Tuesday, May 31, 2011

Aerospace Snapshot - Cold Flow of SpaceShipOne

During test flights of White Knight and SpaceShipOne, the pilots had a long list of tasks to complete. As a result, after release, pilots only had 10-20 minutes of flight time. In preparation for the first rocket-engine test flight, pilot Brian Binnie performed a cold flow of the rocket engine (above photo), in which he followed all the procedures to run the rocket engine, except igniting the oxidizer and fuel. Photo courtesy of Scaled Composites, from SpaceShipOne: An Illustrated History by Dan Linehan.

Thursday, May 26, 2011

From the Pages - Background the M4 Sherman

It was not the most heavily armored tank. In truth, it was tall and ungainly, and its firepower simply couldn’t match the German tanks it faced. 

What it was, however, was a prime example of America's dedication to innovation and soon-to-be-legendary manufacturing capabilities. And by dint of sheer numbers and downright reliability, the M4 Sherman became the winning workhorse of World War II—from the fields of Europe to the islands of the Pacific.

In the following excerpt from M4 Sherman at War, Michael Green and James D. Brown detail the earliest days in the M4's storied legacyfrom the design and manufacturing changes that set it above its predecessor, the M3 Lee/Grant, to its trial by fire in the deserts of North Africa.
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Beginnings of the M4 Medium Tank
On August 31, 1940, the Armored Force Board released detailed characteristics for a new medium tank armed with a turret-mounted 75mm gun. Six months later, the chief of Ordnance requested that Aberdeen Proving Ground proceed with the design of the new tank following completion of upgrade work on the M3 tank series. The chief of Ordnance directed that automotive features of the new medium tank—including the air-cooled gasoline-powered radial powerplant, powertrain, suspension, and track—should be essentially those of the M3 medium tank.

The principal change was moving the hull-mounted 75mm gun into a turret. Also agreed upon was the use of welded RHA or CHA hulls. Increasing the thickness of the vehicle’s armor, while at the same time reducing the number of crew members, was also considered an important goal in order to up-armor the tank without increasing the vehicles’ gross weight.

In June 1941, the Ordnance Committee ordered the building of a full-size wooden mockup and a pilot model of the new tank designated the T6. Upon completion of the wooden mockup, followed by a few design changes, Aberdeen Proving Ground started to manufacture a complete pilot tank with a CHA hull and turret. Rock Island Arsenal started building a pilot tank with a welded RHA hull. The turret would come later, as the turret design was not yet ready for production.

Tuesday, May 24, 2011

Aerospace X-Ray - The Orbiter's Pressure Vessel

The pressure vessel is essentially the crew compartment, and is the only element of the Orbiter pressurized throughout the flight. The pressure vessel is separated into three distinct areas. The flight deck contains the flight controls and displays, the mid-deck comprises the living space, with the equipment bay below. Photo courtesy of NASA, from NASA Space Shuttle Owners' Workshop Manual by David Baker.

Thursday, May 19, 2011

Military Snapshot - 327th Glider Infantry Regiment Troops Take to the Water

Due to a shortage of glider tow-planes, elements of the 327th Glider Infantry Regiment, 101st Airborne Division embark for Utah Beach on LCVPs. Part of General Howell's C-Force, they were originally slated to arrive on D-plus-2, but instead hit the beach on D-Day. Photo courtesy of the National Archives and Records Administration, from Normandy: Breaching the Atlantic Wall by Dominique Francois.

Tuesday, May 17, 2011

Beyond the Book - Q & A with Robert F. Dorr, author of "Mission to Berlin"

With the release of his new book, Mission to Berlin: The American Airmen Who Struck the Heart of Hitler's Reich, author and Air Force veteran Robert F. Dorr has shed new light on the experiences of a rare breed of hero, the American bomber pilots and crews who risked their lives over Berlin.

In the following Q & A, Dorr discusses his new book, the larger-than-life heroes whose stories are housed within its pages, and the world-engulfing war that has captivated generations of readers across the globe.


ZENITH PRESS: To family members, historians and enthusiasts born long after World War II, the men who flew, maintained, supported and escorts heavy bombers pilots and crews have acquired a lofty—almost romanticized—status that spans generations. Why do you think that is?

ROBERT F. DORR: No one had ever fought at such great heights, in such terrible cold, with such fast and brutal action taking place all around them. So it was natural that American bomber pilots and crews became the stuff of legend and lore. Today, we realize that we'll never see anything like this again—thousands of aircraft and tens of thousands of men fighting many miles above the earth. These were very young men, citizen-soldiers drawn from our population, caught up in a new and different situation. We have overused the "greatest generation" label, but it is not wrong to say that these achieved nothing less than to save the world. So of course we admire them and hold them high in our thoughts.

Thursday, May 12, 2011

Aviation Snapshot - B-25s Dodging Antiaircraft Fire over Rabaul

In early 1944, after the issue over Rabaul had been decided, Marine Air fielded five PBJ squadrons (dubbed VMB) aboard the bases surround the Japanese stronghold. The PBJs were standard American B-25 medium bombers with a navy/Marine designation. Marine PBJs were the last aircraft to bomb Rabaul, on August 8, 1945. Here, PBJs over Simpson Harbor are tracked by antiaircraft fire. Official USMC Photo, from New Georgia, Bougainville, and Cape Gloucester: The U.S. Marines in World War II by Eric Hammel.

Tuesday, May 10, 2011

From the Pages - Battle for the City of the Dead

The following excerpt is pulled from Chapter 10 ("Tomb Job") of Battle for the City of the Dead: In the Shadow of the Golden Dome, Najaf, August 2004 by Col. Dick Camp.

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“It was like New Orleans meets Baghdad.”
—U.S. Army officer describing the Wadi al-Salaam cemetery

Alpha Company jumped off early in the morning of August 8. “We cleared the little carnival area with negative contact,” Alpha Company’s commander, Capt. Kevin Badger, said. “We didn’t find anything.” The company held up until about 2 p.m., when, Badger said, “Colonel Miyamasu called and told me to initiate operations in AO Mad Dog [Alpha Company’s area of operations].”

First Lieutenant Steven D. Stauch added, “We were basically on station as a kind of reserve for about two hours at that point. We waited for Bravo and Charlie to clear down to Phase Line Bronx, and once they got to that point, then we were brought in to start clearing our sector.” Each company was given about a one-thousand-meter frontage.

Friday, May 6, 2011

Military Snapshot - Treadless in Vietnam

On the morning of June 23, 1968, crewmen from A-35 were on the move on Highway 533 when the tank struck a land mine in the road. In this photo, Staff Sgt. Elwood Houston and Bob Schlagel examine mine damage to A-35, including a blown-off right treat and warped hull. Photo courtesy of Tom Bursott, from Search and Destroy: The Story of an Armored Cavalry Squadron in Viet Nam, by Keith Nolan.

Tuesday, May 3, 2011

Aerospace X-Ray - Forward Reaction Control System Module

The forward reaction control system module is detachable for servicing, and its removal enables access to the lower nose section and upper landing gear bay. Illustration courtesy of NASA, from NASA Space Shuttle Owners' Workshop Manual by Dr. David Baker.