Although I am a layman in aviation, I presume to comment on the letter from retired Captain Julien Evans (24 July), on the basis of the flight-deck recorder transcript from Air France 447, which crashed in the Atlantic in June 2009, killing all 228 people aboard.

Although the French captain must have had a general awareness of the storm ahead, he was unaware of the exact magnitude through failure to monitor the radar adequately. When the senior first officer took over from the captain, the former checked the radar, found it mis-set, adjusted it and saw the hazard ahead.

But a more important problem arose from a design feature specific to Airbus airliners. In Boeings and virtually every make other than Airbus, there is a control column in front of each pilot, the pair linked so the position of either is reflected in the position of the other, visible to other crew members.

Airbus uses a "side-stick" control recessed below the side window and not linked to the opposite control, so the position of the flying pilot's hand may be difficult to see.

When the pitot head iced over, the autopilot, deprived of airspeed information, handed control back to the pilots and it was the junior first officer who remained in control. For whatever reason, ignorance, confusion, panic, he held the stick back, keeping the aircraft in a nose-high attitude in spite of stall warnings.

The senior first officer and captain, on return to the flight-deck, remained unaware of this until too late. Probably in a "conventional" flight-deck, the mismanagement would have been immediately obvious and corrected.

Richard Clatworthy

Beverley, East Yorkshire

BBC comments will spoil Danny Boyle's opening

I can totally understand Danny Boyle's annoyance at learning that the televised Opening Ceremony will be interrupted with "quotations, references and music" to "explain" to the viewer what is happening (report, 24 July).

How does the BBC think the audience in the stadium will understand what they are seeing if they do not have the same "references"? Will they have a running commentary on the PA system?

How insulting to a director of such high standing as Mr Boyle and, indeed, to the television audience to suggest that not everyone will understand what they are seeing.

Why can't we watch it as if we were in the audience? It would be so much more exciting for those of us who did not get a ticket to feel as if we were there.

Gillian Brown

Launceston, Cornwall

Hypocrisy over cash-in-hand

Tax evasion and avoidance is said to deprive the Government of at least £69bn per year. Some estimates are twice that figure. The UK's budget deficit is likely to be between £100bn and £120bn in 2012-13. So tax evasion burns a large hole in the nation's pocket.

David Gauke, the Exchequer Secretary, said HMRC reckoned cash-in-hand accounts for £2bn a year in lost tax revenue. Most households have paid cash-in-hand for the discount, so there is little cross-subsidy by full taxpayers for those who avoid tax just occasionally.

Why lecture us on a couple of hundred pounds when this government is letting millionaires and multinationals off the hook for millions? It is breathtaking hypocrisy, and this Government has no moral right to lecture anyone on what is right or wrong.

Jack H G Darrant

London SW2

Small- and medium-sized enterprises are the backbone of our economy, and it is these businesses that will return us to growth.

Most small business owners pay their taxes (letters, 25 July) and are happy to do so. To suggest that tax avoidance is the default mode for tradesmen is incorrect and offensive. To suggest that cash-in-hand payments are as significant a problem as the wholesale tax avoidance practised by some high-profile corporations is absurd.

We read that the super-rich are hiding as much as £13trn in offshore tax havens. If the Government is really concerned about damage to the Exchequer it should spend more time closing the loopholes that enable this, and less time undermining trust in the country's small businesses.

Jason Stockwood

London EC4

Many tradesmen are self-employed. Consequently, they have to pay tax in advance based on an annual income estimated by HMRC, with settling up at the end of the year. Overpayment takes months to be returned.

Is it moral to pay tax on money you have not yet earned, and may not earn depending on how your business goes?

Eric Evans

Dorchester, Dorset

Does Lloyds TSB harbour secrets?

In the past month, NatWest barred customers from their own money, Barclays admitted manipulating their Libor rate and now HSBC admits laundering drugs money for years. Come on, Lloyds TSB, what are you hiding?

David J Williams

Rhos-on-Sea, Colwyn Bay, North Wales

How science has it over faith

The idea "that all matter was once contained in a space the size of a pinhead" is supported by evidence: the ideas of creationism aren't (letters, 25 July). If science finds further evidence that modifies this view, the idea will be revised. That is where science scores over faith, and why creationists should not teach creationism as science.

Roger Plenty

Stroud, Gloucestershire

North stars

It's no surprise that Orkney has a high quality of life (report, 24 July). I put it down to excellent, truly comprehensive schooling. And a history of producing a high proportion of academics. No class-ridden nonsense about social and financial selection, and no private schools with pushy parents to mess things up.

Alison Sutherland

Kirkwall, Orkney

Rotten joke

BBC Radio 4's Farming Today has exposed the producers of Country Life butter as among those who underpay farmers for milk. We all thought "How wittily ironic" when Johnny Rotten told us on TV, "Do I buy Country Life butter because I care about the British dairy farmer? No, it's his career choice!" Will that ad run and run?

G Puckett

Ashford, Kent