Induction of the Avro
The induction of the AVRO 748 aircraft type in India was the result of the drive of just one man. This is now a part of the history of the country's aviation industry. Having joined the Indian Air Force (IAF) as a Hawai Sepoy (Air Soldier), a rank lower than that of a Private, Harjinder Singh rose to become an Air Vice Marshal (AVM). One of his many initiatives was the construction of an aircraft at IAF Station Kanpur (UP) in early 1958. This was appropriately called Kanpur 1. AVM Harjinder Singh lost the race to introduce this as a basic flying club aircraft to the Pushpak made by Hindustan Aircraft Ltd (HAL) Bangalore. He then made Kanpur II but again lost to HAL's Krishak Mk II. The latter became the Air Observation Post aircraft for the Indian Army.
Frustrated by these two failures AVM Harjinder Singh decided to think big and make a DC-3 (Dakota) replacement. He considered only three candidate aircraft. These were the Handley Page Herald, F-27 Fokker Friendship and the AVRO 748. The first was given up, as it did not seem to find favour anywhere. The F-27 was examined carefully. Its construction required bonding methods, which would have meant air-conditioned hangars. On that one count alone, it was also rejected. This left the AVRO 748 as the sole contender. The AVM's keenness to start producing the aircraft within the Air Force was very great. As a result, its Operational Requirement was a virtual reproduction of its sales brochure. After quick contractual agreements in 1959-60, major assemblies and parts began to be airlifted from Chadderton (Manchester) and Woodford Airfield (Cheshire) to a newly raised IAF unit, Aircraft Manufacturing Depot at Chakeri, Kanpur. The first AVRO 748 assembled in India was ready just a few weeks after the second prototype made its maiden flight at AV Roe & Co at Woodford. It thus became only the third AVRO 748 to take to the air. The production of a transport aircraft by a user air force for its own use must be a very rare case
The Avro's service in India
The 748 during its service with the Indian Airlines has had a very distinguished safety record. A total of three fatal crashes occurred in commercial service of almost three decades. The first aircraft flew into mountains when the IA pilot on a commercial flight descended through cloud, based entirely on his estimated position, without using any navigation aids. He had decided that he knew exactly where he was. The second accident occurred during an instructional flight at IA's training centre at Hyderabad. An instructor and his pupil were killed. After this crash, checks were introduced to ensure that pilots were not inebriated before flight. The third IA aircraft crashed on a clear night while on an ILS approach into Bombay hitting the ground 28 nautical miles short of the runway. All three crashes were almost certainly entirely due to pilot error. Other accidents were non-fatal.
The Indian Air Force currently owns around 60 AVRO 748s. The majority of these are used for communication, carriage of freight and courier duties, especially within the areas of responsibility of various IAF Commands. Seven aircraft were specially equipped for training navigators and four for signals training. All these till recently were engaged in their allotted jobs. Eighteen aircraft were made into pilot trainers. The mod involved only the duplication of the nose wheel steering tiller for the instructor seated on the right. Pilots were trained on these at Yelahanka Air Force Base just north of Bangalore. This base has recently come on the international map with air shows being held at it once every two years. The next one is due in February 2007. The Directorate General of Civil Aviation acquired two aircraft mainly for calibration of navigation and approach facilities at civil airfields. One aircraft was used by the National Remote Sensing Agency for geological exploration and the paramilitary Border Security Force used one aircraft for communications.
Unfortunately, the 748 was never meant to be a military transport. At the request of IAF, its door was enlarged to enable larger cargo items to be loaded and to allow para dropping without hitting the tail plane. However, to load a jeep in it, a 30-ft long ramp was required. The jeep would drive in and insert its front wheels into the aircraft. Then it had to be manually lifted and turned to get it in. Unloading it was just as difficult. Para dropping of troops or cargo even from the aircraft with the enlarged door was considered too dangerous with the risk of hitting the tail plane. The aircraft's performance at hot and high airfields was hopelessly inadequate. Eventually IAF acquired the tail-loading An-32s which were powered specifically for IAF's need for operating in the Himalayas.
The IAF has had four fatal crashes of the 748. The first occurred at Leh killing all 28 persons on board. At Yelahanka during an instructional sortie, the right engine of another aircraft seemed to lose power. It veered to the right, resumed its original take-off heading and then hit the ground and caught fire. The possibility that the engine was feathered either automatically or by the crew and that the aircraft was overloaded cannot be ruled out. The instructor, a pilot of the Navy, the pupil and 28 joyriding pilot officers from Jalahalli were killed. The next crash resulted from fatigue failure of the support of the right engine's jet pipe. It dipped down and damaged the fuel pipeline leading to fire and fracture of the right wing. The relevant mod to prevent such an occurrence may not have been implemented on the doomed aircraft. The crew and an Air Force band perished in this accident. One IAF 748 loaned to Defence R&D Organisation had been modified for establishing airborne early warning technologies. Its radome separated from the support pylons and sliced off the top half of fin and rudder. All eight occupants of the aircraft were killed.
During certification of the 748, the weight-altitude-temperature (WAT) curves were limited mainly by the second segment climb. This concerns the climb after take-off with the undercarriage up, engines continuing at maximum power and flaps still at take-off setting. The aircraft (at V2) must have a climb gradient of 2.4% or else its all-up-weight must be reduced till this requirement is met. However for safety, manuals are based on a gradient of only 1.8%. Surprisingly, in all the years of AVRO 748's service in India there has never been a single accident due to poor performance in the second segment climb. At one time IA pilots had complained about this facet of the aircraft's performance. Under the leadership of Dr Satish Dhawan, Director Indian Space Research Organisation, much investigation was carried out, including ferrying the aircraft to Woodford for trials and back. While the IA fleet was declared to be safe, Rolls Royce undertook some enhancement of power on the Dart engines.
Aircraft Manufacturing Depot later became a part of Hindustan Aeronautics Ltd in October 1964. The 748 acquired numerous prefixes starting from AVRO to HS (for Hawker Siddley) and BAe (for British Aerospace). Now that Woodford is known as the AVRO Division of BAE SYSTEMS, the aircraft can perhaps again be called the AVRO 748. The aircraft has done well for more than 45 years. It is a survivor and so is its name.
AVRO 748 in India - more than four decades on - Gp Capt Kapil Bhargava [www.bharat-rakshak.com]
