Flyers today are more up-to-date about the newer aircraft that airlines are operating. However, not many would know the complex process involved in inducting a new aircraft type like, say, the Boeing 787, into an airline’s fleet.

When an airline decides to get a new variety of aircraft, it has to operate what is called a ‘proving flight’ for getting an Air Operator’s Certificate before it can start flying the plane.

The situation becomes even more complex if the airline wants to start operations to performance limited or critical airfields like Leh, Jammu, Srinagar and Patna as then it has to undergo a second case proving flight to the airport that it wants to fly to.

A proving flight is part of the Directorate General of Civil Aviation’s process for the induction of a new aircraft type in an airline’s fleet. “The flight is to allow the operator to demonstrate to the DGCA the airline’s ability to conduct the flight safely and in accordance with all rules and regulations laid down by the authority,” says a Vistara spokesperson.

A process of testing

A proving flight consists of five sectors (legs) with a total combined block time of 10 hours or more. This may include one diversion to either an en route alternate airport or a destination alternate . The proving flight may originate from any airport and fly to another airport.

In February this year, when Vistara inducted its first Boeing 787, it had to undertake DGCA’s flight proving process. Incidentally, Air India had been operating the Boeing 787 in India and on its international routes for several years before Vistara did a proving flight.

The DGCA website also specifies that revenue passengers or revenue cargo must not be carried on proving flights. “The operator is required to carry non-revenue passengers like company staff or invited guests to simulate a normal passenger load. Non-revenue company cargo or equipment may also be carried,” the website adds.

A proving flight has the pilots, crew, DGCA officials and any airline personnel required to support the flight. During the flight, both flight and cabin crew are tested on their operational knowledge. “Simulated conditions such as medical emergencies, in-flight smoke, navigation failure, may be tested. Non-normal conditions such as engine shutdowns are not simulated in flight. These are tested in the simulator during pilot proficiency checks,” the Vistara spokesperson adds.

From Delhi to Leh

Moving to operating flights to difficult airports, Captain PP Singh, a former IAF pilot and Senior Vice-President, JetLite, recalls doing the first route proving flight for Jet Airways to Leh in early 2000.

“We flew the B 737-New Generation aircraft from Delhi to Leh. With me was a senior official from DGCA, and another captain, an ex-Modiluft pilot who had operated to Leh earlier. The preparation for the flight, including performance calculations, risk assessment and operating procedures, had been going on over the preceding two months. The DGCA official asked the co-pilot to do the landing. Since I was a qualified examiner with Jet Airways, the official wanted to verify the airline’s training capabilities and standards before granting approval to operate in Leh’s tough terrain. We were also asked to practically demonstrate all critical emergency manoeuvres like simulated engine failure during take-off, terrain escape routes, go-around, and landing with one failed engine,” the Captain recalls.

Subsequently, Jet Airways was cleared to operate to Leh and Captain Singh flew every day on the Delhi-Leh sector for over a month, teaching and clearing other pilots.

A proving flight is required for Leh as the runway is surrounded by mountains, and there are no instruments to guide the pilot on to the runway. “The airport elevation at Leh is 10,682 feet and because of the mountains surrounding it, the minimum safe altitude for an aircraft to come overhead is 24,000 feet. Only the last 30 seconds or so before landing are you in a straight flight, otherwise you are constantly manoeuvring to avoid the terrain. All Ground Proximity Warning systems need to be turned off when landing, otherwise you will constantly hear an automated voice telling you that you are too close to the terrain,” Captain Singh says.

A few years later, Captain Singh also did a route proving flight to Thoise, near Siachen, after which Jet Airways was permitted to carry out charters for the army to this airport for over a decade.

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