The parents of 16 students from the German town of Haltern accused Carsten Spohr of never speaking with relatives to apologise — a claim disputed by the airline.
The letter comes amid negotiations with Lufthansa, Germanwings’ parent airline, over compensation for the March 24 crash.
Prosecutors believe the Airbus A320 was intentionally crashed into a French mountain by co-pilot Andreas Lubitz, killing all 150 people on board the flight from Barcelona to Dusseldorf.
Lufthansa has offered around €100,000 per family, depending upon its size.
German lawyer Elmar Giemulla, who represents the Haltern victims, has said the offer is far too low and is seeking at least three times that amount.
In their letter, provided by Mr Giemulla, the parents, along with the fiance and husband of the two teachers who were with the Haltern school group killed in the crash, said Mr Spohr talked to a lot of newspapers, “but you haven’t spoken with us”.
They added: “You saw us at the memorial service in Haltern and the memorial in Cologne. A couple of personal words would have shown us that you were not only there for the public, but also for us.”
They added that Lufthansa’s compensation offer “deeply insults us, and above all else our children”.
Lufthansa spokesman Andreas Bartels insisted Mr Spohr had made every effort to talk with families, and attended not only the services in Haltern and Cologne but had also been to Barcelona and twice to the crash site.
“Mr Spohr was in touch with many relatives and friends and family of the victims but it’s obvious that he was not able to be in personal touch with each and every one of the more than 1,000 relatives that we have,” he said.
Parents of the Haltern victims were among those he talked to, and he also sent a condolence letter apologising to all families, Mr Bartels added.