Navigation over the Pacific

[Windturbin]

Cheers,

Am building missions/campaign over the open pacific. Would like to learn how pilots navigated over the open pacific waters without landmarks and how that relates to the IL-2 in game map. Without using path and icon cheats.

Using Wake Island as an example: The in game map graph has letters and numbers, Wake Island is @ Bm and 42, would these be called sectors? The map also has what looks to me likes longitude and latitudes numbers , Wake Island is @ 220 and 389? Problem is Wake Island is actually Longitude 166.6177 and Latitude 19.2900. What gives?

How did WWII Pilots navigate in the pacific? Anyone know of any good links for study? Can real life 1940's navigation be duplicated in game? Can anyone tell me the basics of how they did it?

[Blackdog_kt]

Basically it was a combination of landmark identification (where available), calculating distance traveled in relation with heading and radio navigation.

For visual navigation things are simple, you just point the aircraft at the correct heading, correct for any wind drift and update your bearings when passing by recognizable landmarks.

Out in the open sea things are more complicated. Pilots needed a weather forecast in order to know what kind of wind was expected at certain altitudes. Then it's a matter of
1) converting indicated airspeed to calibrated airspeed (which is IAS corrected for instrument position errors)
2) converting CAS to true airspeed (which depends on the altitude flown) and
3) extracting the speed over ground (ground speed for short) by adding the vector of TAS to the wind velocity vector.

Once they had that data, they could multiply ground speed by time flown to get the actual traveled distance and since they could read their heading on their compass they knew which direction that distance was traveled towards. At that point they would probably get a protractor to measure the heading angles and draw a line on the map corresponding to the distance traveled according to the map scale.

It's pretty obvious that this is no trivial feat to pull off in a combat situation, which is why briefings and pre-flight planning was such an important part of operations. In the case of single seaters, fighters and generally aircraft without a sizeable crew to have the benefit of a dedicated navigator, what probably happened was that all those calculations were done by the flight planners and presented in the briefing. Then the pilots would keep notes but possibly end up using a much simpler "to do" list, keeping the rest of the data handy in case they needed to deviate from the flight-plan and calculate things from scratch. For example:

1) fly a heading of 030 at X altitude and Z indicated airspeed for 30 minutes to reach waypoint B
2) fly a heading of 100 at A altitude and B IAS for 15 minutes to reach waypoint C

and so on.

As for radio navigation, the latest patches by team daidalos simulate it pretty well and you can probably get much better information by browsing through the patch documentation/manual.

One last thing to note however is that aircraft were increasingly equipped with IFF (identification: friend or foe) devices as early as the battle of Britain, mainly in order to help ground controllers to differentiate between friendlies and hostiles. This had a very useful byproduct in that every aircraft on the controller's radar scope could be identified by a certain signal transimtted by the on-board IFF on the aircraft. This means that a pilot could roughly navigate within the area of radar coverage and then ask the ground controllers for precise vectors towards his intended destination.

This principal is very similar (if not completely identical) to how transponders work on civil aviation aircraft today. I think civilian aircraft use a 4-digit code and military ones use a 7-digit code, but other than that transponders are found on every aircraft that wants to qualify for flight following services or instrument flying.
Even on a cessna trainer there will a transmitter on board the aircraft with a 4-digit display, with each digit's available range numbering from 0 to 7. There are certain pre-set codes for emergencies or un-tracked VFR flying, but other than that the ground controllers assign a code to each aircraft in every other instance.

This way, you might be flying from point A to point B under guidance of the ground controller until you reach the boundaries of his responsibility. Then the controller will hand you down to the controller of the next "slice" of airspace and instruct you which code to use for identification (i think aircraft tend to keep the same 4-digit code for the duration of their flight):

"Cessna (registration number), contact(place name) control/departure/arrival (depending on phase of flight) at (radio frequency)"

The pilot repeats the instruction to acknowledge it, tunes into the frequency of the next controller and contacts him with his approximate position (x miles southwest of a certain navigation fix for example), at which point the controller might respond with

"Roger Cessna (registration number), squawk 3520"

That last part is the controller telling the pilot to make sure his transponder is using 3520 as the identification code and then transmit a special radio pulse which causes the aircraft's "blip" to light up briefly on the controller's radar scope. This way he can easily pick off that one aircraft among many and decide if he should let him go on his way ("resume own navigation") or give him other instructions in case there is traffic ahead or a course correction is necessary.


This was probably done in a much different way back during WWII, but the basic premise is identical: a controller identifies an aircraft on his scope via an IFF signal and then he can give navigation instructions as needed.

I was recently reading some articles about night-fighters in WWII where it's clearly described. For example, it was common practice for allied crews flying mosquitoes or P-61 black widows over occupied Europe and Germany in the latter stages of the war to get a fix via ground control when they scored a kill, in order to pinpoint the location of the crash site and be able to confirm it. As soon as they had shot down a target, they would climb high enough to be picked up by the friendly radar that was guiding them towards potential targets if they were not already visible to them, at which point the controller would identify them and give them an accurate fix on their position.

In the case of the Pacific theater there was not a handy chain of ground based stations available, but many of the ships in the carrier fleets were equipped with some sort of radar. I wouldn't be surprised if there was a flight controller on each carrier, monitoring their flights in a similar manner and providing them with vectors back home as soon as he could pick them up on his radar screen.

[Romanator21]

It's worth mentioning that the dauntless (and maybe wildcat) had a very short control stick to allow for a pull-out chart table for doing dead-reckoning. :)

Since 4.10, DT have added the option of showing waypoints on the in-flight map without having to display the "GPS" player-icon cheat (No Mini-Map Path option). If you zoom in, the way-points will show angle and length of the leg. Just maintain a speed and heading and you'll be fine with that.

If you're in an online DF map, there are no way-points given at all, but you can make some basic calculations as the side of each grid represents 10km.

[Windturbin]

Basically it was a combination of landmark identification (where available), calculating distance traveled in relation with heading and radio navigation.

For visual navigation things are simple, you just point the aircraft at the correct heading, correct for any wind drift and update your bearings when passing by recognizable landmarks.

Out in the open sea things are more complicated. Pilots needed a weather forecast in order to know what kind of wind was expected at certain altitudes. Then it's a matter of
1) converting indicated airspeed to calibrated airspeed (which is IAS corrected for instrument position errors)
2) converting CAS to true airspeed (which depends on the altitude flown) and
3) extracting the speed over ground (ground speed for short) by adding the vector of TAS to the wind velocity vector.

Once they had that data, they could multiply ground speed by time flown to get the actual traveled distance and since they could read their heading on their compass they knew which direction that distance was traveled towards. At that point they would probably get a protractor to measure the heading angles and draw a line on the map corresponding to the distance traveled according to the map scale.

It's pretty obvious that this is no trivial feat to pull off in a combat situation, which is why briefings and pre-flight planning was such an important part of operations. In the case of single seaters, fighters and generally aircraft without a sizeable crew to have the benefit of a dedicated navigator, what probably happened was that all those calculations were done by the flight planners and presented in the briefing. Then the pilots would keep notes but possibly end up using a much simpler "to do" list, keeping the rest of the data handy in case they needed to deviate from the flight-plan and calculate things from scratch. For example:

1) fly a heading of 030 at X altitude and Z indicated airspeed for 30 minutes to reach waypoint B
2) fly a heading of 100 at A altitude and B IAS for 15 minutes to reach waypoint C

and so on.

As for radio navigation, the latest patches by team daidalos simulate it pretty well and you can probably get much better information by browsing through the patch documentation/manual.

One last thing to note however is that aircraft were increasingly equipped with IFF (identification: friend or foe) devices as early as the battle of Britain, mainly in order to help ground controllers to differentiate between friendlies and hostiles. This had a very useful byproduct in that every aircraft on the controller's radar scope could be identified by a certain signal transimtted by the on-board IFF on the aircraft. This means that a pilot could roughly navigate within the area of radar coverage and then ask the ground controllers for precise vectors towards his intended destination.

This principal is very similar (if not completely identical) to how transponders work on civil aviation aircraft today. I think civilian aircraft use a 4-digit code and military ones use a 7-digit code, but other than that transponders are found on every aircraft that wants to qualify for flight following services or instrument flying.
Even on a cessna trainer there will a transmitter on board the aircraft with a 4-digit display, with each digit's available range numbering from 0 to 7. There are certain pre-set codes for emergencies or un-tracked VFR flying, but other than that the ground controllers assign a code to each aircraft in every other instance.

This way, you might be flying from point A to point B under guidance of the ground controller until you reach the boundaries of his responsibility. Then the controller will hand you down to the controller of the next "slice" of airspace and instruct you which code to use for identification (i think aircraft tend to keep the same 4-digit code for the duration of their flight):

"Cessna (registration number), contact(place name) control/departure/arrival (depending on phase of flight) at (radio frequency)"

The pilot repeats the instruction to acknowledge it, tunes into the frequency of the next controller and contacts him with his approximate position (x miles southwest of a certain navigation fix for example), at which point the controller might respond with

"Roger Cessna (registration number), squawk 3520"

That last part is the controller telling the pilot to make sure his transponder is using 3520 as the identification code and then transmit a special radio pulse which causes the aircraft's "blip" to light up briefly on the controller's radar scope. This way he can easily pick off that one aircraft among many and decide if he should let him go on his way ("resume own navigation") or give him other instructions in case there is traffic ahead or a course correction is necessary.


This was probably done in a much different way back during WWII, but the basic premise is identical: a controller identifies an aircraft on his scope via an IFF signal and then he can give navigation instructions as needed.

I was recently reading some articles about night-fighters in WWII where it's clearly described. For example, it was common practice for allied crews flying mosquitoes or P-61 black widows over occupied Europe and Germany in the latter stages of the war to get a fix via ground control when they scored a kill, in order to pinpoint the location of the crash site and be able to confirm it. As soon as they had shot down a target, they would climb high enough to be picked up by the friendly radar that was guiding them towards potential targets if they were not already visible to them, at which point the controller would identify them and give them an accurate fix on their position.

In the case of the Pacific theater there was not a handy chain of ground based stations available, but many of the ships in the carrier fleets were equipped with some sort of radar. I wouldn't be surprised if there was a flight controller on each carrier, monitoring their flights in a similar manner and providing them with vectors back home as soon as he could pick them up on his radar screen.

Perfect, exactly what I was looking for, thanks guys

[Pips]

During WWII US naval aviators used the 'whizz wheel' as a basic tool for overseas navigation. See here:
http://en.wikipedia.org/wiki/E6B

[heloguy]

During WWII US naval aviators used the 'whizz wheel' as a basic tool for overseas navigation. See here:
http://en.wikipedia.org/wiki/E6B

Same tool used today. Increasingly less and less because of new technology, but a basic skill still learned in any flight school, and a basic tool required on every flight.