THE YAK-52 STORY

Following the exchange of letters held between the governments of

Romania and USSR on July 15, it was decided to manufacture the Yak-52 in

Romania in large series. It was decided the investment in a new plant,

intended to be used exclusively for the series production of Yak-52.

Here, in what was later called FCAv- Fabrica de Avioane Usoare (Light

Airplanes Factory) in Bacau, the Romanian prototype (s/n 780102) was

finished and rolled out on April 28,1978.

Among the aircraft manufacturers from the former USSR, the OKB A.S.

Yakovlev developed a wide range of types, from small light trainers

(UT-2, Yak-18, Yak-50,-52,-53,-54,-55), to fighters equipped with piston

engines (Yak-1,-3,-7,-9) or jet engines (Yak-15,-17, -19,

-21,-23,-25,-28 ), including VTOL fighters (Yak-36,-38,-141) and to

business/regional transport aircraft (Yak-40, Yak-42).

In 1972 was flown the prototype of Yak-50, a single-seater, aerobatics

aircraft, derived from the IAK-18 basic trainer, with an all metal

structure with duraluminium skin, except on the control surfaces fabric

covered; the wing central section as on Yak-18 series was eliminated,

the attachment of the wings being made directly to the sides of the

fuselage. The Yak-50 prototype had fixed undercarriage, but for the

production aircraft a semi-retractable landing gear was adopted, similar

to that on the Yak-18. The new aircraft was equipped with a Vedeneyev

M-14P, 9 cylinders radial air-cooled engine, rated at 360hp, a

supercharged version of AI-14. By the introduction of some elements from

Yak-18A (tandem cockpit, canopy, semi-retractable tricycle

undercarriage- which prevents the damage of the under side of the

fuselage and wings in case of "wheels-up" landing) in the new design of

Yak-50, resulted the design of Yak-52 trainer. The aircraft was intended

to replace the Yak-18 of the DOSAAF, a necessary of 1000 aircraft was

estimated for the following 10 years.

For the production of the aircraft was selected I.R. Av. Bacau (I.Av.

Bacau from 1978 and Aerostar S.A. since 1991). This company had already

a long experience in the overhaul of military jets (Yak-17, -23, MiG-15,

-17, -19, -21, IL-28) and was main contractor in the construction and

testing of the prototype of the IAR-93 ground attack aircraft - the

first major military aircraft program in Romania after the end of the

WW2, under a joint program with Yugoslavia. The detailed design started

in URSS in 1975 and the technical documentation started to arrive in

1976 and it was translated. The factory began also the construction of

the assembly jigs. The initial design featured stringers spot-welded to

the wing cover panels, as well as rivets with countersink. Because these

two technologies proved to be non-economical, their use in the

production process was abandoned. The Soviet prototype was brought from

USSR in the deck of an AN-12. The aircraft was never flown in Bacau,

being used only as a mockup.

The manufacturing of the first Romanian prototype started in 1977 within

the airframes overhaul facility of I.R.Av., while in the plant

specialized in the production of landing gears, hydraulic& pneumatic

equipment of I.R.Av. started the production of the landing gear for

Yak-52 , as well as of the components of the aircraft pneumatic system.

The Romanian prototype( c/n 780102) was finished and rolled out on April

28,1978. After several ground tests, the first engine runs were made on

May 9,1978 and around May 20 performed its first unofficial flight with

the pilot Teodor Coman at controls. At that time the aircraft was not

painted and was provisionally registered to the Romanian Air Force as

Red 0102. It was later painted in the colors of DOSAAF and registered as

Yellow 01. It was handed-over to the Soviets after the official

reception flight performed on July 22,1978 by Dmitri Mitikov, test pilot

of Yakovlev OKB. After the manufacturing of a first batch of 2 aircraft

till the end of 1978 (c/n 780102 - "01" and 780103 - "02"), plus an

airframe for static tests (c/n780101), and another for dynamic tests

(c/n 780104) in the following year was started the series production,at

first with aircraft c/n 790105 (01) followed by 2 batches of 5 aircraft,

5 batches of 10 aircraft, and all the following batches had 15 aircraft.

Although the intergovernmental agreement provisions allowed deliveries

of the aircraft to Eastern Block countries, after completing the

deliveries to the USSR, due to the huge quantity order by the Soviets,

they were the only customers of the aircraft during that period.

In USSR the aircraft were used within the airclubs of DOSAAF

paramilitary sport flying organization and was used as basic trainer for

students often not older than 14-15. The official entry in DOSAAF

service took place on May 8,1979 on Tushino airfield. The first DOSAAF

pilots to fly the Yak-52 were Kasum Najmutdinov - the trainer of the

aerobatics team of USSR and Yuri Komitzin - the Chief of the Central

Airclub.

In the '80s the only customer for Yak-52, except USSR, was the Romanian

Air Force, which introduced the aircraft at the beginning of 1986 as

IAK-52 in the inventory along the IAR-823 basic trainer within Air

Liaison Group, based on Focsani airfield, at that time part of the

Scoala Militara de Ofiteri de Aviatie "Aurel Vlaicu" (The Military

Aviation School) of Bobocu-Buzau, 23 aircraft being delivered in the

following years. Today, the unit is subordinated to the Romanian Air

Force Academy "Henri Coanda", which took over all the assets of the

former military school during the reorganization process held in 1995.

During the manufacturing process , the aircraft was subject to certain

upgrades, as follows:

- the rounded wingtip, made from welded metal sheet was removed,

starting with the 16th aircraft (c/n 790301). So, the wingspan was

reduced from 9.5m to 9.3 m.

- the installation of a stall speed sensor and warning SSKUA-1A ,

starting with aircraft c/n 822801 and also for the aircraft already

delivered, starting with c/n 800901.

- the replacement of the Landis-5 radio station with Baklan-5, starting

with the 121st delivered aircraft (c/n 801101).

- the replacement of the Varley battery with 12ASAM-23 starting from c/n

822502 in production, as well as for all the aircraft already delivered.

- the reinforcement of the wing spar attachment joints to the fuselage

was introduced on aircraft c/n 866501 (rolled out in April 1986)

following the Service Bulletins 59R and 60R.

Some other less important upgrades were: the relocation of the

warning lights on the cockpit instrument panels, the modification of the

aileron hinges, the modification of the undercarriage axes, in order to

make them suitable for the installation of skis (in the Yak-52 delivery

set for the USSR a set of skis was provided for winter use; they could

be installed in the place of the wheels, but in this situation the

landing gear cannot be retracted).

The OKB also released in the '80s the preliminary design of a light

attack version Yak-52PSh, which was intended for use in Afganisthan.

Anyway, it was canceled in early design stage.

At the end of 1991, after the delivery of a last batch of 40 aircraft,

the long term contract with USSR expired and due to the political and

economical changes in the former USSR, it wasn't renewed.

Like a irony of fate, the first signs of interests were received from

Western countries (USA, Canada, UK). The first deliveries to private

customers in US were made in 1992 and continued in 1993. They were

attracted by the aerobatics performance of the aircraft, as well as by

its fame ("the aircraft on which the Red Army pilots were trained") and

its "warbird" look. Up to date, several Yak-52 were delivered from the

manufacturer to private users in UK, USA, Canada, Italy, Denmark, but

there are many Yak-52 users in other countries. In 1995 were reported

around 40 Yak-52s in UK and more than 200 in USA.

Between 1991 and 1993 there was an attempt to "westernize" the Yak-52 by

the installation of a 6-cylinder, boxer, 300 hp Lycoming engine and by

the refinement of the geometry (canopy, tail) and a new cockpit

accommodation. Two experimental models (functional mockups) named

"Condor" were made by the modification of two old Yak-52 airframes, some

ground engine runs were performed, but the program was canceled before

the first flight. Some British users installed a propeller spinner or a

Hoffman HO-V183K 3-blades propeller on their Yak-52s. The new propeller

reduced the vibration level and increased the rate of climb with 2 m/s.

The propeller is already certified by CAA for installation on Yak-50,

which is equipped with the same M-14P engine.

Although it was for more than 15 years in production, in the '90s the

Yak-52 was selected by air forces as basic trainer. As mentioned above,

Romania was the first country to use the Yak-52 as true basic military

trainer. Following the selection of Yak-52 by the economical office of

the Hungarian army to equip the Szolnok Replotiszti Foiskola (Szolnok

Military Flying School), belonging to the Magyar Honvdsg Replo

Csapatai (Hungarian Air Force), during the first quarter of 1994, 12

aircraft were delivered and started the training flights. The aircraft,

named in Hungarian spelling Jak-52 were registered Red 01 to Red 12 and

were equipped with GPS and transponder. Today the aircraft are in the

inventory of the 3. Kikpzoreplo-szzad (3rd Training Squadron) of the

MH-89 Szolnok Vegyes Szllitreplo - Ezred (MH-89 Szolnok Joint

Transport Regiment) along with An-2, An-26, Mi-2 and Mi-8.

In 1997, 12 aircraft were delivered to Vietnam. They are assigned to the

Trung Doan (Regiment) 910 based at Nha Trang - the unit used for primary

training within the Vietnamese People's Air Force.

After the disappearance of the former USSR, some Yak-52s left on the

former DOSAAF airfields in Lithuania were brought by the country into

military use within the two squadrons of SKAT (Voluntary Border Guards),

now KASP (Krasto Apsuagos Savanoriskos Pajegos - Voluntary State Defense

Service). Eskadrile I at Kyviskes has 4 Yak-52 in service (only 2

airworthy) plus one on a pole as gateguard and another 9 in storage ,

while Eskadrile II at Silute has 3 Yak-52s.

On October 9,1998, AEROSTAR S.A. has celebrated 20 years from the debut

of the manufacturing of Yak-52, the aircraft no. 1800 performed an

aerobatics display. Aerostar has set up an upgrade program for the

aircraft which has in view the replacement of the Russian instruments

with equivalent western ones, the increase of the fuel capacity and the

installation of a lighting system for night flying. The delivery

configuration is optional, depending on the customer's request.

Now, after over 20 years since the production started, the Romanian

manufacturer Aerostar S.A. has recorded more than 1800 Yak-52s

delivered, and due to the new economical conditions and to a good

management of the company, the production still continues.

Yak-52 Technical Data Sheet

Type: tandem two-seat trainer

Powerplant: 1 X Vedeneyev (VMKB) / Aerostar M-14P, 9 cylinders radial

air-cooled engine, rated at 268kW (360hp), driving a V-530TA-D35, two

blade, constant speed propeller;

Dimensions

Length Overall: 25ft 5in (7.745 m);

Wing Span: 30ft 6 1/4 in (9.3 m);

Height Overall: 8ft 10 1/4 in (2.70 m)

Weights

Empty Weight: 2,238 lb (1,015 kg);

Max T-O Weight: 2,877 lb (1,305 kg);

Max Fuel Load: 220 lb (100 kg, representing a total capacity of 122

liters);

Performance

Max Level Speed: at 3,280 ft (1,000 m):145 kts (270 km/h; 167 mph);

Never-exceed Speed: 194 knots (360 km/h; 223 mph)

Max Rate of Climb: at S/L: 23 ft/s (7 m/s);

Max Ceiling: 13,125 ft (4,000 m)

T-O Run: 558 ft (170m);

Landing Run: 985 ft (300m)

Range: 296 NM (550 km; 341 miles)

Max g loading: +7/- 5 g