"Why Big Guns on the A-4"
Sun Mar 02, 2008 3:24 pm
Dave
Cindy asked why the A-4 had bigger guns than the F-86?
Response, "Well the Navy guys had to make up for something they were lacking elsewhere..."
It took a few minutes before she got that one...
Tom
Cindy asked why the A-4 had bigger guns than the F-86?
Response, "Well the Navy guys had to make up for something they were lacking elsewhere..."
It took a few minutes before she got that one...
Tom
????
Mon Mar 03, 2008 10:16 am
Please note that the Mighty Navy started with the proper weapon in the A-4 while our beloved jr. birdmen and their F-86 started with a peashooter and worked their way up 
Mon Mar 03, 2008 11:00 am
Does anyone have information on why the 50 cal was kept on the initial F-86s? Was the adoption of a large gun system because of the abundance of the 50 cal system or just the resistance to change up to the 20mm or larger.
The Gunval program on the F-86 shows recognition of the problem, see an earlier posting:
http://warbirdinformationexchange.org/p ... hp?t=19927
The effect of the 50 cal and other armament systems was well tested in WWII. The designs of aircraft and engines later were borrowed and copied in some instances, why the delay in gun systems?
The Gunval program on the F-86 shows recognition of the problem, see an earlier posting:
http://warbirdinformationexchange.org/p ... hp?t=19927
The effect of the 50 cal and other armament systems was well tested in WWII. The designs of aircraft and engines later were borrowed and copied in some instances, why the delay in gun systems?
Mon Mar 03, 2008 12:48 pm
The initial reasoning was three-fold -
1) Cannons did not (at that time) use tracers. Pilots liked tracers as the gunsights were still not all that great at lead computing so you needed to know where your rounds were really going. Now there's all sorts of other issues to that (tracers tend to fall faster than standard rounds and they gave away that you were firing) but they were viewed to be less important.
2) Rate of Fire. At the time, Hispano HS.404 cannon used by the US only fired at somewhere around 600 rounds-per-minute while an AN/M2 fired at 800.
3) Number of rounds. Because of the higher weight and volume of the 20MM rounds, you couldn't carry as much ammunition. As such, while you could sequence your .50's and get somewhere around 45 seconds of continuous fire, you would only get 20 seconds worth of 20MM in the same aircraft.
With the advent of reliable, accurate, and automatic ranging gunsights, the loss of tracers wasn't as much of an issue and the need for so many rounds was diminished as you tended to miss less with the new gunsights, so the conversion to cannon began in earnest. As well, with the creation of the M61 "Vulcan" cannon, the rate of fire issue was resolved and the use of link-less feed systems and cylindrical ammunition drums allowed for more ammunition to be carried in the confined space of a fighter.
One other thing to consider as well is that many early cannon had relatively low velocity rounds. As such, they didn't penetrate armor as well nor did they have the ability to "reach out" as well as the higher velocity .50 rounds. This changed with the Mk.12 cannon that armed the Crusader and Skyhawk and continued with the M61, although the Mk.12 reliability issues severely limited its effectiveness even though it could fire at 1000 RPM.
1) Cannons did not (at that time) use tracers. Pilots liked tracers as the gunsights were still not all that great at lead computing so you needed to know where your rounds were really going. Now there's all sorts of other issues to that (tracers tend to fall faster than standard rounds and they gave away that you were firing) but they were viewed to be less important.
2) Rate of Fire. At the time, Hispano HS.404 cannon used by the US only fired at somewhere around 600 rounds-per-minute while an AN/M2 fired at 800.
3) Number of rounds. Because of the higher weight and volume of the 20MM rounds, you couldn't carry as much ammunition. As such, while you could sequence your .50's and get somewhere around 45 seconds of continuous fire, you would only get 20 seconds worth of 20MM in the same aircraft.
With the advent of reliable, accurate, and automatic ranging gunsights, the loss of tracers wasn't as much of an issue and the need for so many rounds was diminished as you tended to miss less with the new gunsights, so the conversion to cannon began in earnest. As well, with the creation of the M61 "Vulcan" cannon, the rate of fire issue was resolved and the use of link-less feed systems and cylindrical ammunition drums allowed for more ammunition to be carried in the confined space of a fighter.
One other thing to consider as well is that many early cannon had relatively low velocity rounds. As such, they didn't penetrate armor as well nor did they have the ability to "reach out" as well as the higher velocity .50 rounds. This changed with the Mk.12 cannon that armed the Crusader and Skyhawk and continued with the M61, although the Mk.12 reliability issues severely limited its effectiveness even though it could fire at 1000 RPM.
Mon Mar 03, 2008 4:56 pm
NAVY FJ-3's were armed with 4 20mm's
Chuck
Chuck
Tue Mar 04, 2008 9:44 am
The allies faced the German Mauser MG213C (30mm) and MG213 (20mm) through much of WWII.
http://www.forecastinternational.com/Ar ... vo0417.htm
It is difficult to understand that we waited until the early 50s to develop a similar design of this gun in the T160 and later M39 production version of the revolver cannon. The MG213C had a fire rate of 1200 rounds per minute. Range and hitting power were not an issue beyond 600 yards with HE and ICD rounds.
Rounds available per gun and weight are viewed as an issue, but damage is greater in the larger caliber and requires fewer hits.
It appears that we quickly adapted aircraft designs into the jet age and did little in the area of armament until it began to show a disadvantage in air-to-air combat.
http://www.forecastinternational.com/Ar ... vo0417.htm
It is difficult to understand that we waited until the early 50s to develop a similar design of this gun in the T160 and later M39 production version of the revolver cannon. The MG213C had a fire rate of 1200 rounds per minute. Range and hitting power were not an issue beyond 600 yards with HE and ICD rounds.
Rounds available per gun and weight are viewed as an issue, but damage is greater in the larger caliber and requires fewer hits.
It appears that we quickly adapted aircraft designs into the jet age and did little in the area of armament until it began to show a disadvantage in air-to-air combat.
Tue Mar 18, 2008 7:45 pm
Australian CAC Sabre's came with 2x30mm cannons, 162 RPG.
The English Hawker Hunter came with 4x30mm cannons, 150 RPG, which I think was quite a punch in those days.
Both used Aden cannons.
The English Hawker Hunter came with 4x30mm cannons, 150 RPG, which I think was quite a punch in those days.
Both used Aden cannons.
guns
Tue Apr 08, 2008 3:29 pm
The F-86H also had 30 mm cannons in the later part of thier production. One of the reasons was the migs had cannon and could stay out of range of the 50's and lob cannon shells at ours. Just a note on some of the comments of ex-H pilots.
JOHN
JOHN
F-86H
Tue Apr 08, 2008 5:50 pm
Sorry, previous message should read 20mm, NOT, 30mm:)
JOHN
JOHN