Geoff Thomas
The war of words between the Sukhoi Su-30MK crew and the show's organisers blossomed into a full-scale international argument yesterday.
Was the aircraft which crashed during Saturday's display being flown outside the agreed envelope? Did the organisers insist on the Sukhoi's display programme being reduced to such an extent that it jeopardised the safety of the aircraft?
There is a clear difference of opinion which will only be resolved once the official enquiry publishes its report on the incident.
Le Bourget air show director Edmond Marchegay says the matter will be fully investigated by the military arm of the French defence ministry and if the pilot is found guilty of flying below the regulation minimum altitude, Sukhoi could have constraints placed on its future activities at the Paris air show.
Comments
It's clear from the comments of Sukhoi chief test pilot Viacheslav Averianov, echoed by the Sukhoi design bureau chief Mikhail Simonov, that he holds neither himself nor the aircraft to blame.
"I'm only sorry that we can't do any further demonstrations of our wonderful super-manoeuvrable aircraft this week," he says, "and I'd like to thank the French police, doctors and medical staff who looked after us so well.
"However, one day we shall be back to show you our beautiful aircraft which is undoubtedly the best strike fighter for the first 25 years of the new millennium."
Averianov explains that the accident was not due to any fault on the aircraft. "When we were in our descent manoeuvre - for which we had trained extensively - everything seemed normal.
"But at the end we had the feeling that we were too low and flying towards the houses and this was exaggerated by the sun in our eyes.
"To ensure that we followed the safety regulations of the show, we decided to turn away, still doing our best to recover from the unusually high rate of descent.
Touched
"Thankfully we have a good power-to-weight ratio on full thrust and I was able to slow the descent so that the tail only just touched the ground with the aircraft in a zero roll configuration, little forward speed and a pitch-up of between 100 and 150.
"I did my best until the final moments when we brushed the ground - but it was soon clear that we had to initiate the command ejection.
"The Zvezda K-36DM seats saved our lives, working flawlessly."
In the command ejection, the aircraft commander - in this case Averianov - initiated the sequence which resulted in the canopy being jettisoned before the back-seat occupant, navigator Vladimir Shendrik, was ejected.
The pilot followed micro seconds later, both seats moving in separate pre-programmed directions to minimise the risk of collision.
Averianov also explains that he and Shendrik had undergone extensive training before flying to Paris. Firstly, they spent several hours in the simulator, before flying some of the display in a Su-30A1 and the full programme in the aircraft that crashed on Saturday.
The programme was agreed seven days before leaving for Paris and signed off by designer Simonov. Averianov has made more than 140 flights in the Su-30MK since its maiden flight some months ago.
Ejection
Gay Severin of Zvezda, chief designer of the ejection seat, says the seats first entered service in 1970, although they have undergone considerable modifications since.
Around 12,000 are in service throughout the world and many pilots owe their lives to their zero-to-1,400km/h (750kt) capability. Operable at up to Mach 3, the seats enjoy a 97% success rate in returning pilots uninjured to flying duties - the best ratio in the world.
The next generation of the seat, called the 3.5, will enable pilots to escape at up to Mach 3.5.
The low-altitude capability of this electronic 'smart seat' means that even with uncontrollable roll angles of up to 900, the seat will automatically gain altitude and adjust the escape rocket thrust depending on the weight of the pilot and the flight envelope of the aircraft.
Alexi Fedorov, president of the Russian air force's industrial association, guaranteed that the accident will have no effect on the fulfilment of the Indian Air Force's order for Sukhoi Su-30MKIs.
"I reassure all our customers," he says, "that the accident will have no production or financial impact on Sukhoi. We will change our internal schedule so that we can build another prototype to replace the one which crashed."
Source: Flight Daily News
