What GNAV3/3a can do

The program will assist you in planning a flight anywhere in the world. It can create flight plans from waypoints 
to waypoints (as per area navigators), from manually entered tracks and distances, or from any National Grid 
Reference (United Kingdom only). There are various utilities to help through out a flight and comprehensive 
databases of waypoints and aircraft.

Installation

THE PROGRAM REQUIRES AN SSD TO RUN!

To install this program, turn off your Psion Series 3 and then place the SSD into either one of the SSD drive 
doors, found on the underside of the Series 3, turn on your Series 3 and press the SYSTEM button.

Select the 'Install' option on the 'APPS' menu and in the dialog which appears, set the 'DISK' line to the relevant 
drive (A or B).

GNAV3 or GNAV3a will be shown on the 'Name ' line. (If there is more than one application on the SSD, then 
choose GNAV3 or GNAV3a accordingly using the cursor keys to do so).

Set the 'Position' line to 'Current', 'Last' or 'First' to position the GNAV3/3a icon on the System screen. Press 
ENTER to complete the dialog and install GNAV3/3a.

The initial installation is now complete and it only remains to start the program and run through the setup 
procedure


GNAV3/3a Setup

[Note: (GNAV3a only) The first time that the program is used, the Universal Time Co-ordinate (ZULU) offset 
is required to be set. The current daylight saving setting is checked and you are then shown the system hour and 
the program is waiting for the UTC (Z) hour to be entered. Complete the dialog by pressing ENTER.

 i.e. assuming the system time is 21:20 and the UTC(Z) time is 20:20, to complete the dialog enter 20 as the 
UTC(Z) hour. (This would give an offset of -1 hour from the system clock.]

The next dialog permits tailoring of the way that waypoints are searched for, whether to save the current route, 
set the specific gravity, change the UTC(Z) offset, select a printer and its connection.

Waypoint entry, can be one of two methods 'Enter & Search' or 'Letter Search'.

Enter & Search, allows entry of the exact waypoint name or designator or part of it. Every matching waypoint 
will then be displayed and a choice can then be made. This method will find two waypoints of the same name.

Letter Search, will find the nearest matching waypoint as each letter is typed. This is by far the fastest way of 
finding waypoints, but it will only find the first match, so if two waypoints have the same name, it will not find 
the second one.

Save Route, is by default set to No. If this is changed to Yes, every time that  the program is exited, the last 
route created will always be saved. It will then be reloaded and calculated, then next time that the program is 
used.

Specific Gravity, is required to be set (for fuel conversions). As a rough guide, JET A1 is about 0.79 and 
AVGAS is about 0.725. This option must be set. If it is not, the setting is requested again later.

Change UTC(Z) Offset*, allows the Universal Time Co-ordinate (ZULU) to be reset. See note at the beginning 
of this section (Series 3a only).

Printer, four types of printer are supported, HP Laserjet II, Canon BJ10ex, Star LC24/10 and any 24 pin Dot 
Matrix printer (capable of printing at 20 Characters Per Inch). Set this to None, if there is not a printer attached 
to the Series 3/3a.

Printer Connection, is either Parallel or Serial. The default is parallel.

When the dialog is complete, press ENTER and the program will continue to load. The first time of use, will 
bring up the Aircraft dialog. Enter a type or registration or just press ENTER to see the pre loaded list.

Once an aircraft type has been selected, a prompt to create fuel reserves is given. To do this enter a name for the 
reserves, the amount that the individual leg fuel is to be rounded up to, i.e. 10, 20 etc. 0 will not round up at all, 
where as 1 will round up to the nearest 1 ( 11, 21, 31 etc!). The same applies to the total fuel round up figure. If 
no reserves are required at the moment, press ESC and they can be created later.

Fixed reserves should be an amount of fuel and the variable reserves are a percentage of the hourly fuel burn.

The standard male and female north sea weights are the default weights, change these accordingly.

The setup is complete.
*GNAV3a only


2

Planning


PLANNING

For the first time of use, the main planning screen is presented and the cursor is flashing over the aircraft type. 
To enter waypoints and start planning press S and then enter a waypoint name. As an example, type in ABER 
and press ENTER. If the Enter & Search waypoint method was used, Aberdeen will be showing with it's 
Latitude, Longitude, Variation and waypoint type. If the Letter Search method was used, the Aberdeen would 
have been showing after the 3rd key press.

To select the waypoint, press ENTER. 

The destination is now prompted for. Repeat the above steps, but use EDIN for Edinburgh.

Wind is requested next. To set a wind type in the direction, (degrees magnetic) and then cursor down and enter 
the speed. Press ENTER to complete the dialog. For a variable wind enter 000 as the direction (Variable winds 
subtract the variable wind speed from the true air speed to give the ground speed).

	Note: 360 and 000 for wind direction are NOT the same!

Once the wind dialog is complete, the results will be calculated and shown on the left hand planning screen, with 
the fuel and load requirements on the right hand planning screen.




Diversions

Diversions/Alternates are entered in one of two ways, 'Straight Entry' or 'Find the Nearest Diversion'.

Straight Entry
For this method, either press V, or use the cursor and position over the Div box and press ENTER. Depending 
on the type of waypoint entry method in use, enter the required diversion designator or name, (same as entering 
the start & destination waypoints). The only difference is the addition of 'Find the Nearest Diversion' appearing 
in the dialog. For the Enter & Search method, this will be set to No, for the Letter Search method, pressing the 
keys PSION  V  will select it.

Find the Nearest Diversion
To use this method, select the Div box, by either pressing V or using the cursor key and pressing ENTER.

For the Enter & Search method, change the 'Find Nearest Diversion' option to Yes and press ENTER.

The next dialog to be shown will be asking for the requirements when searching for the nearest diversion. If 
limits are not required, i.e. no minimum range, time limit or specific type of Alternate is required, leave these 
options at 0, 00:00 and Airfield respectively. The 'Use Sector Winds' option defaults to Yes. A DIVERT 
database is prompted (this is automatically created on installation and the Aberdeen waypoint is added to it), if 
no other waypoints have been added to this, select another database. To select another database, change the 
Disk line to read A or B (depending on where the program SSD is installed), and choose either Pooleys* or 
Europe. Press ENTER to complete the dialog.

Note:  A Pooleys* database is not automatically supplied. 

Sector Winds are very useful for determining the nearest diversion with differing winds. Assuming that this 
option remained set at Yes, a further two dialogs will be prompted, these allow the winds to be set for each 
sector, 001 to 090, 091 to 180, 181 to 270 and 271 to 360. Enter the required wind directions in degrees 
magnetic and the respective wind speeds (000 as a direction will set a variable wind speed). Complete the dialogs 
by pressing ENTER each time.

The program will calculate the nearest diversions, in the example used above, the nearest to EDINBURGH. The 
results are shown in the order Track (Trk) / Distance (Dist) / Fuel (Ful), the closest in fuel will be shown first. At 
the top left of the screen, the number of diversions found will be flashing, to select a diversion position the cursor 
over it and press ENTER. If not all of the diversions are shown, select 'Next Page' and press ENTER. Each press 
of the ENTER key will cycle through the diversions found and will eventually end up back at the first one.

After the selection has been made, the wind used is prompted and can be changed if desired (if changed, the new 
figures will be calculated and inserted in the planning screen).

To distinguish which leg is being shown on the screen, the leg not in use will be reduced in size and greyed out 
(for the  Series 3, it will be in normal text). To see the other leg, press the Shift Up key or the Shift Down key
respectively.



Lower Left Hand Planning Screen

For the Series 3a, there are two screens shown (aircraft details and the time & right hand screen status) and only 
one for the Series 3 (aircraft and time).

Aircraft Details (Series 3a only)
This screen shows the current selected aircraft, its maximum take off weight (MTOW), all prepared for service 
weight (APS), disposable load (Disp), fuel units used (F.Units), weight units used (W.Units) and the specific 
gravity (S.Grav). The only items that can be changed on this screen are the Aircraft, MTOW and APS. To select 
these items, use the cursor * and * keys and then press ENTER.

Aircraft	On selecting this item, enter the required aircraft call sign, or 	change the display option to your 
required type and press 	ENTER to see the list. For more details see the aircraft chapter.

MTOW	On selecting this item, enter the required maximum take off 	weight and press ENTER to 
complete the dialog.

APS	On selecting this item, enter the required all prepared for service 	weight and the required 
number of crew. The crew weight can 	be also changed. Press ENTER to complete the dialog.

Note: Changing the MTOW or APS will not permanently change the current aircraft weights, on re-selecting the 
aircraft, its MTOW and APS will be reset to the saved values.


Right Hand Planning Screen

For the Series 3a, there are three screens available, 'Fuel & Load', 'Pax & Frt' and 'C of G', for the Series 3 there 
is only the one 'Loading' screen. To select the different Series 3a screens press the DIAMOND key.

Fuel & Load (Series 3a only)
This screen displays the individual leg fuels (Destination & Diversion), fixed reserves (Fixed Res), variable 
reserves (Variable Res), auxiliary reserves (Auxiliary Res), total fuel (TFuel), Payload, passengers weight 
(Passengers), baggage weight (Baggage), freight weight (Freight), total load weight (Total Load) and the take 
off weight (TOWT).


Pax & Frt (Series 3a only)
This screen is for entering the passenger, baggage and freight information. The cursor defaults to the Male Pax 
line, waiting for the number of male passengers to be entered. To select the other options, use the cursor * and * 
keys, when over the required item, press ENTER.

Male Pax	On selecting this item, the total number of male passengers 	is to be entered and the 
standard passenger weight can be 	changed. Press ENTER to complete the dialog.

Male Pax Wt	On selecting this item, enter the total male passenger 	weight, the maximum figure 
permitted will be shown at the 	bottom of the dialog. Press ENTER to complete the 	dialog.

Female Pax	On selecting this item, the total number of female 	passengers is to be entered and the 
standard passenger 	weight can be changed. Press ENTER to complete the 	dialog.

Female Pax Wt	On selecting this item, enter the total female passenger 		weight, the maximum figure 
permitted will be shown at 		the bottom of the dialog. Press ENTER to complete the 	dialog.

Baggage Wt	On selecting this item, enter the required baggage weight, 	the maximum weight is 
shown at the bottom of the dialog. 	Press ENTER to complete the dialog.

Freight Wt	On selecting this item, enter the required freight weight, 	the maximum weight is 
shown at the bottom of the dialog.
	Press ENTER to complete the dialog.

C of G (Series 3a only)
This screen will graphically display the selected aircraft's centre of gravity envelope (pre defined types only) and 
textually, the C of G, Total moments and Total weight.



Loading (Series 3 only)
This screen will show the maximum take off weight (MW), all prepared for service weight (AP), disposable load 
(DP), total fuel (TF), payload (PL), passenger weight (PX), baggage weight (BG), freight weight (FT), total 
load (TL) and the take off weight (TW).

The MW, AP, TF, PX, BG, and FT weights can be changed by using the cursor * and * keys to select the 
required item and pressing ENTER.

MW	On selecting this item, enter the new maximum take off weight 	required and press ENTER to 
complete the dialog.

AP	On selecting this item, enter the new all prepared for service 	weight required and enter the 
number of crew on board, if 	required. The standard crew weight can be changed. press 	ENTER to complete 
the dialog.

TF	On selecting this item, enter the new maximum total fuel figure 	required, the maximum permitted 
will be shown at the bottom of 	the dialog. Press ENTER to complete the dialog.

PX	On selecting this item, enter either the number of male & female 	passengers, or the male & 
female passengers weights as required. 	The maximum passenger weight is shown at the bottom of the 
	dialog. Press ENTER to complete the dialog.

BG	On selecting this item, enter the required baggage weight, the 	maximum permitted is shown at the 
bottom of the dialog. Press 	ENTER to complete the dialog.

FT	On selecting this item, enter the required freight weight, the 	maximum permitted is shown at the 
bottom of the dialog. Press 	ENTER to complete the dialog.

The only other Series 3 screen available is obtained by pressing the SPACE bar. This screen will show a break 
down of the route fuel, fixed reserves, variable reserves, auxiliary fuel, total fuel (if the fuel units are not the 
same as the weight units, then the converted weight will be shown on the right hand side). The last item is the 
auxiliary fuel figure. If this item is to be changed enter the new figure and complete the dialog by pressing 
ENTER.


3

Waypoints


Waypoints

Waypoints are created in one of three ways, 'Latitude & Longitude', 'Bearing & Distance' and 'National Grid 
References'.

Latitude & Longitude
All waypoints are eventually created using a latitude, longitude and variation. This method requires the 
knowledge of these three items before a waypoint can be created.

To create a waypoint using this method from the planning screen:

If using the Enter & Search method, press S and type in the name of the waypoint to create (for this example 
TEST will be used), then press ENTER. TEST will be looked for in the current permanent and temporary 
databanks, but will not be found. To create TEST, press ENTER when presented with the three buttoned dialog.

For the Letter Search method, press S and then TAB.

The initial waypoint creation screen is presented, asking for the designator (name), type in TEST, cursor down 
to the latitude line and enter N5712.3, representing North 57 degrees 12 minutes and 18 seconds (.3 of a 
minute). Cursor down to the longitude line and enter W00212.3, representing West 2 degrees 12 minutes and 18 
seconds (.3 of a minute). Cursor down to the variation and enter W7.1 representing West 7.1 degrees. DO NOT 
enter anything for the NGR, from waypoint or Bearing/dist lines. Press ENTER to complete the dialog.

The next dialog defaults to an Airfield. The options are Airfield, Rig, Ship, Platform, Navaid or Waypoint. 
Depending on this setting, will affect the next few dialogs (Waypoints do not require frequencies etc). For this 
example choose Airfield and press ENTER


The following dialog permits the entry of any warnings that are to be displayed each time the waypoint is 
selected (i.e. PPR), any radio or navaid frequencies required, any runways, the airfields elevation, the controlling 
authority and any notes that are required (these will also be shown on selection of the waypoint). Press ENTER 
to complete the dialog and save the waypoint in the tempwpts file, stored in the internal memory.



National Grid Reference
To create a waypoint using an Ordnance Survey National Grid Reference (UK only).

Follow the initial steps to create an unknown waypoint.

At the initial waypoint creation screen, type in TEST2 and then cursor down to the NGR line. Type in 
NJ295295. This is an Ordnance Survey Grid Reference, comprising of the area locator letters, in this instance NJ 
followed by the 6 numbers representing the northings and eastings (295 and 295). Once these are typed in press 
ENTER to complete the dialog.

The resulting latitude and longitude will be calculated and inserted into the correct lines. It now remains to enter 
a magnetic variation, for the example type in W7.1 and press ENTER to complete the dialog.

Change the next option to read Waypoint and press ENTER to complete the dialog.

Note that only two items have been requested, warning and notes. (A waypoint does not have radio frequencies, 
runways etc, it may be an intersection between two airways or a visual reporting point for example).

For this example type in TEST2 at the warning line and WAYPOINT at the notes line and then press ENTER to 
complete the dialog.
Bearing & Distance
To create a waypoint using a bearing & distance from a known waypoint, follow the procedure to create a new 
waypoint.

At the initial waypoint creation dialog, type in TEST3 as the designator and then cursor down to the From 
Waypoint line and type in ADN. Cursor down to the Bearing/dist line and type in 165/7 and then press ENTER 
to complete the dialog.

A dialog will appear stating that the program looked for ADN and found ADN, press ENTER as this is correct 
(This facility will permit part of a waypoint to be entered and found, i.e. EDIN  being part of EDINBURGH).

The initial waypoint creation dialog is represented with the calculated latitude, longitude and ADN's magnetic 
variation inserted into the correct lines. For this example press ENTER to complete the dialog.

For the type of waypoint select Navaid and press ENTER to complete the dialog.

Note only four lines are displayed (navaids do not require runways or controlling authorities etc). Type in 
TEST3 at the warning line and NAVAID at the notes line, press ENTER to complete the dialog.


Note: All new waypoints are always stored in the internal memory. It is not permitted to save data to the 
program SSD.


Waypoint utilities
There are six waypoint utilities available via the MENU key, 'Add Waypoints', 'Edit Temporary Waypoints', 'Zap 
Temporary Waypoints File', 'Examine Permanent Waypoints', 'Alphabetically Re-Order File' and 'Select\Create 
Permanent Database'.

To access these utilities from the main planning screen press MENU and then W and then press ENTER


Add Waypoints
This option will bring up the initial waypoint creation dialog as explained previously.

Edit Temporary Waypoints
This option allows viewing and editing of the temporary waypoint file. Highlight this option using the cursor and 
press ENTER. The first temporary waypoint will be showing, press ENTER and if there are any other waypoint 
details to be shown, they will be, otherwise the option line will be shown. For temporary waypoints the following 
options are available, 'Next', 'Back', 'Repeat', 'Search', 'Erase', 'Amend', 'Copy to' and 'Quit'.

'Next' is the default setting and will move along to the next waypoint in the temporary file after ENTER is 
pressed.

'Back' will show the previous waypoint in the file after ENTER has been pressed (if the first waypoint is 
showing, then the last one will be shown next).

'Repeat' shows all the current waypoint details again.

'Search' allows a particular waypoint or part of a waypoint to be found more quickly than cycling through each 
one. On selecting this option, press ENTER and then type in the waypoint or part of it to fins and press ENTER. 
As an example type in ST3 and press ENTER. TEST3 will now be showing.

'Erase' will erase the current waypoint from the temporary file once ENTER is pressed.

'Amend' permits the current waypoint to be amended after pressing ENTER.

'Copy to' allows the current waypoint to be copied to another database. For this example, select this option and 
press ENTER. The next dialog presented is requesting the database to copy the waypoint to (it defaults to the 
current permanent database, although copying to it is prohibited!). Change the disk line to read INTERNAL. 
Note that the database name has changed to DIVERT. Press ENTER and the waypoint TEST3 will be copied to 
the DIVERT database. This is useful for creating a diversions database that can be searched when using the 'Find 
the nearest diversion' facility (save looking through the entire permanent database!).

'Quit' leaves the Edit Temporary waypoint utility.


Zap Temporary Waypoint File
This will erase all the temporary waypoints created. Remember, all waypoints created are stored temporarily, 
unless a permanent database has been created on a different SSD to the program SSD.


Examine Permanent Waypoints
This works in the same way as the Edit Temporary Waypoint facility, without the ability to 'Amend' or 'Erase' 
waypoints that are stored on the program SSD. The only new option  available is the 'Change Dbase' facility.

'Change Dbase' allows the permanent waypoint database to be changed. This can only be done, if more than one 
permanent database file exists. If this is the first time of use, then there are probably not any other permanent 
databases available.

For an example, choose this option and press ENTER. the current database is shown on the top line, Cursor 
down to the disk line and change it to read INTERNAL. The DIVERT database is now showing, press ENTER. 
The permanent database now in use is DIVERT, stored internally. Aberdeen is the first waypoint showing, press 
ENTER and then TAB. All the same facilities as the Edit Temporary Waypoints option are now available, as this 
database is not stored on the same SSD as the program. To change back, select this option and change the disk 
line to read either A or B and press ENTER


Alphabetically Re-Order File
This option will permit the reordering of any GNAV3/3a database file. It will also work on the aircraft file. By 
being able to reorder a file, the search for waypoints or aircraft can be significantly speeded up.

To use this facility, highlight the option and press ENTER. A warning is given that this facility should not be 
used on a Flash SSD, as it would quickly fill it up. THIS IS ONLY TO BE USED ON THE INTERNAL 
MEMORY OR A RAM SSD. As an example, ACRFT.GN3 should be showing on the Filename Name line (if it 
is not, use the cursor keys until it is). Press ENTER and the process will start. This may take a few minutes!


Select\Create Permanent Database
This will permit the selection of or creation of permanent waypoint database files.

Highlight this option and press ENTER. The next dialog gives the options of 'Select' or 'Create'. For this example 
press C. The next dialog is expecting a name of the permanent database to create and where to create it. Type at 
the Name line TEST and then change the disk to read INTERNAL. Press ENTER. The selection is now 
complete and TEST is the active permanent database. TEST can be used, but there are not any waypoints stored 
in it yet. Every time that a new waypoint is now created, the option will be offered to save it temporarily or 
permanently (as the permanent database is no longer on the program SSD, the option to save a waypoint 
permanently will not be offered, if a database stored on the program SSD is in use).

To select a different database, use this facility, but press ENTER to select a database. Change the disk line to the 
required drive and then choose the required database, press ENTER to complete the dialog.


4

Aircraft



Aircraft

There are a selection of aircraft supplied with the program, fuel, weight & cruise data supplied by GAMTA.

To access this information, start at the main planning screen and then press A. The currently selected aircraft is 
displayed at the top of the dialog and the option to change it is presented.

If the required aircraft is known, type in all or part of it at the 'Type or Registration' line and press ENTER to 
complete the dialog. If the aircraft is found, the search characters and the first nearest match will be displayed, 
the option will be set to OKAY. If this is the aircraft required press ENTER, if it is not, change the option line 
and press ENTER.

If the required aircraft is not known, then decide whether to view all the aircraft types available (options are 
fixed wing, helicopters, motor gliders & micro lights). There are not any micro lights supplied with the program. 
Once the option has been changed accordingly, press ENTER and the list will be displayed. A flashing message 
will show how many types are in the file. Highlight the required aircraft and press ENTER, or change the option 
line to Next Page and then press ENTER. This procedure will cycle through the entire file and eventually return 
to the start.

Note: An aircraft must always be selected, if one is not, then the program will keep asking for one.

To create a new aircraft, at the initial selection dialog (accessed by pressing A at the planning screen), type in the 
new name. If there is not a similar type stored, then the program will not find it and then the aircraft list will be 
displayed. Change the 'Select' line to 'New Aircraft' and press ENTER.

The next dialog is the aircraft initial creation screen. Type in the required name or registration, move to the next 
line and select the type (fixed wing, helicopter, motor glider or micro light). The next line is for the True 
Airspeed to be used, next the Indicated Airspeed (used for TAS calculations), then the fuel flow per hour and 
lastly the amount of fuel that the tanks can store. Press ENTER to complete this dialog and move to the next 
one.

The Maximum Take Off Weight (MTOW), All Prepared for Service weight (APS), and the aircraft C of G 
moment are requested. Complete the dialog by pressing ENTER.

The final dialog is for selecting the required fuel units (pds, kgms, usgals, impgals or ltrs), weight units (pds or 
kgms), the speed units (kts, kph or mph), the altitude units (feet or metres), and lastly the distance units (nms, 
kms or stm). Complete the dialog by pressing ENTER and the details will be added to the end of the aircraft file. 
This aircraft will be the active one and back at the planning screen, the new results will be calculated.


5

Reserves & Payloads


Reserves

After a change of aircraft has occurred, if the fuel units are not the same as the previous type, then the current 
fuel reserves will be prompted.

If this is the first time of use, then there are probably not any reserves in use. To create some, if not already 
prompted with the new reserves dialog, then at the reserves list, change the Select line to read 'New Reserves' 
and press ENTER.

Enter a reserves name, for example TEST, set the required leg fuel round up figure (1 for example would round 
the fuel up to the nearest 1, so 40 would round upto 41, and 38 would also round up to 41). Enter the required 
total fuel round up, the amount of fixed reserves and the percentage of variable reserves. The standard male and 
standard female passenger weights default to the standard UK North Sea, so change these accordingly. Complete 
the dialog by pressing ENTER. The new reserves will now be in use and the fuel loading screens will change 
accordingly.

To select another set of reserves, at the main planning screen press R and choose the required one. If no reserves 
are required, simply set the Select line to No Reserves and press ENTER.



Payloads

Fuel loads, passenger, baggage, freight weights and leg fuel breakdown are available for viewing by pressing the 
SPACE bar (for the Series 3a only, the right hand planning screen will display all this information and by 
pressing the * button, the two loading screens can be used the SPACE bar is not functional).

For the Series 3a, the intial right hand screen will display the standard 'Fuel & Loading' details, these consist of 
the fuel required from the start point to the destination, then to the alternate, the fixed reserves, variable reserves 
any auxiliary fuel, the total fuel load for the current sector (TFuel), the paylod available, the passengers, baggage 
and freight weights, the total load and finally the take of weight (TOWT).

If the fuel units are not pounds or kilogrammes, then they will be converted to the weight used in the aircraft 
configuration (the fuel units, weight units and current specific gravity are displayed in the aircraft section of the 
planning screen for the Series 3a only). The converted units appear in square brackets and the corresponding 
weight is shown on the right hand side of the Series 3a display, or dialog for the Series 3.

