Is the RAF "anti-cannon" ?
I don't own this space under my name. I should have leased it while I still could
I would imagine the Marines mission is more up close and personal like the AV 8B. Different mission but common air frame.
Good points, Engines.
To which I would add that the switch from 27 mm Mauser to 25 mm Gatling came at a point where LM was blithely and quite inaccurately convinced that they had weight to burn. Plus, as mentioned, the LCC issues of bringing a new caliber into the system. However it turns out that the 25 needs a new round to deliver A-G and A-A effects without using depleted uranium. Oh well, it's only the taxpayer's money.
Also, as Engines notes, tests of integrated fire/flight control in the 1980s showed higher gun lethality. The Sovs were on this earlier and consequently both cut down the number of rounds and reverted to a non-revolver cannon on the Su family (GSh-301 and 150 rounds, 2800 ft/sec MV). However, it was not fully recognized when the F-22 design was set.
Sticking a Gatling in or on a stealth aircraft is about the most expensive way to go - but that's where we are.
To which I would add that the switch from 27 mm Mauser to 25 mm Gatling came at a point where LM was blithely and quite inaccurately convinced that they had weight to burn. Plus, as mentioned, the LCC issues of bringing a new caliber into the system. However it turns out that the 25 needs a new round to deliver A-G and A-A effects without using depleted uranium. Oh well, it's only the taxpayer's money.
Also, as Engines notes, tests of integrated fire/flight control in the 1980s showed higher gun lethality. The Sovs were on this earlier and consequently both cut down the number of rounds and reverted to a non-revolver cannon on the Su family (GSh-301 and 150 rounds, 2800 ft/sec MV). However, it was not fully recognized when the F-22 design was set.
Sticking a Gatling in or on a stealth aircraft is about the most expensive way to go - but that's where we are.
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Courtney,
Thanks for coming back. I'd respectfully disagree on calibre - I believe that 20mm is just too small for anything except attacking easy air to air targets or soft ground stuff. Most of the calibres around (including the M61 gun's) are also fairly slow.
27mm is actually a very good compromise and an aerodynamically good round - but when I witnessed Diehl's tests on the HE round I was not impressed with their choice of explosive vs. fragment weight. Bit geeky for some - sorry.
Choice of driving band was driven by breech pressures. The 27mm's very large cartridge generates pressures that (at the time) required the metal driving bands. Lower pressure 20mm cannon were able to use plastic bands earlier. We had the same issue with the Aden 25mm, where still bands had to be used. Tailoring of propellant can do a lot to mitigate the issue.
Sorry to see this thread turn into another 'I hate F-35' thread but there it goes. B and C chose a podded gun to preserve signature when the gun's not required, and to reduce impact on internal fuel and weight. The logic for the B and the C (others won't agree) is that they'll fit the gun as and when it's required and of use. On an aircraft that's got severe challenges on internal space, fuel and weight, it makes some sense to me, but that's just my opinion.
The F-35 customer wanted the ability to deliver a useful weapon load at the lowest practicable (careful choice of words there) signature, as well as the option to carry lots more external stuff when signature was less important. That's what the external pylons are about. Yes, stealth is compromised on that fit. And yes, i know that others argue over what a 'useful' load is. Again, the concept makes sense to me, probably not to others though.
Hope this helps a bit
Best Regards as ever to all those making the choices for real,
Engines
Thanks for coming back. I'd respectfully disagree on calibre - I believe that 20mm is just too small for anything except attacking easy air to air targets or soft ground stuff. Most of the calibres around (including the M61 gun's) are also fairly slow.
27mm is actually a very good compromise and an aerodynamically good round - but when I witnessed Diehl's tests on the HE round I was not impressed with their choice of explosive vs. fragment weight. Bit geeky for some - sorry.
Choice of driving band was driven by breech pressures. The 27mm's very large cartridge generates pressures that (at the time) required the metal driving bands. Lower pressure 20mm cannon were able to use plastic bands earlier. We had the same issue with the Aden 25mm, where still bands had to be used. Tailoring of propellant can do a lot to mitigate the issue.
Sorry to see this thread turn into another 'I hate F-35' thread but there it goes. B and C chose a podded gun to preserve signature when the gun's not required, and to reduce impact on internal fuel and weight. The logic for the B and the C (others won't agree) is that they'll fit the gun as and when it's required and of use. On an aircraft that's got severe challenges on internal space, fuel and weight, it makes some sense to me, but that's just my opinion.
The F-35 customer wanted the ability to deliver a useful weapon load at the lowest practicable (careful choice of words there) signature, as well as the option to carry lots more external stuff when signature was less important. That's what the external pylons are about. Yes, stealth is compromised on that fit. And yes, i know that others argue over what a 'useful' load is. Again, the concept makes sense to me, probably not to others though.
Hope this helps a bit
Best Regards as ever to all those making the choices for real,
Engines
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Engines - you are the Gun God. Have a 
EXACTO ?
Does anyone else think they are now making up the soundbite acronym and then figure out how to make it work.
"Extreme Accuracy Tasked Ordnance", I mean, come on.
Actually maybe there is a business opportunity here. Anyone fancy starting up a PR company specializing in tailored acronyms ?
Military and Public Services would net us a fortune for starters.
Big market in mad religious groups as well.
EXACTO ?
Does anyone else think they are now making up the soundbite acronym and then figure out how to make it work.
"Extreme Accuracy Tasked Ordnance", I mean, come on.
Actually maybe there is a business opportunity here. Anyone fancy starting up a PR company specializing in tailored acronyms ?
Military and Public Services would net us a fortune for starters.
Big market in mad religious groups as well.
I don't own this space under my name. I should have leased it while I still could
CM was talking about different drive bands, I see the A10 30mm had two nylon bands. Incidentally, how come the US uses millimetres?
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LO,
Thanks as ever for coming back.
The change of gun on the F-35 was nothing to do with weight - my view from within the programme at the time (informed by more knowledgable BAE types) was not that LM thought they had 'weight to burn' - it was that they had no mechanism for controlling overall aircraft weight (e.g. a Chief Designer).
In any case, the gun change was a straight 'Buy US, not nasty European stuff' effort by GD, aided and abetted by compliant engineers within LM who knew better than to upset the USAF, who just love their Gatlings.
To be fair, there was technical risk with getting the Mauser's linkless feed system designed and tested, but the four barrel 25mm was a new design as well. There were rounds available at the time that met the requirement without DP, the best overall (in my view) was the Raufoss MultiPurpose (MP) design. Others can differ.
LO also makes a quite excellent point about integrated fire/flight control (IFFC). Tested by the US, fielded by the Russians and (I believe) the Swedes. Takes gun system effectiveness to a new level, and quite disregarded by the RAF. The GsH-301 is a good contender for best aircraft cannon around just now, in my view. Compact, light, reliable, and rate of fire good enough. The Russians understand this gun stuff quite well.
Best regards to all those cleaning the barrels,
Engines
PS (Edit): My understanding is that all cannon have been metric from day one - I believe because their design started in Europe (Hispano, Oerlikon). Almost all military gun calibres switched to metric by the 1950s, but some still use the older imperial 'legacy' calibres. This calibre history stuff can get quite geeky, so I'll stop now before I make a mistake....
Thanks as ever for coming back.
The change of gun on the F-35 was nothing to do with weight - my view from within the programme at the time (informed by more knowledgable BAE types) was not that LM thought they had 'weight to burn' - it was that they had no mechanism for controlling overall aircraft weight (e.g. a Chief Designer).
In any case, the gun change was a straight 'Buy US, not nasty European stuff' effort by GD, aided and abetted by compliant engineers within LM who knew better than to upset the USAF, who just love their Gatlings.
To be fair, there was technical risk with getting the Mauser's linkless feed system designed and tested, but the four barrel 25mm was a new design as well. There were rounds available at the time that met the requirement without DP, the best overall (in my view) was the Raufoss MultiPurpose (MP) design. Others can differ.
LO also makes a quite excellent point about integrated fire/flight control (IFFC). Tested by the US, fielded by the Russians and (I believe) the Swedes. Takes gun system effectiveness to a new level, and quite disregarded by the RAF. The GsH-301 is a good contender for best aircraft cannon around just now, in my view. Compact, light, reliable, and rate of fire good enough. The Russians understand this gun stuff quite well.
Best regards to all those cleaning the barrels,
Engines
PS (Edit): My understanding is that all cannon have been metric from day one - I believe because their design started in Europe (Hispano, Oerlikon). Almost all military gun calibres switched to metric by the 1950s, but some still use the older imperial 'legacy' calibres. This calibre history stuff can get quite geeky, so I'll stop now before I make a mistake....
Engines, I think you've completely missed my point.
I said 20mm is for air-to-air not ground targets. Soft or not - although, yes, it could do soft targets. My point there is high rate of fire. Not sure what you mean by "easy" air-to-air targets. A few HE 20mm rounds close to the aim point remains an effective weapon.
I did say that I too think the 27mm round is a good compromise. But there were other possible solutions to breach pressure apart from the land-removing driving band leading to short barrel life. But I still think it's a good round.
As for F-35 hating, sorry, you've hit the wrong guy. I'm sure you've seen enough of my posts to know I am not anti-F-35. Just because I question things does not mean I don't want it to succeed. I see the faults in lots of things, doesn't mean I want them to fail.
Thank you.
Courtney
I said 20mm is for air-to-air not ground targets. Soft or not - although, yes, it could do soft targets. My point there is high rate of fire. Not sure what you mean by "easy" air-to-air targets. A few HE 20mm rounds close to the aim point remains an effective weapon.
I did say that I too think the 27mm round is a good compromise. But there were other possible solutions to breach pressure apart from the land-removing driving band leading to short barrel life. But I still think it's a good round.
As for F-35 hating, sorry, you've hit the wrong guy. I'm sure you've seen enough of my posts to know I am not anti-F-35. Just because I question things does not mean I don't want it to succeed. I see the faults in lots of things, doesn't mean I want them to fail.
Thank you.
Courtney
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Courtney,
Thanks for taking the time to respond.
Firstly, my apologies for inadvertently inferring that you were an 'F-35 hater' - I did not mean that, I know you take a fair view on that programme. Sorry.
On calibre for air to air combat, I will respectfully differ, and I'll explain why.
The overall effectiveness of any gun system can be built up by multiplying probability of a hit (Ph) by probability of a kill (Pk). In some simulations, Ph is calculated for a burst, not a single round, similarly for Pk. In others, the single round values are used, and then Pk is 'added' (sort of) for a burst hit. In both, you could also add a ranging factor in to reflect how often the aircraft might be able to use the gun at all.
What I found in the 90s was that there were no standard models for calculating Pk, nor was there much reliable data around the Pk of various rounds. The best data available was from a series of live firing trials carried out in the 80s in Norway. Basically, they concluded that high velocity large fragments fired into the aircraft along the fuselage were the best 'killers'. (Interestingly, the Mauser's shell was optimised to blow large holes in wings when entering at right angles). What is (hopefully) indisputable is that a single larger shell has a better Pk than a single smaller shell. I know of no reliable quantitative models for assessing the Pk of a series of hits. I do know that the DERA/AWC models in the 90s were really badly wrong. (Mathematically wrong).
So you need to look at now the round or its calibre might affect Ph. Interestingly, gun rate of fire does not have a massive effect on this. The key factor is time of flight. Shorter time of flight (faster bullet), better Ph. (Bullet shapes were improved in all calibres in the late 90s, using data from Gerald Bull's superman studies). Another factor is the bullet density in the target's area of sky. Again, not directly linked to rate of fire, can be affected by dispersion. This is affected by many things, but at longer ranges, the faster the shell, the better.
Revolvers (and guns like the Gsh-301) reach their full rate from the first round. Gatlings take time to spin up. In a half second burst, most revolvers get more rounds away than a Gatling. (I understand that Gatling users sometimes compensate by using longer bursts, starting before the 'pipper' goes over the target - but this wastes shells).
So, in my view, and informed by the calculations being done in the 80s, 90s and afterwards, the larger (faster) calibres (25mm, 27mm, 30mm) are better air to air systems. I would point out that nearly all the newer systems appearing use these calibres. They also give the system a far better air to ground capability, with much longer range and better target effect. In short, this is why the F-35 went for a four barrel 25mm gun rather than the six barrel 20mm M-61.
I'd go further - looking at overall system weight, power demands, and volume, i believe that revolvers or reciprocating cannon (e.g. Oerlikon, GsH-301) are a better overall system for fighter aircraft use. I know that many will differ, but honestly, it's not all about rate of fire all the time.
That's my view, anyway., not that it matters much.
Hope some folks find this mildly interesting, if not sorry for boring you.
Engines
Thanks for taking the time to respond.
Firstly, my apologies for inadvertently inferring that you were an 'F-35 hater' - I did not mean that, I know you take a fair view on that programme. Sorry.
On calibre for air to air combat, I will respectfully differ, and I'll explain why.
The overall effectiveness of any gun system can be built up by multiplying probability of a hit (Ph) by probability of a kill (Pk). In some simulations, Ph is calculated for a burst, not a single round, similarly for Pk. In others, the single round values are used, and then Pk is 'added' (sort of) for a burst hit. In both, you could also add a ranging factor in to reflect how often the aircraft might be able to use the gun at all.
What I found in the 90s was that there were no standard models for calculating Pk, nor was there much reliable data around the Pk of various rounds. The best data available was from a series of live firing trials carried out in the 80s in Norway. Basically, they concluded that high velocity large fragments fired into the aircraft along the fuselage were the best 'killers'. (Interestingly, the Mauser's shell was optimised to blow large holes in wings when entering at right angles). What is (hopefully) indisputable is that a single larger shell has a better Pk than a single smaller shell. I know of no reliable quantitative models for assessing the Pk of a series of hits. I do know that the DERA/AWC models in the 90s were really badly wrong. (Mathematically wrong).
So you need to look at now the round or its calibre might affect Ph. Interestingly, gun rate of fire does not have a massive effect on this. The key factor is time of flight. Shorter time of flight (faster bullet), better Ph. (Bullet shapes were improved in all calibres in the late 90s, using data from Gerald Bull's superman studies). Another factor is the bullet density in the target's area of sky. Again, not directly linked to rate of fire, can be affected by dispersion. This is affected by many things, but at longer ranges, the faster the shell, the better.
Revolvers (and guns like the Gsh-301) reach their full rate from the first round. Gatlings take time to spin up. In a half second burst, most revolvers get more rounds away than a Gatling. (I understand that Gatling users sometimes compensate by using longer bursts, starting before the 'pipper' goes over the target - but this wastes shells).
So, in my view, and informed by the calculations being done in the 80s, 90s and afterwards, the larger (faster) calibres (25mm, 27mm, 30mm) are better air to air systems. I would point out that nearly all the newer systems appearing use these calibres. They also give the system a far better air to ground capability, with much longer range and better target effect. In short, this is why the F-35 went for a four barrel 25mm gun rather than the six barrel 20mm M-61.
I'd go further - looking at overall system weight, power demands, and volume, i believe that revolvers or reciprocating cannon (e.g. Oerlikon, GsH-301) are a better overall system for fighter aircraft use. I know that many will differ, but honestly, it's not all about rate of fire all the time.
That's my view, anyway., not that it matters much.
Hope some folks find this mildly interesting, if not sorry for boring you.
Engines
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Genuinely wondering - With your research Engines, is the Pk linked to the pure kinetic impact of the round - i.e like a solid slug - or is it linked to the blast / fragmentation effects of rounds that go bang?
Nicked from elsewhere:
MauserWerke GmbH BK-27
At only 100kg this cannon offers a significant firing velocity combined with a relatively large shell, it compares extremely favourably with its counterparts. When compared to the U.S. M-61 with a rate of fire of 6000 shells per minute, the BK-27 seems outclassed with a low 1700 shells per minute. However looks can be deceptive, while the M-61 takes almost a second to reach its full firing rate the BK-27's is almost instantaneous. The Mauser will have fired over 4kg of projectiles in 0.5 seconds while the M-61 scores around 2kg. The M-61 will only exceed the BK-27 after a full second of firing.
At only 100kg this cannon offers a significant firing velocity combined with a relatively large shell, it compares extremely favourably with its counterparts. When compared to the U.S. M-61 with a rate of fire of 6000 shells per minute, the BK-27 seems outclassed with a low 1700 shells per minute. However looks can be deceptive, while the M-61 takes almost a second to reach its full firing rate the BK-27's is almost instantaneous. The Mauser will have fired over 4kg of projectiles in 0.5 seconds while the M-61 scores around 2kg. The M-61 will only exceed the BK-27 after a full second of firing.
The UK guns saga should be seen against the backdrop of the roles envisaged for the aircraft.
The Hunter (aah Hawker) was DFGA, thus guns were considered as dual role. The Lightning (WIWOL) was an AWF – actually all-weather interceptor, where the bomber opposition had guns pointing back at you - thus greater range, and radar ranging and direction. Missiles were designed to overcome these difficulties, so too the problems of much higher airspeeds. Guns made more sense in Europe (F2A) to engage low level strike aircraft.
There was (is) a requirement for guns in ground attack aircraft, unfortunately some were called ‘fighters’ which confused those who should have known better; however with the advent of modern ground-defence systems the debate for guns is open.
The F4 gun was for soft air-air targets in VN; the UK eventually acknowledged the F4s dual role in UKADE and Europe.
The A10 fills a niche role against poorly defended ground targets or had sufficient ECM cover to make it viable.
The future balance might be with a low cost gun attack (depending on the capabilities of ECM suppression) vs high cost stand-off precision weapons.
Yet as we should remember we never fight the war for which we train for (or plan for). No plan survives contact with the enemy – i.e. current sand-wars where psyc ops might be a better weapon – or a gun.
An afterthought; the Lightning was reportedly very effective with guns air-to-ground in Saudi; the high wing loading provided a stable platform - smoothed the ride over hot air bumps and gusts and thus was relatively accurate – and it was 30mm.
The Hunter (aah Hawker) was DFGA, thus guns were considered as dual role. The Lightning (WIWOL) was an AWF – actually all-weather interceptor, where the bomber opposition had guns pointing back at you - thus greater range, and radar ranging and direction. Missiles were designed to overcome these difficulties, so too the problems of much higher airspeeds. Guns made more sense in Europe (F2A) to engage low level strike aircraft.
There was (is) a requirement for guns in ground attack aircraft, unfortunately some were called ‘fighters’ which confused those who should have known better; however with the advent of modern ground-defence systems the debate for guns is open.
The F4 gun was for soft air-air targets in VN; the UK eventually acknowledged the F4s dual role in UKADE and Europe.
The A10 fills a niche role against poorly defended ground targets or had sufficient ECM cover to make it viable.
The future balance might be with a low cost gun attack (depending on the capabilities of ECM suppression) vs high cost stand-off precision weapons.
Yet as we should remember we never fight the war for which we train for (or plan for). No plan survives contact with the enemy – i.e. current sand-wars where psyc ops might be a better weapon – or a gun.
An afterthought; the Lightning was reportedly very effective with guns air-to-ground in Saudi; the high wing loading provided a stable platform - smoothed the ride over hot air bumps and gusts and thus was relatively accurate – and it was 30mm.
Engines, thank you for the recap of QWI course air-to-air gunnery phase day one. I concur. And that is my point. I lost my last attempted response thanks to an unfortunate Mr Apple Pk failure. So forgive me if I'm brief this time.
My original point was about round calibre and rate of fire. You now move on to the types of gun and, I hope most here will appreciate the differences, advantages and disadvantages of auto/revolver/Gatling. We haven't touched modern sighting systems/AI radar radars and the accuracy and relative ease of use.
Muzzle velocity is clearly a factor, but eventually that, in VERY SIMPLE TERMS becomes a sighting and range issue.
You have burst vs round correct. Ph and Pk for an individual round is a variable feast. Hit what, for example? The airframe, a vital system, a void? The comparison I made was between more, smaller calibre HE rounds and fewer, larger calibre HE rounds. The end result of which is potential for a spread of positive Ph rounds with a probability of damaging more vital organs (for example multiple routings of FBW lines) against fewer, larger rounds with a larger damage radius, but with the risk of leaving some redundancy functioning.
I like your maths, but practical experience doesn't always follow the models. My experience with air-to-air practice gunnery, live gunnery trials and test firing against test targets leads me to conclude the difference in requirements for AA and AG. That's all I'm saying.
My original point was about round calibre and rate of fire. You now move on to the types of gun and, I hope most here will appreciate the differences, advantages and disadvantages of auto/revolver/Gatling. We haven't touched modern sighting systems/AI radar radars and the accuracy and relative ease of use.
Muzzle velocity is clearly a factor, but eventually that, in VERY SIMPLE TERMS becomes a sighting and range issue.
You have burst vs round correct. Ph and Pk for an individual round is a variable feast. Hit what, for example? The airframe, a vital system, a void? The comparison I made was between more, smaller calibre HE rounds and fewer, larger calibre HE rounds. The end result of which is potential for a spread of positive Ph rounds with a probability of damaging more vital organs (for example multiple routings of FBW lines) against fewer, larger rounds with a larger damage radius, but with the risk of leaving some redundancy functioning.
I like your maths, but practical experience doesn't always follow the models. My experience with air-to-air practice gunnery, live gunnery trials and test firing against test targets leads me to conclude the difference in requirements for AA and AG. That's all I'm saying.
Engines - The "weight to burn" thing was what I was told at the time, by someone who was probably unaware that the program had lost the plot.
Industrially, the Mauser was a bit of an orphan - the company that was supposed to build it for JSF had started as part of Hughes, then was Macs, then was Boeing, who finally sold their gun line to ATK. I suspect they made a lot more money from the Army than the AF and doubt that they put up much of a fight when GD (I think it was GD by then, having previously been GE) launched the offensive to throw them off JSF. For GD in Burlington it was pretty existential.
Gatlings were more competitive with multiple guns (the typical pre-missile setup) than with a single heavy cannon. As noted, only the US went all the way with the Gatling, but the time-to-rate issue mandates a lot of ammo in a heavy feed system.
Industrially, the Mauser was a bit of an orphan - the company that was supposed to build it for JSF had started as part of Hughes, then was Macs, then was Boeing, who finally sold their gun line to ATK. I suspect they made a lot more money from the Army than the AF and doubt that they put up much of a fight when GD (I think it was GD by then, having previously been GE) launched the offensive to throw them off JSF. For GD in Burlington it was pretty existential.
Gatlings were more competitive with multiple guns (the typical pre-missile setup) than with a single heavy cannon. As noted, only the US went all the way with the Gatling, but the time-to-rate issue mandates a lot of ammo in a heavy feed system.
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LO,
That's a very informative bit on the '27mm Mauser for JSF' - many thanks. I do remember trying to get some details on how a linkless feed would work for a revolver (especially the starting and stopping bit) and there was a bit of a deafening silence.
And you are spot on about GD's 'need to win'.
You touch on a really important aspect, which is how to assess the efficiency of a gun system. My own take (and just my own) is that in a fighter/strike aircraft, performance has to be assessed against the impacts on weight and especially internal volume. Every system on the aircraft has to minimise these, and a well designed gun system does the same. The logic works for helicopters too, in my opinion.
Thanks for the post
Best Regards as ever
Engines
That's a very informative bit on the '27mm Mauser for JSF' - many thanks. I do remember trying to get some details on how a linkless feed would work for a revolver (especially the starting and stopping bit) and there was a bit of a deafening silence.
And you are spot on about GD's 'need to win'.
You touch on a really important aspect, which is how to assess the efficiency of a gun system. My own take (and just my own) is that in a fighter/strike aircraft, performance has to be assessed against the impacts on weight and especially internal volume. Every system on the aircraft has to minimise these, and a well designed gun system does the same. The logic works for helicopters too, in my opinion.
Thanks for the post
Best Regards as ever
Engines
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FM,
Thought I'd try to give you an answer, which is, i think, 'nearly'.
Post WW2, the USAF's requirement for a jet night fighter included a requirement for guns mounted in gimballed turrets that could be fired 'off axis'. (I wonder whether they were influenced by the Luftwaffe's upward firing 'Jazz Music' installations?)
The F89 Scorpion and F-94 Starfire both included nose mounted gun turrets in their designs, but these were binned early on and replaced with batteries of forward firing unguided missiles. These changes were driven by the realisation that effective gun engagements were going to be very difficult to achieve for early jets, and that longer range solutions had to be tried.
Incidentally, the Hughes team working on the radar assisted 'automatic fire control' systems for these aircraft published the very first papers on what came to called 'control theory' - I remember referencing it during my time at Cranfield.
The idea did surface again during the USAF's integrated fire and flight control (IFFC) programme of the late 70s. The trial aircraft (F-15, I think) had its M61 Gatling system modified to allow a very small amount (I think somewhere between 2 and 4 degrees) of gun deflection. This was linked to a high rate hydraulic actuation system, driven by the IFFC system. The idea was to allow the gun to make small but important high rate corrections to the aiming solution without moving the aircraft. I seem to remember that the system worked extremely well.
Hope this is vaguely interesting
Best Regards as ever
Engines
Thought I'd try to give you an answer, which is, i think, 'nearly'.
Post WW2, the USAF's requirement for a jet night fighter included a requirement for guns mounted in gimballed turrets that could be fired 'off axis'. (I wonder whether they were influenced by the Luftwaffe's upward firing 'Jazz Music' installations?)
The F89 Scorpion and F-94 Starfire both included nose mounted gun turrets in their designs, but these were binned early on and replaced with batteries of forward firing unguided missiles. These changes were driven by the realisation that effective gun engagements were going to be very difficult to achieve for early jets, and that longer range solutions had to be tried.
Incidentally, the Hughes team working on the radar assisted 'automatic fire control' systems for these aircraft published the very first papers on what came to called 'control theory' - I remember referencing it during my time at Cranfield.
The idea did surface again during the USAF's integrated fire and flight control (IFFC) programme of the late 70s. The trial aircraft (F-15, I think) had its M61 Gatling system modified to allow a very small amount (I think somewhere between 2 and 4 degrees) of gun deflection. This was linked to a high rate hydraulic actuation system, driven by the IFFC system. The idea was to allow the gun to make small but important high rate corrections to the aiming solution without moving the aircraft. I seem to remember that the system worked extremely well.
Hope this is vaguely interesting
Best Regards as ever
Engines
Originally Posted by HTB
As for strafe against ground targets from a Tornada GR (Not the GR1A, though, the cannons gave way to the recce sensors and recording equipment), the profile for target acquisition, aiming and squirting, recovery and running away were better suited to the benign range enviroment. The exposure time and crew focus on shooting and recovering in a hostile scenario would have made the aeroplane quite vulnerable to small arms fire from the hundreds of annoyed troops below.
And you would need the right sort of bullets for the intended target, taking into consideration ricochet and effectiveness (armour/soft skinned); generally more misses than hits (on the range), limited amount of ammunition. Cost/benefit analysis - not really worth the risk and effort.
And you would need the right sort of bullets for the intended target, taking into consideration ricochet and effectiveness (armour/soft skinned); generally more misses than hits (on the range), limited amount of ammunition. Cost/benefit analysis - not really worth the risk and effort.
And it's more fun too.
https://m.youtube.com/watch?v=fbUbZ8cgEqA
JAJ - you are quite correct that the range and accuracy on the 27mm is often overlooked. Even on the GR1 we 'ceased' at a similar range as the Aden users 'opened'. The velocity at the target was similar to what the Aden achieved at the muzzle. It really was a step-change in capability and poorly understood by those who only knew the old 30mm Aden.
JAJ - you are quite correct that the range and accuracy on the 27mm is often overlooked. Even on the GR1 we 'ceased' at a similar range as the Aden users 'opened'. The velocity at the target was similar to what the Aden achieved at the muzzle. It really was a step-change in capability and poorly understood by those who only knew the old 30mm Aden.
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JTO,
You are absolutely right about the capability of the Mauser 27mm. It remains an excellent gun, the only issue being the very high cost of ownership due to its unique calibre.
I'd only suggest that as 'old' as the Aden 30 is, its ballistic characteristics are still in the same ballpark as those of the modern GsH-301 - low muzzle velocity, heavy shell. In the 90s, RO offered the RAF and RN an improved Aden 30 round using low drag and Multipurpose (MP) technology, which would have delivered a useful improvement in range and lower dispersion, but no takers.
The Aden 25 programme was an attempt to deliver a much better performance from an existing gun. The gun worked, but the programme was undone by poor attempts at gun/aircraft integration. (The US approach, where the gun designers also design gun mountings, gun pods and ammunition feeds, is, in my experience, much more sound).
The real step change in gun effectiveness, which has gone largely unremarked in the West, is the advent of radars that can deliver very accurate range and range rate at typical gun engagement ranges. This. in turn, leads to much better fire control solutions. Also, modern aircraft computing systems are delivering updates hundreds of times a second instead of twice a second. As the Sea Harrier FA2 showed, these deliver much, much better accuracy and high hit probability, even with lower rates of fire.
Best Regards to those bothering to read this - please tell me when you're bored.
Engines
You are absolutely right about the capability of the Mauser 27mm. It remains an excellent gun, the only issue being the very high cost of ownership due to its unique calibre.
I'd only suggest that as 'old' as the Aden 30 is, its ballistic characteristics are still in the same ballpark as those of the modern GsH-301 - low muzzle velocity, heavy shell. In the 90s, RO offered the RAF and RN an improved Aden 30 round using low drag and Multipurpose (MP) technology, which would have delivered a useful improvement in range and lower dispersion, but no takers.
The Aden 25 programme was an attempt to deliver a much better performance from an existing gun. The gun worked, but the programme was undone by poor attempts at gun/aircraft integration. (The US approach, where the gun designers also design gun mountings, gun pods and ammunition feeds, is, in my experience, much more sound).
The real step change in gun effectiveness, which has gone largely unremarked in the West, is the advent of radars that can deliver very accurate range and range rate at typical gun engagement ranges. This. in turn, leads to much better fire control solutions. Also, modern aircraft computing systems are delivering updates hundreds of times a second instead of twice a second. As the Sea Harrier FA2 showed, these deliver much, much better accuracy and high hit probability, even with lower rates of fire.
Best Regards to those bothering to read this - please tell me when you're bored.
Engines
