Tiềm lực quân sự Hoa Kỳ - Phần 3

Tặng Gabeo
Like most Soviet tanks, the PT-76 has limited ability to depress its main gun, and therefore cannot fire effectively from defilade. Its amphibious design makes it unnecessarily large for its weight class and allows less armor protection than in other light tanks. Because of its relatively thin armor (maximum thickness 14 mm in the hull, 17 mm in the turret), it is vulnerable to artillery fragments and .50 caliber machine gun fire. The fact that the commander is also the gunner and radio operator reduces his effectiveness as an observer. The PT-76 also lagged behind other Soviet armored fighting vehicles in having no night vision equipment and no NBC protection system for the three-man crew.
http://www.fas.org/man/dod-101/sys/land/row/pt-76.htm
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Trong khi đó
.50 armor-piercing cartridges would go on to function as an anti-aircraft and anti-vehicular machine gun, with a capability of completely perforating 0.875" (22.2 mm) of face-hardened armor steel plate at 100 yards (91 m), and 0.75" (19 mm) at 547 yards (500 m).
Được andrewtran sửa chữa / chuyển vào 11:30 ngày 12/11/2009

Được kiepngheo2 sửa chữa / chuyển vào 11:37 ngày 12/11/2009

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Cùng chung một câu chuyện lịch sử cả.Nhưng M48 còn mạnh hơn T-54>Nhưng thực tế sau 1972 LX và TQ viện trợ thên cho Bắc VN gần 1000 xe tăng và thiết giáp.
South Vietnamese M-48s and M-41s fought bravely in the defence of South Vietnam in the so called Ho Chi Minh Offensive in 1975. In several incidents in which the South Vietnamese Army successfully defeated NVA T-34 and T-55 tanks and even slowing the North''s offensive. However since the United States Congress passed bans on the transfer of fuel and ammunition to South Vietnam, the American-made tanks were soon out of ammunition and fuel and where abandond to the North Vietnamese Army in 1975 which put them in predictably short service of the Vietnamese People''s Army after the war ended in May 1975.

EM có thể thay đổi ko khí tí không ??
http://autonet.com.vn/vn/tinthegioi/6372/di-taxi-dac-biet-o-baghdad/index.aspx
Sân bay Baghdad nằm ở rìa phía tây của thủ đô. Khoảng cách từ sân bay đến trung tâm Baghdad chỉ khoảng 24 km nhưng giá vé cho mỗi chuyến xe ít nhất là 4.600 USD. Với mức giá 200 USD/1km, bạn sẽ được ngồi trên những chiếc xe và đi trong tiếng nổ của bom bên lề đường, tiếng máy bay ném bom gầm rú, tiếng nổ của những chiếc xe tự sát, tiếng súng bắn tỉa hay tiếng rocket.

Bác Doan nói theo cảm tính rồi. M-72 không dùng ngòi nổ cơ nhưng dùng cảm biến điện. Nó cảm ứng áp xuất và chấn động.
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Chết, thế ra tớ nhầm à?
Bác làm ơn thì làm ơn cho trót, giải thích luôn hộ tớ nếu LAW-66 không dùng ngòi chạm nổ thì dùng loại ngòi gì nhé! Cái "cảm biến điện" ở đây dùng thay ngòi nổ chăng? Nó "cảm ứng áp xuất và chấn động" để làm gì?
À quên, áp suất chứ không phải "áp xuất", bác ạ!

Đọc đi này:
Tác giả bài viết, đã tham gia chế tạo tăng PT 76

Các thông số PT 76 được đặt hàng bởi nhà nước
năm 1947:

Dòng cuối cùng chính là yêu cầu chịu được đạn 14,5 mm kể cả của súng chống tăng 14,5 mm thời đó.
Sau đó thông số về trọng lượng, cỡ pháo có thay đổi nhưng yêu cầu về giáp không thay đổi

Khổ bác Doan quá. Xem lại đi bác à. Thực tế nguyên tắc kích nổ của M-72 và RPG-7 chả khác nhau mấy. Khác là cái cơ chế truyền tải điện mà thôi.

F-22 tiếp tục bị kiện vì sơn quá nhiều lớp RAM làm máy bay trục trặc
November 11, 2009
Ex-Lockheed engineer claims F-22 tech ''defective''
By GREG BLUESTEIN
Associated Press Writer
A former engineer for defense contractor Lockheed Martin Corp. claims in a federal whistleblower lawsuit that the company knowingly used "defective" stealth coatings when building its F-22 Raptor stealth jets.
Darrol Olsen, a stealth engineer who was fired by Lockheed in 1999, claims Lockheed "falsely certified" the coatings between September 1995 and June 1999, saying they had passed stealth tests and concealing results that showed otherwise. Olsen said in the lawsuit he was told to "stay out of it" when he complained to his superiors.
The whistleblower suit was originally filed in October 2007 in California and was unsealed earlier this year. It was transferred to federal court last week in Atlanta, near where the jets are assembled at Lockheed''s facility in Marietta.
The case comes a month after President Barack Obama signed a measure ending production of the $140 million superfighter, which critics maintain is poorly suited for anti-insurgent battles in Iraq and Afghanistan.
The Air Force would not immediately comment on the complaint. Lockheed said in a statement it "does not believe there is any merit to the allegations and will vigorously defend this matter in court."
Olsen contends Lockheed applied more than 600 pounds of extra layers of coatings so the jet could pass the stealth tests required by the Air Force. The layers were needed because the coating rubbed off when exposed to jet oil, fuel and water, the complaint said.
It left the supersonic fighters with "extremely thick coatings (that) have proved brittle" and the coatings designed to be paper-thin have now compromised the superfighter''s velocity and maneuverability, the lawsuit said. It said the process has essentially painted a "bulls-eye target" on aircraft designed to avoid radar detection.
In the lawsuit, Olsen is asking the judge to order Lockheed to pay the federal government $50 million for each of the 183 F-22''s built or under construction as part of the contract. He is also asking the judge to order Lockheed to pay his legal fees.
Olsen could not be reached for comment and his attorney did not immediately return calls seeking comment.
Several whistleblower lawsuits have been filed over the years targeting other high-profile Air Force projects, but this appears to be the first filed against the controversial Raptor project, said Richard Aboulafia, an analyst at the Teal Group, an aerospace consulting firm.
"There have been claims of huge cost overruns against the Raptor, but it''s largely not been targeted by lawsuits," Aboulafia said. "This is not a typical charge ?" and it might be the only of its kind."
John D. Gresham, a researcher and defense analyst who is writing a book on the F-22, said Lockheed and the Air Force go to great lengths to preserve the coating and that engineers have an "absurdly small" margin for error. He said the aircraft has gone through several generations of development since Olsen left the company a decade ago.
"In our business, that''s an eternity," he said. "If I was a judge, I''d throw it out on that basis alone."

Chuyện anh kỹ sư bị sa thải kiện cáo trở lại công ty cũ của mình . Xưa rồi lão dầu đen à.
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PT-76 tháp pháo mặt trước có thể chịu đạn 14.5mm chỉ chổ đó thôi. thân xe nhiều chổ chỉ vỏn vẹn 9mm dính 12.7mm còn đi chứ nói chi 14.5mm..các nhà sản xuất chơi chử mà.
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Thế hệ sau M-72