Timeline #1 - The 509th; From
Inception to Hiroshima
Spring 1943 - Tibbets returns to the U.S. to
participate in the B-29 program.
Summer 1943 - Tibbets reports to Wichita, Kansas for
Summer 1943 - Training assigned to Smokey Hill
Airfield near Salina, Kansas.
Summer 1943 - Tibbets reassigned to Grand Island,
Nebraska to start a training school for B-29 pilots.
Summer 1943 - Tibbets goes to Alamagordo, NM to work
with E. J. Workman, a UNM physics professor to study the vulnerability
of the B-29 to attack.
Summer 1943 - Tibbets flies a "stripped"
bomber for the first time during testing, and found that it handled
better than a fully equipped plane.
Fall 1943 - Army Air Force decides to use B-29 to
deliver the atomic bomb.
2/28/44 - 393rd Bombardment Squadron created.
3/11/44 - 393rd activated as part of the 504th
4/27/44 - Lt. Col. Thomas Classen chosen as commander
of the 393rd.
4/27/44 - General "Hap" Arnold hand picks
Tibbets to command the new project.
9/5/44 - Tibbets flies B-29 to Colorado Springs in response to a call
from General Uzal G. Ent, Commander of the 2nd Air Force.
Introduced to Navy Capt. William Parsons and Norman Ramsey, Ph.d., a
professor at Columbia University. Is asked to organize a combat
force to deliver a new type of explosive device that is so powerful, its
full potential is unknown. Ramsey then explained the secret of the
new bomb. Tibbets is asked to devise a way to increase the
distance between the bomber and the blast of at least 8 miles. The
bomb bay would have to be modified. 15 B-29's and approximately
1,800 people will be assigned to the new group. Tibbets and Albury
fly to Wendover Field in Utah (formerly a P-47 training base) and choose
it as their training base. General Ent offers Tibbets the 393rd
Bombardment Squadron as the nucleus of the new outfit. Tibbets
becomes commander of the 393rd, and Lt. Col. Tom Classen becomes Tibbets'
9/8/44 - Tibbets sets up
headquarters at Wendover Field.
9/11/44 - 393rd
personnel arrive, including 15 B-29's with flight and ground
crews. In addition, Tibbets personally chose the following:
Tom Ferebee - Bombardier; George Carron - Tail Gunner; Dutch Van Kirk -
Navigator; Wyatt Duzenbury - Flight Engineer; Bob Lewis - Pilot; Charles
Albury - Pilot; Charles Sweeney - Pilot; James Van Pelt - Navigator;
Kermit Beahan - Bombardier; and Jacob Beser - Radar Specialist.
- 393rd reassigned from 504th Bombardment Group to the Second Air Force.
- 509th Composite Group was constituted.
- 509th CG officially activated, and became the new higher headquarters
for the 393rd Bombardment Squadron.
Early 1945 -
Original 393rd B-29's replaced with new ones direct from the assembly
lines, modified to Tibbets' specifications.
- 1st Ordinance Squadron (assigned to arm the bombs) joins the 509th.
- 1200 support personnel of the 509th sail to Tinian aboard the
troopship SS Cape Victory from Seattle, WA.
- Advanced air eschelon arrived on Tinian,
- B-29's began arriving on Tinian. Upon their arrival, the 509th
became a part of the 313th Bomber Wing of the Twentieth Air Force.
The 509th remained in relative isolation on the island, near North
7/20/45 - 509th flew its first mission
over Japan, followed by more missions on the 24th, 26th and 29th using
groups of 2 to 6 planes, practicing precision bombing rather than area
7/25/45 - The War Dept. issued orders
to General Spaatz, Commanding General of the US Army Strategic Air
Forces, readying the 509th for action. ("click" here to view
the actual "directive")
7/26/45 - The
USS Indianapolis dropped anchor off Tinian and unloaded a 15 foot wood
crate which contained the firing mechanism for the "Little
Boy" bomb. A bucket which contained the first slug of uranium
235 was also on board. Each was brought to the bomb assembly hut.
(The second piece of uranium was carried from Oak Ridge to Tinian by Lt.
Del Genio aboard a B-29) (2 other B-29's carried two more pieces for the
"Fat Man" plutonium bomb.
General Spaatz arrived on Guam and brought an order from General Groves
authorizing the dropping of the first SPECIAL BOMB on one of four
targets, Hiroshima, Kokura, Niigata, or Nagasaki sometime after August
8/3/45 - General Groves sent "Special
Bombing Mission #13" designating Hiroshima as the target. The
secondary target is Kokura. (The 12 previous missions were
It was determined as being unsafe to drop the
atomic bomb from an altitude of less than 30,000 feet.
The mission to Japan and back to Tinian would take
about 14 hours.
It would take a B-29 two minutes to fly 8 miles.
It takes the bomb 43 seconds to drop from 31,000
feet to the point of detonation at about 2,000 feet.
The shock wave will travel at 1,100 ft./sec.; 40
sec. to travel 8 miles.
B-29 would be 6 miles away vertically when the
The most effective maneuver for increasing the
distance would be to make a sharp 155 degree turn after releasing
Practice missions involved dropping bombs from
30,000 feet at a target 400 feet in diameter.
Initially practiced with conventional 2,000 lb.
Soon employed "Pumpkins" which were the
same size and weight as the SPECIAL BOMB.
Originally practiced from Batista Field in Havana,
5 planes were sent out at a time on 10 day
training missions over the Carribean.
Sweeney frequently accompanied Tibbets as co-pilot
on their many trips to Los Alamos meetings, flying into Kirtland AFB
"The Green Hornet Line" was the name
used when shuttling scientists and other personnel back and forth
from Wendover to Los Alamos.
When the 509th was first organized, it was assumed
that the outfit would be divided, with one unit going to Europe and
the other to the Pacific.
Tinian is an island in the Marianna's Chain which
includes Guam and Saipan.