On 25 March 1986, three Antonov An-32 transport planes departed Muscat, the capital of Oman, in a staggered formation for the Indian Air Force base at Jagmagar.

Initially, the Indian Air Force were using Douglas DC-3 Dakotas and Fairchild C-119 Flying Boxcars for their transport. In the 1980s, spurred by the developing relationship between Leonid Brezhnev and Indira Ghandi. The Soviet Union made the offer of new aircraft at ‘friendship’ prices. The Ministry of Defence decided that the medium transport aircraft should be replaced with the new Soviet-built An-32, an upgraded and re-engined version of the An-26. The then Joint Secretary (Air) is said to have stated, ‘sign as many aircraft as you want, for after a few years even a car may cost more than them.’

The Indian Air Force were the first customer of the An-32 and purchased 125 aircraft on a 20-year military credit arrangement with no interest liability.

The large order of aircraft allowed the Indian Air Force to re-equip eight squadrons with the An-32 as transport, bombers and para-droppers: the No.12 Squadron “Yaks” in Agra, the No.25 Squadron “Himalayan Eagles” (“B” Flight Only) in Chandigarh, the No.33 Squadron “Caribous” in Sulur, the No.43 Squadron “Ibex” in Jorhat, the No.48 Squadron “Camels” in Chandigarh, the No.49 Squadron “Paraspears” in Jorhat, the Paratroopers Training School in Agra and the Transport Training Wing in Yelhanka.

A modernised An-32 is today worth about $15 million US dollars. There are a total of 240 An-32 aircraft in use by military operators around the world and the Indian Air Force is still the primary user. Of the original 125 aircraft purchased by the Indian Air Force, 105 are still in service, and the fleet is currently undergoing modernisation — a long-term project which has been expedited in the aftermath of the second disappearance.

The then brand new An-32 aircraft began arriving in 1984 with three years to complete the order.

On the 25th of March in 1986, the deliveries were still in progress and there were three new aircraft on the last leg of their ferry flight, from Oman to India. They took off at ten minute intervals, forming a staggered formation to fly to the Indian Air Force base at Jamnagar. Each aircraft carried three crew and four passengers for the two hour flight over the Gulf of Hormuz and the Arabian Sea to Jamnagar.

The weather that day was ‘fair’ and the route straight-forward. The first of the three An-32s landed at the coastal airport after an uneventful flight. The next aircraft to land was the third of the formation. The middle aircraft, tail number K2729, was missing.

The two surviving An-32s had believed themselves to be within close proximity of each other throughout the flight, however they had no idea that the middle aircraft was no longer with them. There was no radio call or signs of distress.

The loss of the An-32 straight from the factory was, of course, an issue, as well as the pointless deaths of the seven souls on board. But on top of this, the Indian Air Force was also under scrutiny as they’d lost another An-32 just three days earlier, when a military flight on weather reconnaissance crashed into a mountain at nearly 19,000 feet while descending through cloud.

As a result of the political situation, the search and rescue operation was massive. And yet, they turned up no results. The media reported that “it was as if the sea had gobbled up the entire aircraft and buried it deep in its watery grave.”

No one had a clue what could have happened. The An-32 was on its delivery flight and should not have been at risk of any sort of physical failure. The pilots were experienced. The route itself was straight-forward and the weather was clear. There was no reason to suspect sabotage. And yet, the plane was gone, disappeared out from under its two companions without a sound.

With no distress call and no debris, the case soon grew cold. The investigation gave up, citing the probable cause of the loss of the An-32 as simply ‘Unresolved’.

However, the Indian Air Force later discovered evidence that on the same day, the US Navy had supposedly lost an aircraft and launched a separate search and rescue operation which equally found nothing. The interesting point was that the missing plane had been based on an aircraft carrier which was known to be in the same area where K2729 was believed to have gone down.

Apparently, the US Navy aircraft also simply vanished without a distress call and the wreckage of that aircraft was never found. Since the two military investigations were both conducted separately (and the US investigation has never been confirmed by the Navy), the possibility of a mid-air collision was never seriously considered. If that were the case, it could help to explain why both aircraft vanished so suddenly.

However, this theory poses as many questions as it answers. How was it that neither of the two An-32 in loose formation saw any sign of the US Navy aircraft? If there was a mid-air collision, why didn’t the An-32 bringing up the rear see the explosion? How could two aircraft disintegrate over the calm seas not leave any trace of debris visible on that fair day. And finally, why has the US Navy has never officially admitted that an aircraft vanished in the Arabian Sea on that day, although there were published reports of two missing airmen lost at sea and presumed dead?

The mystery of An-32 was highlighted in the Indian press in 2014 when Malaysian Airlines flight 370 disappeared. They could not have known that another An-32 was about to vanish in similar inexplicable circumstances…

This is the first half of a chapter from my upcoming book, Without a Trace, which explores over two dozen aviation mysteries. If you enjoyed it, please consider buying the book!