That could require the direct intervention of the White House, since Mr. Bush has personally handled decisions on issuing clearances for the N.S.A. eavesdropping program.
The officials said that seconds after issuing the clearance the controller realized the plane was aiming at the wrong target and tried to stop it.
At 10 01, air traffic control issued a clearance to land at Eveleth, and the pilot was given permission to descend to 4,000 feet.
Officials in Ecuador said on Thursday that the document was invalid, because it was issued without clearance from senior officials by a diplomat who had exceeded his authority.
He said he worked for an agency that could issue me clearance, and had me sign an affidavit absolving him from responsibility in the case of my untimely demise.
This study was issued ethical clearance by the Cameroon National Ethics Review Committee (CNERSH) with reference number 2013/11/385/L/CNERSH/SP.
MPEC/R/10/1, dated 4th July 1980), the Vice-Chancellor of the University of Dar es Salaam (UDSM) was empowered to issue research clearance to the university's staff on behalf of the government and the Tanzanian Commission for Science and Technology (COSTECH).
In addition, he said, the agency will study whether to change the way that controllers issue clearances to pilots. Controllers have long been permitted to give a single clearance that covers a plane all the way from a terminal to the end of a runway.
This was followed by issuing a research clearance letter by the Vice Chancellor, by then Prof. Gerald Monela, that was submitted to the local leaders in the study area after which an agreement was made to conduct the study.
According to CENIPA, the air traffic controllers contributed to the accident by originally issuing an improper clearance to the Embraer, and not catching or correcting the mistake during the subsequent handoff to Brasilia Center or later on.
