Zyzygie’s Mumbles and Rambles

[Zyzygie]

Gloster Meteor Mk 8 A77-368

"...On display in the Australian War Memorial is one of the most war weary of aircraft, Gloster Meteor Mk 8 jet fighter, Ex RAAF serial number A77-368. This aircraft flew with the RAAF in Korea performing no less than 485 operational missions and flying time in theatre of 484 hours. Very few aircraft in the RAAF can claim that level of utilization in any conflict..."

"...A77-368 was constructed by Glosters (The Gloucestershire Aircraft Company Limited) of Cheltenham UK as an F.8 Fighter and allotted an RAF serial WA952, however it never served with the RAF and was instead sent to Korea as part of an allocation of Meteor's to the RAAF to replace the 77 Sqn North American P51 aircraft which were by then outdated. Even the Meteor as a WWII era aircraft was not a competitive fighter any longer and as such it was relegated to ground attack duties after a period of difficult engagements in the fighter role, as with the P51 before it. The Meteor was nonetheless an excellent ground attack aircraft and the 77 Sqn aircraft performed extremely well with an enviable record of 15,000 missions in Meteors, five MiG-15s and destroying 3,700 buildings, 1,408 vehicles, ninety-eight railway engines and carriages, and sixteen bridges. The cost was very severe however with 40 Meteors lost and 25 RAAF pilots killed..."

The 77 Squadron was awarded a Korean Presidential Citation for its service in the Korean conflict:

"...Probably its most profound accolade was the Korean Presidential citation awarded in late 1951. However from an Australian perspective, praise from one's own countrymen is always highly valued. The Battalion 2 IC and later Commanding Officer of the 3rd Battalion, Royal Australian Regiment (3RAR), Major (later Lieutenant Colonel) I.B. (Bruce) Ferguson praised the provision of close air support to 3RAR by 77 Squadron in a major attack it carried out near Pakchon on 5 November 1950."

"3RAR had called for preparatory bombardment of Chinese positions on a line of hilltops overlooking the Pakchon–Sinanju Road in the Taeryong Valley, before 3RAR launched their attack. No. 77 Squadron was the squadron on call and responded, firing rockets and dropping napalm on the Chinese positions, before following up with strafing runs against Chinese troops fleeing their positions. After several hours of close fighting, 3RAR gained their objectives."

Major Bruce Ferguson later described No. 77 Squadron's close air support as "the closest I have ever seen" and commented, "It was an all Australian show … the boost to morale was amazing when we recognised the planes of 77 Squadron overhead."

No. 77 Squadron RAAF - Wikipedia

"...Following the signing of the Korean Armistice Agreement on 27 July 1953, the squadron remained in South Korea on garrison duties—initially at Kimpo, later at Kunsan—until transferring to Iwakuni on 12 October 1954.[16][115] It departed for Australia on 19 November and arrived in Sydney on 3 December, having been based overseas for eleven years, a record for an RAAF unit.[116] Its performance in the early days of the war has been cited as a factor in the United States' decision to ratify the ANZUS treaty in September 1951.[117] The squadron's casualty rate in Korea was twenty-five percent killed or captured.[118][119] Forty-one pilots died, thirty-five from the RAAF and six on exchange from the Royal Air Force.[118][120] A further seven pilots became prisoners of war.[109][121] Aircraft losses totalled almost sixty, including over forty Meteors, mostly to ground fire.[118][122] The squadron flew 18,872 sorties, including 3,872 in Mustangs and 15,000 in Meteors.[109][123] It was credited with shooting down five MiG-15s and destroying 3,700 buildings, 1,408 vehicles, ninety-eight railway engines and carriages, and sixteen bridges.[118][124]..."

 

[Zyzygie]

"During the Korean War, the RAAF's No 77 Squadron was the sole unit within the United Nations Command which operated the British-built Gloster Meteor Mk 8 jet fighter. In April 1951 the squadron withdrew its P-51 Mustangs from operations to re-equip with the Meteor, returning to Korean skies in July, and remaining until the armistice was signed on 27 July 1953. During this period, the Meteor flew in the air-to-air, bomber escort, combat air patrol and ground attack roles. Its performance in the air-to-air role, in which it was pitted against the Russian-built MiG-15 flown by the Chinese Air Force, is a controversial subject that bears critical assessment..."

"...In the first three combats, between 29 August and 26 September, a single MiG-15 was claimed as damaged, for the loss of one Meteor and three others damaged. This was taken to show that the RAAF aircraft was outclassed in the fighter combat role. A further large-scale clash on 1 December 1951 appeared to reinforce this belief: the success ratio was 3:2 in favour of the MiG-15. The next day, after discussions between the CO of 77 Squadron and the Director of Operations, USAF Fifth Air Force, the aircraft was withdrawn from fighter sweeps into 'MiG Alley' and reassigned to bomber escort and combat air patrol over Allied fighter-bombers. This decision has been the basis of considerable contention ever since, with even some of the pilots concerned later asserting that the change was made with undue haste and that, if the combat pilots had been given the standard of fighter combat instruction that was later applied, the Meteor could have been more successful in the air-to-air role.In the context of the fighter pilot training scenario of the early 1950s, those making such criticisms appear to have a point. In the years immediately following World War II the RAAF had paid little attention to air combat training, and it was not until March 1952 that No 2 Operational Conversion Unit was raised to address training shortfalls that were recognised in Korea..."

"...Also appearing to support the contention that the RAAF might have been too quick to bail out of the air-to-air role with the Meteor are the final shoot-down statistics. These show that in total 77 Squadron only lost four Meteors to the MiG-15, all of them on or before the aircraft was pulled from unrestricted air combat on 1 December 1951, against five MiGs confirmed as destroyed—all after that same date..."

"...One 77 Squadron pilot who actually accounted for a MiG-15 later had the opportunity to practice in the Meteor against Sabres while on exchange with the Meteor Mk 8 RAF in Europe. Based on his observations, he remains convinced to this day that at lower altitudes (up to 6000 metres) an aggressively flown Meteor could out-turn and out-accelerate the Sabre. Another 77 Squadron pilot had earlier expressed the view that the Meteor's manoeuvrability meant that no RAAF pilot should have been shot down by a MiG-15 below 9000 metres unless he made a mistake..."

"...Lack of air combat training and tactics quite probably did limit the ability of 77 Squadron pilots to initially achieve success against the MiG-15. But the contention that extra time spent in the air-to-air role would have enhanced the ability of the pilots still seems questionable. The operational lessons and a critical assessment of the performance of the Meteor and MiG-15 make it obvious that an unacceptably high attrition rate in aircraft and pilots could have been expected if air-to-air operations had continued. Compared to the Meteor, the MiG-15 was far superior in performance. The initial climb rate of the Russian aircraft was 2900 feet per minute faster than the Meteor, and it was 73 miles per hour faster in level flight; the comparative power to weight ratio (based on empty weight) was 1.76:1 for the MiG-15 and 1.45:1 for the Meteor. These latter figures support the assumption that the MiG-15 would have faster acceleration than the Meteor. Another performance figure that clearly identifies the difference between the two fighters was their critical Mach number. The Meteor was rated at 0.87, after which it developed compressibility problems, a phenomenon that was not so evident in the MiG-15.The basic difference between the two aircraft was that the Mark 8 Meteor was the ultimate single-seat fighter development of an obsolescent design incorporating the technology of the early 1940s, while the MiG-15 belonged to an entirely new generation of design considerations. The Meteor's twin-engine layout recognised the low power of the pioneer turbojet engines with which it was fitted, and its wings were straight and thick, whereas the MiG-15 (and the Sabre) incorporated later German thin swept wing technology..."

"...The MiG-15 formations tactically controlled air combat over Korea. They initiated combat on their terms, and the performance of the MiG-15 enabled them to break contact in a like manner. No matter how well trained the Australian pilots may have been, the performance of the Meteor always placed it at tactical disadvantage in the air-to-air role. Analysis of the individual actions when MiGs were shot down by Meteors strongly suggest that these were simply situations where Chinese pilots made the mistakes..."

http://airpower.airforce.gov.au/APDC/media/PDF-Files/Pathfinder/PF009-Meteors-Versus-MiGs.pdf

 

[BiffF15]

"During the Korean War, the RAAF's No 77 Squadron was the sole unit within the United Nations Command which operated the British-built Gloster Meteor Mk 8 jet fighter. In April 1951 the squadron withdrew its P-51 Mustangs from operations to re-equip with the Meteor, returning to Korean skies in July, and remaining until the armistice was signed on 27 July 1953. During this period, the Meteor flew in the air-to-air, bomber escort, combat air patrol and ground attack roles. Its performance in the air-to-air role, in which it was pitted against the Russian-built MiG-15 flown by the Chinese Air Force, is a controversial subject that bears critical assessment..."

"...In the first three combats, between 29 August and 26 September, a single MiG-15 was claimed as damaged, for the loss of one Meteor and three others damaged. This was taken to show that the RAAF aircraft was outclassed in the fighter combat role. A further large-scale clash on 1 December 1951 appeared to reinforce this belief: the success ratio was 3:2 in favour of the MiG-15. The next day, after discussions between the CO of 77 Squadron and the Director of Operations, USAF Fifth Air Force, the aircraft was withdrawn from fighter sweeps into 'MiG Alley' and reassigned to bomber escort and combat air patrol over Allied fighter-bombers. This decision has been the basis of considerable contention ever since, with even some of the pilots concerned later asserting that the change was made with undue haste and that, if the combat pilots had been given the standard of fighter combat instruction that was later applied, the Meteor could have been more successful in the air-to-air role.In the context of the fighter pilot training scenario of the early 1950s, those making such criticisms appear to have a point. In the years immediately following World War II the RAAF had paid little attention to air combat training, and it was not until March 1952 that No 2 Operational Conversion Unit was raised to address training shortfalls that were recognised in Korea..."

"...Also appearing to support the contention that the RAAF might have been too quick to bail out of the air-to-air role with the Meteor are the final shoot-down statistics. These show that in total 77 Squadron only lost four Meteors to the MiG-15, all of them on or before the aircraft was pulled from unrestricted air combat on 1 December 1951, against five MiGs confirmed as destroyed—all after that same date..."

"...One 77 Squadron pilot who actually accounted for a MiG-15 later had the opportunity to practice in the Meteor against Sabres while on exchange with the Meteor Mk 8 RAF in Europe. Based on his observations, he remains convinced to this day that at lower altitudes (up to 6000 metres) an aggressively flown Meteor could out-turn and out-accelerate the Sabre. Another 77 Squadron pilot had earlier expressed the view that the Meteor's manoeuvrability meant that no RAAF pilot should have been shot down by a MiG-15 below 9000 metres unless he made a mistake..."

"...Lack of air combat training and tactics quite probably did limit the ability of 77 Squadron pilots to initially achieve success against the MiG-15. But the contention that extra time spent in the air-to-air role would have enhanced the ability of the pilots still seems questionable. The operational lessons and a critical assessment of the performance of the Meteor and MiG-15 make it obvious that an unacceptably high attrition rate in aircraft and pilots could have been expected if air-to-air operations had continued. Compared to the Meteor, the MiG-15 was far superior in performance. The initial climb rate of the Russian aircraft was 2900 feet per minute faster than the Meteor, and it was 73 miles per hour faster in level flight; the comparative power to weight ratio (based on empty weight) was 1.76:1 for the MiG-15 and 1.45:1 for the Meteor. These latter figures support the assumption that the MiG-15 would have faster acceleration than the Meteor. Another performance figure that clearly identifies the difference between the two fighters was their critical Mach number. The Meteor was rated at 0.87, after which it developed compressibility problems, a phenomenon that was not so evident in the MiG-15.The basic difference between the two aircraft was that the Mark 8 Meteor was the ultimate single-seat fighter development of an obsolescent design incorporating the technology of the early 1940s, while the MiG-15 belonged to an entirely new generation of design considerations. The Meteor's twin-engine layout recognised the low power of the pioneer turbojet engines with which it was fitted, and its wings were straight and thick, whereas the MiG-15 (and the Sabre) incorporated later German thin swept wing technology..."

"...The MiG-15 formations tactically controlled air combat over Korea. They initiated combat on their terms, and the performance of the MiG-15 enabled them to break contact in a like manner. No matter how well trained the Australian pilots may have been, the performance of the Meteor always placed it at tactical disadvantage in the air-to-air role. Analysis of the individual actions when MiGs were shot down by Meteors strongly suggest that these were simply situations where Chinese pilots made the mistakes..."

http://airpower.airforce.gov.au/APDC/media/PDF-Files/Pathfinder/PF009-Meteors-Versus-MiGs.pdf

Zyzygie,

Counter point: Do you have a laydown of squadrons in theater at the time the Meteors were pulled? Or in other words, did the 5th AF DO make the right call based on assets available with the training they already have? It would be nice to take time out while in theater to go from not prepared for air to air combat to being prepared for such. It's usually based on academic lectures, training by IP's (Instructor Pilots) who are actually proficient at the training objective, and time. The last in a combat theater, where you should be contributing is something you don't have enough of.

A combat squadron must produce enough flyable jets to accomplish it's tasking. After those jets are done, and with enough data points on reliability one may then fly extra sorties for the purpose of training. If one must stand down their squadron in order to be trained, then either the whole war must take a time out, or a decent sized shift in ops that may or may not focus on the Commanders objectives. In other words what the heck are you doing here if you aren't trained?

Cheers,
Biff

 

[Dimlee]

Commander of 64th IAK General Lobov in his memoirs boasted the operation planned by him and conducted by MiG-15s of 176th GIAP on 1st December 1951. According to Lobov, Meteors of RAAF were ambushed with losses of 12 from 16. Russian historians in subsequent researches lowered that number down to 9 Meteors. RAAF accepted 3 losses on that day, 1 KIA, 2 POW (No.77 Squadron).
Taken from my current reading:
https://amzn.to/2tPfsYN
The book is heavily biased in many parts but this battle is given more or less fair description.
Also in Wiki:
Battle of Sunchon (air) - Wikipedia
3 Meteors lost in one mission, probably the worst day for RAAF?

 

[Zyzygie]

Zyzygie,

Counter point: Do you have a laydown of squadrons in theater at the time the Meteors were pulled? Or in other words, did the 5th AF DO make the right call based on assets available with the training they already have? It would be nice to take time out while in theater to go from not prepared for air to air combat to being prepared for such. It's usually based on academic lectures, training by IP's (Instructor Pilots) who are actually proficient at the training objective, and time. The last in a combat theater, where you should be contributing is something you don't have enough of.

A combat squadron must produce enough flyable jets to accomplish it's tasking. After those jets are done, and with enough data points on reliability one may then fly extra sorties for the purpose of training. If one must stand down their squadron in order to be trained, then either the whole war must take a time out, or a decent sized shift in ops that may or may not focus on the Commanders objectives. In other words what the heck are you doing here if you aren't trained?

Cheers,
Biff

They were originally a ground attack squadron flying Mustang P51s.
They then moved over to Meteors while in Korea. They were not retrained as specialist fighter pilots during the changeover.

If you read the background in the hyperlinks it will make much more sense.

 

[Zyzygie]

Commander of 64th IAK General Lobov in his memoirs boasted the operation planned by him and conducted by MiG-15s of 176th GIAP on 1st December 1951. According to Lobov, Meteors of RAAF were ambushed with losses of 12 from 16. Russian historians in subsequent researches lowered that number down to 9 Meteors. RAAF accepted 3 losses on that day, 1 KIA, 2 POW (No.77 Squadron).
Taken from my current reading:
https://amzn.to/2tPfsYN
The book is heavily biased in many parts but this battle is given more or less fair description.
Also in Wiki:
Battle of Sunchon (air) - Wikipedia
3 Meteors lost in one mission, probably the worst day for RAAF?

Yes it was definitely highly biased. If you take Russian claims at face value, they had a multiple kill ratio in their favour against the Sabre. The bottom line is that the 77 squadron lost 40 aircraft in Korea, with the vast majority of losses during their ground attack operations. That makes sense.

Another thing which has to be taken into account is that the MiGs were always in a substantial majority in the dogfights. That would be a big disadvantage for the Meteors from the start.

"...On 1 December 1951, over Sunchon, at least twenty Soviet-piloted MiGs from the 176th Guards Fighter Air Regiment (176 GvIAP) attacked a formation of fourteen Meteors. Both sides apparently overestimated the scale of the battle and the damage inflicted to their opponents: three Meteors—one flown by Pilot Officer Vance Drummond—were lost, but Soviet pilots claimed nine destroyed; Australian pilots claimed one MiG shot down and another damaged, from a formation of at least forty, though Russian sources suggest that all the MiGs returned to base and less than twenty-five were available to 176 GvIAP at the time.[101][102..."
No. 77 Squadron RAAF - Wikipedia

Again, the fact that they received the Presidential Citation indicates that they were performing a highly valuable service. The Americans had abandoned their heavy bombing program due to unsustainable losses incurred from MiG attack. That made the light bombing operations of the Meteor all the more important.

For the MiGs to counter the Meteor ground attack operations, they had to come down below the 20,000 feet level where the Meteor was competitive. Most of the kills against the MiGs took place during this phase of the Meteor's war.

 

[Zyzygie]

"...The Meteor will be forever remembered as the first British jet fighter to enter squadron service and the only jet-powered Allied fighter to see action in the Second World War. Subsequent development was limited as a result of its relatively conventional airframe, but with its powerful Rolls-Royce Derwent 8 engines, a well-flown F.8 was quite capable of causing an upset if a Sabre pilot attempted to mix it in mock combat below 20,000 ft. The Meteor was also immensely strong, and many pilots owe their lives to its rugged construction..."

Meteor From the Cockpit

Meteor from the Cockpit

 

[Zyzygie]

"...We had more fun in the 'unofficial' engagements, which were usually against the early Sabres..." "...Above 25,000 ft the Sabre was totally superior because all it had to do was take advantage of its greater speed range and dive away. If the Sabres were above you to start with, your only defence was to execute a hard break towards the attack. Each time you carried out such a defensive manoeuvre at height you lost energy and became progressively slower and more vulnerable, while the Sabres (if they knew what they were about) zoom-climbed back above you for another attack. On the other hand, if you managed to find F-86s below you and they were tempted to try and 'mix it', the Meteor could give them a very nasty fright. At 20,000 ft or below, the Meteor could out-turn, out-accelerate and out-climb a Sabre. It also had much more effective airbrakes..."

Meteor from the Cockpit

The bottom line is that the Meteor was not suitable for bomber escort duty at high altitude, but was eminently capable in the fighter-bomber role, where they could look after themselves if MiGs tried to come down to mess with them.

The MiG had a service ceiling of 50,000 feet, which was better than any Allied aircraft. Its climb rate was also better (5 minutes to 30,000 feet as against 5.8 minutes for the Meteor). That meant they could easily employ the strategy mentioned for the Sabre outlined above at altitudes above 6,000 metres (20,000 feet).

 

[Zyzygie]

Grumman Panther vs. Russian MiGs:

It seems that at least some Panther versions had the Rolls Royce Nene, similar to the MiG. It also had four 20mm cannons, arguably much superior to that of the Sabre with its .5 inch Brownings.

It also seems that the Panther has a similar history to the Meteor. It was diverted away from direct confrontation with the MiGs -
"...This didn't mean Panther pilots were out of danger. Most of the eighty-seven thousand sorties flown by Panthers over Korea were ground-attack missions targeting bridges or logistical centers. The F9F-2 was modified to lug up to two thousand pounds of bombs and 127-millimeter rockets on six outer-wing pylons and two racks under the fuselage, though lighter loads were usually carried.
These raids met withering antiaircraft fire—but the Panther proved exceptionally tough, a quality that saved the lives of numerous pilot that would make an indelible mark on American history..."

 

[Zyzygie]

The Panther and the Meteor may both have been rugged, but they were not in the same league as this 18-engined flying truck:

Tomorrow's Wings - Plane & Pilot Magazine

 

[Zyzygie]

W.G.Carter on jet design philosophy:

The Meteor F4 thrust to weight ratio was 0.5 and the claimed time to 30,000 ft was 5 minutes.

The philosophy of the Meteor F4 with two 3600 lb. thrust Rolls Royce Derwent 5s.
The fastest-climbing jet fighter until the arrival of the MiG 15 coming into service in 1949, and even then it was still close.

 

[Zyzygie]

A commentary on Nazi war projects in Flight, September 1945:

 

[Zyzygie]

About Adolf Galland: German World War II general and fighter pilot (1912-1996) - Biography and Life

"...During his time with the Argentine Air Force (FAA) he flew the British Gloster Meteor. Galland commented, mindful it was a contemporary to the Me 262, that it was a fine aircraft. He claimed that if he could have fitted the Meteor engines to the Me 262 airframe he would have had the best fighter in the world..."

Los Gloster Meteor en acción!



It seems from the video that the roll rate was about 5 seconds/360 degrees at takeoff (say 150 knots) at sea level, as against 3.8 seconds at 400 mph and 5000 ft. reported by Eric Brown for the Me 262.

 

[Zyzygie]

From Flight, July 1946. The Me 262 as bomber:

 

[GrauGeist]

The Hs132 was a dedicated dive-bomber, where the pilot was in the prone position.

Still curious about the Me262 "Schnellbomber II" part, stating 2 hours of flight time. The Me262 (all versions) had just enough fuel onboard to allow for a max. flight time of 90 minutes, but typically 30 minutes if it were engaged in combat.

 

[Zyzygie]

From Flight

It looks like the second version may be fatter and slightly longer in order to increase internal fuel stowage as well as accommodate the bomb?

 

[nuuumannn]

"...During his time with the Argentine Air Force (FAA) he flew the British Gloster Meteor.

Argentina was the first export customer of the Gloster Meteor. Very interesting video, Avro Lincolns there too. A Meteor Mk.IV outside the Fuerza Aerea Argentina HQ in BA.

Meteor Buenos Aires

 

[Zyzygie]

The state of British jet engines in 1946.

Flight:

 

[Zyzygie]

"...Throughout the Hispano's life, fine-tuning of installations was required to make it reliable in wing mountings. Guns mounted in the much more rigid fuselages of such aircraft as the Whirlwind, Beaufighter and Mosquito caused far fewer problems. Once working properly, the big cannon was a formidable weapon. Compared with the MG-FF it was slightly faster-firing at 10 rps, and its much bigger cartridge cases generated a considerably higher muzzle velocity, which improved both hit probability and penetration."

"While the Allies never introduced the Minengeschoss technology, so their shells only carried half the HE/Incendiary (HEI) load, the heavy Hispano shells' better penetration meant they could inflict considerable damage. The Hispano soon changed from a 60-round drum magazine (as mounted in Spitfire Mk. IIB and Mk. VB – Ed.) to a belt feed (Mk. VC and later) giving much greater ammunition capacity, which the MG-FF never had, other than in an obscure night fighter installation. The penalty was that the Hispano was almost twice as long as and double the weight of the German gun; unwelcome features for wing-mounted weapons."

"RAF fighters carried a mixture of HE or HEI and plain steel "ball" (practice) rounds (which had good penetration) until the emergence of the semi-armour piercing incendiary (SAPI) in 1942, after which the standard loading was 50/50 HEI and SAPI. The German cannon were not exclusively loaded with Minengeschoss, but used them mixed with older-type HEI-T shells (retained because, unlike the M-Geschoss, they could carry a tracer) and later some API rounds as well, in varying proportions."

"The Germans were not satisfied with the MG-FFM, which had been adopted as an interim measure pending the development of a purpose-designed cannon. This duly emerged as the Mauser MG 151, which gradually took over from 1941. Initially, the Mauser had been designed to use a high-velocity 15 mm cartridge, but it saw relatively little service in this form. Wartime experience led to the cartridge case being modified to accept the 20 mm shells from the MG-FFM, surrendering muzzle velocity and penetration in the interests of far greater destructive effect. The 15 mm version was available with HE shells, but they were considered too small. The resulting MG 151/20 was intermediate in size, weight and muzzle velocity between the MG-FFM and the Hispano, but was faster-firing at 12 rps. It was a superb design which the Americans later tried to copy, producing some 300 guns in .60 inch (15.2 mm) calibre, designated T17, but they never adopted it."

"Later in the war, various new German guns emerged with calibres of up to 50 mm. Their use was really prompted by the difficulty the Luftwaffe was experiencing in shooting down USAAF B-17 bombers. The most significant ones were the Rheinmetall-Borsig MG 131, MK 103 and MK 108."

"The MG 131 was a 13 mm HMG intended to replace the RCMGs in both fixed and movable mountings, and therefore kept as small and light as possible, making it the least powerful HMG to see service. The other guns were both in 30 mm calibre but otherwise very different. The MK 103 was a huge, high-velocity slow-firing gun, while the MK 108 fired much smaller, low-velocity cartridges at a very creditable 10 rps, and was only half the size and weight. Their 30 mm M-Geschoss HEI shells were highly effective, containing four times as much HE as the 20 mm version, and three or four hits with these could bring down a bomber, compared with 20 hits with 20 mm ammunition..."

Cannon or Machine Gun? – The Second World War Aircraft Gun Controversy — Variants & Technology | history | Reference

20mm Hispano vs 30mm MK 108:

 

[Zyzygie]

From Flight Global archives:

German jet developments.

The writer remarks on the fact that all German engine manufacturers settled on axial flow compressors. The British went mainly for centrifugal compressors, with a parallel development project for an axial flow compressor engine. The biggest problem with the centrifugal was that it had to be spun much faster (nearly twice as fast) as the axial. Because centrifugal force is a function of the square of the rotational speed, that meant an extremely creep resistant alloy was needed for the turbine blades. They achieved this through the development of the new high nickel-chrome alloy "Nimonic" (typically consisting of around 50% nickel and 20% chromium with additives such as titanium and aluminium).

The centrifugal was much more robust and reliable for an early development engine, but the axial was the way to go in the long run for thrusts above about 2000 lb.f.