Flight test results for the Digital Integrated Automatic Landing Systems (DIALS): A modern control full-state feedback design

The Digital Integrated Automatic Landing System (DIALS) is discussed. The DIALS is a modern control theory design performing all the maneuver modes associated with current autoland systems: localizer capture and track, glideslope capture and track, decrab, and flare. The DIALS is an integrated full-state feedback system which was designed using direct-digital methods. The DIALS uses standard aircraft sensors and the digital Microwave Landing System (MLS) signals as measurements. It consists of separately designed longitudinal and lateral channels although some cross-coupling variables are fed between channels for improved state estimates and trajectory commands. The DIALS was implemented within the 16-bit fixed-point flight computers of the ATOPS research aircraft, a small twin jet commercial transport outfitted with a second research cockpit and a fly-by-wire system. The DIALS became the first modern control theory design to be successfully flight tested on a commercial-type aircraft. Flight tests were conducted in late 1981 using a wide coverage MLS on Runway 22 at Wallops Flight Center. All the modes were exercised including the capture and track of steep glidescopes up to 5 degrees

Reconfigurable multivariable control law for commercial airplane using a direct digital output feedback design

The ability of a pilot to reconfigure the control surfaces on an airplane after a failure, allowing the airplane to recover to a safe condition for landing, becomes more difficult with increasing airplane complexity. Techniques are needed to stabilize and control the airplane immediately after a failure, allowing the pilot time to make longer range decisions. This paper shows a design of a discrete multivariable control law using four controls for the longitudinal channel of a B-737. Single control element failures are allowed in three of the four controls. The four controls design and failure cases are analyzed by means of a digital airplane simulation, with regard to tracking capability and ability to overcome severe windshear and turbulence during the aproach and landing phase of flight

CONSTITUTIONAL LAW-POWER OF STATE TO DISCRIMINATE AGAINST FEDERAL GOVERNMENT BY TESTAMENTARY TRANSFER STATUTE

Decedent, domiciled in California, made a testamentary gift to the United States. By an interpretation of the state probate code, the California Supreme Court held the gift invalid and directed distribution to decedent\u27s heirs. The United States asserted unconstitutional interference with the federal government\u27s power to receive gifts. On appeal to the United States Supreme Court, held, affirmed. The California Probate Code did not violate the supremacy clause of the Constitution, and no unconstitutional discrimination was effected against the federal government thereby, even though the statute allows testamentary gifts by state domiciliaries to the state and prohibits testamentary gifts to the United States. United States v. Burnison, 339 U.S. 87, 70 S.Ct. 503 (1950)

Differential GPS for air transport: Status

The presentation presents background on what the Global Navigation Satellite System (GNSS) is, desired target dates for initial GNSS capabilities for aircraft operations, and a description of differential GPS (Global Positioning System). The presentation also presents an overview of joint flight tests conducted by LaRC and Honeywell on an integrated differential GPS/inertial reference unit (IRU) navigation system. The overview describes the system tested and the results of the flight tests. The last item presented is an overview of a current grant with Ohio University from LaRC which has the goal of developing a precision DGPS navigation system based on interferometry techniques. The fundamentals of GPS interferometry are presented and its application to determine attitude and heading and precision positioning are shown. The presentation concludes with the current status of the grant

Implementation and flight tests for the Digital Integrated Automatic Landing System (DIALS). Part 1: Flight software equations, flight test description and selected flight test data

Five flight tests of the Digital Automated Landing System (DIALS) were conducted on the Advanced Transport Operating Systems (ATOPS) Transportation Research Vehicle (TSRV) -- a modified Boeing 737 aircraft for advanced controls and displays research. These flight tests were conducted at NASA's Wallops Flight Center using the microwave landing system (MLS) installation on runway 22. This report describes the flight software equations of the DIALS which was designed using modern control theory direct-digital design methods and employed a constant gain Kalman filter. Selected flight test performance data is presented for localizer (runway centerline) capture and track at various intercept angles, for glideslope capture and track of 3, 4.5, and 5 degree glideslopes, for the decrab maneuver, and for the flare maneuver. Data is also presented to illustrate the system performance in the presence of cross, gust, and shear winds. The mean and standard deviation of the peak position errors for localizer capture were, respectively, 24 feet and 26 feet. For mild wind conditions, glideslope and localizer tracking position errors did not exceed, respectively, 5 and 20 feet. For gusty wind conditions (8 to 10 knots), these errors were, respectively, 10 and 30 feet. Ten hands off automatic lands were performed. The standard deviation of the touchdown position and velocity errors from the mean values were, respectively, 244 feet and 0.7 feet/sec

Vertical Navigation Control Laws and Logic for the Next Generation Air Transportation System

A vertical navigation (VNAV) outer-loop control system was developed to capture and track the vertical path segments of energy-efficient trajectories that are being developed for high-density operations in the evolving Next Generation Air Transportation System (NextGen). The VNAV control system has a speed-on-elevator control mode to pitch the aircraft for tracking a calibrated airspeed (CAS) or Mach number profile and a path control mode for tracking the VNAV altitude profile. Mode control logic was developed for engagement of either the speed or path control modes. The control system will level the aircraft to prevent it from flying through a constraint altitude. A stability analysis was performed that showed that the gain and phase margins of the VNAV control system significantly exceeded the design gain and phase margins. The system performance was assessed using a six-deg-of-freedom non-linear transport aircraft simulation and the performance is illustrated with time-history plots of recorded simulation data

FEDERAL PROCEDURE-PROPER VENUE IN PATENT INFRINGEMENT ACTION AGAINST CORPORATION

Plaintiffs brought an action for patent infringement against defendant corporation in the Federal District Court for the Southern Division of California, alleging only defendant\u27s residence within the district. Defendant moved to dismiss the complaint on the ground that defendant, being a Delaware corporation, did not reside within the district, thus rendering the venue defective. Plaintiffs replied that the word resides, as used in the patent infringement venue section of the code, which states that any civil action for patent infringement may be brought in the judicial district where the defendant resides, or where the defendant has committed acts of infringement and has a regular and established place of business, is controlled by the definition of residence in the general venue provision for suits against corporations. The general provision states that the judicial district wherein the corporation is incorporated or licensed to do business or is doing business . . . shall be regarded as the residence of such corporation for venue purposes. Held, the patent infringement venue provision being the exclusive venue provision controlling such suits, defendant does not reside within the district since it is not an inhabitant thereof. The definition of residence in the general venue provision does not control. Venue within the district is therefore improper and the action must be transferred. Gulf Research and Development Co. v. Schlumberger Well Sitrveying Corp., (D.C. Cal. 1950) 92 F. Supp. 16

PATENTS-EXCLUSIVE LICENSES-LICENSOR AND LICENSEE RELATIONSHIP- LLICENSEE\u27S OBLIGATIONS

Patent licensing is today, as always, a very significant part of patent law. Since royalty licenses allow a patentee to realize pecuniary benefits from his invention without yielding ownership, as he would by an assignment, they are especially attractive to an inventor who anticipates considerable commercial success for his contribution, and who does not desire to lose all control of the invention for a lump sum, the adequacy of which must be, at best, speculative. From the licensee\u27s standpoint, it is usually advantageous to be free of competition from others also operating under the same patent monopoly, at least within a limited area, and consequently an exclusive license is to his advantage. There is no question but that an exclusive license presents various advantages to both parties, and the proportion of patent licenses which are of an exclusive nature is therefore considerable. A peculiar relationship, however, arises between patentees and their exclusive licensees, which does not arise in the case of an ordinary nonexclusive license, and which entails certain implied obligations on the part of the exclusive licensee. The patent licensee\u27s obligations, while established in other fields of contract-license law, have recently been questioned, and will undoubtedly be the storm center of conflicting policies for some time to come. The subject is therefore considered to be of interest, and it is the purpose of this comment to summarize the position of the courts on the matter as it has been expressed up to the present time

Guidance and control system research for improved terminal area operations

Several guidance and control system research and development activities aimed at improving the operational capabilities of commercial aircraft in the terminal area are described. The guidance and control systems were designed to improve the capacity and efficiency of terminal area operations, enhance the approach and landing capability of aircraft in adverse weather conditions, and reduce the impact of aircraft noise perceived on the ground. Specific performance features include the ability to capture and track steep glideslopes, use short final approaches, perform flares with reduced longitudinal touchdown dispersion and execute high speed runway rollout and turnoff. Results obtained from simulation studies or flight tests are shown for each of the algorithms

CONTRACTS-RIGHTS OF THIRD PARTY BENEFICIARY-EFFECT OF MICHIGAN BENEFICIARY CONTRACT STATUTE

On agreement to make mutual wills, Stephen and his two sisters entered into an agreement whereby the sisters agreed to will to Stephen, or in event Stephen predeceased them, to his wife, all property which they should receive from their father. Stephen did predecease the sisters, whereupon they executed new wills with no provision for Stephen\u27s widow. Upon death of the last sister, the widow\u27s bill for specific performance of the agreement was dismissed by the circuit court. In affirming on appeal, the Michigan Supreme Court held that the agreement as to Stephen and all other persons except the sisters being without consideration, the sisters were each bound only at the option of the other while both lived, and each could revoke with the other\u27s permission. Execution of the new wills showed a common purpose to do away with all agreements to leave plaintiff anything, the will of each sister amounting to a revocation of the agreement, to which the consent of the other sister is fairly to be inferred in the absence in the contract of any stipulation requiring revocation to be in writing. Rose v. Southern Michigan National Bank of Coldwater, 328 Mich. 639, 44 N.W. (2d) 192 (1950)