Mile-High, No Quads?

A few days back, I happened to see a BBC documentary on the now defunct American carrier, Pan-Am, titled Come Fly With Me - the Story of Pan Am. The documentary traced the evolution of the airline from propeller aircraft to the jet-age heralded by the Boeing 707.

Instantly, I was taken back to the 1980s. That is when I took my journey on a quad-jet - the Boeing 707, of Uganda Airlines, probably between Entebbe and Nairobi. That was an amazing jet, with a splendid livery in the colours of the Ugandan flag - a crested crane on the tail and prominent yellow, red and black band that stretched along the fuselage.

Then followed journeys on Boeing 707s of Air-India and Zambia Airways. The Centaur on the Air-India Boeing 707 tail always looked smart. I still cannot fathom why Air-India dumped the Centaur.

The first Zambia Airways Boeing 707 I saw was at Lusaka Airport, in October 1984, at twilight, with its tail, an orange Z stylised as an eagle, set on a green background. We flew on that beauty to Bombay, in what was my most memorable intercontinental flight.

As we approached the Indian airspace, dawn broke and we woke up. It was enthralling to see two engine nacelles hanging from the wing, against the backdrop of the azure Indian Ocean. What ensued was a quick visit to the cockpit, led by an eager stewardess. The flight crew were Zambians, and were happy to show off their smart cockpit to me, a precocious 8-year old, before they commenced their descent. Those were different days and innocent thrills of seeing a flight deck at work were easy to come by. Today that's unimaginable, for obvious, security reasons.

We flew on a trijet, McDonnell Douglas DC10 after that, which was again pretty smooth, but not quite like a quad - the thrill was lacking.

My last flight on a quad was on the Air Mauritius Airbus A340 from Plaisance to Bombay in October 2005. That was a pretty interesting flight - seeing the slim red nacelles hanging from the wing was a sight to behold.

In the last few years, I flew largely on Boeing 737s, Airbus A320s, Airbus A330s and Boeing 777s. But these flights were completely devoid of the thrill that one has of peering out of the window and seeing two nacelles hanging underneath the wing!

The era of quad-jet airliners which started with the Boeing 707 in the 1960s, seems to be ending now, with twin-jets being deployed for the job. Last month, Airbus announced that it was discontinuing the A340 line. With this development, the choice of quad-engine aircrafts reduces to just two - the Boeing 747-8 family and the Airbus A380. These Jumbos are niche products, which would not make much sense for most airlines. With limited flexibility of operations, these Jumbos can operate only from a limited number of airports around the globe, as a result of which we'll see fewer and fewer quads with each passing year.

A lot has been said about the efficiency and reliability of the twin-jets, which have been extended operations certified or ETOPS certified for non-stop intercontinental operations. For a few years now, they have been deployed for non-stop operations from India to the US East Coast, overflying the the Arctic. This cuts the flying time, bypassing a stopover in continental Europe.

The twin-jets, Boeing 777, Boeing 787 and Airbus A330 have specially designed engine with a diameter exceeding the quad-engine nacelles by a factor of over 1.5. The higher diameter provides for the increased airflow through the engine for the required lift.

But twin-engines lack the redundancy that the quads provide. I dread to think of a situation on a twin-engine overflying the Arctic and one engine fails. Where would the aircraft land?

But an aviation enthusiast would lament the loss, the excitement of being mile-high (pun unintended) on an intercontinental flight and peering down upon two engines!