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When pigs fly: a new cranial in 2010.

'Good enough' often becomes the basis for 'the way things always have been done.' In the case of the current flight-deck cranial, what was good enough for maintainer head and hearing protection in the 1950s no longer is good enough to keep maintainers safe in 2008.

The first generation of today's flight-deck cranial, designed by Capt. Ralph L. Christy, Jr., a Navy flight surgeon, and Mr. David M. Clark, of the David Clark Company, used "Mickey Mouse" earmuffs Earmuffs are objects designed to cover a person's ears for protection. They consist of a thermoplastic or metal head-band, that fits over the top of the head, and a pad at each end, to cover the external ears.  in the original cranial-helmet system. This "state of the art" head and hearing protection was worn to protect against the F2H-2 Banshee's twin Westinghouse J34 turbojet turbojet: see turbine.
turbojet

Jet engine in which a turbine-driven compressor draws in and compresses air, forcing it into a combustion chamber into which fuel is injected.
 engines, capable of producing 3,140 pounds of thrust each.

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As time progressed, so did naval aircraft. Dialing the clock ahead 53 years, FA-18s carry two General Electric F404-GE-402 afterburning engines, capable of 18,000 pounds of thrust each and producing up to 150dB of noise! Unfortunately for the maintainers of these powerful and capable aircraft, time nearly stood still. Modern aviation-maintenance crews wore nearly the same head and hearing protection as their Banshee brethren generations earlier.

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The HGU24/P and HGU-25(V)2/P are commonly and collectively known as the cranial. While this design has withstood the test of time, it fails to meet nearly all modern-safety standards for hearing protection, impact protection, and electrical shock prevention, and it fails to support several key 21st century mission scenarios.

CPG CPG

central pattern generators.
3 Command Master Chief, ABHCM(AW/SW) Wynn Young, was among the first to report hazardous shortcomings of the cranial. He developed a point-paper, which highlighted the cranial's failure to support NAVAIR NAVAIR Naval Air Systems Command  00-80T-106, requiring the use of night vision devices (NVDs) on amphibious flight decks, as well as the 'can do' spirit of the fleet maintainer. The paper noted that fleet solutions, however noble and well-intentioned, often result in non-standard, unsafe practices. NVD attachment to the cranial often results in poor NVD eye alignment, vision and face hazards, and cracked cranial-impact shields.

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Further, NAVAIR AIR 4.6, Human Systems Department, conducted surveys of more than 1,000 flight-deck personnel on board CVNs, LHAs, LHDs, and across fleet squadrons. The survey included a detailed assessment of cranial-helmet fit and maintenance condition (e.g., earmuff headband tension, earcup foam and cushion integrity), earplug ear·plug  
n.
1. An object made of a soft, pliable material, such as cotton or rubber, and fitted into the ear canal to block the entry of water or sound.

2. An earphone, especially one that fits into the ear.
 use and insertion depth, and headsize measurements. Worn without earplugs, the cranial provides approximately 21 dB of noise attenuation Loss of signal power in a transmission.
Attenuation

The reduction in level of a transmitted quantity as a function of a parameter, usually distance. It is applied mainly to acoustic or electromagnetic waves and is expressed as the ratio of power densities.
 when correctly fit, worn, and maintained. All survey subjects reported wearing a cranial helmet with earmuffs, but 75 percent of subjects were issued a questionable size (most wore the largest of four sizes available), and 41 percent of earcup cushions and foam inserts were deteriorated, hard, creased, or missing. Many maintainers, who were issued even the largest of the four cranial sizes, reported being in severe pain after wearing them 5 minutes.

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A detailed cost analysis found that the cost to build, maintain and replace the old cranial was not a good value. Survey data showed approximately two hours are required to build one complete cranial system from scratch, with an additional 45 minutes needed to configure NVDs. Maintenance averaged an additional 25 to 45 minutes per cranial. From 2000 to 2004, about 750,000 individual parts were purchased for the cranial, averaging 187,500 parts per year. Currently, up to 22 individual parts are ordered to configure a cranial (not including NVDs and mountings). These results strongly supported a decision to develop and field a new state-of-the-art cranial.

As a result, NAVAIR worked with two vendors, Adaptive Technologies, Inc., (ATI) and Creare, Inc., to develop new FDC-design concepts. Both vendors developed FDC prototypes designed to meet or exceed initial performance requirements. The Naval Safety Center then hosted multiple open forums with the fleet to gather firsthand feedback on the ATI and Creare prototypes and to iron out key performance requirements. These fleet inputs, together with NAVAIR technical requirements, were approved in early March 2008. The 65-page performance specification for the FDC was approved as PMA PMA (papillary-marginal-attached),
n a system of epidemiologic scoring of periodontal disease devised by Schour and Massler in which the symbols denote the areas involved in gingival inflammation.

PMA Progressive muscular atrophy
202-000/R-0.

This performance specification establishes minimum performance and validation requirements for a modular FDC helmet to be worn by aircraft handlers and maintainers working in, on and around military aircraft positioned throughout global-climate ranges shipboard and ashore. The FDC will meet OPNAVINST OPNAVINST Office of the Chief of Naval Operations Instruction  5100.19 and 5100.23 safety requirements, and provide improved hearing protection (about 43 dB), speech intelligibility, ANSI (American National Standards Institute, New York, www.ansi.org) A membership organization founded in 1918 that coordinates the development of U.S. voluntary national standards in both the private and public sectors. It is the U.S. member body to ISO and IEC.  Z89.1-1997 impact protection, electrical-shock protection, a stable NVD-mounting platform, and be compatible with CBR protective clothing. The FDC will be modular in design to allow tailoring to various work environments and to reduce maintenance labor man-hours and logistical burden, including a FOD-free design (no clips to remove) and pre-applied reflective tape by the vendor! The plan is to offer the new FDC-cranial system as an individually-issued item to improve sizing fit, comfort and hygiene.

In late March 2008, the FDC program was authorized to move into the systems design and development (SDD (Software Design Description) The architecture of an information system. See IDD. ) phase. In this phase, both ATI and Creare will conduct laboratory-performance validation testing and initial fleet assessments. Fleet assessments are planned for third quarter FY09. A Milestone "C" decision to field the FDC is scheduled first quarter FY10.

Mr. Janousek works at NAVAIR, Code 4.6.7.4 and Ms. Bjorn is with Human Systems, Code 4.6.
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Title Annotation:Air Wing TOOLBOX
Author:Janousek, Jim; Bjorn, Valerie
Publication:Mech
Date:Jun 22, 2008
Words:885
Previous Article:When sparks fly.
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