New Delhi, July 13 -- Aviation expert Sanat Kaul on Sunday raised concerns over the preliminary report of the Air India 171 crash investigation, stating that it is "not ok."

He emphasised the need for pilots to be included in the probe panel, as per the International Civil Aviation Organisation's (ICAO) charter.

"Well the report, with the National Emblem, from the Ministry of Civil Aviation is not signed, that is correct. It should have been signed. But I don't think the report is ok. We should wait for the final report, and the final report may not align with the preliminary report; there can be several changes in the final report," Kaul told ANI here.

Kaul stressed that a pilot familiar with Boeing 787 systems or at least 737 experie...