Atypical cracks were discovered on the lower center wing joint. I have to say here, that i really, really believe that there are many improvements designed into the new center wing box. Gross dimensions of the center wing box are 440 inches span, 80 inches chord, and 32 inches depth. Of those, five met the requirements for the temporary grounding because they lack an extended service life center wing box and had accumulated 15,000 equivalent flight hours, said. In accordance with the tcto, indepth visual and modified nondestructive inspections of the wing box are being conducted on affected ch and jmodel aircraft that have not received the extended service life center wing box and have greater than 15,000 equivalent flight hours. Hidden fatigue cracks suspected in c firefighter wingloss. Nov 16, 2006 center wing boxes on c s have been showing cracks earlier than expected. Air force grounds 123 c hercules aircraft after cracked wings. In 2006, the air force began replacing center wing boxes on c s after the boxes began showing cracks earlier than expected. Wing box replacements in the usfs cs fire aviation. The cracks on the lower center wing joint were discovered on an air national guard c hmodel at robins air force base, ga. The cnsatm upgrade will allow the c fleet to be deployed worldwide.
A redesign of the cwb is therefore a bare essential in the life extension program. In accordance with the tcto, indepth visual and modified nondestructive inspections of the wing box are being conducted on affected c h and. Workers guide the center wing box as it is lifted from a c hercules. Aug 21, 2019 miller suspended c operations for 123 of the 450 total force c hercules aircraft following the discovery of cracks in the rainbow fitting that holds the inner and outer wing sections together. Nov 15, 2006 workers guide the center wing box as it is lifted from a c hercules. In the past few years, many c aircraft have developed fatigue cracks in.
The reduced service life of the sof c airframe can be attributed to two primary factors, these are. Aug 08, 2019 more than a quarter of c hercules in service at air mobility command will be temporarily grounded. A c j taxis on the flightline at little rock air force base, ark. Miller suspended c operations for 123 of the 450 total force c hercules aircraft following the discovery of cracks in the rainbow fitting that holds the inner and outer wing sections together. Aug 08, 2019 the cracks on the lower center wing joint were discovered on an air national guard c hmodel at robins air force base, ga. The order applies to ch and jmodel aircraft that have not received the extended service life center wing box and have greater than. Aug 08, 2019 air force grounds more than 100 c aircraft over wing crack worries. Air logistics center upgrades center wing boxes on cs u. Cracks found in air national guard c wing parts prompt. Air logistics center upgrades center wing boxes on cs. The structural configuration of the c center wing box is illustrated in figures. Center wing inspections for fatigue cracking, have captured our attention as. Usaf pulls onefourth of cs to inspect for cracks air.
The air combat commander removed 123 of 450 c aircraft from service aug. C hercules the c is a 4 engine tactical transport aircraft built by lockheed that over the years has become the principle tactical airlift platform for militaries worldwide. The c upper and lower rainbow fittings provide the structural connection support between the aircraft center wing box and the outer wing as shown in figure 1. Figure 9 from air force c rainbow fitting diagnostic. Aug 21, 2019 in accordance with the tcto, indepth visual and modified nondestructive inspections of the wing box are being conducted on affected c h and jmodel aircraft that have not received the extended service life center wing box and have greater than 15,000 equivalent flight hours.
Cracks found in c wing parts prompt partial grounding of. Amc c rainbow fitting inspections complete scott air. However, even if the center wing box was a solid block of titanum or even \unobtanium\, c missions and crews would find a way to impose fatigue into the structurenothing is perfect except this web sitethanks, casey. More than a quarter of c hercules in service at air mobility command will be temporarily grounded. Pdf air force c rainbow fitting diagnostic technology. Air mobility command c fitting inspections complete. Miller suspended c operations for 123 of the 450 total force c hercules aircraft following the discovery of cracks in the rainbow fitting that holds the.
In the past few years, many c aircraft have developed fatigue cracks in the center wing box rainbow fittings. As a result, members of the 402nd aircraft maintenance group have removed the center wing box from aircraft 831212 and will replace it with a new center wing box as part of the first step in. In the mid2000s, center wing boxes cwb on c s began showing cracks earlier than expected. Boeing announces c total life extension program jul 19. These cracks can be a significant flight safety risk, when the damage. In 2006, the air force began replacing center wing boxes on cs after the boxes began showing cracks earlier than expected. As a result, members of the 402nd aircraft maintenance group have removed the center wing box from aircraft 831212 and will replace it with a new center wing box as part of the first step in addressing the problem. Little rock afb is home to the largest c fleet in the world. Aug 05, 2014 the air force is extending the service life of its fleet of c combat delivery aircraft by replacing center wing. Center wing boxes on c s have been showing cracks earlier than expected.
These cracks can be a significant flight safety risk, when the damage is extensive. Aug 10, 2019 of those, five met the requirements for the temporary grounding because they lack an extended service life center wing box and had accumulated 15,000 equivalent flight hours, said col. Wouldnt surprise me one bit this acft had wing box cracks undetected. The air force is extending the service life of its fleet of c combat delivery aircraft by replacing center wing. Jun 18, 2008 c hercules the c is a 4 engine tactical transport aircraft built by lockheed that over the years has become the principle tactical airlift platform for militaries worldwide. Maryanne miller, air mobility command commander, ordered the temporary removal of 123 of 450 total force c hercules from service on aug. The structural configuration of the c center wing box is illustrated in figures 1, 2, 3, and 4. The replacement program was to ensure the viability of the c hercules fleet through 2030 and beyond, the air force said. Air force grounds more than 100 c aircraft over wing crack.
Jan 11, 2014 a wing box is the core or backbone of an aircraft. Other smaller fatigue cracks were also found along the parting line on the lower. Us air force pauses flight ops for more than a hundred cs over. Usaf pulls onefourth of cs to inspect for cracks air force. In a c it sits atop the fuselage and forms the attachment point for both wings. Oct 22, 2007 i have to say here, that i really, really believe that there are many improvements designed into the new center wing box. In accordance with the tcto, indepth visual and modified nondestructive inspections of the wing box are being conducted on affected ch and. Other smaller fatigue cracks were also found along the parting line on the lower wing skin. Air force for decades and is projected to continue to accrue flight hours for years to come as a highly capable platform utilized for numerous mission profiles. Northrop grumman ng, chalet cd01 technology services is offering legacy c hercules operators a center wing box cwb restoration solution. Cracks found in c wing parts prompt partial grounding. A threephase project is under way at warner robins air logistics center, robins air force base, ga. Air force grounds more than 100 of c aircraft after.
Northrop grumman offers c center wing box restoration. Amc c rainbow fitting inspections complete air force. A c deployed from the montana air national guards 120th airlift wing sits on the ramp as the sun sets at ali al salem air base, kuwait, on july 29, 2019. In order to detect the existence of cracks in the rainbow fittings so that they can be repaired, implementation of labor intensive eddy current. Air force grounds more than 100 c aircraft over wing crack worries.
Air force c rainbow fitting diagnostic technology development. Aug 08, 2019 indepth visual and modified nondestructive inspections of the wing box will be conducted on affected c h and jmodel aircraft that have not received the extended service life center wing box and have greater than 15,000 equivalent flight hours. One commonality c owners may face is the center wing box issue. Cs in the us inventory in particular have been under intense utilization by all services as the number of engagements, small wars and insurgencies not to.
In the mid2000s, center wing boxes cwb on cs began showing cracks earlier than expected. Mar 08, 2008 in the past few years, many c aircraft have developed fatigue cracks in the center wing box rainbow fittings. Air force grounds more than 100 c aircraft over wing. The upper surface of the wing box is composed of four panels. A cj taxis on the flightline at little rock air force base, ark. In addition, the center wing box cwb structure, which is common to both the c and sof ci. Center wing boxes on cs have been showing cracks earlier than expected.
Maryanna miller ordered 123 of the 450 total force c hercules aircraft to undergo inspection after cracking was found on the lower center wing joint, also known. After atypical cracks were discovered on the lower center wing joint or rainbow fitting during programmed depot maintenance. Nov 15, 2006 center wing boxes on c s have been showing cracks earlier than expected. Maryanne miller, the air mobility command commander, ordered the temporary removal of 123 of 450 total force c hercules from service on aug. The c system program office at robins air force base, ga recommended the grounding after inspections of the center wing box structure, which sits atop the fuselage and forms the attachment point for both wings and all four engines, revealed cracks. View entire discussion 344 comments more posts from the videos community. Amc commander directs temporary removal of 123 cs from. Cracks found in air national guard c wing parts prompt partial. A failure of the wing box during flight could be catastrophic. Us air force pauses flight ops for more than a hundred cs. C s in the us inventory in particular have been under intense utilization by all services as the number of engagements, small wars and insurgencies not to. Advanced technology center wing box concemual despgnicost study. More than a quarter of c hercules in service at air mobility command.
The center wing box structure is then disassembled in order to. The upper and lower rainbow fittings on the c connect the outer wings with the center wing box, which sits over the fuselage. The c basic fuel system has required no major modifications to resolve safety concerns. Amc c rainbow fitting inspections complete edwards air. Outer wingbox of c center wing box research showed that the center wing box cwb is the largest driver in maintenance costs. Figure 4 from air force c rainbow fitting diagnostic. Figure 2 c upper and lower rainbow fittings the primary cause of the cracking is from common fatigue that occurs almost exclusively on the inboard rainbow fittings. It included all c models except the jmodel, the newest model in the fleet. Indepth visual and modified nondestructive inspections of the wing box will be conducted on affected ch and jmodel aircraft that have not received the extended service life center wing box and have greater than 15,000 equivalent.
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