Although often viewed as a last ditch super-weapon, the Me 262 was already being developed as project P.1065 before the start of WWII. Plans were first drawn up in April 1939, and the original design was very similar to the plane that would eventually enter service. The progression of the original design into service was delayed by a lack of funds, many high ranking officials thought that the war could easily be won with conventional aircraft, and therefore most of the available government funds were used for the production of other aircraft.
Swept wings had been proposed as early as 1935 by Adolph Busemann, and Willy Messerschmitt had researched the topic from 1940. In April 1941, he actually proposed to fit a 35° swept wing (Pfeilflügel II) to the Me 262. Though this suggestion was not implemented, he continued with the projected HG II and HG III high-speed derivatives of the Me 262 in 1944, which were designed with a 35° and 45° wing sweep respectively. The production Me 262 had a leading edge sweep of 18.5° primarily to properly position the center of lift relative to the center of mass and not for the aerodynamic benefit of increasing the critical Mach number of the wing (the sweep was too slight to achieve any significant advantage). The aircraft was originally designed as a tail-dragger which it was built as in the first (Me 262 V1) through fourth (-V4) prototypes, but it was discovered on an early test run that the engines and wings "blanked" the stabilizers, giving almost no control on the ground. Changing to a tricycle landing gear arrangement, firstly as a fixed undercarriage on the fifth prototype aircraft, then a fully retractable one on the sixth and succeeding prototypes, corrected all of these problems immediately.
The first test flights began in April 1941, but since the BMW 003 turbojets were not ready for fitting, a conventional Junkers Jumo 210 engine was mounted in the nose, driving a propeller, to test the Me 262 V1 airframe. When the BMW 003 engines were finally installed the Jumo was retained for safety which proved wise as both 003s failed during the first flight and the pilot had to land using the nose mounted engine alone.
The V3 third prototype airframe became a true jet plane when it flew on July 18, 1942 in Leipheim near Günzburg, Germany, piloted by Fritz Wendel. The 003 engines which were proving unreliable were replaced by the newly available Junkers Jumo 004. The Jumo 004 was more reliable, but it also caused problems since the Me 262 had to compete with the Arado Ar 234 for the engines.
Test flights continued over the next year but the engines continued to be unreliable. The production of the aircraft was slowed mainly by the engine troubles. An order from Hitler that the new Me 262 must also be part bomber played little part in comparison. Although airframe modifications were complete by 1942, production never began until 1944 when the production engines -- which due to the shortage of strategic materials like tungsten and chromium had to be completely redesigned to employ alloys of inferior temperature resistance -- finally started to work.
Jet engines have less thrust at low speed than piston or turboprop engines and due to this, acceleration is relatively poor. It was more noticeable for the Me 262 because all early jet engines (before the invention of afterburners) responded slowly to throttle changes. The introduction of a primitive autothrottle late in the war only helped slightly. Conversely, the higher power of jet engines at higher speeds meant the Me 262 enjoyed a much higher climb speed. Used tactically, this gave the jet fighter an even greater speed advantage than level flight at top speed.
Operationally, the Me 262 had an endurance of 60 to 90 minutes.
Source:
Messerschmitt Me 262 Schwalbe / Sturmvogel