A jumbo jet captain has been praised for asking an off-duty pilot to step in for an emergency landing when his co-pilot fell ill.
The 35-year-old co-pilot first became ill when the plane was over Newfoundland but by the time it was half way across the Atlantic a decision had to be taken to divert to Dublin and get him to hospital.
There were 16 crew and 266 passengers on board the Boeing 747.
A report by the Air Accident Investigation Unit (AAIU) found that an off-duty pilot was identified among passengers by the cabin crew.
The 46-year-old was qualified on a smaller Boeing plane, the 767, and worked for another airline, but had 11,000 hours flying experience.
The AAIU said the Lufthansa captain checked his pilot's licence and identity and asked him to sit in the sick flight officer's chair on the flight deck.
The captain commanded and supervised the off-duty pilot as he monitored actions during the emergency.
The plane's approach into Dublin, the landing and taxiing were uneventful, the report found.
The AAIU said it had no issue with the off-duty pilot being asked to step in even though he normally flies on planes smaller than the jumbo jet.
"Although the aircraft size and the number of engines were dissimilar, nevertheless the same operational philosophy and systems design tend to carry from one aircraft to another within a manufacturer's line of products," the AAIU found.
"Consequently this pilot was a good choice and was adequately equipped to provide additional assistance in this situation.
"Incapacitation of a flight crew member is a serious incident and placed the operation outside the certification requirements of a minimum of two qualified pilots to operate the aircraft.
"The situation was dealt with in a professional manner by the commander who, assisted by his cabin crew, employed the principles of CRM and located another pilot to assist him."
At the time of the incident a Lufthansa spokeswoman said the off-duty pilot was fully licensed to fly.
By Ed Carty, Press Association