DEFENCE Minister Lindiwe Sisulu has drawn a veil of secrecy over the operations of the air force by demanding that a parliamentary committee give guarantees of confidentiality before it can be briefed.

Lt-Gen Carlo Gagiano was to have briefed the joint standing committee on defence yesterday, but the briefing was called off after Ms Sisulu wrote to the committee saying effectively that this could happen only if the committee met behind closed doors.

Lt-Gen Gagiano was certain to have faced questions about the recent flights that shadowed President Jacob Zuma's Boeing Business Jet on a flight to New York as well as the air force's inability to keep many of its new jet fighters and trainers in the air.

He would also have fielded questions about the state of the VIP transport squadron, which has been involved in a number of incidents.

Ms Sisulu has frequently refused to answer parliamentary questions, saying the information was classified - most famously when she refused to reveal details of President Jacob Zuma's past flights on the grounds that it would compromise his security.

When the committee met there was no sign of a delegation from the air force. Then committee chairman Sediane Montsitsi told the members he had received a letter from the minister, of which he read the contents.

Ms Sisulu said "Section 199 (8) of the constitution requires that oversight of the security services should be done in a manner determined by national legislation or rules and orders of Parliament because the information required might be classified".

"I would therefore require that you urgently provide me with the necessary legislative framework that would ensure the protection of the information made available to the joint standing committee on defence, so that I may authorise the South African Air Force to brief yourselves. Without this framework the air force would be in breach of the constitution and the Defence Act and unable to brief the committee."

She added that the "challenges" facing the air force were very important and it needed the support of Parliament. "I therefore urgently need the (committee) to provide the necessary assurances of information security," she said.

Mr Montsitsi suggested that the committee write to the speaker to request a closed meeting. The ANC used its majority muscle to push this resolution through, despite objections from Democratic Alliance MP David Maynier. He argued that committee sessions could only be closed if it was reasonable and justified in a democratic society.

Mr Maynier said the onus was on Ms Sisulu to show that the information was classified and its disclosure would prejudice the operation of the defence force or the lives of serving members. He suggested a legal opinion be sought from Parliament's legal advisers.

Lt-Gen Gagiano resigned late last year because of the problems in the air force. Ms Sisulu declined to accept his resignation and ordered him to return to his post but accepted the resignation of the director-general of the Department of Defence, Mpumi Mpofu.

Lt-Gen Gagiano resigned after taking responsibility for a mishap with a military aircraft that caused Deputy President Kgalema Motlanthe to miss a visit to Scandinavia.

"He was informed that the best way of taking responsibility was not to resign, but to remain and sort out the problem. He accepted that his resignation was rejected."

Lt-Gen Gagiano was admitted to hospital early in November with symptoms of stress.

Some of the incidents which have plagued the air force's reputation include one in which a VIP aeroplane that it chartered developed technical problems as it was taking off from Waterkloof Air Force Base in Pretoria last month. Mr Motlanthe was on board the aircraft at the time.

In September, the aircraft the deputy president was flying on to attend the opening of the Rugby World Cup in New Zealand missed its first landing slot. In 2009, his aircraft was forced to make an emergency landing while flying back from Libya. Then there were revelations that two pilots who flew Mr Zuma to the US earlier this year had been implicated in a failed coup in Equatorial Guinea in 2004.