Scheme of the cabin of the aircraft "An-24", its characteristics and photos

"An-24" is a passenger turbine-propeller aircraft. It is intended for small and medium-range airlines. In its design there are 2 turboprop powerful engines (AI-24 series No. 2 or AI-24T) with an air-type screw (АВ-72, АВ-72Т). It has a flight range of 3000 km, a cruising speed of 490 km / h, a maximum takeoff weight of 21 tonnes. This aircraft was produced from 1959 to 1979. More than 1,000 units of such aircraft were manufactured. Up to now, over 300 units are in use. In general, the AN-24 aircraft is used in the CIS and in African countries. This is a reliable fact. We will consider this model in more detail.

History

The development of a turboprop twin-engine "An-24", the operation of which was envisaged on local airlines, began in 1958 at GSOKB-473 them. O.K. Antonova. It was carried out on the basis of the decision of the Council of Ministers of the USSR No. 1417-656 of 18.12.1957. According to this document, the An-24 aircraft, the characteristics of which will be indicated below, must carry passengers with a load of 4000 kg for a distance of up to 400 km from a certain Speed - at 450 km / h. The use of AI-24 engines was also envisaged.

The An-24 plane carried out the initial flight on October 20, 1959. In this case, at its helm, there was a crew commanded by test pilot Lysenko GI. The subsequent factory and state tests fell on 1961.

The serial production of the An-24 began in the first half of 1962 at the Kiev plant No. 473. In September of the same year, the first passenger flight was carried out. On October 31, 1962, the An-24 aircraft began operating on the Kiev-Kherson route.

Production of this aircraft was carried out until 1979. From 1962 to 1979, more than 1,200 units were produced. Of these, 1028 were manufactured by the Kiev aviation plant "Aviant". The analogue of this aircraft was also produced in China. Its name was "Y-7".

The design and layout of the An-24 aircraft

This model is an all-metal freestanding monoplane on which a high wing is located. There is also a chassis of a three-post type, on which there are two front paired wheels. The An-24 passenger airplane consists of the following parts:

• Fuselage type "semi-monocoque".
• Power set - stringers and beams. Connections - kleesvarnye.
• The layout is traditional: in front - the cabin crew, then between the luggage compartments - the passenger compartment with a cupboard and toilet.
• Wing: power set - two side members and 23 nerfuries.
• Flaps: on the center wing - single-slit. They are deviant. Next - double-slotted retractable. Ailerons are split here.
• Feathering is a traditional type with an additional ventral keel.
• Chassis: three-axle with swivel front rack.
• The wheels are double. Regulation of pressure in them is carried out on the ground.
• Power installation: 2 TVD AI-24. In this case, the power is 2550 liters. from. There is a screw with variable pitch. Its diameter is 3.9 m.

Advantages of construction

Here are the advantages:

1. Increased the useful volume of the fuselage. This is due to the high location of the center wing.
2. Essential absence of rupture of the wing in the upper part and manifestations that reduce the lifting force of the diffusive effect at the junction with the fuselage. This is an important property. As a result, the aerodynamic properties of the wing increase. The diffusive effect implies the separation of the boundary layer of the flow due to the interference of the main one. It arises at the junction of the wing and fuselage.
3. Good transverse and longitudinal stability of the aircraft. It is saved because of the absence of flow stall, and also at supercritical angles of attack.
4. Presence of a high arrangement of engines. This makes it possible to operate the An-24 aircraft on unpaved airfields, since foreign objects are not sucked into the engine.
5. The high wing does not obstruct the view of passengers and facilitates loading operations.

disadvantages

However, there are disadvantages of this design. They are as follows:

1. Extended chassis racks require a large nacelle. This leads to an increase in resistance.
2. In comparison with the low-level plan in this model, a less effective air cushion is created during takeoff and landing .

The An-24 plane. Wing characteristics

In this case it is:

• Area: 74.98 m².
• Profile:
  - 1-7 ribs (TsAGI-C5-18 is used);
  - 8-11 ribs - transitional profiles;
  - 12-23 - TsAGI-SV-13.

In this model, the ribs are twisted relative to the root at an angle of 2.5 ° to 0 °. This, in combination with the profile change, provides the aerodynamic and geometric twist of the wing, thereby ensuring lamination of the flow. This leads to a reduction in resistance, an increase in lift and the effectiveness of ailerons, as well as an increase in the speed causing the effect of the flutter.

• Elongation: 11.7. This is the ratio of the square of the span to the area.
• Narrowed out: 3.92. This is the ratio of the chord length of the root rib to the cantilever.

The constriction and elongation in this case are chosen in such a way that in combination with the twist ensure a uniform load on the wing and reduce the drag. There is also a symmetric flow stall on sections of large angles of attack.

• Sweep: no center section. Further to the console - 6,5 ^о .
• Transverse V. Only at the console - -2 ^о .

This provides lateral stability. As a result, controllability is increased when one of the engines fails. The same is facilitated by an increase in the vibrational stability and a decrease in the roll in the direction of the failed motor.

• Mounting angle of the wing: 3 ^о . Selected to reduce the resistance of the fuselage due to its location along the stream at cruising speed.
• Aileron is asymmetrical biconvex. Here, aerodynamic compensation is 29%.

Modifications of the specified model

In this case it is:

• «An-24V». Passenger airplane for 50 seats. He is the basic original type. It is possible to re-equip it with cargo and administrative.
• «An-24RV». It is equipped with a booster turbojet engine, capacity of 1950 liters. from. As a result, a quick start of the main engines is ensured.
• "An-24T" is a purely transport variant with a cargo hatch in the lower part of the fuselage. The feathering in this case has two tail fins along the sides of the hatchway.
• "An-24RT" is also a transport type with an accelerating engine, like the one from An-24RV.
• "An-24LP" - a modification for extinguishing forest fires.

Specifications

The aircraft "An-24" has the following technical characteristics:

• Type: "An-24".
• Wing span: 29.2 m.
• The length of the fuselage: 23.52 m.
• Parameter of aircraft height: 8.32 m.
• Wing area: 72.46 m². At modifications with single-slit flaps of the centroplane - 74.98 m².
• Weight: empty - 13.3 tons; Equipped - 13.75 tons.
• Payload: 4.6 tons of cargo / 48 passengers / 38 soldiers / 24 stretchers.
• The maximum takeoff weight is 21 tons. For AN-24RV, 21.8 tons. On modernized aircraft, considering the chassis's strength is 23.5 tons.
• Weight of fuel: 4.76 t.
• Crew: 5 people.
• Installation power: 2 TVD AI-24A to 2550 liters. from. In the modification of "An-24RV" one engine for turbo charging is added.

Availability of flight performance

In this case it is:

• Cruising speed: 490 km / h.
• Practical range: 990 km.
• The maximum speed is 540 km / h.
• Range of distillation: 2820 km.
• The ceiling is practical: 9100 m.
• Run: 500 m.

The result

Having familiarized with the above, you can fully imagine what the An-24 aircraft looks like. In general, the model is not bad. In those days, the An-24, a photo of which is in this text, was considered high-class in its kind.