Its design and use followed a comparable path to those taken by the German Luftwaffe with the Junkers Ju 88 and the British Royal Air Force with the De Havilland Mosquito.
It was initially used for daylight ground attack missions during the Battle of Moscow, but this proved to be costly since the aircraft was unarmored.
The production line also replaced the RSI-4 radio with model that had greater range and added a camera for the Pe-3's reconnaissance role.
Crews complained bitterly that the lack of frontal armor made them vulnerable to defensive fire from German bombers.
Flash hiders installed on the guns and curtains covering the windows cured the first problems, but the lack of armor could not be rectified immediately.
Automatic leading edge slats were fitted and the nitrogen fuel tank pressurization system was replaced by one that used inert gases from the engine exhaust.
[5] Many of these changes were made to aircraft before Pe-3bis production resumed in April 1942 and combat-use revealed several additional problems that had to be addressed in a second Pe-3bis prototype, which began its State acceptance tests in May 1942.
[6] Reloading the nose guns proved to be time-consuming, taking up to 45 minutes, and the night-firing of the port-side UBK continued to blind the pilot.
The changes meant that the cartridge cases from the ShVAK cannon could not be collected, making the skin and lower fuselage vulnerable.
The original mounting for the dorsal UBT machine gun provided an excellent field of fire, but lack of aerodynamic balance prevented the gunner/navigator to use its full range.
22 in early 1944, but these were more lightly armed than earlier versions, with only a single ShVAK cannon in the wing center section and one UBK in the nose.
[8] The first Pe-3s were issued to the 95th High-Speed Bomber Aviation Regiment in August 1941 and it was initially committed to the ground attack and escort roles after retraining through September.
A few days later six Pe-3s escorted C-47s carrying a British military delegation flying from Vologda to Moscow and successfully defended against several German attacks on the transports.
This was a very high loss rate and a number of units began to conduct less risky reconnaissance missions to minimize casualties.
[8] With production terminated in October due to the evacuation of the factory, the number of available Pe-3s could not sustain as many units and many began to convert to other aircraft or roles.
The 9th Bomber Aviation Regiment was directly assigned to the Chief of Staff of the Air Force at the end of November 1941 and received the additional task of leading groups of fighters and attack aircraft to their targets because their pilots could not navigate on their own.
[16] On 5 February 1942 the 511th Bomber Aviation Regiment was based at Tula and lost three of its eight Pe-3s on strength to a German air raid.
[8] A single Pe-3 was captured by the Finns when it had to make a forced landing in marshy ground near Lake Inari on 28 November 1942.
It served with PLeLv 48 and was converted into a photo-reconnaissance aircraft in 1944 before being destroyed by a Soviet bombing raid on the airfield at Lappeenranta on 2 July 1944.
Another round of trials was conducted by aircraft of the 2nd Guards Fighter Corps of the PVO in Leningrad between February and May 1943 and it was approved for service the next month.