J.Forsgren The Thomas-Morse MB-3 (A Centennial Perspective on Great War Airplanes 60)
The Thomas-Morse MB-3
Clearly inspired by contemporary European pursuits, most particularly the French SPAD XIII, the MB-3 in fact resembled a scaled-down single-seat variant of the earlier MB-2. Design responsibility yet again rested on B D Thomas. The MB-3 promised to be a high performance pursuit, with maximum speed of 150 mph (241 km/h) and an initial climb rate of 1,500 ft (457 m)/min being envisaged. Using the R.A.F. 32 airfoil, Thomas created a single-seat pursuit of orthodox fabric-covered wooden construction. Power was provided by a 300 h.p. liquid-cooled Wright H (a licence-built Hispano-Suiza) engine, which, despite having a tendency to vibrate badly, was deemed as being suitable for pursuit aircraft. A contract for four MB-3 prototypes, A.S.40092-40095, was signed on September 27, 1918, at a cost of $ 66,000. However, Thomas-Morse was not the sole manufacturer struggling to secure contracts for the new Air Service single-seat pursuit. In fact, prototypes of no less than six different pursuits were entered into the fray.
Apart from the MB-3 these included the Pomilio FVL-8, the Lewis & Vought VE-8, the Engineering Division Verville VCP-1, the Loening M-8 and the Ordnance Engineering Corporation Type D. Out of these, only the MB-3 and the Ordnance Engineering Corporation Type D secured production contracts.
The first MB-3 prototype was first flown on February 21, 1919 by Frank H. Burnside. Overall, the MB-3 performance was deemed as excellent, with the aircraft being able to climb "almost vertically" to an altitude of 2,000 ft (610 metres). 10,000 ft (3,048 metres) was reached within less than five minutes. The four prototypes carried an armament of twin 0-3 in (7,62 mm) machine guns, mounted in the upper front fuselage. The first prototype, A.S.40092, subsequently underwent destructive static tests at McCook Field in April 1919. These tests indicated that the MB-3 airframe did indeed possess sufficient strength.
The second prototype, A.S.40093 (McCook Field serial number P66), was despatched to McCook Field for trials. The 'McCook Field MB-3 Evaluation report' was submitted on February 20, 1920. Although possessing excellent speed and climb performance, the MB-3 was also criticized on a number points:
"The airplane is easily taxied; is steady and easily controlled on take-off, and leaves the ground quickly.
The airplane is well balanced and controls are normal in action.
The airplane maneuvers well in all positions.
The pilot has poor vision in the air, his head being too far below the level of the top wing. View is all right for landing.
In landing the airplane is easy to hold off and has no tendency to ground spin or nose over.
Cockpit is entirely too small. It is badly cramped in every way, even for pilots of small stature.
This makes it difficult to locate motor controls conveniently.
This airplane has caused an endless amount of work from the maintenance standpoint, a large share of which was due to the fuel installation. After nearly every flight the main tank developed leaks, due to its complicated shape comprising many sharp corners. Also the tank had a very flimsy support, resulting in its breaking through the bottom of the fuselage after about 10 hours' flying. This was due also in part to the trapping of the overflow oil from oil tank between gas tank and bottom of fuselage, causing the veneer to rot out. A great deal of trouble was experienced with the cooling system until a new radiator was installed with different method of piping. There was no fire wall between motor and gas tanks.
On the new Thomas-Morse MB-3 (the fourth prototype), an attempt has been made to remedy the majority of the faults mentioned above. The cockpit has been lengthened but is still entirely too narrow. A new fuel installation has been made which has already given endless trouble through its gas pumps, check valves, bypasses, etc., apparently none of which had been tested or tried.
After less than two hours' flying one of the main fittings in the wing section of the fuselage was found broken. In replacing the fitting it was discovered that it was necessary to make up special wrenches in order to tighten up certain brace rods in this section of the fuselage.
It was found necessary to cut holes in the engine section of fuselage in order to get at magnetos.
The new airplane, being slightly heavier, does not maneuver quite as rapidly as the old one. The new shutter control when closed throws the airplane out of balance, making it slightly tail heavy.
This new airplane has not been flown enough to get definitive information as to maintenance.
(Signed) J.M. Johnson, Test Pilot.
In the event, following necessary modifications, Thomas-Morse secured a contract (No. 265) on June 19, 1920 for 50 MB-3s plus spares, a mere three days after an order for a similar quantity of Orenco Type Ds. The cost for the MB-3 contract amounted to $720,432.75.
The production MB-3s differed from the prototypes in a number of respects. In response to the McCook Field report, the fuselage had been lengthened somewhat (albeit not widened), the wing-mounted radiator also being slightly off-set to starboard from the fuselage centreline, making it possible to fit a 12-gallon gravity fuel tank. The vertical fin was also cut down in size. These modifications resulted in an empty weight increase of 130 lb.
By early 1921, MB-3 production was progressing rapidly. Tentative plans for the distribution of the first 14 production aircraft included four to be transferred to McCook Field, two for the Air Service Technical School, based at Chanute Field, and eight for the Field Officers School, based at Langley Field. The remaining 36 MB-3s were to be delivered to the 1st Pursuit Group at Kelly Field.
However, the MB-3 troubles were far from over. Having discovered handling as well as engine cooling problems in the first production MB-3, Lieutenant J.A. Macready took off from Ithaca in the eleventh production MB-3, A.S.63341, on March 30, 1921. During a high speed diving test with the engine merely ticking over, the leading edge of the upper wing caved in. Lieutenant Macready was lucky to get down in one piece, with his MB-3 overturning during the forced landing.
Macready's report on the accident stated: "One of my duties was to test the maneuverability as a fighting airplane. The dive on the enemy is one of the primary functions of combat. With this in mind, and also to note the effectiveness of the closed shutters, I dove the plane at a very steep angle with the power off. I was carefully studying the airplane as it dove, intending to keep a margin of safety and refraining from any quick movements of the controls that would cause undue strains or stresses.
Suddenly I heard a terrific report or crashing sound and felt the plane heavily jarred. I thought that the propeller had broken and crashed into a wing. The pilot can see the top of the top wing from his seat. Looking up, I observed that practically the entire top of the wing was gone, and that webs and woodwork was bare with the fabric stripped from them. The entire leading edge of the wing had collapsed and stripped the top fabric from the wing, leaving it with almost no lift or sustaining power."
Miraculously, Macready only suffered a few cuts and bruises. After extracting himself from the wreckage, Macready ordered guards placed close to the MB-3 until it could be thoroughly inspected by an Engineering Division representative. He also called McCook Field, relating details of his accident. Incidentally, the problem of the upper wing fabric covering being ripped off in a dive was not an unknown event. During 1918, several such cases occurred in Nieuport 28s flown by US pilots over the Western Front.
Macready's near-fatal crash resulted in prolonged trials involving strengthening the upper wing. Series production by Thomas-Morse was halted until these problems had been overcome, not recommencing until early 1922. Nevertheless, on May 11, 1921, Thomas-Morse secured a supplemental $ 26,396.21 contract for strengthening the wings of "last 49 airplanes and spares." Another contract, dated October 21, 1921, called for "reinforce wings of last 36 airplanes and 9 sets of spare upper wings (and) make 16 other changes." This second contract amounted to $ 88,100.00. It seemed as if Thomas-Morse would indeed become the Air Service's primary supplier of pursuit airplanes.
The task of investigating Macready's accident was assigned to the National Advisory Committee for Aeronautics (NACA). Established in 1915, NACA was "to supervise and direct the scientific study of the problems of flight with a view to their practical solution", as well as to "direct and conduct research and experiment in aeronautics". In 1919, NACA moved to Langley Field (named after Samuel Pierpoint Langley of Aerodrome fame) north of Hampton, Virginia.
One MB-3, A.S.63335, the fifth production airplane, was loaned to NACA in January 1923. While at Langley Field, the serial number NACA 8 was assigned to the MB-3. The subsequent investigation carried out resulted in 'Report No. 193. Pressure Distribution Over The Wings Of An MB-3 Airplane In Flight'. According to the report, in order to establish pressure distribution over the wings during different flight modes, holes in the surface of the wings were connected to multiple recording manometers located in the fuselage. The results were recorded photographically through 30 diaphragm capsules. The report states, in part: "The wing section is shown in Figure 1 together with the R.A.F. 15 section for comparison. It is very interesting to note the great divergence between the actual section turned out by the contractor and the R.A.F. 15 section which was supposed to be used. The change was probably made after the original design was laid out to accommodate deeper spars, but instead of adopting a thick, but still efficient section, the upper surface of the R.A.F. 15 was simply bulged out over the spars. The resulting section undoubtedly gives a high-speed performance distinctly inferior to the R.A.F. 15.
"It was considered desirable to make a number of changes in the standard airplane, first from the point of safety, and second to facilitate the test. The more important are enumerated below:
1. The radiator and the fuel tank were removed from the center section, which was made to conform with the wing section. This was done in order to prevent disturbance of the air flow in this section of the upper wing, to provide greater visibility for the pilot, and to permit loading the manometers with film conveniently.
2. A 180 H.R Lamplin radiator was placed just over the axle and was found to give very satisfactory cooling.
3. The rear center section bulkhead was changed so that it aligned with the rear center section strut, both to allow more room for placing the multiple manometers and to give greater strength and rigidity to the center section.
4. A number of heavy ribs were put in both the upper and lower wings, as several wing failures on this type of airplane indicated insufficient strength here.
5. When the wings were re-covered, the stitching was closely placed to prevent the fabric's stripping.
6. Heavier interplane struts were installed to prevent lateral deflection.
7. A number of fittings were replaced by ones of heavier metal and the engine section was stiffened.
8. The tip of the balance on the elevator was removed to prevent hunting of the longitudinal controls.
9. The rudder post was stiffened to prevent vibration.
10. All of the military equipment was removed to make room for the instruments.
11. A four-bladed propeller, which was put on the airplane, somewhat reduced the vibration.
"Such extensive changes, of course, took a considerable length of time, but it was felt that they were justified because the nature of the present test demanded very violent maneuvering and the instruments installed required a minimum of vibration. The pilot reported that the airplane as rebuilt could be handled easily and was a decided improvement over the original model."
The report's conclusions recommended an overall increase in the strength of the wings to avoid the fabric being ripped off. The lower surfaces of the leading and trailing edges "should be stiffened."
On November 1, 1923, the MB-3 was returned to the USAAS.
In the end, the high-performance fabric-covered biplane would soon be replaced with all-metal designs, thus making the report's recommendations obsolete. Even though the majority of the wing area of such airplanes would remain fabric-covered, the leading edge was usually shaped out of duralumin, which meant that the wing had a greater overall strength.
Thomas-Morse MB-3 Technical Data
Source: Jane’s All the World's Aircraft, p. 482a
Type of machine: Single-seater biplane.
Name or type No. Of machine: M.B.3.
Purpose for which intended: Fighting.
Span: 26 ft.
Overall length: 19 ft.
Maximum height: 8 ft Chord: 5 ft. 3 in.
Total surface of wings: 250 sq. Ft.
Engine type and h.p.: 300 h.p. Hispano-Suiza.
Weight of machine empty: 1,360 lbs.
Load per sq. ft.: 8 lbs.
Petrol tank capacity in gallons: 65 gallons
Performance:
Speed low down: 164 m.p.h.
Landing speed: 55 m.p.h.
Climb:
To 1,000 feet: 20 secs.
To 10,000 feet in minutes: 4 mins. 52 secs.
Total weight of machine loaded: 2,000 lbs.
Two Browning machine guns
Useful load (with water): 800 lbs.
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."
An Improved Pursuit, the MB-3A
On February 21, 1921, bids from six manufacturers were received for producing either batches of 50 or the entire contract of 200 aircraft. The highest bidder was Dayton-Wright ($2,201,000), followed by L.W.F. ($2,133,000), Curtiss ($1,982,000), Thomas-Morse ($1,926,000), Aeromarine ($1,832,000), and Boeing ($1,488,000). With War Department funding being substantially lower than during wartime, spending as little as possible on as much equipment (in this case, pursuit aircraft) as possible opened the door for Boeing.
For the War Department, it was a question of dividing the order among several manufacturers, thus ensuring the short-term survival at least of some companies in a highly-competitive field. This would be more expensive than awarding the entire order to a single manufacturer. Being on the brink of survival, the small Seattle-based Boeing would make the utmost to secure the order:
"The cold word from Dayton in January (1921) was that there wasn't enough money to keep even a small part of the airplane industry alive. It was going to be a case of survival of the fittest. The L.W.F. Company was in the hands of receivers already... The only new planes the Army could buy were two-hundred MB-3 type pursuits designed by the Thomas Morse Company, Egtvedt learned on a Dayton visit.
"Everybody is going to be scrapping for that order," said Major Fleet (the McCook Field contracting officer).
"Will you give all two hundred to one company?" asked Egtvedt.
"We're getting bids on quantities of fifty to two hundred."
In Seattle the challenge was taken up. They'd have to bid low, or there was no use bidding. Phil Johnson unrolled the drawings and called in the shop foremen, one by one, to get their ideas as to the amount of work on the various parts. Then they met in Gott's office. When the estimates were added, the price came to $ 10,175 per plane for fifty; $ 6,617 for two hundred.
Ed Gott (Boeing V.P.) went to Dayton for the bid opening. Major Fleet began reading the bids: "Aero Marine, $1,832,000; Boeing, $1,448,000; Curtiss, $1,982,000; Dayton-Wright, $2,201,000." Gott was concerned. "We must be off," he thought.
"L.W.F., $2,133,000; Thomas Morse, $1,936,000." Gott was now thoroughly alarmed. Thomas Morse had built the airplane. Morse's figure was $478,000 higher than Boeing's. A $400,000 loss would mean disaster.
"Boeing is low at $1,448,000."
A silence followed. Gott looked around. Some of the men were glaring at him. When the meeting broke up, none of them came over to congratulate him. They gathered in small groups. "He'll lose his shirt," someone was saying. A Curtiss man came up with a friendly air. "You can withdraw," he counselled. Gott went to the Miami Hotel and called Phil Johnson. "Everyone says we'll go broke at these figures. Think we should withdraw?"
"We're in business," boomed Phil. "Let's stick to our guns. We can build 'em for that, easy."
Boeing backed Phil up. But there was still a question about the bid being accepted. The whole thing was now in the hands of Washington. The pressure was on General Menoher, chief of the Air Service, to split the business. There were reports that it was up to Secretary of War Weeks, that it was up to President Harding, that the whole project might be dropped for another year while the Secretary of War and Secretary of Navy resurveyed the arms program.
Five weeks had elapsed when Ed Gott, beetled and drawn, went to Secretary Weeks.
"I will have made my decision by next Saturday," the Secretary said. "The question is whether it is worth an extra $800,000 for us to split the business up. I don't think it is. I don't think the President will favor it. But I must look into it thoroughly."
On April 21, 1921, the $1,837,626.38 contract was awarded to Boeing. This included a total of $164,000 to cover the cost of spares and support gear, as well as crating, etc. As noted in the bid, the cost for each airframe was $6,617, less government-furnished equipment (GFE) such as engine, armament, and instruments. No Boeing model number was assigned to the MB-3A.
At the same time, the investigation into the cause behind the upper wing failure suffered by Lieutenant Macready was under way by NACA. Until the exact cause and remedy had been established, production by Thomas-Morse of the MB-3 would not begin in earnest until early 1922, with first delivery taking place on July 29. The month before, Boeing had completed its first, improved MB-3A. The last MB-3A, A.S.68436, was delivered on December 27, 1922. For the US aircraft manufacturers, securing a single contract for 200 military aircraft would remain unsurpassed for the next seventeen years. The decision to award the MB-3A contract to a single company did not sit well with the other bidders.
In late 1921, Boeing began work on the MB-3A. Series production was still some way off, though. Compared to the earlier MB-3, the MB-3A featured a number of structural changes. These included relocating the radiator from the upper centre wing to the fuselage sides. Fuel capacity was also increased. The improved Wright H-3 engine developed 320 h.p. A redesigned empennage was fitted to the last 50 production aircraft (this was not retro-fitted to earlier aircraft). According to a Change Order, dated September 11, 1922, the revised empennages would be fitted to the last 100 production aircraft. The continuous engine cooling problems led to McCook Field using the second production MB-3, A.S.63332 (P164) to change the location of the radiator from the upper centre wing to two fuselage-mounted radiators.
One sample MB-3 was sent to Boeing, but this was soon written off at Seattle in a landing accident. With Boeing's own airfield being insufficient, it was decided to perform test flights of completed aircraft using the parade ground at Camp Lewis, an army base located some 30 kilometres from Seattle. The first flight of a Boeing-built MB-3A took place on June 7, 1922. Unfortunately, the pilot hit a small ditch upon landing, resulting in the aircraft overturning in front of the assembled Boeing and Army dignitaries. However, this inauspicious beginning did not matter much.
According to the Engineering Division at McCook Field, the MB-3A "has provided the Air Service with a new improved Type I pursuit airplane from which the faults of the earlier design, the Thomas-Morse MB-3, have been carefully eliminated."
Problems with the MB-3A persisted though, with one factory-fresh airplane being lost on November 5, 1922. During a test flight, Frank Tyndall had to bail out due to structural failure. In the process, Tyndall became the second US member of the Caterpillar Club.
General Billy Mitchell, who flew his personal MB-3A, A.S.68264, polished jet black and nicknamed Hawk, the MB-3A was "As good as if not superior to any pursuit type in the world."
Incidentally, development of an improved variant, unofficially known as the MB-3B, nearly reached fruition. The MB-3B would have featured a fuselage lengthened by two feet to improve directional and longitudinal stability, as well as ailerons on all four wings. In retrospect, it may be considered a good thing that the MB-3B never materialized. With the all-wood airframe of the MB-3A causing both production and maintenance problems, continuing the development of an already obsolete design would have been a bad idea. Boeing strongly believed that an improved pursuit would be required by the Air Service. Initially, the use of duralumin, as used by Thomas-Morse in their TM-23 pursuit, was considered but rejected. The result was the Boeing 15, which, construction-wise, was greatly influenced by the Fokker D.VII. Interestingly, three Fokker D.VIIs had been transferred to Boeing in 1921. It may be recalled that the Fokker D.VII was considered the best pursuit of the Great War. The fuselage of the Fokker D.VII consisted of a welded steel-tube frame, which greatly contributed to the aircraft's inherent strength and ease of construction. Both the fuselage and the wooden wings were fabric-covered. One of the Fokker D.VIIs was flight tested, with the other two being subjected to destructive static testing. It can be said with ample justification that the Fokker D.VII provided the source of inspiration for the long line of pursuits developed by Boeing during the mid-to-late 1920s. The Boeing 15 was to be powered by a 435 h.p. Curtiss D-12 engine, having a welded steel-tube fuselage and tapered wings. The preliminary design of the Boeing 15 was finalized on January 10, 1923.
It is worth noting that on September 27, 1923, Boeing was awarded a contract for three PW-9 pursuits for testing at McCook Field. The Air Service subsequently placed several orders for developed variants of the basic PW-9. Between the mid-1920s and early 1930s, Boeing would become a major supplier of pursuit airplanes to the US Army Air Corps (renamed from the US Army Air Service in July 1926), as well as the US Navy and Marine Corps. However, the story of these airplanes are outside the scope of this book.
In USAAS/USAAC Service
Following the end of the Great War (as it was commonly referred to at the time), the USAAS Pursuit squadrons were reorganized. On August 22, 1919, the 1st Pursuit Group (PG) was formed at Selfridge Field, Detroit, Michigan. The 1st PG consisted of four Pursuit Squadrons (PS); the 147th PS (later renamed 17th PS), which had been reconstituted on April 27, 1919, the 27th PS, reconstituted on April 28, 1919, the 94th PS, reconstituted on June 27, 1919, and the 95th PS, reconstituted on August 12, 1919. Initially, Curtiss JN-4s were flown before the 1st PG moved to Kelly Field outside San Antonio, Texas, on August 31, 1919. Having arrived in Texas, SE 5as, SPAD XIIIs and Fokker D.VIIs were delivered to the 1 st PG. Apart from forming the USAAS's first tactical Pursuit Group, one of its squadrons served as a conversion unit for pilots arriving from various flight schools. On June 30, 1921, the 1st PG transferred from Kelly Field to Ellington Field.
Prior to this, the first Curtiss-built Orenco D had arrived at Kelly Field in late November 1920. Initially, the Orenco D was considered an excellent pursuit aircraft. In the event, more than 50 Orenco Ds were delivered to the 1st PG. However, it was soon discovered that quality control during manufacture was sub-standard, resulting in a number of complaints. Following a fatal accident in 1921, the pilot's trust in the Orenco D evaporated, with the type being withdrawn soon afterwards.
With production of the MB-3 progressing well, it was said that 25 MB-3s were to be delivered to the 1st PG in April 1921. However, as described earlier, Lieutenant Macready's accident in an early production MB-3 resulted in delivery being delayed until early 1922. As a result of the problems with the Orenco D and non-delivery of the MB-3, the SE5as, SPAD XIIIs, and Fokker D.VIIs had to remain as first-line equipment until 1922.
The 1st PG pilots seemed fairly pessimistic about the home-grown Orenco D and Thomas-Morse MB-3, instead favoring the 200 h.p. Fokker D.VII and the SPAD XIII powered by the 180 h.p. Wright E engine. About 20 SE 5as were also serviceable, with only half that number being required for pilot training. Another SE 5a was flown by the Commanding Officer of the 1st PG, Major Carl Spaatz.
In March 1922, the first MB-3s finally arrived at Ellington Field. However, numerous problems with the new pursuits were soon reported: "Due to faulty construction of these planes, the time required for maintenance and necessary repairs and alterations to keep these planes in serviceable condition is excessive. It is the unanimous opinion of the pilots of the First Group (Pursuit) that the Thomas Morse MB-3 plane lacks may (sic) of the essential qualities required in a first class pursuit plane."
By May 25, 1922, 36 MB-3s had been delivered, with 20 being serviceable. Orders were received from the Chief of the Engineering Division at McCook Field to identify, as quickly as possible, the various modifications recommended for inclusion in the Boeing-built MB-3As. Intensive flight trials resulted in the majority of the MB-3s suffering structural damage, from bowed wing struts, leaky fuel tanks, cracked bulkheads and loose stabilizer fittings. Remarkably, following the conclusion of the flight trials, only one MB-3, A.S.63352, remained serviceable.
On June 22, 1922, flight training at Ellington Field ended, with the 1st PG being transferred back to Selfridge Field.
Meanwhile, the MB-3A delivery schedule called for fifteen aircraft (A.S.68340 to 68364) to be delivered to Mather Field for distribution among domestic USAAS units. Another fifty-one MB-3As (A.S.68365 to 68415) would also be shipped to Maher Field, and delivered overseas. These units included the 3rd Pursuit Squadron (reformed on January 25, 1923), based in the Philippines, and the 6th Pursuit Squadron based at Wheeler Field in Hawaii. The latter squadron was joined on May 1, 1923 by the 19th Pursuit Squadron. The 24th Pursuit Squadron (redesignated as such on January 25, 1923), based at France Field in the Canal Zone from April 1922, also received MB-3As. The final twenty-one MB-3As (A.S.68416 to 68436) were to be transferred to Kelly Field's 43rd School Squadron.
MB-3As were also used by the Air Service Tactical School (ASTS) and the Air Service Technical Training School (ASTTS).
In the mid-1920s, several MB-3As were rebuilt by the Fairfield Air Intermediate Depot (F.A.I.D). These aircraft were sent to Kelly Field near San Antonio, TX, where they were used for advanced training by the 43rd School Squadron. Here they joined obsolete MB-3s modified as advanced trainers and redesignated as MB-3Ms. Some MB-3Ms were still in service in 1929.
In USMC Service
Originally built to an Army contract (serial numbers A.S.64374-64384), 11 MB-3s were purchased by the US Navy, but did not serve with the Navy; instead they were transferred to the US Marine Corps. The original contract, dated May 16, 1921, covered ten MB-3s and two MB-7s. When one of the MB-7s was destroyed during the 1921 Pulitzer Air Race, it was replaced by an eleventh MB-3, ordered on December 2, 1921. This contract was a "rare example of joint Army-Navy administrative cooperation".
The final MB-3 was delivered in February 1922. Upon arrival at Gerstner Field, Louisiana, it was discovered that the MB-3s engines and armament were in poor condition, requiring refurbishment. Issued with the serial numbers A-6060 to A-6070, the MB-3s were shipped to Norfolk, before being transferred to Quantico. The MB-3s equipped 'F' Flight of the Third Air Squadron, providing a nucleus for developing pursuit aircraft tactics.
One USMC pilot, Captain Ford O. 'Tex' Rogers, had to bale out of s/n A-6062 when manoeuvring in rough weather. Rogers' verdict was that the MB-3 was "fast, tricky and as tiring as hell to fly (and that) they were somewhat prone to ground loop." The remaining MB-3s were consigned to storage in July 1922, having served for less than six months. However, it was not until November 1923 that the aircraft were sold back to the USAAS.
The MB-3 As An Air Racer
During the early 1920s, USAAS aircraft regularly participated in air races. Air racing caught the imagination of the American general public, with such events usually drawing huge crowds. The participating aircraft represented the forefront of aeronautical development, both with regards to airframe and engine. As a result, much money and resources were invested in developing air racing aircraft by various manufacturers across the USA, with both the USAAS and US Navy showing a keen interest in such aircraft. The first air race in which a Thomas-Morse aircraft took part was the 1920 Pulitzer Trophy Race, held on Thanksgiving Day at Mitchel Field, Long Island. The race was named after Hungarian-born Joseph Pulitzer (1847-1911), who after immigrating to the USA in 1864, made his fortune in publishing. Late in his life, Pulitzer developed an interest in aviation.
In 1916, five years after the death of the father, Pulitzer's three sons revealed plans to stage a Coast-to-Coast Continental air race. The race was to take place following the end of the Great War, and then become an annual event. Such a race was held in the summer of 1919. However, out of the 63 contestants, only eight completed the cross-country return flight. Tragically, nine aviators died during the race. As a result, the cross-country race was not repeated.
For the 1920 Pulitzer Trophy Race, four laps of a triangular 33-mile race track was to be completed. Out of the 45 participants, two were MB-3s. These were the second and third prototypes respectively. The first of these was flown to second place (the winner being the Verville-Packard VCP dedicated air racer) by Captain Harold Evans Hartney at an average speed of 148 mph. Hartney's MB-3 (the second prototype, A.S.40093, racing number 41) was a standard aircraft, not having been modified prior to the race. Flying the second MB-3 (A.S.40094, racing number 43), 2nd Lieutenant Leigh Wade had to abort on the second lap due to a technical malfunction. Having an unmodified MB-3 ending up in second place spoke volumes for the MB-3s performance, and, in particular, its speed. The fact that an MB-3 had ended up in second place could possibly have influenced the decision to order the type into series production.
The 1922 event did take place between October 7 and 14 at Selfridge Field outside Detroit. There were 15 USAAS and US Navy contestants, the War Department having apparently realized that military participation would be worth both the cost and effort. Although half-a-dozen MB-3As had been entered in the Pulitzer Air Race, the participation of the MB-3As were eventually reduced to that of the John L. Mitchell Trophy Race. It was thought that the MB-3As would stand little or no chance against purpose-built air racers. The latter included the all-metal Thomas-Morse R-5 (also known as the TM-22), which was powered by a 600 h.p. Packard engine. Nevertheless, two quickly modified MB-3As, racing numbers 61 and 62, were prepared to take part in the race. The MB-3As were to be flown by Lt Thomas K. Matthews and Lt George P. Tuortellot, were withdrawn before the race was to begin. In the end, the R-5s ended up at the lower end of the field, finishing in tenth and eleventh places. Disassembled and transferred to McCook Field, one of the R-5s were flown intermittently before being grounded in mid-1923. Consigned to storage, both R-5s were allotted for static fatigue tests.
Instead of participating in the National Air Races (an all-embracing name for the different kinds of events involved), the John L. Mitchell Trophy Race was created by General Billy Mitchell. This was in honor of the memory of his younger brother, who had been killed in a flying accident in France on May 26, 1918. General Mitchell stipulated that only pilots and aircraft of the 1st Pursuit Group were allowed to compete in the John L. Mitchell Trophy Race. The six MB-3As originally destined to take part in the Pulitzer Air Race were assigned to the Mitchell Trophy Race instead. In order for any speed records attained over the 50 km (31 mile) triangular course to be registered with the Federation Aeronautique International (FAI), the metric system was used. Recalculating miles into kilometres was seen as difficult.
The six pilots were; Capt. O.W. Broberg (racing number 55), Capt. H.M. Elmendorf (53), Capt. A. Guidera (51), Lt B.K. McBride (52), Lt D.F. Stace (54) and Lt J.D. Summers (56). The youngest of the six pilots was 22-year old Donald Stace, who had accumulated less than 100 hours in the air. However, Stace was the unit's Assistant Group Engineering Officer, serving with the Service Squadron. Having a pilot from the Service Squadron beat the pilots from the tactical squadrons was seen as a huge incentive. In order to increase the chances of victory, Stace's MB-3A, A.S.68257, underwent modification work to increase its speed. This included removing all appurtenances, such as radiator shutters and upper wing compass, fairing in the wing struts, as well as literally polishing the pursuit until it shone. The night before the race, the MB-3A was varnished with the fuselage footstep being faired over. Stace also managed to fly the course beforehand in a SPAD XIII.
At 1135 hours on October 14, the six MB- 3As were lined up for take-off, watched by 25,000 eager spectators. Stace was first off, followed in quick succession by McBride, Summers, Broberg, Elmendorf and Guidera. The six MB-3As passed across the starting pylon in tight formation, with Stace in the lead, his careful preparations appearing to work as intended. Incredibly, Stace gained one minute for each of the three laps, with Elmendorf losing one minute. On the third lap, Summers had to abort, landing back at Selfridge Field. Despite having his leather helmet blown away, Stace was first across the finishing line.
His average speed was 148 mph, having remained in the air for 50 minutes and 25.73 seconds. Guidera was the runner-up at 136,1 mph (54 minutes and 48.32 seconds). Broberg came in third at 135,3 mph (55 minutes and 7.87 seconds). At fourth place was McBride at 134,6 mph (55 minutes and 23.11 seconds) with Elmendorf occupying fifth place at 124,7 mph (59 minutes and 48.77 seconds). Having been forced to abort on the third lap, Summers must have been hugely disappointed as his average speed on the two laps was 137 mph. Had he been able to continue, Summers could have occupied second place in the race.
This first John L. Mitchell Trophy Race was considered a huge success, becoming known as the 'Thomas-Morse Race'. Apart from securing the trophy, Stace also received $ 400 from car manufacturer Dodge to be spent on a shiny new Dodge automobile. The MB-3A flown to victory by Lt Stace crashed on January 26, 1923, during a gunnery exercise. The pilot, Lt Schulz, was killed.
The 1923 National Air Races was due to take place at Lambert Field outside St. Louis, Missouri, on October 4, 5 and 6. For some reason, the itinerary initially did not list the John L. Mitchell Trophy Race among the events. Nevertheless, five MB-3A pilots - and their respective alternates - were announced on August 20 as participants; 1Lt Thomas W. Blackburn (alternate 1Lt Leland C. Hurd), 1Lt Thomas K. Matthews (1Lt Hobart R. Yeager), 1Lt George P. Tourtellot (1Lt Arthur J. Liggett), 1Lt J. Thad Johnson (1Lt Edward M. Haight), and 1Lt Russell L. Meredith (1Lt Louis C. Simon).
The participant's list was amended in late September to add a sixth pilot, Capt Vincent B. Dixon, with Capt Burt E. 'Buck' Skeel, while removing 1Lt Meredith. The sixth alternate would be Frank O'D Hunter. By including a sixth aircraft, this would emulate the 1922 event.
A mere six weeks prior to the National Air Races scheduled dates, the John L. Mitchell Trophy Race was eventually included as event 8a.
Despite poor weather, upwards of 100,000 spectators gathered at Lambert Field.
For the John L. Mitchell Trophy Race, MB-3As of the 1st Pursuit Group flew four laps over a 124 mile (50 km) course, the same as the 1922 race. The winning pilot would be given the chance to fly the most modern and high-powered air racer in the following year's event. Taking off at 1300 hours, the six pilots flew at extremely low altitude, further enhancing the spectator's desire for action. At the start of the third lap, problems with the fuel lines forced Matthews to land prematurely. Just before crossing the finishing line, the engine of Tourtellot's MB-3A quit due to lack of fuel. Putting the aircraft into a dive, Tourtellot hit the ground hard. Incredibly, his MB-3A bounced upwards making it across the finishing line. However, Tourtellot had been beaten by B E Skeel. Having taken off last, Skeel secured first place at an average speed of 146.45 mph (50 minutes and 54.95 seconds). Tourtellot's speed averaged 143.21 mph (52 minutes and 4.24 seconds). Ending up in third place was T W Blackburn at 141 mph (52 minutes and 51.07 seconds). Competition between J T Johnson and V B Dixon was intense, with Johnson securing fourth place at 139.20 mph (53 minutes and 34.18 seconds), beating Dixon by a margin of just over six seconds. Dixon's average speed was 138.94 mph (53 minutes and 40.22 seconds).
The day of the Thomas-Morse MB-3A as an air racer had passed. Purpose-built air racers were to dominate the following year's events. Tragically, Bert Skeel would perish when his Curtiss R-6 crashed during the 1924 National Air Races.
Movie Stars
The visual legacy of the MB-3A is completely due to the 1927 movie Wings. Perhaps the last great of Hollywood's silent movies before the advent of 'talkies', Wings was a massively huge undertaking. The aerial combat sequences were created using almost the entire fleet of Air Service combat airplanes. The War Department made available some 220 aircraft (including Curtiss P-1s starring as German pursuits, DH 4s, Douglas O-2s, and Martin NBS-1 bombers), along with other equipment and personnel. However, the participating MB-3As are not playing themselves, but rather French SPAD and German Albatros D.III and Fokker D.VII pursuits! The MB-3As were modified to fit their roles as French and German pursuits. Apart from being adorned with French-style camouflage, the MB-3A 'SPADs' had their engine cowlings and machine gun installation modified to make them more similar to the original SPADs. Additionally, the fin was painted in such a way as to imitate a SPAD XIII fin. At this stage, the MB-3A was thoroughly obsolete as a pursuit, with several being utilized as advanced trainers. One might speculate that if actual filming would have begun in late 1927, no MB-3As would have been involved.
Two MB-3As obtained by Paramount were intentionally destroyed during filming. The respective aircraft met their end by being fired into the air by means of an air pressure gun. One of these scenes involved David Armstrong's (Arlen) 'Fokker D.VII' ending up against a building. The fin and rudder of this particular MB-3A had been modified to look like that of a Fokker D.VII. The second MB-3A was sent crashing into a lake. One (other?) MB-3A was modified as an Albatros D.III (including the removal of the inner wing struts), and set up in an inverted position in front of the cameras.
Remarkably, only one fatal crash occurred during the filming of Wings. This occurred in November 1926, MB-3A serial number A.S.68385 crashing en route to Kelly Field. Two other US Army Air Corps airplanes sustained damage during the filming. (Incidentally, in his autobiography Squadron of Death, Richard Grace makes reference to a fatal crash on the Wings set: "It was during this period that a certain event happened which had a psychological effect on me. One of the fliers tried to make a turn too quickly and lost his flying speed. He immediately crashed into the ground and was instantly killed. The type of ship he was flying was not much faster than the one I was to crash. The nature of the ground into which he plunged was not as hazardous as hitting posts and shell holes. I began to wonder."
This may, or may not, describe the fate of MB- 3A A.S.68385.
It goes without saying that the War Department were very concerned about damage being sustained to government-owned airplanes during the shooting of Wings. Nevertheless, given the large amount of pilots and airplanes involved, the safety record obtained during the filming schedule was very good.
The most famous aviation scenes in Wings were the intentional crashes of an original SPAD (which would force land into no-man's land and turn turtle) and a Fokker D.VII being 'shot down' while taking off. Both of these crashes were performed by Hollywood's premier 'crash engineer' Richard Grace. In the Fokker D.VII crash, Grace broke his neck, earning him a long hospital stay.
The story of Wings begins in early 1926, when Hollywood writer, and former pursuit pilot, John Monk Saunders presented the idea of a movie to be based on aerial combat during Great War to Paramount Pictures producer Jesse L. Lasky. According to Saunders, the air war was a "virgin-province", and "a subject whose proper medium of presentation was the screen." Initially, Lasky balked at Saunders suggestion, stating that the cost would be "appalling", and could such a movie be made on a limited budget? Saunders response was that "It couldn't... If it were attempted at all, it must be done on a grand scale. The very magnitude of the subject demands heroic treatment."
After some deliberation, Paramount agreed to Saunders proposal. The working title for the movie was Wings, with Saunders to provide a script outline. Twenty-eight year-old William Wellman, himself a former Lafayette Flying Corps pilot, was chosen to direct the epic. The story involves two American pilots of the 39th Aero Squadron, Jack 'Speed' Powell and David Armstrong (played by Charles 'Buddy' Rogers and Richard Arlen respectively). The leading role as volunteer ambulance driver Mary Preston went to Clara Bow (Hollywood's 'It Girl', who at the time was the world's biggest female movie star). The second main female role of Sylvia Lewis, the love interest of both Powell and Armstrong, went to Jobyna Ralston.
Richard Arlen held one advantage over his co-stars; he could fly. In 1917, Arlen enrolled in the Royal Flying Corps, learning to fly at Camp Borden in Canada. Discharged in early 1919, Arlen made his way to Hollywood the following year, eventually becoming a contract actor. Both he and co-star Rogers were relatively unknown actors when chosen to appear in Wings. During the shooting, Rogers had to learn to fly. Although neither Arlen nor Rogers were allowed to fly any of the numerous military airplanes, they nevertheless had to be filmed close-up while in the air. Richard Arlen: "We were using the first motor-driven cameras which were mounted in a lithe in front of the cockpit... The four hundred feet reels ran off at about ninety feet a minute which gave us only a little more than four minutes of picture.
"Bill Wellman would tell us on the ground what he wanted us to do in the air... We would waggle our wings when ready and then take over as producer, director, and actor. We would hold up the proper number of fingers for takes one, two, or three. If we thought the scene was bad we would run a finger across our throats for a cut.
"That was why Wellman wanted actors for Wings who could fly. Buddy couldn't. But he learned damn quick!"
(During the Second World War, 'Buddy' Rogers served as a US Navy test pilot.)
Directed by 28-year old William Wellman, a Lafayette Flying Corps veteran, Wings was based on the Battle of Saint Mihiel. Recreating the battlefield at Camp Stanley, including trenches, shell craters, and barbed wire involved 600 Mexican workers, who completed the work in two months under the supervision of 2nd Infantry Division engineers. The budget was $ 2 million ($ 28.88 million in 2019 dollars), a huge sum. Among the Air Service pilots flying before the cameras were Hoyt S. Vandenberg and 'Hap' Arnold. Although set in 1918, Wellman had no qualms about using mid-1920s equipment, from uniforms, vehicles, weapons to airplanes. Nevertheless, as described above, the MB-3As were modified to look like SPAD pursuits. Filming was centred at and around Kelly Field outside San Antonio, Texas.
The story in Wings revolves around two young pursuit pilots, Jack 'Speed' Powell (Charles 'Buddy' Rogers) and David Armstrong (Richard Arlen). Both are in love with the same girl, Sylvia Lewis (Jobyna Ralston), but she only has feelings for Armstrong. (Incidentally, Ralston would later marry Arlen in real life.) Unbeknownst to Jack, another girl, Mary Preston (Clara Bow) has a crush for him.
Both Powell and Armstrong quickly become experienced pursuit pilots. On one mission, Powell is shot down into no-man's land, but manages to return to his unit. (This scene saw the first of Richard Grace's two crashes for Wings.)
While in Paris on leave, Jack gets roaring drunk, ending up with Mary Preston. In the morning, Mary leaves Jack at the hotel, never mentioning her name. He later discovers that his love for Sylvia Lewis is unanswered. Disgusted, he turns against Armstrong, refusing to have anything to do with him.
One day, they are ordered to fly a mission together to shoot down observation balloons. When intercepted by German pursuits, Powell leaves Armstrong to his fate. Disgusted by his own behavior, Powell makes a solitary flight across the enemy lines. Seeing German fighters taking off, he shoots down a Fokker D.VII (Grace's second intentional crash) before dogfighting a second German plane. Powell also manages to shoot this one down, which crashes into a French farm. Landing in a nearby field near the crashed, black-painted MB-3A (thinly-disguised as a Fokker D.VII), Jack is devastated to find a mortally wounded Armstrong in the pilot's seat.
Following the end of the war, Powell returns home. There he meets Sylvia, forcing himself to say that her wait for Armstrong is over, also recounting his role in his friend's death. Powell also get reacquainted with Mary, whom he does not recognize as the girl he spent the night with in Paris. She does not reveal herself to Jack, either.
Following six months of planning, actual filming began on September 7, 1926, ending exactly seven months later, on April 7, 1927. Recreating the Saint Mihiel battle involved 165 airplanes, 3,500 troops, and many pre-set explosions. Just this scene took a $300,000 slice out of the $ 2 million budget. The aviation sequences took six months to complete. One reason for this was William Wellman's insistence to film the aerial combat sequences against a cloudy sky, declaring that to the general public, viewing airplanes against a blue sky made them seem immovable. The aerial combat scenes were color-tinted in blue, red or yellow to enhance the emotional effect, each frame being hand-painted! A very basic soundtrack was initially used for the noise of the machine guns firing or engines purring away. This was achieved in quite a novel way. Large vertical holes were cut into the film, millimetres away from the sprocket holes. When the film was shown, a lever engaged these holes, creating the noise of machine guns or engines. This required a huge, complex machine, similar to the mechanized nickelodeon popular during the early 20th Century, which out of necessity had to have a purpose-designed railway car for transportation between selected venues. When shown at regular cinemas, Wings was a silent movie.
Wings premiered at the Criterion Theatre in New York on August 12, 1927, with the west coast premiere, in Los Angeles, taking place on January 15, 1928. With Charles Lindbergh having flown nonstop across the Atlantic only a few months earlier, public interest in aviation was unprecedented. Wings was a huge success, constantly breaking attendance records all over America. In May 1929, Wings also secured the first Academy Award for Best Picture. Wings eventually grossed $3.6 million at the box office. According to aviation movie historian James H. Farmer, "With Wings the airplane had finally come into its own on the screen. In Wings it had also forever lost its innocence."
Wings footage later appeared in other Paramount movies; Now We’re in the Air (1927), Legion of the Condemned (1928) (which sadly has been lost to history), Young Eagles (1930) and Eagle and the Hawk (1933).
In 2012, Wings was made available on DVD. Along with Hell’s Angels, released in 1930, Wings can be regarded as among the best of all Great War aerial combat movies.
Thomas-Morse MB-3A Technical Description
The following technical description is quoted from the contemporary Technical Bulletin No. 34
"The standard Boeing MB-3A is an Air Service Type I, single seater pursuit airplane of externally braced biplane construction. It is powered by a standard Wright Model H-3, 320 h.p. engine swinging either a two or four-bladed propeller. The structural features are briefly described in the following:
Wings. - The two-bay cellule of the standard MB- 3A has no stagger. It is an externally braced structure with streamline brace wires and spruce interplane struts. The upper wing which carries the gravity fuel tank and the water expansion tank is continuous with two ailerons inserted in the trailing edge at the tips. The lower wing has two panels, which are attached directly to the fuselage wing butt on each side. Wood construction is used thruout.
Fuselage. - The structure is of the conventional wood construction with laminated ash and spruce longerons and wooden cross members braced by diagonal wires with turnbuckle adjustment. The lower wing butt is built integral with the bottom of the fuselage which has a maximum width of 3 1/2 feet across this portion, the width of the fuselage proper being only 2 1/2 feet with a maximum depth of about 4 feet. Fabric covering is used on both wings and fuselage.
Tail Surfaces. - The new tail surfaces shown herewith are of wood construction with fabric covering. The elevator is built about a box spar formed of two "I" section members with flanges joined by means of plywood. Conventional "I" section ribs made with spruce capstrips and mahogany webs in which several lightening holes are cut, are built on to the spars with the capstrips serving as spacers.
The same construction is used for the stabilizer, except that this structure employs two spars, front and rear, which are not joined with plywood at the top and bottom as in the case of the elevator. This plywood, however, extends from the front spar forward to the leading edge on both top and bottom. Lightening holes are cut in the rib webs and also in the plywood along the leading edge.
The rudder and fin are of wood construction also, the former consisting of one main box and a channel section, joined by ribs of the same design as those used in the elevator and by plywood glued to top and bottom flanges. The fin is constructed with a single laminated main spar, to the upper part of which the rudder is hinged. And two small auxiliary vertical spars of plywood to which the ribs are joined. The leading edge is made of laminated spruce milled and routed to shape. The whole structure is covered with 3-ply mahogany plywood with large lightening holes cut thru between the spars and ribs.
The general construction of the old style tail surfaces with the short vertical fin and balanced elevator and rudder is somewhat similar to that used in the new tail surfaces. These are used on the first one hundred fifty airplanes built under this contract.
Chassis. - Spruce struts supporting a continuous streamline axle fitted with elastic cord shock absorber and 28 by 4 inch straight-side wheels and Goodyear tires comprise the two-wheeled landing chassis used on this airplane. The axle, proper, consists of the two short shafts, one for each wheel, supported between the spreader tubes. The structure is strengthened by vertical streamline brace wires.
Power Plant. - The power plant consists of a standard Wright H-3 engine capable of developing 320 horse power at a normal speed of 1800 r.p.m. The engine is fitted with one Stromberg NAD-6A carbutetor with standard mixture control effective to ceiling, and an automatic spark advance, ignition being furnished by two Dixie magnetos.
Fuel system comprises two leak-proof tanks, the main tank of 33 gallons capacity being located in bottom of fuselage directly in front of pilot and the 12-gallon gravity tank being placed in the center section of upper wing. Fuel is lifted from main tank by suction thru a line strainer to an engine-driven bellows pump which forces it thru a 3-way cock directly to carburettor or to both carburettor and gravity tank, the latter overflowing into the main tank. Gravity pressure alone may be used to operate system is case of pump failure.
Water cooling is effected by means of two side radiators of Thomas-Morse manufacture, supported on padded ash sills on each side of fuselage opposite cockpit. The expansion or reserve tank, which is provided with an automatic pressure relief valve to prevent excessive loss of water under adverse conditions, is placed in the upper wing. Part of the water which has been heated by the engine, is circulated around the intake manifold, thus heating the gasoline mixture. Cooling is regulated by shutters over radiators. These are controlled from the cockpit.
Equipment. - In addition to the requisite flying equipment, this airplane carries oxygen and radio apparatus, two life preserver cushions and fire extinguisher. Provision for carrying camera is made also. Armament consists of two .32 caliber synchronized aircraft guns with necessary ammunition boxes, chutes, and sights. One of the airplanes at McCook Field has been equipped with electric landing lights and other night flying accessories."
MB-3A Technical Data and Performance Characteristics
Type: Single-seat pursuit/advanced trainer
Engine: 1 x 320 h.p. Wright H-3
Wingspan: 26 ft 0 in (upper) (7,92 m) 24 ft 6 in (lower)
Length: 20 ft (6,0958 m)
Height: 7 ft 8 in (2,59 m)
Wing area: 228 sq ft (21,23 m2)
Empty weight: 1,716 lb (779 kg)
Military load: 767,82 lb (348,59 kg)
Armament: 205,32 lb (93,21 kg)
Equipment: 84,5 lb (38,36 kg)
Fuel: 264 lb (119,85 kg)
Oil: 34 lb (15,43 kg)
Empty weight: 1,716 lb (778 kg)
Gross weight: 2,485 lb (1128,2 kg)
Maximum speed at sea level: 140 mph (225 km/h)
Cruise speed: 125 mph (201 km/h)
Climb rate: 1,350 ft./min (411 m)
Service ceiling: 19,500 ft (5,943 m)
Endurance: 2.25 hrs
Armament: 2 x 0.32 machine guns
Colors and Markings
The four MB-3 prototypes were finished in the standard 1918 camouflage; olive drab (or khaki brown) on the upper surfaces and vertical fin, with all other areas being cream (or ivory). The latter included the wing struts, etc. The pair of MB-3 prototypes which were transferred to McCook Field, 40093 and 40095, had been repainted overall olive drab by mid-1920. At least one, and most likely all four prototypes, were marked with the red, blue, and white roundel (official national insignia between January 1918 and August 1919) with the rudder being adorned with blue, white, and red (forward) vertical stripes. The respective serial number, 40092 to 40095 appeared prominently in large black figures on both sides of the fuselage without the A.S. prefix.
In August 1919, the national insignia reverted to the old five-pointed star with a red circle superimposed on a blue roundel. This was carried in four positions, on the upper and lower surfaces of the wings. The MB-3s, as well as the MB-3As were finished in overall olive drab. The respective serial number was applied in large numerals, usually along with the A.S. prefix. The size of the serial numbers were later reduced in size to make room for unit insignia. Airplanes within a particular unit usually carried an individual numeral, which was painted on the fuselage. Occasionally, this was repeated on the wings. The MB-3s which participated in John J Mitchell Trophy Race were adorned with individual race numerals in white on both sides of the fuselage.
The MB-3s used by the US Marine Corps were finished overall olive drab, with national insignia in four positions. The engine cowling was painted grey. Additionally, the USMC insignia appeared in dark red on both sides of the fuselage. The respective serial numbers, eg A-6065, appeared vertically in black on both sides of the rudder. An individual serial number also appeared in white on both sides of the fuselage. Two diagonally stripes (possibly in white) were painted on the upper surfaces on the wings.
The MB-3 and MB-3As tested at McCook Field retained their Air Service colors. A McCook Field serial number, eg P274, was applied on both sides of the rudder.
The MB-3As which appeared in Wings were camouflaged in French and German colors a la 1918.
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