LeO 451. What the battles showed
LeO 451 from GB I/12. Spring-summer 1940
Thus, in the summer of 1939, the first LeO 451s finally began to enter service. Three LeO 451s took part in the Brussels-Evreux air display on July 9, 1939, and eight machines flew over Paris a few days later during the Bastille Day celebrations, although by that time only two (No. 7 on the 29th and No. 3 on the 31st) had been officially accepted by the French Air Force. In early August, a test unit with five 451s and crews from GB I/31, equipped with the Bloch 200 and based in Tours, was created at the Reims Military Aircraft Testing Center. As already mentioned, by September 3, i.e., the beginning of World War II, the French Air Force had accepted only ten LeO 451s (Nos. 3–10, 12, and 15), although the assembly plant had delivered 22 machines.
From the very beginning of the Phoney War, LeO 451 Group GB I/31, armed with five LeO 451s and eight Bloch 200s (bomber groups typically had 13 to 15 aircraft), flew strategic reconnaissance sorties and suffered its first combat loss on October 6th: LeO 451 No. 6 was damaged by two Bf.109s and finished off by anti-aircraft fire. It became clear that even a modern bomber without fighter cover could not conduct reconnaissance deep in enemy territory. And there was no cover—the main fighter, the MS 406, was even slightly slower than the LeO 451.
However, before the outbreak of the real war, i.e., on May 10, 1940, the main losses were due to accidents and disasters. One French blogger counted 20 of them, apparently some of which ended successfully, i.e., without casualties and with the possibility of recovery. But at least nine aircraft were lost irretrievably (Nos. 1, 4, 7, 17, 32, 62, 96, 98, 111), and at least one more aircraft (No. 111) was lost during transfer to CRAS. Considering that 222 aircraft were produced before May 10, and only 94 were in service (probably excluding the damaged aircraft), the statistics are depressing.
In almost all cases, accidents and disasters occurred during takeoff or landing. Louis Bonte, chief engineer of the flight test center, recalled: "It was discovered that the aircraft was somewhat unstable in the longitudinal direction at very low speeds. However, since its stability and damping under all other flight conditions were almost perfect, it was decided to overlook this deficiency." Furthermore, this deficiency was exacerbated by the use of undersized tail washers, which were exposed to turbulence from the landing gear and its doors during takeoff and landing. As a result, the slightest imbalance—a momentary loss of power in one engine or a gust of crosswind—transformed the aircraft's straight-line motion into an unpredictable curve. In this case, the aircraft could bank, the wingtips could touch the ground, and this sometimes resulted in a belly landing and fire, or, even worse, a rollover.
Here is one of the aircraft's ratings:
Taking off the Lioré 45 was always difficult; the aircraft tended to bank sharply to the left or right. When the pilot couldn't maintain a level flight, the landing gear often succumbed to the lateral pull of the aircraft's weight; the plane would end up belly-down and almost always burst into flames. Therefore, the crew always felt a slight tension until the speed became sufficient for the pilot to control the aircraft.
According to Guillaume de Fontanges, who learned to fly this aircraft in the spring of 1940 and became an instructor, the LeO 45 was difficult to take off and even more difficult to land, but "in the air it was a wonderful aircraft, impeccable and well-armed" (though line pilots disagreed with this last point, as discussed below). But overall, all sources agree that once the aircraft gained speed and altitude, it became maneuverable and easy to control:
The aircraft performed superbly in flight. Its powerful damping allowed for easy instrument flight, even in cumulonimbus clouds and icing conditions. Controllability was excellent. Henri Stackenburg (SNCASE test pilot) performed loops and rolls in the empty aircraft.
But still, first it was necessary to take off and land safely.
It wasn't until March 1940 that test pilot and engineer Jacques Lecarme developed a new takeoff procedure. Before the war, Lecarme had worked at CEMA and participated in the development of the future LeO 45, and then, as a reserve captain, he was called up and served in GB I/12. The essence of the method was that the tailwheel was kept on the ground until the speed reached 90 km/h, after which the pilot had to quickly pull the throttle stick away from himself (in French, aviation The throttle control was "not like a human's"—to increase engine power, the pilot had to pull the throttle back and forth to lift the rear of the aircraft above the propeller turbulence. After this, the aircraft could safely reach takeoff speed. With the introduction of this method, which was very different from the previous one and still had to be mastered, the number of takeoff accidents actually decreased. A more radical solution, i.e., tail washers with a larger area, was only implemented after the capitulation. Incidentally, the German administration immediately approved the request for their installation.
By May 10, only three bomber groups (GB I/12, II/12 and I/31) had been fully re-equipped with the LeO 451, while GB I/11, II/11, I/23, II/23 and II/31 used them simultaneously with the outdated MB 210. For LeO 451 aircraft, the war began on May 11 and ended on June 24, although preparations for ferrying all aircraft with the necessary range, including, of course, the LeO, to North Africa had already begun in mid-June.
A few more side views of production aircraft
How did the most modern French bombers perform in combat? In short, not very successfully. For a national project like the LeO 451 program, the results were more than mediocre. First, I'll quote Pierre-Yves Hennin's article "Le Léo 45, réussite ou chemin de croix de l'aviation française?" ("The Leo 45: Success or Cross for French Aviation?"):
Of the 365 LeO 45 aircraft acquired by the French Air Force before the Armistice, including 65 in June, 135 were lost: 45 shot down in combat, 72 destroyed by bombing or deliberate attacks, and 18 lost in transport accidents, resulting in the deaths of 119 crew members, 30 of whom died in accidents. While total losses did not exceed production during this period of active operations, they were more than double the number of aircraft in service on May 10. Although complete data is lacking, the percentage of aircraft lost in combat can be estimated at 10% of the number of sorties flown.
The primary user, the 6th Groupement, consisting of four bombardment groups (GB I/12, GB II/12, GB I/31, and GB II/31) and numbering between 25 and 50 operational aircraft, flew 400 sorties and dropped 320 tons of bombs. According to the report of its commander, Colonel Lefort, it lost 35 aircraft shot down and 40 destroyed by enemy action (damaged beyond repair in flight or on the ground), 21 killed and 64 missing, "most of whom were subsequently declared dead," as well as 16 killed in accidents during retraining. Another source mentions 314 takeoffs, of which 216 achieved their targets, resulting in the loss of 64 aircraft, 29 of which did not return from their missions.
Perhaps more striking than the high level of losses, both in men and aircraft, is the meager results: 320 tons of bombs for Gruppement 6, a maximum of perhaps 450 for all units participating in Operation LeO 451, or 10% less than the tonnage the Luftwaffe would drop four months later in a single night on Coventry. This is remarkably little for an aircraft that mobilized the greatest efforts of the French aviation industry.
The primary user, the 6th Groupement, consisting of four bombardment groups (GB I/12, GB II/12, GB I/31, and GB II/31) and numbering between 25 and 50 operational aircraft, flew 400 sorties and dropped 320 tons of bombs. According to the report of its commander, Colonel Lefort, it lost 35 aircraft shot down and 40 destroyed by enemy action (damaged beyond repair in flight or on the ground), 21 killed and 64 missing, "most of whom were subsequently declared dead," as well as 16 killed in accidents during retraining. Another source mentions 314 takeoffs, of which 216 achieved their targets, resulting in the loss of 64 aircraft, 29 of which did not return from their missions.
Perhaps more striking than the high level of losses, both in men and aircraft, is the meager results: 320 tons of bombs for Gruppement 6, a maximum of perhaps 450 for all units participating in Operation LeO 451, or 10% less than the tonnage the Luftwaffe would drop four months later in a single night on Coventry. This is remarkably little for an aircraft that mobilized the greatest efforts of the French aviation industry.
In fact, no one disputed the unimpressive results; the question was who was to blame. The aforementioned Jacques Lecarme places the blame squarely on the French air command: "Unfortunately, the panic-stricken high command used it contrary to common sense, negating its enormous advantages and greatly increasing losses... Attacks at too low an altitude, without fighter escort, belated and inappropriate orders to engage, poor crew training, faulty communications."
All of this is absolutely true: attacks on tactical targets, such as vehicle columns and crossings, were mostly carried out from low altitudes, around 500 meters—the ideal altitude for German 20mm cannons. The chain of command was too slow, and communications were constantly problematic. And yes, from around the beginning of June, flights without fighter escort became the norm, although for the first few days, the lack of escort could be a legitimate reason to avoid a combat mission.
But this is not the whole truth. I quote from Cuny-Danel's book:
Gruppement 6 was ordered to stand by, but it did not enter combat until the following day, 11 May. That day, at 11:00, eight aircraft from GB 1/12 and four from GB II/12, loaded with 10 and 100 kg bombs, took off to attack enemy columns invading Belgian Limburg in the direction of Tongeren, across two bridges that remained intact over the Albert Canal, near Maastricht, at an altitude of 800 m. Lack of contact with the fighters whose cover patrols were supposed to join the expedition over Maubeuge-Elesmes meant that the LeO was ordered to turn back while flying over Cambrai. At around 5:00 pm, a second sortie to the same target carried six LeO 451s from GB I/12 (Nos. 14, 25, 41, 54, 60, 63) and seven from GB II/12 (Nos. 37, 40, 43, 44, 45, 46, 70), which were covered at Villers-le-Guise by 18 MS 406 fighters from GCs II/6 and III/3. LeO 451 No. 70 from GB II/12 returned to the airfield almost immediately, as its on-board telephone had failed.
Since I have quoted about the first day of the war for LeO 451, it makes sense to quote about the last one:
June 24 was the very last day of operations in the French campaign. Eleven sorties were requested from GB I/12 and GB II/12 in the afternoon. Five LeO aircraft from the former were to attack a convoy of trucks on the road from Romans to Moirens. In fact, it appears only two aircraft were able to intervene: No. 53 (Lieutenant Delattre), which attacked this objective, and No. 402 (Captain Lecarme), which attacked the bridge at Culot.
Between them were descriptions like this:
On the afternoon of the 18th (May), two aircraft from GB I/12 joined seven from GB II/12 to bomb concentrations in the area of Guise, Landrecies, Fumoy, Saint-Quentin and Avesnes. Ten LeO 451 aircraft from GB II/12 were scheduled to take off, but mechanical problems prevented No. 38 from leaving the runway (engine vibration) and forced No. 112 (undercarriage not retracted) and No. 152 (on-board telephone failure and lack of hydraulic pressure in the gun mount) to turn back. Unable to find fighter cover to escort them to the target, these aircraft of GB II/12 returned with their bombs...
Only GB I/12 and GB II/12 deployed on May 30. Five aircraft from GB I/12 took off at 6:30 a.m. to bomb the bridges over the Somme and the canal at Abbeville. Cloud cover below 100 meters forced them to turn back 20 minutes later. Taking off again at 5:30 p.m., four of them completed their mission despite intense anti-aircraft fire, which hit Captain Rees's No. 53. Of the three LeOs from GB II/12 that were supposed to join them, gas leaks from the pneumatic system forced No. 151 to remain on the ground, and No. 92 to rest due to problems with its propellers and gun.
Only GB I/12 and GB II/12 deployed on May 30. Five aircraft from GB I/12 took off at 6:30 a.m. to bomb the bridges over the Somme and the canal at Abbeville. Cloud cover below 100 meters forced them to turn back 20 minutes later. Taking off again at 5:30 p.m., four of them completed their mission despite intense anti-aircraft fire, which hit Captain Rees's No. 53. Of the three LeOs from GB II/12 that were supposed to join them, gas leaks from the pneumatic system forced No. 151 to remain on the ground, and No. 92 to rest due to problems with its propellers and gun.
The second phase of the Battle of France began at dawn on June 5.
The enemy attacked in force along the entire front line, and the French resisted desperately, realizing they no longer had the necessary reserves to close potential breaches. On the eve of disaster, Groupement 6 was reintroduced into the battle as a true assault force, attempting to stem the onslaught. tanksOn the morning of June 6, its total strength was 58 LeO 451, of which only 21 were considered "combat ready."
That afternoon, a joint sortie by four groups began on the critical Chaulnes, Pressoir, and Lyon-en-Santerre sector. Frequent equipment failures significantly reduced its impact on operations. GB I/12 had four aircraft on alert, with a fifth serving as a possible replacement. Two of them, including reinforcements, were able to take off separately, but a radio message ordered them to return to Montbard. Only two of the five LeOs deployed by GB I/31 took off normally. The third completed only one circuit and immediately landed after an engine failure.
A barrage of German fighters awaited LeOs #202 and #286 as they crossed the front line near Roye. #202 dropped its bombs, and both landed at Nangis. Curiously, the failure rate was lower for the other two groups: one failure for every five takeoffs in GB II/12 (low oil pressure) and one failure for every seven sorties in GB II/31. After an aerial engagement with Messerschmitts, LeO #271 of II/31 crashed with one engine failure, and radio operator Gaudry was wounded by a bullet.
Ten Messerschmitt 109s and five twin-engine Messerschmitt 110s rushed to attack four LeOs from II/12 as soon as they appeared in the line. Only the crew of First Lieutenant Deprette, pilot No. 49, managed to bomb the target indiscriminately. He was also the only one to reach Tavo after a fierce battle in which he claimed victory over a Messerschmitt 109. The other two enemy fighters were likely shot down by other crews before crashing to the ground.
The enemy attacked in force along the entire front line, and the French resisted desperately, realizing they no longer had the necessary reserves to close potential breaches. On the eve of disaster, Groupement 6 was reintroduced into the battle as a true assault force, attempting to stem the onslaught. tanksOn the morning of June 6, its total strength was 58 LeO 451, of which only 21 were considered "combat ready."
That afternoon, a joint sortie by four groups began on the critical Chaulnes, Pressoir, and Lyon-en-Santerre sector. Frequent equipment failures significantly reduced its impact on operations. GB I/12 had four aircraft on alert, with a fifth serving as a possible replacement. Two of them, including reinforcements, were able to take off separately, but a radio message ordered them to return to Montbard. Only two of the five LeOs deployed by GB I/31 took off normally. The third completed only one circuit and immediately landed after an engine failure.
A barrage of German fighters awaited LeOs #202 and #286 as they crossed the front line near Roye. #202 dropped its bombs, and both landed at Nangis. Curiously, the failure rate was lower for the other two groups: one failure for every five takeoffs in GB II/12 (low oil pressure) and one failure for every seven sorties in GB II/31. After an aerial engagement with Messerschmitts, LeO #271 of II/31 crashed with one engine failure, and radio operator Gaudry was wounded by a bullet.
Ten Messerschmitt 109s and five twin-engine Messerschmitt 110s rushed to attack four LeOs from II/12 as soon as they appeared in the line. Only the crew of First Lieutenant Deprette, pilot No. 49, managed to bomb the target indiscriminately. He was also the only one to reach Tavo after a fierce battle in which he claimed victory over a Messerschmitt 109. The other two enemy fighters were likely shot down by other crews before crashing to the ground.
I think this citation is more than sufficient. In most cases, the list is repetitive: frequent breakdowns, primarily of engines, propellers, landing gear, hydraulic and pneumatic systems; lengthy repairs; an ever-dwindling number of escort fighters. Moreover, the overwhelming majority of combat sorties were at low altitude against tactical targets. Attacks on airfields or fixed installations, like the BMW plant near Munich, are a very rare exception.
As a result, in the war the LeO 451 had to fight, the pride of French aviation was significantly inferior to the rather unremarkable American Glenn-Martin 167F, which, in fact, was originally planned for reconnaissance. All reference books on the latter contain the following quote:
The Glenns (an unofficial nickname given to them by the French military) were quickly deployed to mainland France to participate in combat operations at the front, where they performed admirably, demonstrating sufficient speed and excellent maneuverability for an aircraft of their class. They sometimes managed to evade enemy fighters. Furthermore, in 400 sorties against the Germans, they suffered a loss rate of only 4%, significantly better than the 16% suffered by LeO 451s and their crews over the same targets.
Glenn-Martin 167F
Upon closer examination, some corrections emerge, but the essence remains the same. Indeed, the Glenns, of which the French Air Force received only 140-150 aircraft (another 40-50 remained unpacked in their crates) and which were divided into four groups (GB I/62, GB II/62, GB I/63, and GB II/63), in a shorter period of time (from May 22, 1940) carried out 363 combat sorties against Germany and 55 against Italy, i.e., more than Groupement 6 had carried out since the beginning of the war. Combat losses amounted to 17 and 1 aircraft. Moreover, they bombed the same targets—troop columns and concentrations, bridges, and crossings. The combat load on such sorties was also 16 x 50 kg of bombs. As for the percentage of losses, I don’t know how they were calculated; most likely, only combat losses were involved; the important thing is the ratio itself.
The Glenns were three-seaters, lacking armor or protection, but other factors apparently proved more important: higher ground speed—approximately 440 km/h (270 mph), better maneuverability (after all, 10,5 and 6-7 tons are quite a difference, while the Glenn had a lower wing loading), four forward-firing machine guns, backup controls for the navigator, and significantly smaller dimensions—the American had a fuselage diameter of only 1,2 meters (the LeO's maximum section cross-section was 2,375 x 1,32 meters) and a wing area of 50 m² (55 sq ft). At the same time, the LeO's advantages—the ability to carry 2 tons of bombs over a long range at high speed—were practically unclaimed.
The only relative success of LeO was that its top gunners and radio gunners shot down 10 to 12 German Bf 109 and Bf 110 fighters (meaning confirmed victories from Ehrengardt tables), which is approximately twice as many as the Glenns. Interestingly, Cuny-Danel's book states that the lower gunners with their single 7.5 mm machine guns scored more victories than the upper gunners with their 20 mm cannon.
Naturally, after the Battle of France, the LeO 451 continued to serve in many air forces—as part of the Vichy Air Force, they participated in the attack on Gibraltar, fought in Syria in 1941, and in North Africa in 1942 during Operation Torch, as well as with the Free French Air Force, the Luftwaffe, the Italian Air Force, and even the US Air Force. There's no point in recounting all these events; we can only focus on the Syrian-Lebanese campaign (also known as Operation Exporter), and even then only because it was after it that senior officers wrote detailed reports on the aircraft's combat performance.
LeO 451 with USAF stars
The Syrian-Lebanese Offensive of 1941 was a strategic military campaign waged by the Allied Forces—specifically, the British, Australian, and Free French forces—against the Vichy French forces that controlled Syria and Lebanon. The campaign lasted from June 8 to July 14, 1941, and ended, like all other French Army campaigns of the period, in defeat. This defeat was primarily due to defeat on the ground.
LeO 451 No. 187 of GBI/31. Summer 1941, Damascus airfield.
Three groups armed with LeO 451 took part in the combat operations: GB I/12, GB I/25 and GB I/31. The official report of July 29, 1941 lists the following number of LeO 451 aircraft: sent to the Levant: 49 aircraft, of which: 45 arrived in Syria, 3 crashed in Italy, 1 burned in Athens. Lost during combat: 30 aircraft, including: 5 shot down, 11 destroyed on the ground, 6 crashed, 3 remained in Syria. Returned from Syria: 19 aircraft, including 1 crashed in Athens.
In Syria, in June-July 1941, LeO 451 operated in much less difficult conditions than in May-June 1940: in the Levant, in fact, the enemy did not have the same overwhelming superiority in fighters (the British aviation used Hurricane, Curtiss P-40B fighters, and initially even the ancient Gloster Gladiator) and anti-aircraft guns (40 mm Bofors), and the crews, like the command, had time to better master these aircraft, which had already received tail washers of an increased area.
The effectiveness of bomber aviation in general, and the LeO 451 in particular, is considered much higher than it was against the German army that year, although errors in its use were still rife—Kuhni and Danel write of the command's insistence on using 100- and 200-kg bombs against a dispersed enemy, and the level of cooperation with the army was below any criticism. For example, there was an incident when ground command, fearing an airborne assault, erected obstacles on the runway of an airfield in Damascus, forgetting to warn the pilots. As a result, three LeO 451s were lost. Defense and, in particular, the air defense of airfields was also very weak - more aircraft were lost from P-40B attack actions than from attacks on ground targets.
The combat loss rate (5 aircraft lost in 482 sorties) was very low, around 1%. British light anti-aircraft fire, also significantly less dense than the Wehrmacht's the previous year, proved relatively ineffective, downing only two LeOs. However, it should be noted that it contributed significantly to the aircraft's absence, which suffered minor but unpleasant damage.
As a result, the reports published after the fighting are quite interesting. The reports of GB I/12 and I/31 commanders have survived. They are too extensive to be published here in full, especially since the list of complaints about the aircraft (engines, propellers, landing gear, pneumatic system) exactly matches those described above. Nevertheless, a review of some observations from that time is interesting: the aircraft was considered very durable. However, the fabric covering of the flaps and control surfaces seemed vulnerable (both to engine oil splashes and stone impacts).
The offensive armament proved inadequate in various ways: some bombs (100 and 200 kg) were ineffective against the targets they attacked, due to poorly selected fuses and insufficient fragmentation. The 10 and 50 kg bombs, on the other hand, proved extremely effective. The process of loading the aircraft was too long and inconvenient, creating excessive restrictions and risks. Bomb bays were located very close to the ground, and mechanics had to lift 50 kg bombs on their knees.
The camera system was used extremely rarely; the few reconnaissance sorties were conducted visually. Although planned, the use of a panoramic camera would have been virtually impossible due to the lack of an aperture for this purpose. Furthermore, the groups lacked photographic equipment. Communications had hardly improved since 1940. Radio equipment was generally satisfactory, while onboard telephones were much worse. However, tactical communications were practically ineffective and somewhat limited the effectiveness of interventions, which were almost entirely conducted at the direct request of and in the interests of ground forces.
But the bulk of the criticism fell on the aircraft's defensive armament. Initially touted as a strong point, it proved ineffective in reality. Rather than judge it based on our current knowledge, let's turn to the opinion of Commandant Lauzin of GB I/31, who learned lessons from the Syrian campaign of 1941: "This aircraft's armament requires serious modernization:
- replacement of the cannon, the rate of fire and duration of fire of which are insignificant, with a set of 3 or 4 machine guns, providing a significant density of fire in the rear part and allowing mutual protection of aircraft in the squadron;
- dismantling the Boysson turret, which proved to be insufficiently fast and frequently malfunctioning (air circuit); some of its weight could be used to advantage to protect the fuel tanks. […] Removing the gun would also make it possible to return to a single-fin system (as in the original design - but here Lozen is mistaken, since the Amiot 340 originally had a single-fin design) and eliminate the disadvantages that the double-fin armament entails from a piloting point of view;
- acceptance of duplication at the radio operator’s firing point.”
Mounting 4 machine guns on the Boysson carriage, developed for the Amyot, but quite suitable for installation on the LeO
In fact, the installation of a twin-gun pod for the MAS machine guns in a lowerable nacelle was proposed as early as the early 1940s. That the nacelle was considered impractical and dangerous for the radio operator should come as no surprise. The following was written about a similar design on the early He 111:
The lower, retractable "C turret" created enormous aerodynamic drag when deployed. The mechanism would often jam, making it impossible to retract; sometimes, the gunner would remain outside. During landing, the unretracted turret would touch the ground, a surefire recipe for disaster. Simply sitting in the "C turret" was quite uncomfortable—windy and cold. When attacked by fighters, the unprotected gunner often became the first casualty, as statistics from the Spanish War attest.
It is unlikely that the situation with the gondola on the LeO, which also did not have a single gram of armor, was much different.
LeO 451 lowerable gondola
It's worth noting, incidentally, that Commandant Lozen had trespassed on sacred ground—he had questioned the French doctrine's insistence on the need for a twin-fin tail for rearward defense. Without delving into the armament issues here, it's worth noting that Colonel Lefort, commander of Bomber Group No. 6, the primary operator of the LeO 451, shared this opinion:
It may be asked whether the single-fin empennage is not more advantageous from the point of view of fire-defence capabilities than the twin-fin empennage adopted at a time when neither flank nor side attacks were considered effective.
LeO 451 as a transport aircraft in the Luftwaffe
Since it is not my goal to tell the whole story history This extraordinary bomber, then we can end here. Writing about all its modifications—with the most varied engines, specialties—from minesweeper to transport aircraft, its service under various flags—is too vast a task. Perhaps under different conditions, i.e., with more powerful engines, fine-tuned mechanisms, without the senseless waste of more than a year and a half, its capabilities would have been fully realized. But alternative history is for another forum.
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