Taechi T-627

Taechi T-627
T-627G, early production version
Role	Civil and military trainer
National origin	Menghe
Manufacturer	Taechi Aircraft Design Institute
Designer	Taechi AIC
First flight	4 September 1975
Introduction	1977
Primary user	Menghean Army Aviation
Number built	300+

The Taechi T-627 is a type of primary trainer developed for the Menghean Armed Forces. It uses a conventional low-wing monoplane design with an opposed-piston engine and tricycle landing gear. It is the first Menghean single-engine trainer aircraft in which the pilot and instructor sit side-by-side. Though initially developed as a military trainer, it also sees widespread use as a civil trainer, private aircraft, and liaison aircraft.

Development

The T-627 was developed as a replacement for the Chikai Ch-114, the first Menghean primary trainer developed after the Menghean War of Liberation. The Ch-114 was developed on an expedited schedule with extensive use of prewar parts and design experience, including the Donghae Gi-27 engine from the Chikai Type 40 fighter. Its performance and reliability, however, were both subpar, so the Army requested design work on a new primary trainer in 1972.

Design work was handed to the Taechung Aircraft Design Institute, which had been established to design light utility aircraft. To assist with development, the recently-reconstituted Chikai Aircraft Design Institute was merged into Taechung, resulting in the "Taechi" designation. The first prototype completed its first test flight in 1975, and the type was accepted for mass production in 1977.

Design

The Taechi T-627 is the first Menghean single-engine trainer aircraft in which the pilot and instructor sit side-by-side. This layout allows the instructor to see the pilot's conduct and instruments, and to have a clearer view forward when taking control of the plane. There is also space behind the pilot and copilot for a removable bench with seatbelts and space for three passengers. This bench could also be removed in pieces through the doors, creating space for a laid-down stretcher or up to 500kg of cargo. This feature was indended to give the T-627 a secondary role as a liaison aircraft, able to evacuate wounded personnel, deliver essential supplies, or transport a high-ranking officer and 1-3 staff members. Models built after 1992 instead feature two permanent side-by-side seats with a cargo door in the left side of the fuselage behind them.

Unlike either its predecessor or its successor, the T-627 does not feature backup combat capability, such as underwing mounting points for pylons. The type was judged unfit for ground attack, and weapons training would be conducted on tandem-seat trainer versions of combat aircraft.

The powerplant is a Taechung Tokki 6-cyliner opposed-piston engine, later revealed to be an unlicensed copy of the Lycoming O-540. Models built after 1992 use officially-licensed O-540 derivative engines with improved performance. The T-627 has better performance than the Ch-114, but was still judged inaequate to prepare pilots for high-performance aircraft, leading to a design request for an improved primary trainer in the early 2000s.

Operational history

Large numbers of T-627 trainers were produced for the Menghean Armed Forces in the 1970s, 1980s, and 1990s, where they served as the main trainer aircraft for both Menghean Army Aviation and Menghean Naval Aviation. In both services, the T-627 served as an intermediate step between ab initio trainer aircraft and operational conversion trainers--or, following the purchase of 36 Hawk T1 airframes from Anglia and Lechernt, lead-in fighter trainers. The type was generally well-liked for its relability, visibility, and handling, especially compared to the Ch-114, but still subpar in its performance.

In addition to military customers, Taechi also produced a considerable number of T-627 airframes for the DPRM's civilian flight training agencies, to train the pilots of passenger aircraft, utility aircraft, and crop dusters. A small number were also purpose-assigned to deliver essential supplies like spare parts and medicine to remote locations, though the state delivery service operating them became defunct in the mid-1980s and was not resuscitated after the Decembrist Revolution. Instead, large numbers of ex-civil and ex-military T-627s were put up for private purchase starting in 1989 as part of a bid to restore Menghe's reserves of hard currency and cut military spending.

As a result of this sale program, the type gained a small following among general aviation customers abroad, primarily for their rare status as ex-DPRM warbirds. In 1992 the Taechi Aircraft Plant resumed low-rate production for the civilian market, introducing the T-627D, which featured safety and performance improvements and more modern avionics. This type became a staple of emerging Menghean flying clubs, and helped feed the renewed demand for civilian pilots.

Variants

B-342

First flying prototype.

T-627G

Early production model, produced between 1977 and 1984 for both military and civil use.

T-627N

Improved model, introduced in 1984 with production halted in 1988. Differences include more robust landing gear and some differences in the avionics. Due to its short production runtime, and disruptions to production during that time, it is the rarest mass-produced T-627 variant.

T-627D

Introduced in 1992 when Taechi resumed mass-production. Features a legally licensed IO-540 engine for improved performance, two fixed rear seats rather than a removable straight-backed bench for improved passenger safety, and a larger cargo door on the left side, as well as lighter fuselage construction. The controls and avionics were also updated.

Specifications (T-627D)

General characteristics

• Crew: 2 (pilot and instructor)
• Capacity: 2 passengers
• Length: 8.24 m (27 ft 0 in)
• Wingspan: 10.00 m (32 ft 10 in)
• Height: 2.52 m (8 ft 3 in)
• Wing area: 15.00 m² (161.5 sq ft)
• Empty weight: 900 kg (1,984 lb)
• Max takeoff weight: 1,500 kg (3,307 lb)
• Fuel capacity: 360 L (95 US gal; 79 imp gal) (internal)
• Powerplant: 1 × Lycoming IO-540 air-cooled flat-six engine, 216 kW (290 hp)

Performance

• Maximum speed: 310 km/h (193 mph; 167 kn) at sea level
• Cruise speed: 290 km/h (180 mph; 157 kn)
• Stall speed: 98 km/h (61 mph; 53 kn) (flaps down, power off)
• Never exceed speed: 400 km/h (249 mph; 216 kn)
• Range: 1,800 km (1,118 mi; 972 nmi)
• Endurance: 6 hr
• Service ceiling: 5,600 m (18,400 ft)
• g limits: +6, -3G
• Rate of climb: 7.49 m/s (1,475 ft/min)