Browse Topic: Regulations
This specification establishes the requirements for brush plating of cadmium by electrodeposition.
In the last years, new rotorcraft configurations have increased the attention among industries, through which the tiltrotor one due to its capability of combining both rotorcraft and aircraft advantages. However, there are situations where the vertical take-off mode could be enhanced in hard environmental and flight conditions. Therefore, to address this challenge, this work aims to develop a methodology to characterize a roll take-off model for a general tiltrotor configuration in such situations. By combining the integration of the equation of motion and geometrical assumptions, the runway distance is determined for an acceptable range of nacelle tilting angles. The process is developed by meeting the requirements defined by the regulations, combining the aircraft certification standards (CS23 and CS25) with the available tiltrotor certification basis from the FAA project #TC3419RC-R. Following the Nominal application, a sensitivity analysis is carried out, which studies the main effects on the results by varying one variable at a time in terms of weight, wing-loading, and disk-loading.
Aircraft development efforts are rapidly shifting toward the use of distributed electric propulsion. As the industry moves along a path to full electrification, hybrid propulsion systems will be increasingly employed where battery technology does not support a fully electric design. The fuel systems in new aircraft designs can be challenging, and the existing regulatory framework may not be capable of dealing with unique aircraft designs that do not neatly fit within existing categories. This presents a challenge to aircraft designers. Fuel remains essential to the propulsion system, and an optimal, yet simple fuel system will be necessary to leave room in the design trade space for more challenging and risky functions. Understanding the certification requirements and having a basic knowledge of the tradeoffs in fuel measurement accuracy are the key elements necessary to support a systems approach to optimizing a fuel measurement subsystem.
U.S. Army Aviation has extensively managed critical aircraft components based on the technical requirements and methods outlined in AMCOM Regulation 702-7 Flight Safety Parts/New Source Testing Program Management. This paper provides an overview of the newly revised AMCOM Regulation 702-7, previously published in October 2000. This update was necessary to keep up with the updated requirements of high tier documents, such Public Law 108-136, DA Pam 95-9, and other related regulations. This effort has produced a new AMCOM Regulation 702-7 Critical Safety Items (CSI), Critical Application Items (CAI), and New Source Testing (NST) Program Management, officially released in June 2017. The revised document addresses the complete quality oversight controls for CSIs and includes newly defined oversight and control requirements for CAIs. Furthermore, the new revision has been clarified by incorporating lessons learned while eliminating confusion and ambiguity from the previous document. The appendices have been revised to better describe technical and quality requirements for manufacturers and overhaul sources for CSIs, and also detail the Army programs in place to provide confidence that items inducted into the Army supply system are safe and conforming. In this paper, various technical aspects of CSI, CAI, and NST that have been established for US Army rotary wing aircrafts are presented and discussed in detail.
ABSTRACT The paper presents quantitively the range of challenges that attend the S-70i Black Hawk start production - from prototype building to serial production. This article focuses not only on engineering tasks however partially also describes challenges connected to the following areas: business, quality, logistic, manufacturing planning and organization, ground and flight testing, pilots and mechanics training and jobs, PR activity. The volume of presented information are regulated and limited by the ITC regulations and IP protections.
ABSTRACT The current certification requirements for multiengine rotorcrafts for takeoff and landing performance do not always provide a safe approach to the scenarios where the helicopters actually operate if compliance demonstration is achieved with the current accepted methods. Several critical aspects of these methods do not to produce "safe" flight envelopes and provide insufficient or inadequate operational information. The current regulations are long dated and not updated to reflect the advance in technology. The current accepted methods of compliance for the definition of the H-V envelope for multi-engine helicopters do not ensure the airworthiness required for all possible operations. For this reasons, the H-V envelope should not be considered a limitation for all CS29 multi-engine configurations and substituted by performance that would allow defining a safer envelope. Particular attention should also be given to operations over elevated helidecks and oilrigs where the environment is extremely demanding and not predictable. In order to get approval for these kinds of operations, specific testing methodology should be developed and approved. A detailed list of proposed changes for the Advisory Circular and applicable regulation is considered and new acceptable compliance methods for the following subjects are proposed for: Cat B Take Off; H-V envelope; Cat A performance for elevated/oilrig helidecks; Takeoff performance influential factors. The incorrect definition of the applicability of the H-V envelope has created an unsafe regulatory case also in the operational rules (AIR-OPS) for Operations in performance class 2 with exposure from helidecks.
ABSTRACT Hybrid Unmanned Aerial/Underwater Vehicles (HUA/UV's) have the challenge of robustly operating within and transitioning between two vastly different environments. To meet this challenge, an amphibious quadrotor was constructed and its transition performance quantified using motion capture under manual control. The approach is novel in that it performs transition without active buoyancy control or increasing the number of rotors. The loads across air-water transition were quantified using a controlled single motor-propeller pod and a six-axis load cell. Experimental results were compared against blade element momentum theory (BEMT). The BEMT model correlated well with experimental thrust data when the propeller was in 'fully in air' or 'fully in water' environments. A simplifying dimensional analysis of the model predicted first order relations between electronic speed controller measurable parameter of revolutions per minute against the variation in fluid density. Derived parameters of effective density, entry offset depth, and critical depth were introduced and discussed. The first order relations showed agreement with experimentally derived data, suggesting that "effective density" may have a role in enabling attitude regulation across the air-water interface.
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