By S. Pradeep

Plane layout 1 (1998) 89—104

It is acknowledged in such a lot flight dynamics texts that the phugoid approximations offer bad estimates whereas the quick interval approximations are exact. The survey during this paper unearths that there are not less than 5 approximations to the phugoid. the level of departure of every of those from the precise price is decided for a reasonably large database representing numerous plane in numerous flight stipulations. it truly is stumbled on that almost all of them are insufficient in predicting the phugoid features appropriately. still, approximations to the phugoid frequency that appear to have remained disregarded are obvious to be exemplary. however, no precious approximation exists for the phugoid damping. With this history, a clean approximation for the phugoid mode is placed forth herein. it truly is derived via equating the coefficients of the fabricated from the quick interval equation (which has been proven to be very actual) and the phugoid equation (as but unknown) to the coefficients of the fourth-order attribute polynomial. the recent approximation is proven to be actual.

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D. MacDonald and his team conducted RCS measurements on two scale models, the returns averaged out as the same for those of the U-2, which were much larger than for the all-metal Gusto 2S, which was itself larger than for Gusto 2A, which incorporated RAM. Three days later the panel communicated its findings to James Killian, the president’s scientific advisor. Bissell called Johnson with the bad news on 26 November, pointing out that actually the two designs compared quite favourably, but the crunch issue had again been RCS, an area where Convair was still clearly ahead.

Trapeze formed a slow wave structure, which induced currents that suppressed the rhombic lobes otherwise generated by the U-2’s wing and tail planform. The sides of the U-2’s fuselage generated a large reflection at some frequencies. Each long wire behaved as though it were a series of separate wires, or dipoles, counteracting the radar signal. With two U-2s dedicated to project Rainbow up at Watertown, flight tests against radars on the Indian Springs AFB range provided mixed results. Trapeze reduced 70MHz returns by 20dB and S-band returns by about 10dB.

Furthermore, it was stipulated that the new design should be powered by two Pratt & Whitney J58 turbojets. Remarkably, in just over two weeks it’d not only decided upon the basic design, but had also considerably modified the FISH radar model into the larger Kingfish configuration, and from 15 August 1959 used it to undertake a series of 70MHz radar tests at Indian Springs AFB – the results of which would turn out to be similar to those achieved by the A-12. They included William Gordon, the Pratt & Whitney Florida general manager, Don Pascal, Norm Cotter, Dick Coar and Ed Esmeier.

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