score:15
First of all, claims that VSS lost 4000 planes in the first three days of war is somewhat dubious. This is mostly based on German sources, which is understandable since Soviets usually omitted exact data from this embarrassing period . Only recently more information came to light, which portrays the situation in a somewhat different light. VVS certainly had enormous losses, and Luftwaffe established aerial superiority over the front, but losses were not that high. You can watch this interesting video that gives somewhat a more balanced view on the situation. Now to the main question.
VVS, like any part of RKKA, was deeply affected by Tukhachevsky affair and subsequent purges. This came at an especially bad time, because the whole Red Army (including air force) was going into process of expansion in preparation for looming war. Purges were continuing well into 1941, and for example some of the victims were VVS generals Pavel Rychagov, Yakov Smushkevich and Ernst Schacht. As elsewhere in Red Army, VVS was also paralyzed by a climate of fear, indecision and lack of initiative. Commanders and pilots with combat experience from Spanish civil war were especially suspicious - instead of learning from their experience and improving tactics and organization, they were often arrested and any change was refused. For example, Soviet pilots learned to use finger four formation in Spain, but when they came back home they were forced to revert to obsolete Vic formation. To sum this up, in most critical time VVS was led by inexperienced and yes-man with little operational skill.
Technical obsolescence also played its part. In 1941 the Soviet main fighter was still the I-16, which was fine in 1930's but could not compete with all-metal fighters with inline liquid cooled engines like Bf-109. There were also lots of biplane I-15 and I-153s, and the main bomber was the Tupolev SB, too slow and lightly armed and armored to survive in 1941, especially without fighter escort.
In addition, Fighter escort was difficult to organize, as was any large formation, because Soviet radios were of notoriously poor quality. This was perhaps the biggest technical flaw of entire Soviet air force, as well as in ground force (tanks and artillery) .
It is worth mentioning that of the new Soviet fighters starting production in 1941, only Yak-1 was somewhat successful, while LaGG-3 and MiG-3 were actually less useful then old I-16, especially their early variants (LaGG-1 and MiG-1 and early series of LaGG-3 and MiG-3) . Soviets did not have enough strategic materials to create all metal planes until 1944, so they used plywood extensively which had a negative effect on durability.
Quality of Soviet pilots was also poor on average immediately before and during the war. Aces like Alexander Pokryshkin had good flying experience before the war, or were luckily retained somewhat longer in flying school like Ivan Kozhedub. Before the expansion of the VVS in 1939-1940 , theoretically at least, a new Soviet pilot would have 110 flight hours (80 on trainers, 30 on combat type they were training on). also, they would have a few dozen hours of flight before that in various youth flight clubs. In 1940, in order to speed up the process, this was almost halved, and as war progressed it was not uncommon to have new pilots barely able to take off and land on the airplane they were supposed to fly in combat. New pilots could have only 25 flight hours, while German pilots in 1941-42 had around 150-200 flight hours when they started their combat carrier. In 1941 the situation was also complicated by the fact that all pilots (experienced and "green") were switching to new types of aircraft and didn't have much flight time to familiarize with them.
Finally, it is true that Luftwaffe surprised the VVS on June 22, 1941 and destroyed lot of planes on the ground (although how much of those were serviceable is dubious ) . The main culprit for this was Stalin himself who simply refused to believe Germans were about to attack. As a consequence, most of the planes were not dispersed, not camouflaged, and German reconnaissance flights days before the attack were not intercepted to avoid provocation. Commanders on the ground didn't have the initiative to do things on their own and prepare man and machines for combat. Instead, even when the war started some of them forbid their pilots to shot at the Germans, until late in afternoon of June the 22nd, when Moscow announced start of the hostilities.
Upvote:-3
According to WW2 researcher Mark Solonin, one of the most important reasons of huge losses in the beginning was the unwillingness of soviet soldiers to die for the authoritarian regime and their mass desertion. There were a lot of live memories of the 193x repressions.
In his recent interview (in Russian) Solonin says something like "History proved again that an army of slaves does not fight well".
Update. Here's a review of Solonin's book about the first days of air combats. He works with raw numbers from archives to debunk the myth of the “destructive first attack”.
Upvote:5
A vast majority of success of Blitzkrieg hinged on surprise factor which was available only in the earlier stages of war:
https://www.britannica.com/topic/blitzkrieg
Blitzkrieg, (German: “lightning war”) military tactic calculated to create psychological shock and resultant disorganization in enemy forces through the employment of surprise, speed, and superiority in matériel or firepower.
Imagine that you neighbor a potentially hostile country. Imagine that country is getting its air force airborne in the thousands and preparing for an attack.
How are you going to know about it?
Spotter and recon aircraft cant just fly into that country's airspace without war being declared. Your spotters on the ground can only see what they can see with their eyes or binoculars. Interwar technologies like listening to aircraft sound only work when they are sufficiently close. You dont have radar, leave side a proper early warning system that works with the large radar network which you dont even have.
And enemy is amassing thousands of aircraft a few hundred kilometers from the border. Even if you somehow learn about it, how are you going to be sure if it is not large scale maneuvers as opposed to an actual surprise strike?
So even if a spy you have in that country reports you that something is happening, it is very difficult for you to actually act on that information because if you do mobilize your forces and attack your enemy, you would have started the war if the intelligence was wrong and they were not preparing.
That was the situation which faced USSR at the start of the war. They wanted to be prepared for the upcoming war, and to an extent they did prepare for it, but they didn't want to mobilize fully to risk giving Germany the opportunity to declare that Soviets were going to attack them and using it as a casus belli. And they would prefer to stay out of the war at least a few years more to prepare better.
https://history.stackexchange.com/a/31110/24363
What's worse, a lot of spies in Germany were informing Soviets about the impending attack, so they knew that an attack was coming. But the timing was a problem - previous reports were erroneous on attack date, and attack was postponed a few times. So Soviets expected an attack, but they expected it a few months to six months later.
So there you have the formula for success of Blitzkrieg
Germans come with thousands of planes, in formation, organized, with proper targets and objectives, what's more, with radios, just crossing the border in short notice, rushing towards Soviet airfields and aircraft which were just being alerted and scrambled. Even noticeable numbers of defending aircraft successfully take off, the disorganization would cripple their defense efforts.
There you go - if you catch your enemy on the ground or taking off, Blitzkrieg is easy. This is the way Germany was able to wipe out a lot of Soviet aircraft so easily.
Same thing happened in Battle of France despite France being on full alert and ready - it was just very difficult in early stages of war without radar networks and proper air defense coordination to fight against thousands of aircraft crossing your border - early in the war attacker had the advantage.
Same for Pearl Harbor - catch them on the ground, unawares.
But everything changed when Luftwaffe crossed the channel to attack Britain:
Not only Britain had extensive radar networks to cover the approach to the country, but also they had the advantage of having the channel and North Sea in between them and their enemy - which was already being watched by large numbers of observer aircraft just built for that purpose (like Avro Anson). So they were doubly prepared, so to speak.
All of that preparation was topped with a centralized air defense system which coordinated everything.
Results are well known - Blitzkrieg was suddenly not so blitzy anymore. Germans took some time to understand just how British were able to know when and from where they were attacking. A big change from the earlier surprise attacks they were so used to in early stages in the war. And they started bleeding aircraft and pilots like there was no tomorrow.
So to summarize:
Luftwaffe was able to repeat that feat by attacking unprepared enemies in repeated occasions.
Upvote:17
The Wikipedia article cited in another answer lists among reasons
...equipment, like that of the Red Army, was largely obsolescent and suffering from prolonged use.
The Great Purges had also hit aircraft manufacturers, and the loss of personnel ended the Soviet lead in aircraft design and aeronautics (...) The aviation industry was disrupted, severely, and while the damage caused was later patched up in 1941, months of idleness and disorganisation contributed to the disasters in 1941.
While numerically the strongest air force in the world, the VVS was an imbalanced force in comparison to the British, Americans and Germans at the time of Barbarossa. It relied on too few established designers and an over-centralised system which produced aircraft that fell behind the standards of most powers. The VVS was also profoundly influenced by Giulio Douhet, and the theory of air power that was focused on the offensive, and bombing the enemy heartland. It was overloaded with inadequately designed bombers, which were expected to survive in combat. In 1938 production of light and strike aircraft as well as fighters was to be cut in two to allow for more bomber aircraft to be produced.
The purges affected the leadership of the VVS. In June 1941, 91 per cent of major formation leaders had been in place for just six months. With the exception of Major General Aleksandr Novikov, commanding the Leningrad District, most would fail in their posts and pay for that failure with their lives. A critical operational omission of the VVS was the failure to disperse its aircraft. Soviet aircraft was left closely ‘bunched’ into groups, and lined up on airfields, making a very easy target for the Germans.
Upvote:45
The Soviets were caught by surprise and suffered massive casualties as a result. See this Wikipedia article. Lots of aircraft were destroyed on the ground, not the air.
The first attacks began at 03:00 on 22 June. The Soviets had been caught by surprise, their aircraft bunched together in neat rows which were vulnerable. The results were devastating ... At the end of the day, German reports claimed 1,489 Soviet aircraft destroyed on the ground alone.
When the Soviets did respond, because of the surprise, the response was uncoordinated and ineffective:
The Stavka were stunned by the initial assault and took several hours to realise the disastrous situation and respond. They ordered every available VVS bomber into the air. Without coordination and fighter escort, they suffered catastrophic losses, and flew, quite literally, to the "last man".
Once surprise wore off, the Soviets were much more effective.