Don't cry for me - I booked a flight on Aerolineas Argentinas

EQV is airline shorthand for "equipment varies". On AR1131, it certainly does. The Argentinian airline flies the sector from Madrid to Buenos Aires with a state-of-the-art Boeing 747-400 (you know, the jumbo with an extended upper deck and turned-up wing tips). But to reach the Spanish capital, you will travel on a very, er, variable plane belonging to a different airline.

HOW DID this curious state of affairs come to be? Some years after the Falklands War, Aerolineas Argentinas began flying to and from Britain. The airline used a jumbo for the whole trip, with a stop in Madrid, and, for a time, in Paris as well. Given that most of the passengers were only interested in the Madrid-Buenos Aires leg of the journey, that left a lot of empty seats for the intra-European sectors. Some of these were sold off cheap; indeed, until no-frills flights arrived, the airline provided the cut-price way to reach either Paris or Madrid from London.

Now, though, the airline is trying to match supply with demand. So it subcontracts the Gatwick-Madrid leg to a company with smaller planes. Which is why British travellers who want to go no further than the Spanish capital will find themselves flying on AirPlus Comet.

JUST LIKE in the olden days, I thought as I picked up the phone and dialled Aerolineas Argentinas's London office. Yes, there was a seat available on the days I wanted. A ticket would cost a very reasonable £81 return, much less than British Airways or easyJet for the same trip. And when they said "ticket", they meant it. This antiquated document was posted out and arrived the very next day, having been sent special delivery, at a cost of £4 to the airline. (I don't know about you, but these days, real tickets make me nervous; one more thing to remember.)

At the gate at Gatwick, I detected some nervousness among my fellow- passengers. Perhaps they were fretting about the small twin-jet we were to fly on, though its safety record is excellent. Maybe one or two were anxious about the presence of a pair of customs men: South American flights attract special attention from HM Customs.

The officials had plenty of time to check out the passengers as they checked out of Britain, because the plane left nearly an hour late - though no one explained why.

On board, it resembled a charter jet circa 1990 - which was around the time the plane had been built. But unlike 21st-century no-frills airlines, at least we got some free food. Two hours after we were due to leave - by which time it was lunchtime in London, past lunchtime in Madrid, and darn close to lunchtime in Buenos Aires - "lunch" arrived. It comprised a tiny dish of tuna and peppers, followed by a miniature ham sandwich. Thanks for the tapas, I thought, uncharitably, where's the main course?

WHEN AIRLINE staff start using the term "operational reasons" half-an-hour after your homeward plane was due to leave, you know you should start worrying. After protracted obfuscation about when the plane from Spain might leave, the ground staff revealed that departure had been put back by three hours.

When we finally got on board, the plane initially looked very lopsided: our boarding passes had been issued for an MD88, where the seats are five-abreast. But the plane we were assigned was an Airbus A310 ("Another rave from the aviation grave," said a disgruntled passenger, with little regard for the nerves of anxious flyers). Instead of a long, thin plane with plenty of legroom, we had a short, fat aircraft in a knee-crushing configuration. Equipment Varies, indeed.

Instead of reaching Gatwick mid-afternoon, we arrived mid-evening. Does the "Plus" in AirPlus Comet mean: add several hours to promised journey time?

Aerolineas Argentinas: 0800 096 9747