Originally Posted by DaveReidUK
(Post 10057310)
Reportedly WFU due to shortage of spares.
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Re: Source
The Guardian reports, citing Iranian media: An Iranian news website said the plane had recently rejoined the air fleet after seven years of undergoing repairs. “The plane which crashed today faced technical problems midair during a recent flight a few weeks ago,” Roozarooz news reported. An Instagram post from Aseman Airlines two months ago that announced the plane was back in service after seven years was deleted this morning after the plane crash, Roozarooz reported. |
The missed approach from MDA demands accurately tracking an NDB back bearing. Not every ADF installation does back bearings as well as front bearings.
How many crews today can do a good wind correction on an NDB bearing? Was there any calibration flown on the approach? Even more exciting would be flying a missed from as much as 4000' below the MDA. Was calibration for the missed flown from just above the runway? |
Originally Posted by RatherBeFlying
(Post 10058663)
The missed approach from MDA demands accurately tracking an NDB back bearing. Not every ADF installation does back bearings as well as front bearings.
How many crews today can do a good wind correction on an NDB bearing? Was there any calibration flown on the approach? Even more exciting would be flying a missed from as much as 4000' below the MDA. Was calibration for the missed flown from just above the runway? I believe the recent installation of the VOR/DME is evidence that Iran was on the path to improvement at this difficult airport. |
Originally Posted by Hotel Tango
(Post 10057506)
We don't know yet of course but I would very much doubt that aircraft serviceability had any role in this. More likely a scenario relating to weather and procedures.
The economic sanctions placed on Iran years ago caused quite a few aircraft to be sidelined. |
TEHRAN, Iran (AP) - Iranian search-and-rescue teams on Tuesday offered the first images of the site of an airplane crash in southern Iran that killed 65 people, with officials hoping to reach the aircraft's "black boxes" to learn exactly what downed the flight.
State television aired footage showing the plane crash site against the side of a snow-covered mountain near Yasuj, some 780 kilometers (485 miles) south of Tehran, Iran's capital from which the Aseman Airlines flight took off on Sunday. A helicopter pilot interviewed by state television said the crash site appeared to be only 30 meters (100 feet) from a peak on Mount Dena in the Zagros Mountain range. "Some large parts of the plane, which were labeled with the Aseman company logo, were seen," said the pilot, identified by state TV only as Capt. Soheili. |
the wreckage had been found through drone images before the air force's helicopters were deployed. |
What size of drone?
Are we talking 'pilotless aircraft'? - or a portable toylike device? Edited to add:- |
NDBs?
Originally Posted by RatherBeFlying
(Post 10058663)
Not every ADF installation does back bearings as well as front bearings.
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Blockage by terrain could limit the use of an NDB. Flight inspection has to verify signal strength for both the approach and missed approach. A weak signal can cause a false bearing.
It will be interesting to learn whether the flight flew the procedure correctly to well below MDA, then did a missed approach. |
It's hard not to feel for this crew. Who knows if they pushed limits but the captain was a veteran and presumably familiar with both airport and the limitations of the approach; as sad end to what was probably a distinguished career.
Not the type of approach facility I would want to deal with in those conditions; especially when they could have had a VOR DME approach there. Was there radar cover in the area or where they expected to let down using own nav? That could explain the end result if the aircraft only had basic kit. |
Originally Posted by RatherBeFlying
(Post 10058663)
The missed approach from MDA demands accurately tracking an NDB back bearing. Not every ADF installation does back bearings as well as front bearings.
How many crews today can do a good wind correction on an NDB bearing? Was there any calibration flown on the approach? Even more exciting would be flying a missed from as much as 4000' below the MDA. Was calibration for the missed flown from just above the runway? How the heck would you do an NDB approach? |
I think the poor chap is getting confused with a Back Course ILS. He obviously has never flown an NDB let down in his life (unlike me).
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2 Attachment(s)
Europian Datum 1950 is using in Iran. The height difference from WGS-84 is 30.24 meters.
Therefore, I think it started to decline about 1 km earlier. The distance along the axis of the runway differs by approximately 60 meters (2 arc seconds). Sorry, the distance along the axis of the runway differs by approximately 30 meters ( abt 1 arc seconds). |
Originally Posted by aterpster
(Post 10057104)
Jeppesen has only two charts. [...]
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That occurred to me, too. It would be interesting to see state source; i.e., the official Iranian chart in their AIP. I doubt that is available on-line, though.
Jeppesen is careful, but not perfect. In any case, the accident did not occur in the area of the base leg. |
Actually, the Iran AIP is online, but I couldn’t access the charts on an iPad, requires desktop.
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They are Non Directional Beacons, surely?
not the onboard equipment |
Everyone is discussing the interesting approach, but it is not clear to me that the aircraft even reached the Yasouj NDB to commence the approach.
Those are some serious Mountains north of Yasouj, and tall mountains, strong winds can create extreme problems in maintaining altitude. So far, information on the route of the flight has been pretty sketchy. :confused: |
ironbutt57:
Exactly so; the NDB is the bit on the ground and the ADF is the bit in the aircraft. |
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