A400m news

[Matt308]

Kruska, your comment about the C-17 being expensive is true, but don't forget that other countries have bought the C-17. Australia, Canada, UK with others on line such as a shared fractional ownership amongst NATO countries.

The A400M is looking to get 50hrs flight time on the C-130 installed TP400 turboprop before A400M flight test in Sept. All I have read is that that date is likely to slip... again.

[Kruska]

Hello Matt308,

Yes I think it will still take quite some time for the M400 to become operational, but sooner or later it will.

Regarding UK, Canada, Australia, I might be wrong, but I think those C-17’s are leased from the USAF not bought. Anyway it is a shame that Germany never bought a few in the 80’s/90's, but before Somalia the German government never acknowledged it usefulness. What happened to this (can’t get the name right now) Boeing? 2 jet engine, highwing mounting STOL transporter the USAF was evaluating in the 80’s? IIRC this aircraft had a very good potential.

In 1984 I was at Altus Oklahoma, having a go at the C-5 simulater - heck of a fun we had, really impressive buggers.

Regards
Kruska

[Matt308]

Yes the lease aspects are somewhat correct, but I think that recently they have become lease to own. I do know the NATO discussions were for leases until the A400M came along, as I recall.

And the Boeing aircraft was the YC-14 (two engine). The McDonnell version was the YC-15 (4 engine). I've seen the YC-14, they have it at the Pima Air Museum. And talk about a high winged airplane! I can't wait until the A400M flies though, she looks freakin' awesome!

From GlobalSecurity.org
__________________________________________
McDonnell Douglas used the externally blown flap (EBF) concept with a four-engine configuration and large double-slotted flaps that extended over 75 percent of the total span for the YC-15 prototypes. The YC-15 already had a rear cargo ramp and soft-field landing gear. It also had unusually large tail surfaces, which increased the safety of the demonstration program.

John P. Campbell of NASA Langley had conceived the innovative externally blown flap concept in the mid-1950’s as a relatively simple approach to augment wing lift for low-speed operations. In this concept, the exhaust from pod-mounted engines impinges directly on conventional slotted flaps and is deflected downward to augment the wing lift. The magnitude of lift augmentation is extremely large, and the resulting lift can be as much as twice the value for a conventional aircraft. However, no serious consideration was given to the EBF concept initially because of the severe high-temperature impingement on the wing and flap surfaces from the turbojet (no bypass or fan flow) engines used at that time. Also, the relatively small mass flow from such engines was a limiting factor for lift augmentation. In addition, considerable concern was expressed over potential control problems in the event that an engine became inoperative during flight at low speeds with high-power settings. With the advent of turbofan engines, however, the efflux from the engines was relatively cool, and large quantities of air became available for increased airflow through the flaps. The turbofan engine, therefore, provided the breakthrough mechanism that permitted researchers to evolve and mature the applications of the EBF concept.

Employing "under-surface blowing" to achieve STOL capability, the YC-15's wings were configured with sets of double-slotted flaps which could be extended downward directly into the jet flow from its four turbofan engines. Part of the exhaust was directed downward by the flaps while the rest passed through and then downward over the flaps by means of the "Coanda effect" (air turning on the convex side of an aerodynamic surface). The YC-15 convincingly demonstrated the feasibility of this concept which would later be incorporated into the design of the C-17 transport.

The YC-15 was the first military transport to use supercritical wings, a major innovative technology conceived and developed through wind-tunnel research by Richard Whitcomb at NASA Langley. Whitcomb’s supercritical wings incorporate advanced airfoils that enhance the range, cruising speed, and fuel efficiency of aircraft by producing weaker upper-surface shock waves, thereby creating less drag and permitting higher efficiency. McDonnell Douglas subsequently incorporated supercritical wing technol-ogy in the C-17 design.

The McDonnell Douglas YC-15 Advanced Medium STOL (Short-Takeoff and Landing) Transport aircraft landed at Edwards at the end of its maiden flight on 26 August 1975, and was joined by the second prototype in December of that year. The YC-15 demonstrated exceptional STOL performance in its flight-test program with an approach speed of only 98 mph and a field length of 2,000 ft at a landing weight of 150,000 lb.

Though originally conceived as a potential replacement for the venerable C-130 Hercules, funding cuts limited the YC-15 to the role of an advanced technology demonstrator. A lack of money presented an insurmountable obstacle. Although the US Army and the Military Airlift Command backed procurement of the AMST, the escalation of costs, from $5 million per aircraft in 1970, to twice that much in 1977, and an estimate of $20 million by 1982, killed the production of either prototype.

One of only two YC-15 prototype aircraft that was produced in the 1970’s had been in AMARC’s desert storage for a period of 17 years. This aircraft was identified to play a new role as a test bed for advanced technology. In order to meet this need, the AMARC workforce in conjunction with Boeing worked on the YC-15 for several months on site. After more than 15 years in storage in the Arizona desert, in late 1996 the McDonnell Douglas YC-15 was brought out of mothballs to continue its mission as an advanced technology demonstrator. It was the first Air Force developmental aircraft leased back to a contractor under a Cooperative Research and Development Agreement. The primary reason for the agreement was to provide a prototype to explore new technology applications for the C-17 and other airlift aircraft. Without the use of the YC-15 for airlift testing to assist the lone C-17 test aircraft, the Air Force would have to rely on the operational C-17 fleet, which was already heavily tasked with global commitments. The YC-15, which first flew in 1975, had been stored at Davis-Monthan Air Force Base in Tucson, Ariz., the home to the Air Force's Aerospace Maintenance and Regeneration Center, an Air Force Material Command facility. Refurbishment was being done by both McDonnell Douglas and AMARC crews. The result: a successfully refurbished and flight ready aircraft departed AMARC in 1997. The YC-15 operated out of McDonnell Douglas facilities in Long Beach, CA.

[Matt308]

And here's the YC-14 write-up from GlobalSecurity.org Part I -
______________________________________________
Boeing's YC-14 used two GE F103/F1A engines mounted forward and above the wing, their exhaust blown across the upper surface of the wing and flap system in order to create powered lift. This location also gave the airplane a quieter noise footprint. In the upper surface blowing (USB), concept, the engines were mounted so that the exhaust spread over the upper surface of the wing for enhanced circulation and lift augmentation in STOL operations. NASA and industry studied the USB concept extensively from the middle 1950s to the 1980s using an extensive variety of wind-tunnel investigations, static engine tests, and piloted simulator studies that culminated with the Boeing YC-14 prototype military transport.

In the 1950s, researchers explored employing the efflux of engines to augment wing lift using the jetflap concept to remove the limitations of conventional high-lift devices. The magnitude of maximum lift obtained in this approach can be dramatically increased — by factors of three to four times as large as those exhibited by conventional configurations — permitting vast reductions in field length requirements and approach speeds. This revolutionary breakthrough to providing high lift led to remarkable research and development efforts.

One of the most promising powered-lift concepts is the upper surface blown (USB) flap. In this approach, the jet engine efflux becomes attached to the wing upper surface and is turned downward over a trailing-edge flap (Coanda effect), there by increasing lift. This mode of operation produces aerodynamic and acoustic loads on the airplane that are significantly higher than those experienced by conventional airplanes. These higher loads indicate a need for special design efforts to prevent fatigue failures and to obtain acceptable cabin-interior noise levels. In July 1969, the Defense Science Board produced a report urging the use of prototyping by DoD to yield better, less costly, more competitive weapon systems. Deputy Secretary of Defense David Packard was a strong advocate of the prototyping approach and, in 1971, an Air Force committee recommended six systems as candidates, including a lightweight fighter (which subsequently evolved into the F-16) and the AMST.

Later that year Boeing’s preparations for a response to an anticipated Air Force request for proposal (RFP) to design, build, and flight test an AMST Technology Demonstrator rapidly crystallized as the company began to develop its candidate for the competition. John K. (Jack) Wimpress received the AIAA Design Award in 1978 for the YC-14’s conception, design, and development, and he was the only Boeing person to be with the YC-14 Program from its inception to its end.

Boeing had accumulated considerable expertise in powered-lift concepts, having proposed the EBF concept for its unsuccessful C-5 competitor as previously discussed and having conducted flight research with NASA using the Boeing 707 prototype (known as the 367-80) modified with sophisticated leading-edge devices and BLC on both leading- and trailing-edge flaps. Along with most of the aeronautical community, Boeing had maintained an awareness of NASA’s development of various powered-lift concepts. In its RFP preparations, Boeing examined several powered-lift concepts, including boundary-layer control and, of course, the EBF. Early on, the company was convinced that a twin-engine design offered considerable advantages for the AMST from the perspectives of cost and safety. BLC would not provide the level of lift required via engine bleed air, and the use of an underwing, pod-mounted twin-engine layout for an EBF configuration would require the engines to be located very close to the fuselage to minimize rolling and yawing moments if an engine became inoperative. Boeing was concerned that large aerodynamic interference effects would occur with such an arrangement, particularly at cruise conditions. Thus, Boeing was searching for a new concept that would permit the deflection of jet flow behind a twin-engine arrangement.

Boeing had analyzed the previously discussed exploratory upper-surface blowing tests published a decade earlier and was interested if NASA had since conducted additional research on the concept. Semispan USB research had been conducted in the NASA Langley 12-ft tunnel. An examination of the preliminary results revealed that the magnitude of lift generated was as high as had ever been seen for any powered-lift system. The Langley data were the key enablers for a twin-engine STOL configuration layout. In particular, with the engines on top of the wing, they could be placed close to the centerline of the airplane without causing large aerodynamic inference with the fuselage. Boeing immediately started to build wind-tunnel models to verify the NASA data with geometric and engine parameters more closely representing configurations that Boeing was actually considering. By the end of 1971, Boeing was hard at work in several wind tunnels assessing and refining the twin-engine configuration.

When the Air Force RFP for the AMST prototypes was released in January 1972, it called for the very impressive capability of operations into and out of a 2,000-ft semiprepared field at the midpoint of a 500 nmi mission while carrying a 27,000-lb payload both ways. By comparison, the C-130 series in operation at that time required field lengths almost twice as long to lift a 27,000 lb payload. Following the submittal of its proposal in March 1972, Boeing conducted many wind-tunnel and engine test-stand investigations to refine its proposed design and to identify and solve potential problems. In November, Wimpress again visited Langley for an update on NASA’s USB research activities. Joe Johnson and Dudley Hammond both reported on testing being conducted in their organizations and showed Wimpress experimental data that verified the high-lift performance that Boeing had submitted in its proposal.

On November 10, 1972, the Air Force selected Boeing and McDonnell Douglas as contractors to work on the AMST prototypes. Following the contract award, Boeing launched an aggressive development program to actually design the airplane. Considerable efforts were required for the development of an acceptable USB nozzle, and a major technical surprise occurred when Boeing discovered that the forward flow over the airplane during lowspeed operations had a degrading effect on the USB flap, reducing the jet spreading and causing separation ahead of the flap trailing edge. This phenomenon had not been noted in earlier NASA or Boeing wind-tunnel testing. Results from those earlier tests had led to the conclusion that forward speed effects would not significantly impact the flow-turning capability of the nozzle. Boeing added vortex generators to the YC-14 configuration to re-energize the flow and promote attachment on the USB flap during STOL operations. The vortex generators were extended only when the USB flap was deployed beyond 30° and were retracted against the wing surface during cruise. Boeing adopted a supercritical airfoil for the wing of the YC-14 based on internal aerodynamic research following the 747’s design. Initially, senior aerodynamicists at the company were reluctant to accept such a radical airfoil shape.

After reviewing ongoing supercritical wing research at Langley led by Richard T. Whitcomb, they were impressed by the performance of a supercritical airfoil applied to a Navy T-2C aircraft in a research program by Langley. Confidence in the design methodology for the new family of airfoils was provided by close correlation of wind-tunnel predictions and actual flight results obtained with the T-2C. With the NASA data in hand, Boeing proceeded to implement the supercritical technology for the YC-14 and for its subsequent civil commercial transports, including the 777.

Applications of supercritical wing technology to larger transport aircraft in the United States began with prototype military transports in 1976—Boeing’s application to the YC-14 and McDonnell Douglas’ application to the YC-15. The supercritical airfoil, developed at the Langley Research Center, uses a unique geometric shape to control the characteristics of the supersonic flow in a manner to minimize drag and enhance the cruise efficiency of the transport. The curvature of the middle region of the upper surface of the supercritical airfoil is significantly reduced and carefully tailored to result in a more rearward location and substantial decrease in the strength of the shock wave, and drag for a given lift coefficient is reduced.

During the development process, Boeing was faced with determining the size of the horizontal tail and its placement on the configuration. The initial proposal airplane had a horizontal tail mounted on the end of a long extended body atop a vertical tail with relatively high sweep. However, as the design evolved it became apparent that the proposal configuration would not adequately accommodate the large nose-down pitching moments of the powered-lift system or ground effects. Boeing examined the parametric design information on longitudinal stability and trim that Langley tests had produced in the Full-Scale Tunnel and the V/STOL Tunnel, indicating that it was very desirable to place the horizontal tail in a position that was more forward and higher than the position that Boeing had used for the proposal configuration. These Langley data provided critical guidelines in the tail configuration’s revision for the YC-14’s final version.

[Kruska]

Hello Matt308,

Yes, correct thank you – YC14 – my poor memory . I just goggled and Britain originally leased 8 C-17 and now it buying them over plus some new orders. Australia and Canada did buy them according to Wiki…

Thanks for the descriptions, I will be off for the next 2-3 weeks, got to sell some stuff so don't miss me too much in the meantime

Regards
Kruska

[Matt308]

And here's the YC-14 write-up from GlobalSecurity.org Part II -
______________________________________________

By December 1975, Langley had negotiated with Boeing to obtain full-scale data on a USB high-lift system. Boeing conducted full-scale powered ground tests of a complete YC-14 wing-flap-fuselage segment at its Tulalip test facility to evaluate the effectiveness and noise levels of its powered system. During the tests, sound levels and pressure distributions were measured by Boeing over the USB flap and the fuselage next to the flap. These data were made available to Langley under the special research contract. Langley’s interest was stimulated in part by the fact that the engine nozzle of the YC-14 design incorporated a D-nozzle (a semielliptical exit shape), which differed from the high aspect-ratio rectangular nozzles that had been used at Langley in the full-scale Aero Commander tests previously discussed. With the full-scale YC-14 data in hand, Langley proceeded with a test program to determine the adequacy of subscale models to predict such information, including the development of scaling relationships required for the various technologies involved.

A 0.25-scale model static ground tests of the Boeing YC-14 powered lift system were conducted at the outdoor test site near the Full-Scale Tunnel for correlation with full-scale test results. The model used a JT-15D turbofan engine to represent the CF6-50D engine used on the YC-14. The tests included evaluations of static turning performance, static surface pressure and temperature distributions, fluctuating loads, and physical accelerations of portions of the wing, flaps, and fuselage. Results were obtained for the landing flap configuration over a range of fan pressure ratio for various ground heights and vortex generator modifications.

The USAF YC-14 prototype STOL aircraft, first flight tested in 1976, successfully implemented optical data links to exchange data between the triplex computers. Optical coupling was selected to maintain inter-channel integrity. Each sensor output is coupled t o the other channels so that each computer has data from each of the sensors. Identical algorithms in each computer consolidate the data enabling equalization and fault detection / isolation of the inputs. The computers are synchronized to avoid sampling time differences and to assure all computers are receiving identical data inputs. The optical communication medium was used to eliminate electromagnetic interference effects, electrical grounding loop problems, and the potential propagation of electrical malfunctions between channels.

The behavior of pressure fluctuations measured on the airframe of a prototype high lift jet transport (YC-14) are characterized in terms of a particular jet exhaust flow field idealization, jet mixing noise, and exhaust shock noise. Generalized spectrum shapes and scaling relations for peak level and frequency of peak level were developed, and the frequency is found to depend on jet exhaust velocity and aircraft velocity. Comparisons are made with near-field engine exhaust noise of a conventional jet, and results suggest that the same two exhaust noises are important for both aircraft types. Surface fluctuating pressure data are assessed, and results suggest that the jet mixing and exhaust shock noise source characterizations for the YC-14 have useful applicability to conventionally configured jets.

One quarter scale static ground tests of the Boeing YC-14 powered lift system were conducted for correlation with full scale test results. The 1/4 scale model utilized a JT-15D turbofan engine to represent the CF6-50D engine employed on the YC-14 advanced medium STOL transport prototype aircraft. The tests included evaluation of static turning performance, static surface pressure and temperature distributions, fluctuating loads, and accelerations of portions of the wing, flaps, and fuselage. Results are presented for the landing flap configuration over an appropriate range of fan pressure ratio as affected by several variables including ground height and vortex generator modifications. Static turning angles of the order of 60 deg were obtained. The highest surface pressures and temperatures were concentrated over the upper surface of the flaps in the region immediately aft of the upper surface blown nozzle.

Flow turning parameters, static pressures, surface temperatures, surface fluctuating pressures and acceleration levels were measured in the environment of a full-scale upper surface blowing (USB) propulsive-lift test configuration. The test components included a flightworthy CF6-50D engine, nacelle and USB flap assembly utilized in conjunction with ground verification testing of the USAF YC-14 Advanced Medium STOL Transport propulsion system. Results, based on a preliminary analysis of the data, generally show reasonable agreement with predicted levels based on model data. However, additional detailed analysis is required to confirm the preliminary evaluation, to help delineate certain discrepancies with model data and to establish a basis for future flight test comparisons.

The YC-14 prototype’s first flight occurred on August 9, 1976. YC-14 and YC-15 airplane capabilities were evaluated in a flight test program at Edwards Air Force Base in early November 1976. By the end of April 1977, the very successful YC-14 Program had exceeded all its projected goals in terms of flight hours, test conditions accomplished, and data accumulated. The performance goals were met in terms of maneuvering, field length, and touchdown dispersion. Following the flight test program, Boeing demonstrated the YC-14 to U.S. forces in Europe, including an appearance at the Paris Air Show in June. The airplane impressed the crowds at the air show, performing maneuvers formally considered impossible for a medium-sized transport. After the European tour, the YC-14 arrived for a demonstration at Langley Air Force Base on June 18, 1977, where its outstanding STOL capability and crisp maneuvers stunned not only the Air Force observers but many of the NASA-Langley researchers who had participated in USB studies that helped contribute to the design and success of this remarkable airplane.

The YC-14 flight test program ended on August 8, 1977, exactly 1 year after it began. Unfortunately, the anticipated mission of the AMST did not meet with Air Force funding priorities at the end of the flight evaluations (the B-1B bomber was by then the top Air Force priority), and the AMST Program ended. In 1981, the Air Force became interested in another transport, one having less STOL capability but more strategic airlift capability than the AMST YC-14 and YC-15 airplanes. That airplane was ultimately developed to become today’s C-17 transport. The two YC-14 prototype aircraft were placed in storage at the Davis Monthan Air Force Base, and one was later moved to the Pima Air Museum in Tucson, Arizona, where it is displayed next to one of the YC-15 aircraft.

[Soren]

Denmark should've saved its money for purchasing the A400M instead of the C-130's it recently bought. A mistake IMO, but not a huge one as the C-130 still is a good transport a/c.

As for looks, well the A400M looks pretty sexy

I hope it'll be capable of what the C-17 is, which is a challenge.

[Matt308]

A challenge indeed...

C-17
_________________________
Crew: 3: 2 pilots, 1 loadmaster
Capacity:

102 troops or
36 litter and 54 ambulatory patients
Payload: 170,900 lb (77,519 kg) of cargo distributed at max over 18 463L master pallets or a mix of palletized cargo and vehicles
Empty weight: 282,500 lb (128,100 kg)
Max takeoff weight: 585,000 lb (265,350 kg)
Powerplant: 4× Pratt & Whitney F117-PW-100 turbofans, 40,440 lbf (180 kN) each
Fuel capacity: 35,546 US gal (134,556 L)
Performance
Cruise speed: Mach 0.76 (450 knots, 515 mph, 830 km/h)
Range: 2,420 nmi (2,785 mi, 4,482 km)
Service ceiling 45,000 ft (13,716 m)
Max wing loading: 150 lb/ft² (750 kg/m²)
Minimum thrust/weight: 0.277

A400M
________________________________
Crew: 3 or 4 (2 pilots, 3rd optional, 1 loadmaster)
Capacity: 37,000 kg (82,000 lb)
116 fully equipped troops / paratroops
66 stretchers accompanied by 25 medical personnel
Empty weight: 70 tonnes (154,000 lb)
Max takeoff weight: 141 tonnes (310,852 lb)
Total Internal Fuel: 46.7 tonnes (103,000 lb)
Max. Landing Weight: 114 tonnes (251,000 lb)
Max. Payload: 37 tonnes (82,000 lb))
Powerplant: 4× EuroProp International TP400-D6[11] turboprop, 8,250 kW (11,000 hp) each
Performance

Cruise speed: 780 km/h (420 kt,485 mph Mach 0.68 - 0.72)
Initial Cruise Altitude: at MTOW: 9,000 m (29,000 f)
Range: at Max. payload: 3,300 km (1,782 nmi) (long range cruise speed; reserves as per MIL-C-5011A)
Range at 30-tonne payload: 4,800 km (2,592 nmi)
Range at 20-tonne payload: 6,950 km (3,753 nmi))
Ferry range: 9,300 km (5,022 nmi)
Service ceiling 11,300 m (37,000 ft)
Tactical Takeoff Distance: 940 m (3 080 ft) (aircraft weight 100 tonnes, soft field, ISA, sea level)
Tactical Landing Distance: 625 m (2 050 ft) (see above)
Turning Radius (Ground): 28.6 m

C-130J
_________________________________
Crew: 4-6 (at least 2 pilots, crew chief, and 1 loadmaster; additional loadmaster and navigator are usually part of the crew)
Capacity:
92 passengers or
64 airborne troops or
74 litter patients with 2 medical personnel
Payload: 42,000 lb (19,090 kg) including 2-3 Humvees or an M113 Armored Personnel Carrier
Wing area: 1,745 ft² (162.1 m²)
Empty weight: 75,562 lb (34,274 kg)
Useful load: 72,000 lb (33,000 kg)
Max takeoff weight: 155,000 lb (70,305 kg)
Powerplant: 4× Rolls-Royce AE 2100D3 turboprops, 4,637 shp (3,458 kW) each
Performance

Maximum speed: 362 knots (417 mph, 671 km/h)
Cruise speed: 348 knots, 644 km/h (400 mph, 643 km/h)
Range: 2,835 nm (3,262 mi, 5,250 km)
Service ceiling 28,000 ft, 8,540 m (8,615 m)

[Matt308]

Note that basic airlift performance of each is half as you move down the scale of C-17, A400M, C-130J.

So depending upon your mission, each may be perfectly suitable. But the raw airlift comparison between C-17 and A400M is silly. Just as is the A400M vs C-130 is equally silly.

[Soren]

The C-17 is also capable of switching its engines in reverse right upon landing, which looks very impressive. I for one was impressed when I firsthand for the first time saw how short its take off & landing roll was.

Emmidiately after taking off the C-17 can commence a flight attitude I previously thought impossible for such an a/c. And after landing it just reverses into its parking space, which means it requires very little space to operate compared to for example a C-130.

[Matt308]

Soren, you too have seen the high performance take-off and landing o fthe C-17? I have mentioned this many times, but at a local show at McChord AFB, the demonstration was nothing short of draw dropping for an aircraft that large.

[Soren]

Yup, saw it a couple of years back. Really impressive! Took off on a stretch I normally would associate with a high powered Cessna! The take off & landing roll of that a/c is just amazing. And then there's the flight attitude, again am I looking at a transport a/c here ? I think jaw dropping is a good expression Matt!

And then there was the engine reverse, a really nice feature.

Like I said, I was impressed.

[Matt308]

How you managed to get "jaw dropping" from my stupid "draw dropping" typo is beyond me. Another time where my mind and my fingers are not cooperating.

[Soren]

Hey scr*w the typos, as long as we understand each other!