Nav Logs and Charts…

**JDCAVE** · 22nd March 2023, 01:59

Ok. I’m calling this “Post opter hoc.” I’ll lay money on it that none of these were completed during operations. Clearly some of them summarize several navigators but even the first example way too neat to have been completed on ops!

https://www.rafcommands.com/archives...chart-and-log/.

Jim

**CZ_RAF** · 22nd March 2023, 07:03

Hi Jim, my thoughs was quite similar - I cannot imagine how to write such a nice log without any mistake during the night raid... Maybe when his log has been selected as an "example", the navigator has been asked to re-write it once more?

Pavel

**Richard** · 22nd March 2023, 20:39

Hi Jim, the font looks very familiar - the same as sample 441s in the GROPE manual, Nav bulletins etc. I’ll post an example at the w/e, away from home at present.

Richard

**JDCAVE** · 22nd March 2023, 23:04

Thanks Richard. I had downloaded them from TNA and I'm pretty convinced they were done in the comfort of an office rather than an aircraft.

Jim

**Jagan** · 24th March 2023, 13:05

The Navigation Log here https://www.rafcommands.com/wp-conte...4-1325-129.jpg is done ahead of the flight as it requires hours of prep with the maps - which is the case even today for General aviation pilots embarking on their Cross Country flight tests. They are not done on the aircraft but before the mission by the navs/lead nav. Even for that - its an amazing piece of work.

The Nav Observations here http://www.rafcommands.com/wp-conten...-1325-129a.jpg are probably the subject of this debate. were those observations written after the flight was done?

**JDCAVE** · 24th March 2023, 15:28

Originally Posted by Jagan

The Navigation Log here https://www.rafcommands.com/wp-conte...4-1325-129.jpg is done ahead of the flight as it requires hours of prep with the maps - which is the case even today for General aviation pilots embarking on their Cross Country flight tests. They are not done on the aircraft but before the mission by the navs/lead nav. Even for that - its an amazing piece of work.

The Nav Observations here http://www.rafcommands.com/wp-conten...-1325-129a.jpg are probably the subject of this debate. were those observations written after the flight was done?

Concerning the Form 441, only the Flight Plan is completed prior to take-off. The rest of it (the bottom half of that page) “Navigational Observations/General”, is a “log” of the navigation and operational details during the flight. It was completed real-time during the flight and it was a back and forth between the chart and the log. Typically, it became progressively more and more “untidy” as the operation progressed. GEE and H2S Fixes were recorded as a “+” on the chart with the details of that recorded on the 441. Navigators were told to avoid recording “Lats and Longs” in the log, but Gee positions were recorded and H2S positions as distances and bearings:

“Kassel Bears 270 [270^o] Rel” with “CoT” [Compass T] 56^o, = 326^o [270^o +56^o] recip [reciprocal bearing] 146^o, [326^o-180^o].”

“rel” refers to relative to aircraft, with the nose of the aircraft being “0” degrees so 270 abeam to port wing, i.e. to port.

Understand how quickly a position changes “abeam” at an airspeed of 170 and in the stress of being over enemy territory and possibly combat! That’s why H2S positions are highly uncertain fixes.

Air positions are recorded on the chart and the difference between an air position and a Gee fix goes into the calculations for winds, which inform the navigator on wind speed and direction. These calculations become crucial when the navigation is dependent on dead reckoning navigation when outside of Gee range. Wind speed and direction estimates from the more experienced navigators were sent back (w/t) to Groups who subsequently summarized these and then “broadcast” winds back to crews, the so-called “broadcast” winds.

I’ve spent “days” pouring over the chart and logs for Chemnitz 5/6-March-1945.

Jim