The paper descr ibes a compo nent-based compu tationa l envir onment for imple menting aircr aft desig n probl ems. The envir onment is condu cive to takin g advanta ge of the paral lelisms inher ent in the probl em and distr ibute the indiv idual disci plines on machi nes most appro priate to their needs while insul ating the developer and the user from the compl exity of the underly ing commu nications const ructs. Commo n Objec t Reque st Broke r Archi tecture and Java progr amming langu age are used to encap sulate disci pline codes as "obje cts". An inter face file ident ifies all the infor mation neede d by a user of the objec t. Legac y codes are "wrap ped" using Java' s nativ e inter face metho dology and each such code is calle d from a modul e which impleme nts the servi ces of the objec t. A serve r progr am ties the imple mentation to the inter face. Data and file manageme nt are accom plished using Java' s datab ase connecti vity to acces s a comme rcial relat ional datab ase manag ement syste m. Java' s Beans Devel opment Kit is used to imple ment the disci plines and sub-t asks as reusable compo nents that provi de a graph ical inter face for user input as well as facil itate inter active and visua l objec t conne ctivity and probl em execu tion progr ess monit oring. This appro ach has been used to implement a simpl e aircr aft desig n optimizat ion probl em, the analy sis part of a large scale high speed civil trans port desig n optim ization probl em, and a stand alone aerod ynamic optim izer.

This paper will focus on the practical incorporation of "tunnel-in-the-sky" and synthetic vision concepts from a flight simulation software perspective. Piloted, rotorcraft flight simulation analysis of these concepts has been an ongoing activity in the Boeing Flight Simulation Laboratory in Philadelphia. The theoretical basis and advantages in augmenting pilot situational awareness was well presented by Robert R. Wilkins. 1 In this paper, the technical issues involving design architecture, visual perception and verification of these concepts will be addressed. Some of these issues include architecture optimization for future enhancements, tunnel correlation and conformality with out-the-window terrain, validation of pilot visual cues and integration of tunnel and synthetic vision concepts. Future work and directions will also be discussed, for both tunnel symbology-based guidance and synthetic vision situational awareness, in the context of practical realization in a rotorcraft flight simulation environment.acceleration of gravity T H = tunnel height -ft H B = barometric altitude -ft T HDG = tunnel heading -deg H P = pressure altitude -ft T T = tunnel turn radius -deg F F = function factor -normalized T W = tunnel width -ft F pv Δθ = flight path vector delta pitch -deg T Y = tunnel yaw -deg F pv Δψ = flight path vector delta yaw -deg V A = true airspeed -kn K PHI = gain on bank angle V C = calibrated airspeed -kn K TAE = gain on track angle V G = groundspeed -kn K XTD = gain on cross track deviation V R = reference speed -kn N G = north cig coordinate -ft V RC = vertical velocity -ft/s N Xwp = next waypoint index -unitless X L = aircraft longitude -€ ˙ P O = push-over rate -deg (deg/min/s) S L = tunnel segment length -feet XTD = aircraft cross track S S = tunnel segment spacing -feet deviation -perpindicular TAE = aircraft track angle error -difference distance from aircraft between tunnel course and aircraft center of gravity to tunnel ground track angle -deg ground track -ft T A = tunnel altitude -ft Y L = aircraft latitude -(deg/min/s) € ˙ φ = aircraft roll rate -deg/s Z B = tunnel flight profile height -ft θ = pitch angle -deg BRYCHCY ET AL. 240 ΔP Y = power cue vertical offset -in. (display) ϑ (5) = fifth order polynomial ΔT = simulation execution time -s quantity -unitless ΔT C = command-frame time -s ψ = aircraft heading -deg ΔT F = lead-frame time -s € ˙ ψ = aircraft yaw rate deg/s ΔT L = look-ahead time -s ψ M = aircraft magnetic heading -Δθ Y = pitch cue vertical offset -in. (display) deg φ = aircraft bank angle -deg ψ T = aircraft true heading -deg