torsdag 21. mai 2020

Helikopter - Cyclone, Super Hawk og VH-92 - Alle med Fly-By-Wire - militaryfactory.com


Årsaken til havariet i Middelhavet med en Canadisk Cyclone, er ikke klarlagt. US Navy vil bistå med å få vraket hevet fra 3000m dyp. Det er mulig at havariårsaken kan ha sammenheng med FBW, et system det har vært mye trouble med i den Canadiske utgaven av Sikorsky S-92A. Sistnevnte, som opereres av Bristow og Helikopter Service i Nordsjøen og nordover, har ikke FBW. Etter mye støy valgte NAVAIR Sikorsky som leverandør av det nye presidenthelikopteret som opereres av US Marines. Akkurat nå er det grunn til bekymring hos både NAVAIR og Sikorsky. Havarihelikopteret benyttet en såkalt ELT, Emergency Locator Transmitter, som faller av i havariøyeblikket. Den flyter og sender posisjonssignal til COSPAS/SARSAT. Samme enhet inneholder også data tilsvarende det som finnes i ELT/CVR, altså den såkalte svarte boksen. Undertegnede har fulgt med i utviklingen av S-92A siden 1992 hvor maskinen, i form av en mock-up, ble vist for styret i HS A/S hvor jeg var med. Vi ble lovet en maskin som kunne fly i 150kts med MTOW. Den dag i dag tror jeg ikke det går over eksempelvis 3 timer uten å riste i stykker. Jeg har fløyet maskinen med både lav- og høytmontert halerotor. Jeg opplevet maskinen som uferdig. Den vibrerte noe inn i  ...... over 120 kts. (Red.)


VH-92 har vært testet ut på "The Presidential Lawn" - Foto USMC


The Sikorsky VH-92A, based in the military-minded S-92 helicopter, is set to be introduced sometime in 2020-2021 for Presidential transport service.

The Sikorsky VH-92 is under development to become the next Presidential helicopter serving the United States Marine Corps (as "Marine One"). The model is a heavily modified, military-minded version of the proven Sikorsky S-92 platform and is set to succeed the storied Sikorsky VH-3 line currently in use. The VH-3 had its own roots in the Cold War-era SH-3 "Sea King" navy helicopter (detailed elsewhere on this site). The VH-92 will join in the running history of vital presidential transports which began with President Dwight D. Eisenhower in a Bell UH-13J "Sioux" (eventually followed, more formally, with use of a Sikorsky UH-34 "Seahorse").

The base S-92 model in Sikorsky's product line is detailed as a medium-lift, utility-minded rotary-wing vehicle crewed by two personnel and can be outfitted to accomplish a variety of tasks from transport passengers to hauling cargo. The model was introduced in 2004 and has gone on to be adopted by a variety of commercial industries around the world with at least 300 examples have been built to date (2019). Variants of this successful design include the new Canadian military's CH-148 "Cyclone" maritime helicopter (also detailed elsewhere on this site).Using this framework, the VH-92 continues the proven traits of the original. Power is from 2 x General Electric CT7-8A turboshaft engines developing 2,520 horsepower each driving a four-bladed main rotor and four-bladed tail rotor (the latter facing starboard). The main rotor blade sits close to the fuselage roof line while the tail unit is raised. Ground-running is made possible by a tricycle (retractable) wheeled undercarriage. Outboard sponsons are noted along the fuselage sides, each housing a main landing gear leg. With its installed power, the VH-92 can reach speeds of 190 miles-per-hour and cruises near 175mph. Range is out to 549 nautical miles while the service ceiling reaches 14,000 feet.

Internally, up to 19 passengers can be carried in the passenger section (measuring 20ft x 6.6ft) while the two flight crew, both pilots, sit side-by-side at the nose. Transparent panels provide excellent vision for the crew out-of-the-cockpit. A VIP interior will make up comfortable seating for the passengers, mainly the President and staff members. In addition to this, various military-centric systems will make up the survival capabilities of this important helicopter - including redundant flight controls and power supply systems.

Listed empty weight of the VH-92 is 15,500lb against an MTOW of 27,700lb. Dimensions include a running length of 56.1 feet, a width (main rotor included) of 56.3 feet, and a height of 15.4 feet.


Origins of the modern VH-92 form can be traced back to the United States Navy (USN) VXX ("Presidential Helicopter Replacement Program") of 1999 seeking a successor to the aging VH-3D and VH-60 "White Hawk" lines. The two major contenders became Lockheed with its VH-71 "Kestrel" (detailed elsewhere on this site) and the Sikorsky VH-92. Both made it to their respective prototype stages before the Lockheed entry was declared the winner with deliveries hoped for in 2011.

Following Sikorsky protests and growing project costs surrounding the Kestrel, the program was restarted in 2010 which brought the VH-92 back in contention. With the Kestrel eventually bowing out, it fell to Sikorsky to deliver and its VH-92 was formally selected on May 7th, 2014 for development and serial production. A $1.24 billion USD contract from the USN then followed.

Up to twenty-three helicopters are to be built to the VH-92 standard costing American tax payers nearly $5 billion. Twenty-one will make up the formal VH-92A production series while a pair of CH-92A models will be used exclusively for training purposes.

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