Download or read book Preliminary Airworthiness Evaluation of the OH 58C with 3 Axis Stability Control Augmentation System and Improved Tail Rotor System written by M. L. Hanks and published by . This book was released on 1983 with total page 177 pages. Available in PDF, EPUB and Kindle. Book excerpt: This preliminary airworthiness evaluation was conducted on an OH-58C helicopter configured with a 3-axis digital stability control augmentation system (SCAS) and an improved tail rotor. Additional testing on the standard OH-58C equipped with the 3-axis SCAS was required in response to questions which surfaced during working sessions of the Joint Special Study Group investigating 0H-58 loss of tail rotor effectiveness. Testing was accomplished at Arlington, TX (elevation 630 feet), Leadville, CO (elev. 9927 feet) and Alamosa, CO (elev. 7535 feet). Test time totaled 44.2 productive flight test hours. With the improved tail rotor, adequate directional control margins were available for flight at all azimuths out to the wind limits (35 KTAS sideward and 30 KTAS rearward) of the aircraft at density altitudes up through 11,000 feet for a gross weight of 3,040 lb. The overall handling qualities of the OH-58C helicopter equipped with a 3-axis digital SCAS in either tail rotor configuration were significantly improved over the unaugmented aircraft configuration except as stated in the report. TWo handling quality deficiencies were noted.
Download or read book Preliminary Airworthiness Evaluation OH 58C Helicopter Configured with a Mast Mounted Sight written by and published by . This book was released on 1980 with total page 77 pages. Available in PDF, EPUB and Kindle. Book excerpt: The United States Army Aviation Engineering Flight Activity conducted a preliminary airworthiness evaluation of the OH-58C helicopter with a mast mounted sight and Bell Helicopter, Textron Model 570B three-axis stability and control augmentation system. The evaluation was completed in two phases at the Bell Helicopter Engineering Flight Research Center, Arlington, Texas (elevation 630 ft). Phase 1 consisted of an evaluation of a dummy mast mounted sight installed on an instrumented helicopter. This phase was conducted between 15 and 30 October 1980 and 12 flights were flown for a total of 9.7 productive hours. Phase 2 consisted of a qualitative assessment of the handling qualities of the OH-58C configured with the operational Rockwell International sight. This phase was completed on 30 November 1980 in two flights for 1.5 productive test flight hours. The overall evaluation indicated that the OH-58C handling qualities with installed mast mounted sight and three-axis SCAS were satisfactory within the flight envelope tested. No problems were noted that will prevent future operational testing of the system. The addition of a three-axis SCAS significantly improved the OH-58C handling qualities, particularly in low speed flight, and is an enhancing characteristic.
Download or read book Loss of Tail Rotor Effectiveness Evaluation of the OH 58C Helicopter with Directional SAS Stability Augmentation System written by and published by . This book was released on 1988 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt: The U.S. Army Aviation Engineering Flight Activity conducted a loss of tail rotor effectiveness (LTE) evaluation of the JOH-58C. The JOH-58C configuration includes a directional stability augmentation system (SAS) manufactured by the SFENA Corporation, the larger-diameter tail rotor, and the improved engine fuel control. Handling qualities were evaluated at Edwards AFB, California (elevation 2302 feet). Twenty-eight flights were conducted for a total of 26.7 productive flight test hours. Primary emphasis of the evaluation was to evaluate the handling qualities of the JOH-58C in comparison to the standard OH-58C. The limited authority SAS (7% of full control travel) will not significantly reduce the conditions conducive to LTE. The overall handling qualities of the JOH-58were moderately improved compared to the standard OH-58C. The concept of a SAS which damps uncommanded yaw rates demonstrated potential for reducing conditions conducive to LTE. However, the limited authority SAS saturated at small yaw rates (deg/sec) and did not significantly reduce the characteristic high yaw rates and moderate yaw attitude excursions observed in the JOH-58C. The JOH-58C exhibited moderate pitch, roll, and yaw excursions at 15 to 25 KTAS in azimuths from 240 degrees clockwise to 280 degrees. This characteristic was a shortcoming, upgraded from a deficiency for the standard OH-58C. Five additional shortcomings, of which four were previously identified in the standard OH-58C, were noted.
Download or read book Government Reports Announcements Index written by and published by . This book was released on 1985 with total page 924 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Airworthiness and Flight Characteristics of the JOH 58C OH 58X Surrogate Helicopter written by James L. Webre and published by . This book was released on 1986 with total page 133 pages. Available in PDF, EPUB and Kindle. Book excerpt: The US Army Aviation Engineering Flight Activity conducted a limited airworthiness and flight characteristics test of the JOH-58C Light Combat Helicopter (LCH) from 27 June through 23 October 1985. The JOH-58C LCH configuration includes a stability augmentation system manufactured by the SFENA Corporation and a larger-diameter tail rotor. Handling qualities were evaluated at test sites from near sea level (488 feet) to 9980 feet. A total of 49 flights were conducted for a total of 34.6 productive flight test hours. Primary emphasis during the evaluation was placed on evaluating the handling qualities of the JOH-58C in comparison to the standard OH-58C. The overall handling qualities of the JOH-58C were significantly improved as compared to the standard OH-58C. The JOH-58C exhibited less than 10% longitudinal control margin in rearward flight at speeds of approximately 17 knots and above at azimuths between 180 and 210 degrees. This characteristic is a deficiency. The pitch, roll and yaw excursions during low speed flight of the JOH-58C are significantly reduced as compared to the standard OH-58C. These handling qualities characteristics, which were a deficiency in the OH-58C, have been improved shortcomings or were eliminated under the conditions tested in the JOH-58C. Two additional shortcomings were identified in maneuvering flight.
Download or read book Handling Qualities Evaluation of the OH 58A Helicopter Incorporating the Model 570B Three axis Stability and Control Augumentation System written by Raymond B. Smith and published by . This book was released on 1973 with total page 90 pages. Available in PDF, EPUB and Kindle. Book excerpt: A limited handling qualities evaluation of the OH-58A helicopter with a Bell Helicopter Model 570B three-axis stability and control augmentation system installed was conducted to determine its capability to perform instrument flight. Testing was performed by the US Army Aviation Systems Test Activity at Edwards Air Force Base, California. The testing consisted of 25 productive flight hours and was conducted from September through November 1972. The evaluation revealed significant improvements in the aircraft handling qualities with the addition of the augmentation system. The most significant enhancing characteristics provided by the equipment were: (1) increased damping of the lateral-directional oscillation (Dutch roll), (2) improvement of aircraft spiral stability from neutral to convergent, and (3) reduction in pilot effort required to maintain trim flight conditions. This evaluation was of limited scope, and primarily addressed handling qualities. It did not provide a basis to qualify the aircraft for instrument flight.
Download or read book Government Reports Annual Index written by and published by . This book was released on 1985 with total page 968 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1981 with total page 1370 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
Download or read book Handling Qualities Evaluation OH 58A Helicopter Incorporating a Ministab 3 axis Stability Augmentation System written by Edward E. Bailes and published by . This book was released on 1975 with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt: A limited handling qualities evaluation of the OH-58A helicopter incorporating the SFENA 3-axis stability augmentation system called Ministab was performed by the United States Army Aviation Engineering Flight Activity at Edwards Air Force Base, California. The system identified as the SFENA Ministab stability augmentation system was manufactured by the Societe Francaise d'Equipements pour la Navigation Aerienne (SFENA) of France and made available for test by Kaiser Aerospace and Electronics Corporation of Palo Alto, California, who also installed and maintained the system during testing. The testing consisted of 11.2 productive flight hours and was conducted from 20 July through 24 August 1974. This evaluation was of limited scope and consisted of both quantitative data and qualitative pilot comments. The test results show significant improvements in the aircraft handling qualities with the addition of Ministab.
Download or read book Preliminary Airworthiness Evaluation OH 58C Helicopter written by and published by . This book was released on 1978 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt: The United States Army Aviation Engineering Flight Activity conducted a Preliminary Airworthiness Evaluation of the OH-58C helicopter from 21 February through 4 March 1978 at Arlington, Texas. Eighteen flights consisting of 14.7 hours of productive flight test time were flown while conducting a limited handling qualities evaluation of the aircraft. Testing was conducted primary at maximum gross weight (3200 pounds) and aft center of gravity (fuselage station 112) conditions. The possibility of inadvertent activation of the night vision goggle switch located on the pilot cyclic control grip was identified as a deficiency. Activation of this switch during day flight rendered the warning and caution lights unreadable. The most significant difference in flying qualities between the OH-58C and the OH-58A was pitch-up tendency at cruise airspeed and aft center of gravity, which is a shortcoming. Insufficient left directional control in right sideward flight, excessive yaw oscillations in left sideward flight between 15 and 39 knots true airspeed, and excessive pitch and yaw oscillations in rearward flight are also shortcomings. Eight additional shortcomings were noted. (Author).
Download or read book Aeronautical Engineering written by and published by . This book was released on 1982 with total page 748 pages. Available in PDF, EPUB and Kindle. Book excerpt: A selection of annotated references to unclassified reports and journal articles that were introduced into the NASA scientific and technical information system and announced in Scientific and technical aerospace reports (STAR) and International aerospace abstracts (IAA).
Download or read book Government Reports Annual Index Keyword A L written by and published by . This book was released on 1985 with total page 976 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Combined Preliminary Airworthiness Evaluation and Airworthiness and Flight Characteristics Evaluation of the UH 1H with Preproduction Hub Spring and Composite Main Rotor Blades Installed written by Gary L. Skinner and published by . This book was released on 1988 with total page 53 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Army has incorporated a main rotor hub spring on the UH-1H helicopter designed to reduce large main rotor flapping angles which occur during some flight maneuvers. Composite main rotor blades (CMRB), also incorporated, are intended to increase performance and to improve reliability and survivability of the UH-1H. A preliminary airworthiness evaluation was conducted to determine suitability of the combined preproduction CMRB and hub spring configuration for compliance with the CMRB Critical Item Development Specification (CIDS). Due to high vibration characteristics and the occurrence of cyclic control feedback contributing to loss of aircraft control associated with CMRB, additional testing was conducted for comparison with standard metal main rotor blades (STD) and composite main rotor blades constructed with production tooling (PROD CMRB). Flight testing was evaluated under a variety of operating conditions from field elevations of 2302 ft to 9980 ft. Some improvement was noted in out-of-ground effect hover performance with PROD CMRB compared to CMRB, while level flight performance of the CMRB and PROD CMRB was not significantly different. Performance improved for the PROD CMRB compared to STD, but did not meet CIDS requirements. Handling qualities are similar for CMRB and PROD CMRB, and deteriorated when compared to STD with regard to maneuvering characteristics and main rotor speed control during autorotation. (edc).
Download or read book NASA SP written by and published by . This book was released on 1982 with total page 760 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Preliminary Airworthiness Evaluation of UH 60A with an Improved Airspeed System written by M. L. Hanks and published by . This book was released on 1983 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt: The United States Army Aviation Engineering Flight Activity supported a contractor engineering effort to correct the nose-down pitch-over during takeoff and the large, variable position error in the low-speed flight regime of the UH-60A (Black Hawk) helicopter. A Preliminary Airworthiness Evaluation was then conducted with the improved airspeed and stabilator systems in their final configuration as defined by the contractor. Handling qualities and airspeed system characteristics were evaluated for two modified overhead and one nose probe configuration. In addition, airspeed system tests were conducted on a second nose probe configuration. Four shortcomings applicable to the modified overhead probe systems were identified as follows: (1) the annoying longitudinal control, stabilator angle, and indicated airspeed reversals resulting in pitch attitude oscillations during takeoff (upgraded from a deficiency in the standard production aircraft); (2) the high pilot workload required to maintain precise airspeed during transitions to high power, low airspeed climbs; (3) the large, variable airspeed position errors; and (4) unreliable airspeed indications in low airspeed, high power climbs. For the modified overhead probe systems the following should be accomplished: (1) evaluate the proposed installation on the External Stores Support System UH-60 helicopter, and (2) evaluate the proposed installation on an extremely light gross weight UH-60 helicopter.
Download or read book Preliminary Airworthiness Evaluation of the UH 60A with Advanced Digital Optical Control System ADOCS written by Gary L. Bender and published by . This book was released on 1987 with total page 57 pages. Available in PDF, EPUB and Kindle. Book excerpt: The (ADOCS) is being developed on a UH-60A helicopter by the Boeing Vertol Co. to demonstrate the feasibility of a digital optical control system. The U.S. Army Aviation Engineering Flight Activity conducted a Preliminary Airworthiness Evaluation of ADOCS installed on a UH-60A aircraft to evaluate the handling qualities and to provide data for issuance of an airworthiness release for a demonstration of the system to the army aviation community through a guest pilot program. The ADOCS consists of a Primary Flight Control System, which incorporates limited-displacement side-arm controllers for pilot inputs (right-side pilot station only), and an Automatic Flight Control System (AFCS) which is used to augment the basic UH-60A stability. Displacement of the controllers is measured and transmitted optically to digital flight control processors where the control commands are summed with the AFCS commands and sent to the rotor control actuators. The evaluation was conducted at the BV Flight Test Center at Wilmington, Delaware between 25 March and 9 April, 1987 and consisted of 9 flights comprising 17.5 hours (14.9 productive hours). Tests included handling qualities, simulated system failures, and mission maneuvers. Three enhancing characteristics were found: (1) the ease in rolling to and maintaining a desired bank angle; (2) the capability to maintain hands-off stabilized hover with all selectable modes engaged, and; (3) the capability of the barometric altitude hold mode to maintain altitude during simulated instrument flight tasks.
Download or read book Airworthiness and Flight Characteristics Evaluation OH 58C Interim Scout Helicopter written by and published by . This book was released on 1979 with total page 205 pages. Available in PDF, EPUB and Kindle. Book excerpt: The United States Army Aviation Engineering Activity conducted an airworthiness and flight characteristics evaluation of the OH-58C Interim Scout helicopter. Performance, handling qualities, and vibration characteristics were evaluated to provide engineering test data for use in the OH-58C Operator's Manual and to detect any aircraft deficiencies or shortcomings. The OH-58C was tested at Edwards Air Force Base, California (elevation 2302 feet), and alternate test site elevations of 4120, and 9980 feet. A total of 97 flights were conducted for a total of 123.5 flight hours. Due to the more powerful T63- A-720 engine installed in the helicopter, the hover and takeoff capability at heavy gross weights and high altitudes and the forward flight climb performance of the OH-58C is significantly improved over the OH-58A. Performance in terms of power required and fuel flow is slightly degraded when compared to the OH-58A at similar gross weights and altitudes and in general did not meet the estimates of the detail specification for the OH-58C. The handling qualities and vibrations of the OH-58C are similar to the OH-58A when operating at similar gross weights and altitudes. Three handling qualities deficiencies relative to the low speed flight characteristics were identified.
