919 (and shortly thereafter the company adopted the acronym Orenco). Tested by what had by then become known as the Air Service, the Type D received a glowing commendation, but Curtiss submitted the winning bid for the production of a series of 50 aircraft, for which various modifications were introduced. The parent company further developed the design as the Type D2 with unequal-span wings of single-bay configuration, three being ordered by the Air Service as PW-3s. Demonstrating structural weaknesses during ground trials, these were declared unsafe and were not flown. The following data relate to the Orenco-built Type D prototypes.

Max speed, 147 mph (237 km/h) at sea level.
Time to 5,0 ft (1525 m), 4.3 min.
Range, 275 mis (442 km).
Empty weight, 1,666 lb (756 kg).
Loaded weight, 2,432 lb (1103 kg).
Span, 30 ft 0 in (9,14 m).
Length, 21 ft 6 in (6,55 m).
Height, 8 ft 3 in (2,52 m).
Wing area, 261 sqft (24,25 m2).


CURTISS-ORENCO D USA

   The first single-seat fighter of indigenous US design to achieve production status, the Model D was conceived around the 300 hp Hispano-Suiza H eight-cylinder water-cooled engine. The first of four prototypes built by the Ordnance Engineering Corporation (Orenco) was completed in January 1919. Curtiss was assigned a production contract for 50 aircraft and undertook some redesign. This included the introduction of dihedral and overhanging, balanced ailerons, and revision of the engine installation. Of wooden construction with ply-covered fuselage and fabric-covered wings, the Curtiss-built Model D utilised a 330 hp Wright-built derivative of the French engine and carried an armament of two 0.3-in (7,62-mm) machine guns, deliveries commencing in August 1921. One Model D was experimentally fitted with French Lamblin radiators attached to the fuselage sides, and another was fitted with a turbo-supercharger for high altitude trials.

Max speed, 139 mph (224 km/h) at sea level, 136 mph (219 km/h) at 6,500 ft (1980 m).
Climb, 1,140 ft/min (5.8 m/sec).
Endurance, 2.5 hrs.
Empty weight, 1,908 lb (865 kg).
Loaded weight, 2,820 lb (1279 kg).
Span, 32 ft 11 5/8 in (10,05 m).
Length, 21 ft 5 1/2 in (6,54 m).
Height, 8 ft 4 in (2,54 m).
Wing area, 273 sq ft (25,36 m2).

G.Swanborough, P.Bowers United States Military Aircraft Since 1909 (Putnam)

ORENCO/CURTISS D

   The O.E.C. Model D fighter was designed around the 300-h.p. Wright-Hispano engine by the Ordnance Engineering Company of Baldwin, Long Island. Four all-wood prototypes (40107/40110) were built along conventional lines; World War I ended before the first was delivered, but the Army was sufficiently impressed to order 50 production models (63281/63330). Under the prevailing procurement system, the contract was put up for industry-wide bidding and won by Curtiss.
   Span, 30 ft.; length, 21 ft. 4 in.; wing area, 242 sq. ft.; empty weight, 1,776 lb.; gross weight, 2,432 lb.; high speed, 147 m.p.h.

J.Forsgren The Thomas-Morse MB-3 (A Centennial Perspective on Great War Airplanes 60)

The Ordnance Engineering Corporation Type D

  Before continuing with the MB-3 story, it may be of some interest to briefly describe its closest competitor for the role as the Air Service's first indigenous pursuit; the Ordnance Engineering Corporation Type D.
  Formed at Baldwin, Long Island, in the summer of 1916, the Ordnance Engineering Corporation's first offering was a side-by-side two-seat biplane trainer. Known as the Type A, the trainer remained a prototype. In June, or possibly July, the Ordnance Engineering Corporation hired the services of Etienne Dormoy, an experienced aircraft engineer who had previously worked for Societe Pour Aviation et ses Derives (SPAD). By the summer of 1917, Dormoy was a member of the French Aeronautical Mission to the USA. Dormoy's first task was to design a pursuit. Appearing in early 1918, the Type B biplane pursuit was powered by a 160 h.p. Gnome Monosoupape rotary engine. The armament was to consist of three 7.62 (0.3 in) Marlin machine guns. Four Type Bs were ordered, along with five Type C trainer derivatives. However, the USAAS decided against ordering any further Type B pursuits. Nevertheless, the Orenco Engineering Corporation continued work on the Type D pursuit. Powered by a 300 h.p. Hispano-Suiza H 8-cylinder water-cooled engine, the Type D was of wooden construction. The fuselage was plywood-covered, with the two-bay equal-span wings being fabric-covered. Incidentally, in early 1919 the Ordnance Engineering Corporation coined the acronym Orenco. This was made in order to avoid confusion with the Army Ordnance Branch.
  Four Orenco Type Ds (serial numbers A.S.40107-40110) were ordered for evaluation at McCook Field. The Type D received high marks, with test pilot Clarence B. Coombs stating:
  Airplane has good flying qualities, responds very well both taking off and landing. Is slightly tail heavy in climbing positions up to 20,000 feet. Landing qualities are better than normal with single-seaters of this type, the airplane rolling about 600 feet on normal landing. It does not tend to nose over, though it tends to porpoise badly if landed on rough ground, or at high speed. It does not taxy easily, the rudder being small, and the weight on the tail skid excessive. Pilot's vision is better than in the average machine of this type, the top wing offering practically no impediment to vision. View directly ahead is partly impeded due to the depth of the fuselage. Locations of the controls are exceptionally good. The ailerons on this airplane are insufficient in surface, though this is being taken care of in the new wing design. The shutters are very efficient, the radiator being of ample size to cool under any conditions. Some considerable trouble has been experienced with the oil tank, the rivets pulling out. Maintenance has been difficult due to the inaccessibility of certain vital engine parts, this is being taken care of in the new model. Alignment is easy to maintain, no trouble being experienced except the loosening of inner bays. Practically no vibration is noticeable at cruising or wide throttle positions. It has an exceedingly wide speed range, and responds rapidly in combat maneuvers (this plane has not been spun). This airplane handles better than the Sopwith Camel and Snipe, the Thomas-Morse, Nieuport and Morane Parasol rotaries, the Spad and S.V.A."
  At the time, when prototypes of a new military airplane were acquired by the War Department, this also included design rights. As a result, the company which had designed the airplane in question, could not feel secure in obtaining production orders. Instead, bids were requested from different manufacturers. For some manufacturers, including Orenco and Thomas-Morse, this system was to have dire consequences.
  In the event, Curtiss underbid Orenco, receiving a contract (No. 262) for 50 pursuits on June 16, 1920. The Air Service serial numbers were A.S.63281-63330. The cost amounted to $524,000 plus an additional $55,167.37 for spares. The third Type D prototype, McCook Field serial number P-101, was shipped to Curtiss for use as a pattern aircraft. Curtiss eventually delivered a slightly redesigned pursuit, including wing dihedral, balanced elephant ear ailerons, and revised engine installation. Despite losing an important production order, Orenco persisted in developing the basic Type D. Known as the Type D2, this had unequal-span, single-bay wings. Three were ordered by the Air Service as the PW-3 (Pursuit, Water-cooled engine Type 3). However, the PW-3s remained grounded, being subjected to static stress and fatigue tests. It was soon discovered that the aircraft were structurally deficient, as well as displaying crude workmanship.
  Naturally, the Curtiss-built pursuit Orenco D also underwent tests at McCook Field. One major criticism was engine vibration, with the veneer-covered fuselage also vibrating badly. Nevertheless, it was decided that 54 Orenco Ds were to be delivered to Kelly Field outside San Antonio, Texas, for the 1st Pursuit Group. On July 19, 1921, 1st Lt Willard S. Clark was killed in the sixth production Orenco D. The cause of the crash was due to that "poor workmanship was found in the brazed wing strut fittings, and the strut bolts were of very poor material (lowest grade Bessemer screw stock) and the use of such material in places subject to stress 'is a criminal procedure'", with poor workmanship also being severely criticized. Other accidents resulted in a thorough inspection of the Orenco D fleet. The inspection report listed more than 30 points, which, along with a discussion with the Commander of the 1st Pursuit Group, Major Carl E. Spaatz concerning the pilots lack of trust in the aircraft, resulted in a directive, dated May 22, 1922. This stated that out of the 20 Orenco Ds in storage, four were to be transferred to ROTC units for instructional purposes, and the remaining 16 destroyed.
  That Orenco failed to secure the production contract for its Type D pursuit, virtually spelled the end of the company's involvement in aviation. Although further designs were being worked on in the immediate post-war years, Orenco dropped out of the aircraft manufacturing business in 1922. (Incidentally, one Orenco F tourer went on to have a long Hollywood career. Remarkably, this airplane still survives.)

The Ordnance Engineering Corporation Type D Technical Data and Performance Characteristics
   Wingspan: 30 ft (9,14 m)
   Length: 21 ft 6 in (6,55 m)
   Height: 8 ft 3 in (2,52 m)
   Wing area: 261 sq ft (24,24m2)
   Empty weight: 1,666 lb (756 kg)
   Gross weight: 2,432 lb (1,103 kg)
   Maximum speed at 5,000 ft (1,524 m): 144 mph (232 km/h)
   Service ceiling: 22,000 ft (6,706 m)
   Range: 275 miles (442 km)
   Fuel capacity: 55 US gal (208 l)
   Armament: 2 x .30 in machine guns


Pilot Opinions

  Although it would seem that no proper comparative evaluation between the Orenco D and the MB-3 actually took place, the advantages (and disadvantages) of the respective pursuits are clearly revealed in a letter dated September 1921. The letter, written by test pilot Lt John A. Macready, states: "The Thomas-Morse MB-3 and Ordnance D have been officially decided upon as the standard pursuit types for the United States Army primarily because of the excellent results obtained from their performance tests. There are other inherent qualities of these airplanes which make them of less value than seemingly inferior ones. An airplane may have a wonderful performance and yet may not be able to use these qualities to the best advantage in maneuvering. There is a tendency for them to lose their speed in turns, especially in climbing turns which are among the most important airplane performance qualities of combat. This quality seems to be more or less characteristic of airplanes which are inherently unstable and which have a very quick and responsive snap to their controls. The Thomas-Morse MB-3, Ordnance D-1, and Packard-Fokker (P195) have excellent performance in straight-away flight, but the bottom appears to fall out of them in maneuvering. An opposite type to these is the Loening Monoplane. The value of this plane is yet unproven... In quickness and snap, in turning and maneuvering, the Thomas-Morse, Ordnance, and Packard-Fokker are far better, but so much speed and altitude are lost in making these maneuvers that their efficiency is greatly impaired. In a maneuver with the Thomas-Morse the air speed will drop from 140 mph to 60 or 70 mph within a period of one or two seconds, while the Loening will only drop from approximately 126 mph to 90 mph... Maintenance issues features are also very important. The simpler an airplane is the better it should be from the maintenance standpoint. The Thomas-Morse and Ordnance are extremely (sic) unsatisfactory airplanes in this respect.
  "One very valuable quality of pursuit airplanes is their ability to remain steady in flight. The Thomas-Morse and Ordnance are unstable airplanes, which bob around, and constantly change their position in a dive or when maneuvering. This is a distinctly unsatisfactory condition from the standpoint of a gunner about to fire on an enemy airplane. The airplane must be steady in order that the pilot's guns may be turned on the enemy with accuracy. An airplane that is constantly changing its position when its nose is pointed at the enemy airplane is not a good combat airplane, for the reason that accuracy of fire is very difficult... Airplanes such as the Thomas-Morse and Ordnance will never be liked by average pilots in the field because of their undesirable flying qualities, and their instability. These airplanes will be flown by pilots originally, but after the first time difficulty will be encountered in getting them to fly them. They will not fly them for pleasure. If ordered to they will fly them as a duty, but they will have no compunction when the airplanes are damaged, or in pointing out all the undesirable features that they possibly can.
  "Mechanics will work in somewhat the same way. The inaccessible and difficult maintenance will make them dislike airplanes of these types. An airplane such as the Loening, with easy maintenance, and comparatively easy flying qualities, would be liked by both pilots and mechanics." The monoplane Loening PW-2A (a development of the the M-8) preferred by Macready was lost on October 20, 1922, due to wing flutter. The post-crash investigation stated: "that the aerodynamic phenomena in a wing which is weak in torsion are not clearly understood, and in this particular instance has led to disastrous results."