Hmmmm... From Canada, joined May 1999, 2114 posts, RR: 5
Reply 3, posted (8 years 11 months 2 weeks 3 days 19 hours ago) and read 17627 times:
Well, if it happened right after dropping the load, then the plane wants to climb instantly putting stress on the wing/fuselage connection. If there is a weakness in the wing root, then I can believe that caused it. I suppose a tanker would have weakened wing roots from the stress of doing that over and over again during its career.
Bombers, such as the B-52, when they drop their load, it is not instantaneous. The bombs cascade out in sequence limiting the stress at that wing connection. Water bombers release that huge load all at once. Considering that most of them are old airplanes to being with, I wonder how many others are out there waiting to fail like that.
An optimist robs himself of the joy of being pleasantly surprised
This is a crash that occurred in California back in 2002 resulting in the fatalities of the 3 crewmembers. Cause of the accident was a crack in the main wingspar. Here's a link to the NTSB summary report:
Fanofjets From United States of America, joined Apr 2000, 2097 posts, RR: 3
Reply 9, posted (8 years 11 months 2 weeks 3 days 1 hour ago) and read 8137 times:
The Martin 202 had the same problem, and the entire fleet had to be grounded until the problem was fixed. Northwest lost at least two Martins in this fashion, which prompted the airline to sell of its fleet. This was not a problem with the later, much-improved Martin 404.
I heard that the early Lockheed L-188 Electra models had similar problems with wings. And there was the heart-rending crash of a C-5A Galaxy during the Vietnam War, claiming the lives of hundreds of children who were being airlifted to safey.
The aeroplane has unveiled for us the true face of the earth. -Antoine de Saint-Exupery
OPNLguy From , joined Dec 1969, posts, RR:
Reply 12, posted (8 years 11 months 2 weeks 3 days ago) and read 7147 times:
Quoting Fanofjets (Reply 9): I heard that the early Lockheed L-188 Electra models had similar problems with wings. And there was the heart-rending crash of a C-5A Galaxy during the Vietnam War, claiming the lives of hundreds of children who were being airlifted to safey.
If you're implying that the C-5 crash occurred because the wings failed or otherwise had a problem, I think that's incorrect. From globalsecurity.org:
On 04 April 1975 the US was involved in the evacuation of more than 2,000 Vietnamese orphans out of Saigon as North Vietnamese forces marched on the city. A C-5, which was returning to the Philippines after delivering war material, and a C-9 were loaded with children from Saigon'' orphanages and female government employees. These children were to be adopted into families in the United States and Europe. The mission, named Operation Babylift, was the first of more than 30 planned. Workers at the airport carried the children -- more than 100 infants and 140 older children -- into the C-5 one by one. A majority of them were only 2 years and younger. Almost half the children sat in the cargo compartment of the aircraft below, while the remainder sat in the troop compartment upstairs. At 23,000 feet the aft door was torn from the aircraft. The safety investigation would later reveal one of the door locks failed and created a pressure overload on all the other locks. When that happened, it blew out the doors, and the C-5 then experienced a rapid decompression. When the aft door blew out it severed three of the four hydraulic systems as well as the flight controls. The explosion ripped a large hole near the rear of the aircraft. The pilot diverted the plane and headed back to Tan Son Nhut AB, but the C-5 couldn't make it. The pilot made an emergency landing in a rice paddy, within two miles of the base, shearing off the cargo compartment of the aircraft. Many of the orphans were still asleep when the aircraft hit the ground, bounced up, and began to break apart as it hit again and slid to a stop. The entire cargo bay of the aircraft sheared off as the plane tore across the field. Of the 140 passengers below only six survived. Eleven out of the 29 crewmembers lost their lives. The nurses and technicians aboard did their best to save as many children as they could. Thanks to the aircrew's flying skills, however, 176 of the 314 people on board survived, including 150 orphans.
The wings may have separated here, but that was a consequence of the emergency landing in the rice paddy, and not the initiator of the accident itself.
Jetjack74 From United States of America, joined Jul 2003, 7457 posts, RR: 49
Reply 15, posted (8 years 11 months 2 weeks 2 days 21 hours ago) and read 5416 times:
Quoting EMBQA (Reply 6): Early C-130 had a big problem with cracking wing spars.
It also led to a discovery that all C-130A/B/E and early H, and H-2 aircraft would be susceptible to to a centrewing box failure. The USAF doesn't have any A or B models anymore, but still has a sizable number of C-130E/H models in the inventory, and many were discovered with extensive corrosion and cracks in the centre wingbox and faulty wingspars
Propeller auto-procession (due to some structural weakness such as a hard landing or damage to struts inside engine/ reduction gear) combined with Harmonic Coupling with the wing itself which led to catastrophic flutter transmitted to a wing (or both!) wings.
Greasespot From Canada, joined Apr 2004, 3095 posts, RR: 19
Reply 22, posted (8 years 11 months 2 weeks 2 days 15 hours ago) and read 3699 times:
The C-130 and civil model L-382 (they are different)have an ultimate life of the wings....I believe that the wings have to be thrown away at 35,000 hours if they are Type 1 and 2 wings. If they are type 3 wings their ultimate life shoots up to 75000 hours.( i am going by memory as it has been a while since i had anything to do in QA with the Herc.)
There are a lot of inspections on wingbox.....
Sometimes all you can do is look them in the eye and ask " how much did your mom drink when she was pregnant with you?"