The F-105 became affectionately known as the “Thud” by those who flew and maintained it, whether it was due to the sound of 50,000 pounds of metal violently impacting the ground or the humorous abbreviation of the name of Howdy Doody’s Indian opponent, Chief Thunderthud
To replace the F-84F, Republic Aviation started working on a supersonic tactical fighter bomber in 1951. The F-105 Thunderchief, subsequently lovingly referred to as the “Thud,” was the outcome. The YF-105A prototype made its first flight in October 1955, but it wasn’t until June 1959 that the F-105D made its debut. 833 Thunderchiefs of all types were built, including 610 F-105Ds.
The “D” type lets the aircraft use its internal bomb bay for fuel while still being able to carry the entire 12,000-pound weapons load outside. This feature allowed the F-105D to take off with a full load of ammunition and the least amount of fuel possible, refuel in the air, and carry the most amount of cargo possible to the target.
Despite this distinctive quality, the F-105D program was considered for cancellation due to repeated fleet groundings caused by engine issues that led to two tragic accidents.
According to Ted Spitzmiller’s book Century Series, The USAF Quest Air Supremacy 1950-1960, manufacturing blocks led to configuration discrepancies that complicated maintenance procedures and spare part ordering, much as they had with earlier F-105 variants. The kilometers of wiring, hydraulic lines, and gasoline lines were routed and secured incorrectly, causing chafing that ultimately led to shorts and leaks, which brought high maintenance and multiple accidents. To inspect these systems, a standardization initiative dubbed “Project Look-Alike” was carried out between 1962 and 1964.
It was also chosen to deal with the issue of water getting into various crevices and causing major electronic failures and other maintenance issues. It is noteworthy that this problem was discovered during deployments to Europe, where the seasonal weather was significantly worse. However, the failures diminished once access panels were removed and the plane was sprayed with a silver lacquer to seal as much of the aircraft as possible.
Overheating in the afterburner (AB) region of the fuselage was another ongoing issue. To increase the amount of cooling from outside air, two additional air intakes were added, one on either side of the aft fuselage.
Howard Plunkett, author of the book F-105 Thunderchiefs: A 29-Year Illustrated Operational History, with Individual Accounts of the 103 Surviving Fighter Bombers, says: “A ‘constant problem’ is a bit understated. Fuel leaks and overheating caused explosions and aircraft losses. Safety Pack II was the mod that installed the cooling scoops on the left fuselage (among other things) between March – July 1965. It was probably the most significant mod to the F-105 and fixed the problem in time for combat deployments that year.”
The planned production of 1,500 aircraft would be drastically reduced in light of all these issues.
According to Spitzmiller, the term Thunderchief eventually became popular among Republic and its PR team, but those who piloted the heaviest fighter of the era—with a wing loading that ensured a rapid descent rate in the event of an engine failure—applied another appellation. The F-105 was nicknamed the “Thud” by those who flew and maintained it, whether due to the sound of 50,000 pounds of metal crashing to the ground or the humorous abbreviation of the name of Howdy Doody’s Indian opponent, Chief Thunderthud.
Photo by U.S. Air Force