A Turkish Bombardier Challenger business jet has crashed in the mountains of Iran earlier this year, all 11 passengers and crew aboard were killed.
It was carrying a bridal party of the heiress of a business tycoon and her friends. Everyone on board including the pilots were all female.
Iranian civil authority has released the investigation report including the flight data recorder and cockpit voice recorder data.


 The aircraft encountered failure in Airspeed indication .The origin of
Airspeed failure is not cleared now and design information of related system
should be investigated.
 The crew reaction about the failure and reducing engine power caused stall
situation for the flight.
 The aircraft had sufficient altitude to allow the pilot to recover from the stall
situation.
 Flight crew could not perform emergency procedures both for unreliable
airspeed and stall recovery completely.
 The cockpit crew coordination based on CRM principle was not enough.
 The aircraft had integrity before impact to mountain area.

It was very painful to read the CVR transcript.

The captain saw a divergence in airspeed indicators on captain and f/o side during the climb to 38.000 feet, she requested permission to descend, but the airspeed indicator on her side was showing overspeed so she kept pitching the nose, not realizing the pitot-static system was malfunctioning. In the records she pitches the nose up despite the repeating stall warnings, the f/o questions this but doesn't take over and tries to initiate checklist procedure. They didn't have proper communication in the cockpit, they didn't apply the unreliable speed procedures or the checklist for getting out of the stall, and crash the plane almost like a suicidal move. This kind of malfunction is so textbook it's not even funny, every pilot is taught about it and even the people who play flight simulator games know about it.

At 14:38:43, in regard to the situation of the aircraft on the radar which was losing its
altitude and speed simultaneously, the controller asked the pilot "Confirm situation
normal?" but didn't receive any answer. Then, the controller tried to call the flight
several times with no success. There was never any response to other messages.


At 14:39:48, the controller asked THY 757, which was 8 NM forward of TC-TRB, to
call it. The pilot of THY 757 started to call TC-TRB using Turkish language but again
didn't receive any answer.

At 14:40:58, the controller shared information regarding TC-TRB with THY 757 that
the aircraft was disappeared from radar scope. The controller asked pilot of THY 757
to call TC-TRB again. THY 575 tried to call it several times, again with no response.
The pilot of THY 757 told radar controller that last time he saw TC-TRB on TCAS
display 6000 feet below his flight level, rapidly losing its altitude.



Here is the full report with lots of detailed photos: https://www.cao.ir/web/english/investigation-reports?p_p_id=NetFormGetFile_WAR_NetForm&p_p_lifecycle=2&p_p_resource_id=getFile&_NetFormGetFile_WAR_NetForm_file=OFZLTzN3cmdzVmJaNTBwa3crZWZmcDVCQXZKSzl2RGtZVlBDNnVFV0d2d3krZzVvQmJPR0xvVDFObUJzbEltRnYzVzZ2cUozelg5KwpXZThlSXFmY1hnPT0=.pdf

What A happy to a sad ending!!

One of the women was pregnant. Another has young kids at home. It's all so sad.