Powered by a 190 hp Continental, the four seat Krishak is a multi-purpose development of the Pushpak. The HAOP-27 Krishak being manufactured as a liaison aircraft for the Indian Air Force and Army, the first flown in 1965.

Hindustan HAOP-27 Krishak Article

In 1961 Hindustan was developing the 90 hp PE-90H flat four piston engines for future versions of the Pushpak.

HAOP-27 Krishak Mk.II
Engine: Continental O-470-J, 225 hp.

The Indian government had agreed to license-manufacture the Folland Gnat jet fighter in place of the Venom. There was some sort of delay in delivery of the tooling and jigging for this new plane and this provoked a production crisis as the very large work force ended up with nothing to do. When Venom production discontinued, management panicked to find alternative work, hence the “PUSHPAK” project.

Aeronca sold the Super Chief Model 11 type certificate to E. J. Trytek of Syracuse, NY. Though Mr Trytek did not manufacture any airplanes, but he did license Hindustan Aircraft of India to build the Chief as the HUL-26 ‘Pushpak’.

About three years before, the small Bangalore Flying Club had an Aeronca Super Chief single engine high-wing monoplane aircraft that they were using for training purposes. A young Indian student pilot was flying the thing and he overshot the grass field on landing and headed for a gate girded by two gate posts. The gate was open and he headed for it to go out on to the road.

Unfortunately he was wider than the gate opening so he hit the starboard wing tip and sheared off about two feet, starting the plane spinning so that it then hit the port wing tip and sheared off approximately the same amount. The aircraft continued spinning and hit the rudder on the post and badly distorted it in turn. The aircraft spun to a stop in the road outside and the student pilot nipped out smartly and disappeared down the road in a cloud of dust, never to be seen again. He was acting on the assumption that he would have to pay for all the damage!

The aircraft was taken back to a small hangar and the wings were removed and it was stored there awaiting repair. After a long period of time they ordered a set of new wooden main spars for the mainplane. Eventually these did arrive but somewhere along the line, lifting hooks had been used which had damaged the wood and the spars couldn’t be used. So the thing sat there in its dormancy and another Aeronca was purchased to continue the flying training.

H.A.L. were aware that this plane was lying there and so, after a management meeting, they sent a truck out to bring it back to H.A.L. where it was quickly dismantled into its smallest constituent parts and spread out over the manufacturing area. On 7 August 1958 they were told to reproduce all the parts. The fuselage was made out of Renolds steel tubing but, since this was not available, they used household conduit which looked like Renolds tubing but was not seam-welded and didn’t have the strength of Renolds.

The plywood panels were fitted in place and they had a fuselage. The original Aeronca engine was used from the damaged Aeronca and was fitted with a new propeller. That was no problem. But there were problems obtaining other original equipment for example, the flying control surfaces were operated by Morse sprockets and roller chain which were also not available. They therefore used ordinary bicycle sprockets and chain plus the usual cables. The control surfaces again were made from household conduit tubing.

The metal ribs were re-manufactured from copies and it was reassembled and fabric covered. The mainplanes were manufactured in the same way and the original wood spars that had been damaged by the hooks had some splice-work carried out on them and reinforcements and the damaged main spars were used. The ribs were copied, fabric covered of course. The original Aeronca had a very deep molded front wind screen. The original windscreen was removed, a light film of oil applied on the inside and then plaster of Paris and straw were dropped onto it to make a very quick mold and this was then sent to the perspex division where they produced an exact copy of the windscreen. Another good example of this procedure was the manufacture of the aluminium brake pedals. The original pedals had ribs which over the course of time had become worn down somewhat. These were sent into the pattern shop and when they came out, they had the same worn markings that were on the old pedals!

The aircraft was completely assembled and then did one flight only on 28 September 1958, a very shallow take-off, a very limited turn around the airfield, one landing, and it never flew again. This event was notified up the ladder to Air Force Headquarters in New Delhi. The Farnborough Air Show was due to start in a few weeks after this. At the Farnborough Show the Indian Government made an announcement that Hindustan Aircraft Ltd. had designed, built and test-flown the Pushpak aircraft in six weeks! Nevertheless, the Pushpak trainer was born and was produced thereafter for use in India.

The prototype Pushpak was joined by a second and entered production in 1959, nine production models were completed in the 1960-61 financial year and more than 25 had been sold to flying clubs in India by the beginning of 1962. The prototype had wooden wings, but production Pushpaks are all metal. They were powered by a Continental C-90.

154 ‘Pushpaks’ were built from 1958 to 1968.

Engine: Continental C90-8F, 90 hp
Wingspan: 36 ft 0 in / 10.97 m
Wing area: 175 sq.ft
Length: 21 ft 0 in / 6.50 m
Height: 9 ft 1 in
Empty weight: 870 lb / 395 kg
MTOW: 1350 lb / 613 kg
Max speed: 90 mph
Cruise speed: 61-74 kt / 70-85 mph / 112-136 kph
Max ROC SL: 500 fpm/152 m/min
Service ceiling: 14,000 ft / 4270 m
Range: 217 nm / 250 mi / 400 km
Seats: 2 side by side
Baggage capacity: 65 lb / 29.5 kg
No. built: 154

Hindustan Aircraft designed and built the first indigenous Indian aircraft, the Hindustan HT-2 two-seat trainer. The HT-2 is of stressed all-metal construction, with semi-monocoque fuselage and two-spar wing. All covering is metal. The fixed oleo-strut undercarriage is attached to the front wing spar, and features hydraulic brakes. Full equipment includes an electric starter and full dual controls and instruments.

Hindustan HT-2 Article

First flying on 13 August 1951, the prototype was registered VT-DFW. The second aircraft, VT-DFY first flew on 19 February 1952 and had the shape of the fin and rudder altered considerably to increase the chord. This was retained on the production aircraft.

The HT-2 received the Government of India’s first Type Certificate, issued on 20 December 1952. By then, several military machines were flying, as well as the prototypes.

The first production aircraft were delivered to the Indian Air Force towards the end of January 1953.

The HT-2 was produced for the Indian Air Force and civilian flying clubs. The HT-2 was a two-seat primary trainer that went on to serve with both the Indian Air Force and Indian Navy, replacing the de Havilland Tiger Moth as the nation’s introductory training aircraft. Pilots affectionately nicknamed the HT-2 the Dalda Tin, referencing its resemblance to a tin of Dalda, a well-known brand of vegetable oil in India.

The type entered service in 1953, powered by a 155-horsepower Cirrus Major III four-cylinder inverted inline engine, the HT-2 could cruise at 115 mph and reach a top speed of 130 mph. Its stall speed was relatively high for a single-engine trainer at 52 mph. With a range of 300 nautical miles and an endurance of three hours and thirty minutes, the aircraft was well-suited for short training hops as well as cross-country flights.

Beyond India, twelve HT-2s served with the Ghana Air Force from 1959 to 1974. The aircraft was also a favorite among civilian flight schools throughout India. Over the course of its production run, HAL built a total of 172 HT-2 airframes. The last examples were retired from active service in 1990. Today, no airworthy HT-2s are known to exist, although several preserved examples can be found on display in aviation museums across India.

Gallery

Engine: Blackburn Cirrus Major III, 155 hp
Wingspan: 35 ft 2 in
Length: 25 ft 2.5 in
Height: 8 ft 11 in
Empty weight: 1600 lb
Loaded weight: 2240 lb
Useful load: 640 lb
Fuel capacity: 26 Imp.Gal
Max speed SL: 130 mph
Cruise: 115 mph
ROC: 800 fpm
Service ceiling: 14,500 ft
Range: 350 mi
Endurance: 3.5 hr
Seats: 2