FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Atlas
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
1962
1962 - 1348.PDF
174 The Dassault Balzac V 001 at Melun immediately before starting ground running. A temporary fixed undercarriage is fitted Balzac VTOL FORERUNNER OF THE MIRAGE II IY the time these words appear, Dassault should have begun practical trials with the Balzac V001, announced in Flight International last week, in preparation for the Mirage IIIV VTOL strike fighter. Dassault, Sud-Aviation and Rolls-Royce are thus entering the "proof of the pudding" stage on what will be the first operational aircraft to rely on a composite powerplant for VTOL and supersonic performance. Because the Mirage HIV also fits—and has been submitted for—the NATO NBMR-3 specifica tion, the sales prospects are hot, to say the least, and Dassault took the unusual step of holding a public roll-out ceremony and exhibit ing the Balzac before it had begun its trials. The NATO bid involves a partnership between Dassault, Sud, British Aircraft Corporation and Boeing, with engine and control contributions from Rolls-Royce, Pratt & Whitney and SNECMA; but it must not be forgotten that the Mirage HIV was originally specified and has been ordered in prototype form by the Armce de l'Air, and is due to enter service in 1966—whatever NATO may decide. It now appears that the NATO BMR-3 choice has been narrowed down to the Mirage IIIV and the Hawker P. 1154, and Dassault are deploying all their forces to extol the virtues of the composite formula against the single-engined formula, while "playing fair" to the extent of not directly "knocking" the 1154. There seems to be some impasse in the situation, because the French will almost inevitably continue their own national programme to produce the Mirage IIIV, while Britain has signified an intention to develop the 1154 for the RAF and Royal Navy, making use of the American funds which have been, and are being, contributed to the development of the Bristol Siddeley BS.100 vectored-thrust engine. Questioned about this rivalry, M Vallieres, director of Dassault, told Flight International that it was mainly a question of timing— the Mirage IIIV was the only aircraft which could be in service in 1966. "Show me," he said, "a BS.100 or an 1154 airframe with proven Mach 2 capability. We have both the engines and a proven Mach 2 airframe." There are numerous points of discussion between the multi engined and single-engined VTOL formula, most of which can easily be turned to the advantage of either type. The issue is slightly clouded, too, by the very rapid success of the Hawker P. 1127 and the rather lengthier development time with the SC.l. But both the 1154 and the Mirage IIIV are very much larger aircraft, designed for much higher speeds, more elaborate weapon systems and greater operational radius. With the concomitant increase in size, econo mic and other factors change radically, and Dassault can put for ward some cogent arguments in favour of nine engines as opposed to one. Beyond an operational radius in the region of 150 miles, the s.f.c. of the appropriate single engine becomes notably worse than that of the better-scaled propulsion engine of the multi engined fighter. Moreover, any improvement in the s.f.c. of the large engine would also be applicable to the propulsion engine and would therefore only serve to accentuate the contrast. Both the French and NATO specifications call for a considerable range. Dassault say that an engine change for the single-engined aircraft req 'ires removal of the whole wing, but we have been taking the complete rear fuselage and tail off fighters for years. Of course, the thrust engine can be removed from the Mirage IIIV without detaching the tail surfaces, but are the lift engines equally simple to remove? Dassault suggest duct losses in the "elbowed" jet pipes of the BS.100. The engine has to occupy the e.g. of the air craft : how is the variable load to be located and controlled to keep the e.g. constant? Can a single intake really be made to serve from zero speed to Mach 2? What about scrubbing and buffeting from the four nozzles ? Dassault claim that the Mirage IIIV will carry a greater payload. The intrinsic reliability of the on/off lift engines is further improved by their needing only a simple fuel control to allow idling and full thrust at low altitude. If one of them fails, the symmetrical engine on the other side of the lift battery can be automatically cut. wjth conseauent reduction of take-off gradient, but bleed air supply is not interrupted and full control remains—at least for long enough to allow the pilot to eject safely if the worst should come to the worst. Lift, thrust and bleed for control do not rely on a single engine. Less logically, Dassault remark that, if one engine were safe, the big jet airliners would be single-engined. M Cabriere, technical director of Dassault, pulled one out of the bag. Computer studies had shown, unexpectedly, that the nine- engined powerplant was indeed lighter than the equivalent single- engine system. Moreover, the single engine must have a thrust of about 35,0001b and therefore be more advanced than anything at present available, whereas there were no development problems in the small lift engine, only its weight had to be reduced. The big engine was also much harder to stretch. Standard lift engines were likely to be used for a number of different aircraft, thus greatly expanding production and lowering costs. The large engine was unlikely to prove amenable to other designs. The Fokker Republic Alliance, which is designed round the BS.100, was not mentioned. The argument goes to and fro, the most interesting feature being that there does not at the moment seem to be a completely clear-cut technical advantage to either side. The French are bitter at the thought that American support for the 1154 may force its adoption by NATO, just as, they say, it forced the adoption of the Fiat G.91 in the LWSF competition some years ago. Perhaps the most cogent argument on the French side is still that the Mirage III V is—they say—the only type which can enter service in 1966. But to return to the serious business of the Balzac V 001, it should first be noted that the name Balzac was chosen because there is a well-known French cinema advertisement which concludes by exhorting the audience to telephone Balzac 0001. The Mirage 001 prototype airframe was accordingly dubbed Balzac 001, and the V denotes its new role as a VTOL test-bed. In fact, all that remains of the original 001 is the fin and wings, the first to exceed Mach 2. Although the main fuselage frames and cockpit section have been retained, the overall structure is entirely new and was made by Sud. A single Bristol Siddeley Orpheus 3 thrust engine, which will eventually allow high-subsonic level speeds, is mounted in the tail with intake ducts arranged to unite and pass between the lift engine batteries, low down in the fuselage. Small intakes with fixed shock cones are fitted. The eight Rolls-Royce RB.108 lift engines are disposed in pairs
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
