Sundog said:One vehicle I would love to see you revisit soon with good drawings in the eAPR is the GRM-29.
ucon said:Hi to all!
There was soviet equivalent of Lockheed "Flatbed" transport - "Romb" project in Myasishchev DB.
AeroFranz said:Does the book say how they were going to load it?
flateric said:Cargo was moved from the back under the rear pair of wings on mobile powered multi-wheel platform (that was at the same time carry trough lower structure of the fuselage between its two 'halves'), then positioned below the 'breach' and lifted up via built-in elevators.
Kind of Galaxy cargo floor travelling on its own across the airfield collecting M1s and then mating back with the bird.
Flat-bed transports could airlift outsize military or civilian cargo. This NASA-sponsored Lockheed-Georgia design has a level loading surface close to the ground. Tanks, such as the 118,500 lb. XMI, or other such cargo could roll on and off. In flight, they would be lashed down, and hauled exposed. A half-cylinder pressurized module could adapt the transport for passenger or freight operation. Or containerized cargo could be loaded aboard and covered with a thin cocoon to provide an aerodynamic fairing.
taildragger said:May be I'm missing something but the whole flatbed concept seems flawed to me and I'm surprised it's seen so much study over the years. The possible advantages don't seem to hold water
FLATBED is a unique aircraft configurational concept (derived by Lockheed-Georgia Company) featuring versatility of payloads which are carried on an open cargo floor - there is no fuselage per se. Flatbed can haul containers, passengers in a removable module, or cargoes and vehicles. Large Army vehicles (tanks and bridge launchers) are literally "carried in the open."
Early assessments of the unusual aspects of the Flatbed concept indicated (a) potential problem areas related to specific technical design details and (b) general concerns related to the overall viability of the concept. Hence, a study was undertaken to assess the feasibility, capability, and economic merit of Flatbed. Such a study has
been accomplished through a non-parametric refinement of a point design. Aspects of the study included refinement of the Flatbed configuration and derivation of three reference aircraft (passenger, cargo, and outsize cargo) for purposes of comparison. The study involved smoke flow studies, optimization of a medium sized aircraft for a range of 4815 km (2600 n.mi.), estimation of weights and performance, prediction of acquisition and operating costs, and recommendations for additional areas of technical study.
Refinement of the basic Flatbed concept produced a low-winged vehicle weighing 57209 kg (123,429 Ibs.), optimized for cruise speed for the passenger role at M = 0.82 at 10,688m (35,000 ft.). Features include a pressurized cockpit section internally hinged to pivot to starboard for front-loading of cargo. A Vee tail was determined to present the best compromise of drag and weight. Four engines are mounted on pylons above the wing in order to permit the cargo floor to be as low as possible to the ground (2.12m or 83.5 in.). The cargo floor is fitted with roller-rail-track guide systems, powered rollers, and compatible fittings on the passenger and pressurized cargo modules.
Study results indicate the Flatbed concept to be viable from a technical viewpoint. The only unusual structural area relates to provision for adequate stiffness in the fuselage aftbody. In aerodynamic terms, the design process has produced a relatively smaller aircraft to accomplish the specified missions because of a lighter weight fuselage and
lesser systems weight.
High altitude cruise speed with either unpressurized or pressurized containers is M = 0.82, which is comparable to conventional passenger type airlines hauling cargo and cargo aircraft such as the C-141 or C-5A. The cruise speeds with outsize military vehicles are above M = 0.5 with ranges compatible with the longest distance required without refueling, 4473m (2415 n<,mi.).
It is specifically noted that Flatbed with the passenger module consumes 11 percent more fuel than a conventional passenger airliner and 14 percent more than an outsize military cargo aircraft. Conversely, Flatbed consumes 6 percent less fuel carrying unpressurized cargo in a cocoon and 8 percent less carrying pressurized cargo — relative to conventionally configured cargo aircraft.
In loadability terms, the 2.12m (83.5 in.) cargo floor height of the Flatbed design is sufficiently low to accommodate loading of containers and roll-on, roll-off of vehicle(s). The lack of dimensional restrictions permits use of shorter and lesser weight ramps (17 degrees vis-a-vis 11 degrees) in comparison with conventional designs. Cargo loading, tie-down, and guide systems appear to be adequate since they are of conventional design. In economic terms, the Flatbed backbone acquisition costs are lower than any of the reference aircraft,, This results, partially, because the RDT&E costs are about 3 percent lower than a comparable conventional cargo airplane, 18 percent lower than an
outsize cargo airplane, and 9 percent lower than a conventional passenger airplane. In the latter case, however, the added RDT&E costs of the passenger module net the Flatbed passenger version about 25 percent higher. Unit production costs of Flatbed, for a comparable production run, are about $1 million lower than a conventional cargo airplane, and $2 million lower than a passenger airliner.
Flatbed DOC's vary between 8 and 26 percent lower than conventional cargo airplanes as a function of production run. (Three cases of varying production runs of Flatbed and the reference airplanes were specified for analysis.) Military life cycle costs are over 30 percent lower than a conventional outsize aircraft. The passenger seat-mile costs
are essentially equal to a conventional airplane except for QC operations which are about 8 percent lower for Flatbed.
Recommendations for additional studies include wind-tunnel tests (particularly of vehicular hauls), possible use of a metal matrix aftbody, and both military and commercial cargo airline operations in realistic scenarios.