Bombers as Interceptors?

[corditeman]

Good, as they say, God...

...Considering the wallowing performance of high-altitude fighters being barely able to hit 40,000 feet, I thought (wholly independently) of a Vickers Victory with a ventral twin 20-mm remote-controlled turret. As an alternative and post-attack mission, hunting Luftwaffe high-altitude fighters trying to intercept the returnees. A bastard to dive with, but very nasty if it got near you. The original design had a tail-turret.

 

[Just Leo]

...Considering the wallowing performance of high-altitude fighters being barely able to hit 40,000 feet, I thought (wholly independently) of a Vickers Victory with a ventral twin 20-mm remote-controlled turret. As an alternative and post-attack mission, hunting Luftwaffe high-altitude fighters trying to intercept the returnees. A bastard to dive with, but very nasty if it got near you. The original design had a tail-turret.

The Vickers Victory was never made. It was planned to have a tail gunner's position with 4 barbettes mounted in the rear of the engine nacelles mounting single 20mm cannons, not a tail turret. The Vickers Windsor, a smaller high altitude bomber, failed to meet speed/altitude specs, and was a horrible airplane. The Vickers 432 high-altitude fighter failed its taxi test, and then failed to meet altitude/speed specs. The Westland Welkin was chosen. Nice to see that someone can have such confidence in Vickers in spite of demonstrated failures.

 

[Riain]

I'd say the biggest problem with bombers as interceptors, before the long range AAM, is the lack of performance advantage over their quarry. The A20, Mosquito, Ju88 and even Do17 were all fast medium bombers with much greater performance than the bombers they were going to intercept, to allow them to do the chase and get into position for the kill.

 

[Carl Schwamberger]

Kind of a borderline case but, in the spring of 1943 a group of B26 bombers returning from a raid on Italy encountered a group of transports headed to Tunisia. There was a melee which included the escort fighters of the opposing groups. Several bombers were credited with shooting down transports.

 

[Michele]

large caliber guns to allow for devastating attacks outside of defensive gun range with cannons capable of destroying aircraft in a single shot,

Others have answered as to the rest.
As to the above, the issue isn't having a longer-ranged gun. You may have it, but if at its longest range it is unlikely to hit anything, especially a moving, flying target, then your standoff capability is only theoretical, not practical.

Whence the understandable choice to opt for trues standoff weapons, missiles.

Now, the question is: if a bomber can carry X AA missiles and it is longer ranged than a fighter, why not use that as a platform for AAms?
The answer is: you shouldn't compare aircraft per aircraft, but cost per cost. If a fighter can carry X/3 AAMs but also costs /4 with respect to the bomber, you just send 4 fighters, which can fire the missiles and also have air-superiority performance if need be, and you also have more AAMs.

Naturally, they might still not have the same range as a bomber, per se. But you usually have workarounds for that, like external fuel tanks, aircraft carriers, bases around the world, aircraft tankers etc. Since all of that is useful for other purposes, too, you are still better off than with a bomber used as a missile platform.

 

[MattII]

Horribly given their slower speed, lower manoeuvrability and the crapiness of bomber armament at actually doing its job without fighter escorts.

Depends which one you go for. After all, the de Havilland Mosquito was originally conceived as a bomber.

 

[yulzari]

. Due to the size of the early radars and the need for a dedicated radar operator. So airframes had to be huge, even at the cost of speed and maneuverability. Therefore the first solution was to take an existing light bomber or heavy fighter and equip it with radar and heavy forward firing guns. Examples were the Messerschmitt BF110 and Junkers Ju88 in Germany and the Douglas Havoc/P.60 in UK/US service. Compare that to the Nortrop P.61 Black Widow that was designed from the onset on as a radar night fighter and ended up a 3-person monstrosity barely smaller then the bomber-conversions it was designed to replace.

By the end of the war however, radar had become considerably smaller, small enough to be fitted in a heavy fighter. So we had the Heinkel He219 in Germany, the Twin Mustang in the US and the De Havilland Hornet in the UK.
.

However, in 1941/2 the Boulton Paul Defiant was a major part of the UK night air defence and (bar the turret) was in the single seat fighter class so it could be done early. What it lacked was firepower and loiter time. It was far from perfect but still effective with good ground direction.

 

[BlueTrousers]

The possibility was seriously discussed in the Cold War. The US Navy's LAMP LIGHT study of 1955 recommended development of a Long Range Interceptor from the B-47, to be equipped with a large radar in a rotodome and ten long-range AAMs and launched to investigate penetrations of the DEW line. There again, that study also recommended equipping the Grand Banks fishing fleet with air search radars and the development of a global marine traffic surveillance system that makes today's AIS look amateurish.

Convair also proposed a version of the B-58 as an interceptor, presumably competing with the F-108.

 

[Cryhavoc101]

Didn't Nimrod carry Sidewiders during the Falklands war

IIRC early in the campaign RAF Nimrods operating from Acension and Lockheed E3s operating from Argentina came across each other - but other than taking photos and swapping hand gestures were unable to do anything about it.

So the RAF decided to mount Sidewinders underwing on a bespoke mounting in case the meeting occoured again.

Regarding bombers being faster than interceptors in the 1930s - the main issue was one of getting the interceptors into the air and into the right place - as bombers during the 30s got increasingly faster and flew higher this problem of carrying out a sucessful interception became so difficult that experts began to make the oft cited claim that the bomber will always get through.

Air defence networks and Radar proved this to be a lie of course.

The issue was repeated in the 50s when USAF Squadrons equipped with F100 Super Sabres found that they were unable to mount interceptions on formations of Bear Bombers even when said bombers were detected 100 miles or more from the West coast such was the performance of both types of Aircraft.

Having a bomber interceptor would not have resolved this issue - having Jet fighters capable of sustained supersonic flight (and one that didn't fall out of the sky as often as the F100) ultimately resolved the issue.

Today I can see a platform such as the Northrop Grumman MQ-4C Triton mounting an APG 77 and other sensors carrying a number of AIM 120Ds or better - they can stay in the air for 24 hours effectively dominating a large area

 

[SactoMan101]

Actually, what made the Ju 88C/G and Do 217 J/N so effective against British bombers at night was the fact the Halifax, Lancaster and Stirling bombers flew relatively slowly during their night bombing missions, making them highly vulnerable to anything that was reasonably faster than the bombers. As such, both the Ju 88 and Do 217 night fighters took quite a toll on British bombers until there were enough de Havilland Mosquito NF versions in service to keep the German night fighters at bay.

 

[zoomar]

If memory serves, the Germans experimented with a cannon-armed He 177 heavy bomber as a day interceptor against USAAF bombers in the 1943-44 period (before the US bombers were escorted). As expected the experiment failed because the He 177s couldn't intercept the aircraft they were attempting to intercept. Other attempts to "drop bombs" on enemy bombers from standard day bombers or heavy fighters were equally ineffective.

Fighter variants of the Ju 88 were serviceable as day interceptor before the arrival of USAAF escorts, and Ju 88's and Do 217s served effectively as night fighters against the RAF. At night, an interceptor doesn't have to be much faster than its quarry, since effective defensive fire from the bomber is so dependent of human vision.

 

[BlueTrousers]

IIRC early in the campaign RAF Nimrods operating from Acension and Lockheed E3s operating from Argentina came across each other - but other than taking photos and swapping hand gestures were unable to do anything about it.

It was an encounter with an Argentine Boeing 707 that prompted the fit. Argentina didn't have P-3s at the time, and has never had E-3s.

The issue was repeated in the 50s when USAF Squadrons equipped with F100 Super Sabres found that they were unable to mount interceptions on formations of Bear Bombers even when said bombers were detected 100 miles or more from the West coast such was the performance of both types of Aircraft.

There were allegedly plans to use B-36s as interceptors. Specifically, by dropping nukes from 50,000 feet on formations of Tu-4s at 20,000 feet. Also, for anti-submarine warfare on the same principle. Never seen any documentation to prove it, but it sounds insane enough to be true.

 

[CalBear]

I think you'll find something similar in the novel The Third World War; August 1985 by Sir J. Hackett. Only it was Soviet Backfires armed with long ranged A2A missiles loose in the Reforger transport plane flights.

So I guess that means Dale Brown didn't come up with it first after all.

Actually I think the first widely available version of the concept was from Larry Bond's Harpoon series (the original miniatures version) in the early 1980s and then in computer version (which pretty much IS the naval combat sections of Red Storm Rising).

 

[CalBear]

Kind of a borderline case but, in the spring of 1943 a group of B26 bombers returning from a raid on Italy encountered a group of transports headed to Tunisia. There was a melee which included the escort fighters of the opposing groups. Several bombers were credited with shooting down transports.

There was also the early WW II doctrine of the USN that used the SBD is a secondary interceptor mode against torpedo planes and scouts. The Dauntless had twin .50 cals cowl mounted, and was actually effective, right up till they ran into A6M escorts. The tactic sort of lost favor at that point.

 

[Saphroneth]

I seem to recall that at some point the US considered the only viable option to intercept a B-36 equivalent bomber with a nuke to be flying another lighter B-36 above it and dropping a nuke on it. That was basically before the invention of reheat/afterburners.

 

[riggerrob]

During the 1930s, Brits developed two turret-equipped fighters to intercept streams of bombers politely flying in formation. The plan was to fly alongside and shred the bombers with broadside fire. The Boulton-Paul Defiant was a passable interceptor ... until it Messerschmitt 109s. Then it fell in droves.

Meanwhile the Fleet Air Arm was developing the Blackburn Roc, turret fighter. The Royal Navy hoped to repeat their success at the Battle of Trafgar by raking enemy fleets with broadsides.
The Blackburn Skua bomber was only marginally more successful. Both Blackburn products were so ugly that they flew because the earth repelled them!

Both the Defiant and Roc were under-gunned with only a quartet of Browning .30 caliber machine guns. .30 calibre was great at shredding WW1-vintage planes made of sticks and fabric, but had difficulty penetrating the armour installed in WW2 airplanes. Unfortunately, you needed .50 cal or 20mm cannon to shoot down WW2-vintage Luftwaffe airplanes.

WI Defiant and Roc sported 20mm cannons?

 

[oldironside]

Both the Defiant and Roc were under-gunned with only a quartet of Browning .30 caliber machine guns. .30 calibre was great at shredding WW1-vintage planes made of sticks and fabric, but had difficulty penetrating the armour installed in WW2 airplanes. Unfortunately, you needed .50 cal or 20mm cannon to shoot down WW2-vintage Luftwaffe airplanes.

WI Defiant and Roc sported 20mm cannons?

It would be almost impossible to fit 20mm cannon into the gun turrets of the time. The best option would be a remotely controlled barbette, but the majority of aircraft that tried this in WW2 suffered dreadful teething and reliability problems.

FW 191, for example, but others included the Me210/410 series, Ju288, He177, Ar240/440, all mounting rifle calibre or 13mm weapons. None of them could be considered outstanding successes. However, the B29 mounted .50 cal turrets which were considered reliable enough for the trip to Japan and back.

 

[hx87]

A full-size 20mm autocannon may be infeasible, but what about 12.7mm machine guns converted to take 20mm, such as Berezin B-20? Any mount that could take the original can take the converted gun.

 

[oldironside]

A full-size 20mm autocannon may be infeasible, but what about 12.7mm machine guns converted to take 20mm, such as Berezin B-20? Any mount that could take the original can take the converted gun.

You are still going to have a bigger gun to accomodate a larger barrel and a new ammunition feed system. According to wiki (I know, I know...) the B-20 came in at around 50 pounds and the comparable 20mm Hispano at on 43 pounds. The original 12.7mm Berezin UB weighed 47 pounds. I don't think that's a weapon the RAF are going to find easy to mount.

A comparison of 20mm and 12.7mm ammuniton.

 

[Cryhavoc101]

During the 1930s, Brits developed two turret-equipped fighters to intercept streams of bombers politely flying in formation. The plan was to fly alongside and shred the bombers with broadside fire. The Boulton-Paul Defiant was a passable interceptor ... until it Messerschmitt 109s. Then it fell in droves.

Meanwhile the Fleet Air Arm was developing the Blackburn Roc, turret fighter. The Royal Navy hoped to repeat their success at the Battle of Trafgar by raking enemy fleets with broadsides.
The Blackburn Skua bomber was only marginally more successful. Both Blackburn products were so ugly that they flew because the earth repelled them!

Both the Defiant and Roc were under-gunned with only a quartet of Browning .30 caliber machine guns. .30 calibre was great at shredding WW1-vintage planes made of sticks and fabric, but had difficulty penetrating the armour installed in WW2 airplanes. Unfortunately, you needed .50 cal or 20mm cannon to shoot down WW2-vintage Luftwaffe airplanes.

WI Defiant and Roc sported 20mm cannons?

There was a lot of crazy ideas before and during WW2

Yes the Rifle calibre MGs were not good enough to

Thats why the British mounted 8 x 303 very fast firing Vickers-Browning MGs on their first line interceptors - thats about 150 RPS

Those same chaps that determined that 4 rifle calibre machine guns were not enough also discovered that upgunning to 4 x .50 cal would not be enough either and therefore not worth changing over to this weapon

A Browning .50 MG is 63 Pounds - the 303 weapon was 23 pounds - and thats before we start considering the weight of the ammo

The .50 is also slower firing so lets assume that we replace the 8 x 303s with 4 x .50 cals our interceptors ROF is now 50 RPS



What the British wanted was a reliable 20mm cannon instead and they got that in the form of the Hispano-Suiza HS.404 - and while much heavier than both the .303 and the .50s the British designers were happy to jump over the .50 and straight to the cannon.

Very few front line Aircraft in 1939 carried sufficient armament - lets put it into context

Spitfire Mk1 / Hurricane Mk1 8 x 303 Vickers-Brownings
MS406 1 x HS 20mm cannon, 2 x 7.5mm Mgs
P36 1 x 50 cal & 1 x 30 cal MGs
A5M 2 x 7.7mm MGs
BF109 E1 4 x 7.92mm MGs

(I know you had limited varients and later varients with better armament but in Aug 1939 this is what you get)

Despite this most of these designs met in combat and proved capable of shooting each other down