N27UADIESEL8 From United States of America, joined Dec 2007, 59 posts, RR: 0 Reply 2, posted (5 years 4 months 4 weeks 5 hours ago) and read 5023 times:
We used to used them as counterweight when the engines were removed on the L1011 and sometimes on the DC-8.
KC135TopBoom From United States of America, joined Jan 2005, 11738 posts, RR: 51 Reply 4, posted (5 years 4 months 4 weeks 5 hours ago) and read 4948 times:
Quoting Gjsint172 (Thread starter): Can anyone shed some light on what the yellow pods are hanging from the engine mounts on this KC-767?
Quoting NWA742 (Reply 1): It's obvious they do it to act as weight for the engines, but I'm not exactly sure why.
Quoting Rwessel (Reply 3): The weights keep the airplane from tipping back onto its tail. Note that the engines, which are quite heavy, are in front of the mains.
They are counter weights, but not for weight and balance to keep it from tipping on its tail. A simple block of weight inside the cargo door will do that, and that is a lot easier thwn removing the engines. The weights are there to keep a weight load on the wings as there is (most likely) no fuel in the main wing tanks.
If Boeing wins the KC-45 contract, this airplane will be the first of 4 flight test tankers, and will be designated the YKC-45A by the USAF.
BTW, Airbus also has an A-330 assembled (less engines) for the same program should NG/EADS win the contract, that A-330 will then become the YKC-45A.
Scbriml From United Kingdom, joined Jul 2003, 11437 posts, RR: 50 Reply 5, posted (5 years 4 months 4 weeks 4 hours ago) and read 4892 times:
Quoting KC135TopBoom (Reply 4): If Boeing wins the KC-45 contract, this airplane will be the first of 4 flight test tankers, and will be designated the YKC-45A by the USAF.
Are you sure? I thought the KC-767 Advanced Tanker put forward by Boeing is based on the yet-to-be-built B767-200ERF (incorporating parts from -200 and -400).
Stitch From United States of America, joined Jul 2005, 26938 posts, RR: 83 Reply 7, posted (5 years 4 months 3 weeks 6 days 20 hours ago) and read 4540 times:
Quoting KC135TopBoom (Reply 4): If Boeing wins the KC-45 contract, this airplane will be the first of 4 flight test tankers, and will be designated the YKC-45A by the USAF.
I do not believe that is the case. That frame is a KC-767 which is a different beast then the KC-767 Advanced Boeing is pitching for the KC-45A RFP as well as the 767-200LRF. That plane likely has 767-200ER wings and undercarriage, while the KC-45A/762LRF will have the wings from a 767-400ER (sans winglets) and the undercarriage from the 767-300F.
I expect the original KC-767 frame will just be scrapped unless it can be used for the JASDF or the Italian Air Force.
Oroka From Canada, joined Dec 2006, 791 posts, RR: 0 Reply 9, posted (5 years 4 months 3 weeks 6 days 8 hours ago) and read 4339 times:
Quoting Stitch (Reply 7): I expect the original KC-767 frame will just be scrapped unless it can be used for the JASDF or the Italian Air Force.
They should beable to use this airframe as a non production typical test airframe and retire it after system validation, or convert it and offer it to another KC-767 operator.
KC135TopBoom From United States of America, joined Jan 2005, 11738 posts, RR: 51 Reply 10, posted (5 years 4 months 3 weeks 6 days 5 hours ago) and read 4306 times:
Quoting Scbriml (Reply 5): Are you sure? I thought the KC-767 Advanced Tanker put forward by Boeing is based on the yet-to-be-built B767-200ERF (incorporating parts from -200 and -400).
You mean the B-767-200LRF. But, the RFP allows the OEMs to build up to four prototypes, which do not have to be configuered as the production airplanes. But, they do have to be able to test all of the final configueration equipment, just not on the same airframe (which is why there are up to 4 YKC-45As). Eventually the four test airplanes will be rebuilt as production airplanes, or scrapped and production ariplanes in their place
Quoting Stitch (Reply 7): I do not believe that is the case. That frame is a KC-767 which is a different beast then the KC-767 Advanced Boeing is pitching for the KC-45A RFP as well as the 767-200LRF. That plane likely has 767-200ER wings and undercarriage, while the KC-45A/762LRF will have the wings from a 767-400ER (sans winglets) and the undercarriage from the 767-300F.
That is correct. This airplane is actually closer to the KC-767J configueration for the JASDF. But, it can still be uised for the USAF flight tetsing.
Quoting NWA742 (Reply 8): What would happen if they didn't keep a load on the wings without fuel in them?
I'm not real sure. But, my guess is something to do with wing alignment.
Rwessel From United States of America, joined Jan 2007, 2005 posts, RR: 2 Reply 11, posted (5 years 4 months 3 weeks 6 days 4 hours ago) and read 4299 times:
Quoting KC135TopBoom (Reply 4): Quoting Rwessel (Reply 3):
The weights keep the airplane from tipping back onto its tail. Note that the engines, which are quite heavy, are in front of the mains.
They are counter weights, but not for weight and balance to keep it from tipping on its tail. A simple block of weight inside the cargo door will do that, and that is a lot easier thwn removing the engines. The weights are there to keep a weight load on the wings as there is (most likely) no fuel in the main wing tanks.
Eh? The weights are there because the engines have been removed. The A/C was in storage, and they had a better use for the engines. Without the engines (given where the engines are mounted on the A/C in question) the aircraft is quite tail heavy, so they added the weights. This is actually quite common.
Sometimes you see a tailstand or a weight attached to the nose gear used instead. And it of course depends on the particular aircraft, and where the engines are mounted, as to what, if anything, is needed.
I do. It's not even like E is next to L on the keyboard!
Quoting KC135TopBoom (Reply 10): But, the RFP allows the OEMs to build up to four prototypes, which do not have to be configuered as the production airplanes.
474218 From United States of America, joined Oct 2005, 6340 posts, RR: 9 Reply 13, posted (5 years 4 months 3 weeks 5 days 21 hours ago) and read 4232 times:
Quoting KC135TopBoom (Reply 4): They are counter weights, but not for weight and balance to keep it from tipping on its tail. A simple block of weight inside the cargo door will do that, and that is a lot easier thwn removing the engines. The weights are there to keep a weight load on the wings as there is (most likely) no fuel in the main wing tanks.
First they are counterweights, they do simulate the weight of the engines, so the aircraft will not tip. Second, putting a block that size and that weigh could (and very likely would) over stress the cargo compartment floor. Third, the engines were not removed to installed the counterweight, the counterweight are installed because the engines are not available too install.
KC135TopBoom From United States of America, joined Jan 2005, 11738 posts, RR: 51 Reply 14, posted (5 years 4 months 3 weeks 5 days 8 hours ago) and read 4153 times:
Quoting 474218 (Reply 13): Second, putting a block that size and that weigh could (and very likely would) over stress the cargo compartment floor.
Each compartment within the cargo compartment (yes, it is divided into sections for accureate weight and balance computations, body stations are also used), can easily handle the weight of two of these blocks (up to 9,000lbs each for CF-6s, RB-211s, or JT-9Ds). So 18,000lbs-20,000lbs are no problem, esspecially for an airplane that isn't moving.
The floors can easily take this amount of static weight.
Zeke From Hong Kong, joined Dec 2006, 7767 posts, RR: 73 Reply 15, posted (5 years 4 months 3 weeks 4 days 23 hours ago) and read 4101 times:
Quoting Stitch (Reply 7): I expect the original KC-767 frame will just be scrapped unless it can be used for the JASDF or the Italian Air Force.
I don't that that is possible due to the International Traffic in Arms Regulations (ITAR).
Quoting KC135TopBoom (Reply 10): But, the RFP allows the OEMs to build up to four prototypes, which do not have to be configuered as the production airplanes. But, they do have to be able to test all of the final configueration equipment, just not on the same airframe (which is why there are up to 4 YKC-45As). Eventually the four test airplanes will be rebuilt as production airplanes, or scrapped and production ariplanes in their place
I don't recall reading anywhere in the RFP the ability of a manufacturer to do as you have stated. it defeats the purpose.
The differences they proposed
Quoting KC135TopBoom (Reply 14): The floors can easily take this amount of static weight.
The floor loading limit is normally about 200 lb/ft^2 for that size aircraft.
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Stitch From United States of America, joined Jul 2005, 26938 posts, RR: 83 Reply 16, posted (5 years 4 months 3 weeks 4 days 21 hours ago) and read 4079 times:
Quoting Zeke (Reply 15): I don't that that is possible due to the International Traffic in Arms Regulations (ITAR).
Current KC-767s - including that one - had their military equipment added at Boeing IDS Wichita, so I would think they would be in compliance with ITAR.
AeroWeanie From United States of America, joined Dec 2004, 1601 posts, RR: 52 Reply 17, posted (5 years 4 months 3 weeks 4 days ago) and read 3974 times:
Quoting Zeke (Reply 15): I don't that that is possible due to the International Traffic in Arms Regulations (ITAR).
They can probably get a license to sell it, as they already have gotten licenses to sell KC-767s to Italy and Japan.
KC135TopBoom From United States of America, joined Jan 2005, 11738 posts, RR: 51 Reply 18, posted (5 years 4 months 3 weeks 3 days 3 hours ago) and read 3878 times:
Quoting Zeke (Reply 15): Quoting KC135TopBoom (Reply 14):
The floors can easily take this amount of static weight.
The floor loading limit is normally about 200 lb/ft^2 for that size aircraft.
That's the same limit we had in the KC-135A, with a plywood cargo floor. You can add multipul sheets of 3/4" (22mm) plywood to increase floor strenght to 500lbs/sqft. How do you think we could carry spare engines, powered ground equipment, and unarmed bomber weapons around?
Quoting Zeke (Reply 15): I don't recall reading anywhere in the RFP the ability of a manufacturer to do as you have stated. it defeats the purpose.
That's why EADS is getting a pax version A-330-200 for the tanker prototype ready now, instead of the A-330-200F version, which will be the actual KC-30 offered to the USAF.
Zeke From Hong Kong, joined Dec 2006, 7767 posts, RR: 73 Reply 19, posted (5 years 4 months 3 weeks 2 days 14 hours ago) and read 3767 times:
Quoting KC135TopBoom (Reply 18): How do you think we could carry spare engines, powered ground equipment, and unarmed bomber weapons around?
Don't know, and I guess you don't either, possibly they were modified in some areas.
The 200 lb/ft^2 is the standard floor loading using containers/pallets in that class of aircraft, it represents a distributed load, not a point load.
Quoting KC135TopBoom (Reply 18): That's why EADS is getting a pax version A-330-200 for the tanker prototype ready now, instead of the A-330-200F version, which will be the actual KC-30 offered to the USAF.
That is not correct, yet another misrepresentation of the truth.
Northrup Grumman offered the KC-30, which was based on the A330-200, not A330-200F.
"I think [the switch to the Freighter model] is inevitable, but right now it%u2019s not in our proposal," said Paul Meyer, Northrop%u2019s VP and general manager for the KC-30 programme."
RedFlyer From United States of America, joined Feb 2005, 4181 posts, RR: 30 Reply 20, posted (5 years 4 months 3 weeks 1 day 21 hours ago) and read 3662 times:
Quoting Rwessel (Reply 11): Without the engines (given where the engines are mounted on the A/C in question) the aircraft is quite tail heavy, so they added the weights.
Quote: "We found ourselves rolling 747s out of the factory with 5,000-pound concrete blocks dangling from their wings where the engines should be," Sutter wrote in his book "Without those weights, the airplanes would have sat back on their tails."
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