The QT-2PC silent experimental aircraft weighs 1134 kilograms, with a length of 9.33 meters, a height of 2.74 meters, a wingspan of 17.37 meters, and a wing area of 16.7 square meters. The aircraft's silent cruising speed ranges from 112 to 128 kilometers per hour, with a maximum ceiling of 4000 meters and a climb speed of approximately 1 meter per second. The aircraft has a range of about 6.7 hours (actual combat testing).Generally speaking, stealth aircraft often refers to radar stealth, which means using special structures and materials to make the aircraft invisible on radar and other detection equipment. However, stealth can also be visual stealth or auditory stealth. The related technologies are still very rarely used on aircraft, but the camouflage coating and muffler used by ground forces have this function. As far as Wei Kewei's editor knows, there is also an aircraft called QT-2PC called auditory stealth.

QT-2PC originated from the X-26 program launched in the late 1950s, which aimed to assist pilots in training on inertial coupling phenomena. At that time, with the increasing strength of engine technology and the continuous increase of aircraft flight speed, the wing size became smaller, and the inertia of the corresponding wings became smaller. The fuselage, which concentrated a larger proportion of weight, became less easy to control during rolling and other movements.

Previously, seaplanes extensively adopted the design of a back engine, which not only kept the engine compartment away from the erosion of waves, but also enhanced the control efficiency of the wings. However, the disadvantage was the sacrifice of speed. In theory, the design of a back engine allows the aircraft to take off with fewer or lower power engines, and changes in the engine also mean a reduction in noise.

In the mid to late 1960s, Lockheed began developing a silent aircraft for reconnaissance and surveillance. The Navy provided Lockheed with two X-26 experimental aircraft modified from gliders, and the company subsequently designed the QT-2PC based on them.The QT-2PC is a uniquely designed two seater lightweight monoplane with a bubble shaped cockpit cover that provides pilots with better visibility. The wings are very narrow and installed on both sides of the rear of the cockpit.

Behind the cockpit is the engine compartment, which is equipped with a 100 horsepower O-200 horizontally opposed 4-cylinder air-cooled engine. The reason for choosing this low-power engine is that the designer intends to use a rear propeller to improve wing efficiency and lower engine noise. The engine drives the transmission shaft installed above the cab through a transmission structure, which extends from the rear of the cab to the front above the nose. There is a support frame to fix the transmission shaft, and the front end is equipped with a 2.54-meter diameter Ole Fahlin 4-plate propeller, which is a sturdy and reliable slow propeller with less noise.

This aircraft combines noise reduction design with the previous X-26 technology, and it met design expectations during flight testing. When flying at an altitude of 1000 feet (about 304 meters) at a speed of approximately 130 kilometers per hour, the noise emitted by the aircraft cannot be heard on the ground, and its noise reduction performance is outstanding.

However, actual combat is the only criterion for testing truth. In order to verify the value of silent aircraft in actual combat, QT-2PC was approved to be sent to Southeast Asia for practical testing in 1968. The aircraft is equipped with corresponding electronic devices before departure, and a lower observation window is installed at the bottom of the fuselage. The surface of the aircraft is sprayed with a deep blue color that is conducive to night flight.

The QT-2PC flew continuously in Vietnam for several weeks, and the pilots always flew the plane at night because there was almost no sound on the ground, so the enemy hardly noticed it. In addition to collecting a large amount of information during nighttime reconnaissance, some high-value targets were also discovered, which had a certain impact on the actions of ground forces.

After practical training, the aircraft returned to the United States in 1969, and its mission came to an end. One of the two planes was collected by the Army Aviation Museum, while the other was retired and sold, apparently converted into a seaplane for continued use.

Source: Military of Strong Countries