Russia's rich literary history includes the short verse Gvozd i Podkova, in which a city falls to invaders because the blacksmith did not have a nail with which to shoe the defending commander's horse.
It is, of course, a variant of a cautionary tale found in several cultures, warning that the gravest consequences can arise from the simplest omission.
Samuil Marshak, the author of the Russian version, was born in Voronezh, the city in which the VASO aircraft plant is situated and where Antonov An-148s are assembled. The distinctive high-winged twinjet, designed in Ukraine but manufactured in Russia, is a symbol of times when political relations between the nations were more co-operative than combative.
Few An-148s have rolled off the line and only two Russian airlines, Angara and Saratov, use them on their networks. Governmental customers include the Russian emergency situations ministry – the authority tasked with co-ordinating the response when, on 11 February, a Saratov An-148 disintegrated in a snow-covered field outside Moscow.
Saratov had flaunted its achievements just two days before the accident, as the country commemorated the official anniversary of Russian civil aviation. The airline proudly declared it had "never been interrupted" in 86 years, since evolving from a small agricultural operation, and was rapidly expanding – also introducing Embraer jets – while "maintaining a high level of flight safety".
Investigation into the loss of flight 6W703 has focused on the pitot-static system, to understand the role that a heating switch – the analogue of the nail in Marshak's poem – might have had in the loss of control.
The effects of icing on sensitive anemometric sensors, and the potentially catastrophic repercussions of misinterpreting instruments or mishandling the response, gained notoriety after Air France flight 447 was lost in a stall from cruise altitude nearly a decade ago.
Investigators are likely to scrutinise Saratov's expansion, to ascertain whether the carrier had adequate training resources and provided sufficient operational oversight. Crucially, they will need to explain why the crew, in the face of corrupt airspeed information, was – like the crew of flight AF447 – unable to intervene effectively, interrupt a chain of deteriorating performance, and prevent an apparently functional aircraft from diving into the ground.
Gvozd i Podkova is a familiar story. But the narrative in which a mix of icing, unreliable instruments and in-flight upset leads inevitably to fatality need not be.