5 FLIGHT PROCEDURES
The TARDIS's flight sequence is quite complex, with many varieties of flight available, all of which are detailed in this chapter. The purpose of this section, however, is to give a broad overview of the mechanics of flight, detailing the varying processes and sequences which the TARDIS will perform.
The navigation and guidance computer system (NAGCS) is a term used to describe the various components which make up the heart of the TARDIS's flight systems. NAGCS performs the majority of processing required for time travel and flight.
Key circuitry and components used in flight include the dematerialisation circuit, responsible for removing the TARDIS from the real word and placing it within the space-time vortex; the same circuit performs the reverse maneouver. The time vector generator (TVG) and space displacement creator (SDC) work together to pilot the TARDIS through the vortex. The power drive provides the raw energy to propel the TARDIS, and is fed with pure artron energy.
Flight cannot begin until the main door has been shut. Due to a safety mechanism, the TARDIS cannot dematerialise with a key in the door lock. Technically a set of coordinates are needed before flight should begin, but the TARDIS will always begin flight once the dematerialise lever has been activated. Without coordinates being set, the TARDIS could travel anywhere. Internally, the coordinates used are from random data in the coordinate system's data capacitor.
The coordinate sub-system is composed of the data capacitor, the potential decoder, and the directional unit. The sub-system stores coordinates entered from the console, encodes them, and then sends data periodically to the NAGCS during flight.
Once the TARDIS has started to dematerialise the flight sequence begins. The power drive is fired-up, and the ship's power mode may change. Immediately the TVG and SDC will shape and manipulate the raw artron energy from the power drive, and the TARDIS will be in flight.
During flight the NAGCS will progess through the universal hierachy levels (UHL), continually changing frames of reference and plotting new time paths (flight vectors) to take the TARDIS closer to its destination. Once the UHL zero is reached, the flight sequence begins to finish. The last stage of the journey may be automated, or manual intervention may be required, in order to supervise the landing process.
Once the journey has began it is possible to operate the ship's doors. This is not recommended, and could cause dimensional instability. As standard practice the door should not be operated until the ship has completely rematerialised and the outside environment has been determined safe.
To land the TARDIS usually locates a stable landing area which will be able to support the ship's weight. If the destination coordinate does to present a suitable landing area, the TARDIS will perform a maneouver known as vortex-skimming. This is done as part of the rematerialisation sequence. Essentially the TARDIS skims along the surface of the space-time vortex, slowly changing its rematerialisation area, until a suitable landing coordinate is found.
Once the TARDIS has completely rematerialised, the power drive and power systems power down, the power-bank recharges, the NAGCS clear and reset, and the astral map performs the reorientation process. These collective activities take between ten and twelve minutes to perform, and no flight should be attemmpted during this time.
The TARDIS will also begin to monitor the exterior environment immediately prior to landing. Some measuring systems will need a brief period of re-adjustment before the console readings stabilse. As part of the reorientiation and measurement process, the time rotor will rotate. Once reorientation is complete, the rotation will cease.
This section discusses often raised issues concerning TARDIS flight, and also introduces the concept of flight modes.
There are few limits on the TARDIS's range of travel. As long as a destination coordinate keeps the ship and its occupants within their collective time streams, the TARDIS will travel to that destination, given that the ship has enough power. It is not unusual for the power bank to deplete during flight, and when the power level drops below a certain minimum, the NAGCS will automatically schedule a landing.
One difficulty with predicting journey times is that the length of flight does not directly relate to the distance travelled. Generally speaking, however, a short flight usually results in a short distance travelled, and longer flights usually take the TARDIS further. There are many reasons why there is not a direct correlation between journey time and distance travelled:
Roughly speaking, intra-planetry and inter-planetry is fairly brief, usually around thirty seconds. Local intra-galactic flight times are measured in minutes, and inter-galactic flight times can take up several hours. As a rough guide, the minimum flight time for a complete flight is thirty seconds, the maximum flight time depends on the power-drain during the flight, but is around twenty-four hours.
There are three types of flight mode which the TARDIS may use during flight. Normally a flight mode is selected at the beginning of the flight, and is not changed throughout. The flight modes are detailed below.
5.3 FLIGHT TERMINATION PROTOCOLS
Normally a flight terminates when the destination coordinates have been reached. There are times, however, when the pilot wishes to terminate the flight prematurely. This may be due to power problems, damage to circuitry, or external influence. The TARDIS will automatically invoke a flight termination procedure if necessary, however, the algorithm picked depends on the flight mode set. There are five flight termination algorithms, described below.
The flight termination control selects the appropriate algorithm. The polite option is not technically a termination algorithm. The control selects either quick, urgent, or emergency mode. Once the mode is selected, the flight can be terminated by manual rematerialisation by use of the dematerialisation lever.
As with any manually-assisted landing, the use of auto power cue (APC) and power-drive control may improve the comfort and overal safety of the landing. Pilots should also note that terminating the fast flight mode is hazardous, and that emergency halt mode should not be used.
An automatic flight termination rarely happens, but if so, the urgent or emergency halt mode is used. Automatic flight termination will occur with or without assistance; the ship's defense mechanism will activate the flight termination, and will sound the danger signal. Pilots should also note that if the TARDIS travels too closely to the surface of the vortex an automatic flight termination will occur.
Once a flight has been terminated the ship must reorientate and regain power, a procedure which takes around twelve minutes. The NAGCS will not clear their datastore for a terminated flight. After this period of time the flight may be recontinued or aborted altogether. To recontinue the flight, the flight termination control must be moved to position (C) for continue. To abort the flight, the flight termination control must be moved to position (A) for abort. If the flight is aborted the pilot must wait an additional period of around ten minutes to wait for the NAGCS to process the terminated flight data and ready for the next flight. This period of waiting can be avoided by moving the flight termination control to abort immediately after landing. A new flight will not begin until flight termination control is moved to position (P) for polite mode.
Standard travel is the name given to the flight sequence which requires the most pilot-assistance during flight. It is called standard travel because all other flight sequences are based on it. Standard travel allows the pilot the most freedom to control the various flight parameters.
As with the all flight sequences, the door must first be closed before the flight can begin. The destination coordinates should now be entered. It should be noted that there exists a procedure for entering coordinates after the ship has dematerialised, this is called the swift flight procedure and is detailed in Section 5.9.
Before activating the dematerialisation lever there exists a number of controls which may be activated to modify the flight sequence. The most important of these is the automatic power cue (APC). The APC function greatly improves the stability and safety of dematerialisation and landing. Without APC the power drive will switch on and immediatly operate at the required energy level for flight, and will shut down just prior to landing. This can result in violent jerks or shudders occuring during a materialisation sequence.
Astute pilots may wonder why APC is an option at all. One reason is that a high output of artron energy at the beginning of a flight is sometimes necessary to overcome high levels of ambient artron intereference. Artron tractor beams can hold a TARDIS on ground, and an APC-enabled flight would not allow the TARDIS to break free, whilst a non-APC dematerialisation might just. Likewise a non-APC landing may enable the TARDIS to be snared out of the vortex to an undesirable landing coordinate.
Pilots may also wish to preset the artron frequency controller. This changes the size and frequency of the artron particle output. Given that the artron input to the power-drive remains constant, increasing the frequency of the artron packets reduces their size, and therefore energy, and likewise by decreasing the frequency of the artron packets the energy per packet is increased. Although the mean energy output is the same, the energy per packet output has changed.
Now the size of artron packets directly affects the speed, technically the relocity and telocity, of the TARDIS. The ship's speed is directly proportional to the average size of artron packet emiited from the power-drive. The ship's vortex power, the ability to travel deeper into the vortex, is directly proportional to the average number of artron packets emitted per unit time. Here the term vortex power covers reverse power-breaking and is also tied to the ship's ability to escape artron interefence.
In summary, if a pilot wishes to increase the speed of the flight, it is sufficient to decrease the artron packet output, at the expense of diminishing power. Likewise, to increase vortex power, it is sufficient to increase artron packet output, and as a by-product lower the size of said packets, therefore decreasing the ship's speed. The trade-off situation can be modified any time during flight, and expert pilots often adjust the artron packet output to suit their needs.
The trade-off mentioned above is complicated slightly by the operation of the power booster unit, which increases the level of artron energy pulled into the TARDIS's systems, and as a consequence, increases the input into the power drive. Increasing the artron input will increase the packet size, assuming no change to the artron frequency controller, and therefore will increase the ship's speed whilst maintaining the current vortex power level. There are limitations to both the power and speed obtainable, refer to Section 6.7.
Some pilots prefer to preset the flight termination protocol. As standard a flight termination protocol has to be set for the flight to begin. As a safety feature, if the switch has been left in the abort or continue position the dematerialisation lever will not start the flight sequence. Many pilots simply leave the switch in the (P) for polite position, which is the recommended policy. Note that the automatic flight termination protocol operates independantly from the flight termination control switch.
Once all pre-flight adjustments have been made the ship can be safely dematerialised via use of the dematerialisation lever. During dematerialisation it is wise to monitor all read-outs containing relevant flight information, such as the relative engine-movement scan, the TCS meter, the TFC meter, the relocity and telocity meters, the power mode, the power-bank reserves, and the power take-up. Pilots should be familar with the dematerialisation theory (See: 7.1) and should take appropriate action in problematic circumstances. Emergency procedures are detailed in Section 4.10. Generally speaking, power input should be increased if a power drain is in progress. Natural or alien interference with the flight systems can be combatted by increasing the artron output of the power drive, and specifically by increasing the vortex power. The antifluxsource delimeter should cancel out most natural forms of radio/artron interference. If in doubt, abort the dematerialisation by resetting the switch. If the flight sequence has began, this action will automatically invoke a flight termination protocol.
The Mark III TARDIS boasts a quick dematerialisation phase (QDP) switch, which shortens the dematerialisation phase to around three seconds. However, the power requirement of this mode is very high, and can leave the power bank depleit of energy, and as a result the resulting journey is often very short.
All Type 40 models feature a dematerialisation sequence called quick flight mode (QFM). QFM is another mode which can be manually activated, but usually is automatically selected when necessary. QFM comes into play whenever a pilot activates dematerialisation before the power bank has properly recharged. Technically, QFM activates if the power bank has less than 111 MJ of energy. Similar to the Mark III's QDP, the dematerialisation sequence lasts only three seconds. In addition, the TARDIS does not fully enter the vortex but merely skims along the top, seriously limiting the range of travel. A typical QFM flight consumes around only 5 MJ of energy. QFM is similar in concept and operation to a quick transference jump, refer to Section for a comparison.
Once dematerialisation has finished the TARDIS is trully in flight. The dematerialisation process creates an audible grinding noise, heard both within and without the TARDIS. As this sound fades away, this is an indication that the ship has finished dematerialising. There are a number of procedures which may be performed in flight, detailed in Section 5.5. The procedures are not necessary for a standard flight, but may be helpful in some circumstances.
Upon zeroing in on landing coordinates and entering UHL stage zero, the TARDIS will issue an audiable prompt to alert the pilot that an assisted landing is required. Whilst the TARDIS leisurly slows down (assuming APC in use), the pilot should prepare for landing. This includes setting the various speed/power controls, and activating the appropriate chameleon circuit mode.
Once all final adjustments have been made the ship be safely rematerialised, by pushing up the dematerialisation lever. This will activate the rematerialisation sequence, and the TARDIS's outer plasmic-shell will slowly appear in the real world. Lazy pilots should note that failure to rematerialise the TARDIS will result in an automatic flight termination sequence, which is not desirable.
The ship has now landed, and during a period of ten to twelve minutes the NAGCS will fully reorientate and clear the time path matrix. The power bank will also recharge to full capacity. Flight should not be attempted during this period.
During standard travel there exists a number of controls which may be advantageous to use during the flight. None of the controls detailed here are vital for flight, but all have their use.
The power drive control changes the ship's power mode, and during flight it offers a choice between normal power mode (upper position) and full power mode (lower position). Full power mode drains the power bank but provides the power drive with an increased amount of artron, which can be converted to more power or speed.
If the ship becomes unstable during flight it is advised to activate the flight stabilisers. The TVG and SDC will create a buffer zone around the TARDIS, hopefully stabilising the flight. The ship will experience a ten percent reduction in speed/power whilst the stabilers are employed. The stabilisers also cancel the ship's spin during flight.
The Mark III TARDIS has two controls to alter the geometry of the ship's time vectors and space displacement rays. Practically, the controls can be used to assist advanced flight maneouvers, or to fine tune the ship's flight through the vortex.
The two most often performed in-flight activities are changing the artron frequency output and altering coordinates. Section 5.4 details the aforementioned activities.
Most pilots prefer to use the automated flight sequence, which requires little effort. The procedure is simple. Close the door and activate the automatic power systems (APS). Ensure the dematerialisation lever is in the lower position. Enter coordinates as preferred. The journey will begin as the coordinates have been confirmed and sent into the NAGCS.
The rest of the flight sequence is fully automated. The pilot need take no further action. The ship will automatically power down and land at the calculated landing coordinate. The APS flight also controls the artron frequency of the power drive. The APC is not automatically controlled, pilots should manually activate this if so desired.
To completely automate the flight sequence the ship can provide the destination coordinates automatically. The pilot simply uses coordinate mode three, catalouge entries, or coordinate mode six, flight recorder. APS can of course be used with these coordinate modes, resulting in an almost effortless flight.
Although many pilots wish to visit planets throughout the universe, it is sometimes desirable to land in outerspace. This section details the changes to standard travel in order to begin and/or end a flight in outerspace. The key control is free float. The free float control allows the TARDIS to safely dematerialise from outerspace, and also to safely rematerialise into outerspace. Here outerspace is defined as a location in space which is not in a defined orbit around any planet or satellite. The location must have a very low force of gravitation.
Setting the coordinate can be a challenge. With free float, the error correcting protocols work differently, as the TARDIS no longer seeks the closest physical object with a significant mass. There are several approaches to selecting an outerspace coordinate; these are all detailed in Section 4.6.
Once the coordinates have been entered the TARDIS is ready for dematerialisation. In outerspace, as a safety measure, this will not happen until free float has been activated. The free float mode does not only inform the NAGCS that an outerspace flight is being programmed, but it also performs crucial stabilisation of the ship's outer-hull in outerspace, by neutralising some forms of drift and essentially creating an area of free space around the TARDIS, an area devoid of any physical interaction/forces.
The rest of the flight sequence procedes as normal. If the destination is in outerspace, the free float mode must be activated prior to landing. Of course if the departure was also from outerspace, then the free float should still be activated.
If the ship has rematerialised in outerspace then the hovermode can be used to move the ship around, this is detailed in Section 5.8.
The hovermode allows the TARDIS to hover mid-air in the presence of gravity. Basically the hovermode allows the TARDIS to become weightless. It works by using the ship's space gravity drive (SGD). The SGD is responsible for motivating the TARDIS in real space, and is used exclusively by the hovermode. The SGD requires an artron feed, and hence hovermode requires the ship to be operating in normal power mode (NPM).
Hovermode works in two different ways. After rematerialisation into outerspace, hovermode can be used for outerspace maneouvers. The mode allows basic movement in three dimensions. After activating hovermode, levers 1D2-1D6 will change in their function, and become hover controls. The levers can be used to move the TARDIS through space. The first three levers control the direction of travel, whilst the last two set whether the TARDIS will move with constant speed, or with constant acceleration, and whether the movement shall be binary-like, that is, move or not move, or whether the rate of movement should be analogue, and related the distance the lever is pushed.
The second use of hovermode is used in combination with take-off or landing. Sometimes a local artron source can interfere with the ship's systems, and maneuvering the TARDIS away from the source can significantly reduce the level of artron energy interference. In this case, hovermode can be activated immediatlely prior to dematerialisation.
Dematerialisation does not have to follow hovering, although this is common. Using the hover thrust adjustment control, the ship can be raised vertically in the air. The movement control is strictly one dimensional: up or down. With the hoverlock switchjed on, the ship's weight is already counteracted, and hence with no thrust set on the thrust control, the ship will just hover, stationary. Moving the thrust lever up will accelerate the TARDIS upwards, but the ship will quickly slow to a stationary hover once the control is switched off. To descend, the hoverlock must be switched off. Without hoverlock, the ship's weight is not counteracted, and with no thrust either, the ship will begin to descend. The ship will crash into the ground without careful pilotting when the hoverlock is not used.
Assuming hoverlock is on, the TARDIS can be dematerialised any time during hovermode. As a caution, note that hoverlock cannot be obtained whilst the TARDIS is in free-fall. Cautious pilots ensure the TARDIS has been hoverlocked before attempting dematerialisation; use the hover thrust control to slow down the TARDIS, and then activate hoverlock. Even if the TARDIS is still moving, hoverlock will halt the ship's movement, assuming the descent speed is low. The main point to note here is that the TARDIS cannot be dematerialised when it is plunging towards the ground as a result of a poor piloting during hovermode.
The TARDIS can also also rematerialise into hovermode. For this to happen, hovermode must be activated prior to landing. ???
A number of modifications can be made to the standard flight sequence, for various purposes. This section details the advanced flight options.
One useful procedure is late coordinate setting. Traditionally coordinates are set before dematerialisation, but with this mode the coordinates can be set after dematerialiation, provided that the corresponding UHL coordinate is entered before the TARDIS reaches the same UHL stage. Hence this flight mode works better with longer flights, as the pilot has more time to enter the full coordinate. If the TARDIS reaches a UHL stage before the pilot has entered its coordinate, the ship uses a null coordinate for its destination coordinate for that UHL level.
There exists a tricky maneouver to cross jump a time track within the space-time vortex. The guidance computer systems normally prevent such a maneouver, but by activating the vortex time tracker, this safety measure is turned off. There are not many reasons to cross jump a time track. Indeed, rematerialising without first jumping back is extremely hazardous, and will result in time friction. It is recognised that cross jumping does have a few uses, such as escaping a timeship which is pursuing the TARDIS through the vortex. ???
The TARDIS itself has the ability to follow another timeship through the vortex, given that the ship being followed leaves a space-time trail. This maneouver is unlike many others, because it results in relying on the navigation systems on the craft which is being pursued! There is no UHL-navigation, the TARDIS simply follows the other craft through the vortex. Hence the entire flight is orchestrated by the guidance computer systems. Once the pursued craft rematerialises, the TARDIS will set a UHL level zero destination coordinate equal to the timeship, and then initiate a standard landing. Note that the time-streams for the two seperate ships are running together, and henceforth landing the TARDIS a short time before the pursued timeship is impossible, as this period has become immutable past.
Sometimes a rematerialisation can become unstable for a variety of reasons. The stabilise materialise phase (SMP) switch attempts to buffer and stabilise the process. A special feature available only on the Mark III and IV, the quick demeterialisation phase (QDP) shortens the dematerialisation process to around three seconds, a similar feature to the QFM. The length of flight is not shortened by the use of the QDP.
The quick transference jump (QTJ) allows the TARDIS to make an near instantaneous jump from one point in space to another. The maximum range is limited by the available power reserves, but is typically in the order of between 1000 km to 10,000 km. The ship must be operating in full power mode, the method to achieve this is outlined below.
Begin the standard flight sequence as usual. Instead of setting many UHL coordinates, only one UHL coordinate may be set. Once this has been entered, activate the QTJ switch. As well as switching on the appropriate circuits, the dematerialisation lever will now no longer function as before. The lever should be lowered now, and the power drive lever should be lowered also, activating the full power mode. At this instance the TARDIS should perform a quick transference jump.
The QTF is similar in concept to the quick flight mode. There are some notable differences. The QTJ does not use the dematerialisation circuit, and the maneouver does not involve entering the space-time vortex, nor removing the ship occupants from the space-time continuum. Although QTJ flight is brief, and distance travelled is small, the flight is performed in the same way as the standard flight. The QTJ is also very quick, but it does consume a fair amount of electrical and artron power, and hence it is not a power saving option like the QFM.
For pilots who feel the need for speed there is the option of using the fast return switch. Fast return provides an effective telocity of around . The ship's relocity is also vastly increased, due to shrinking of the space-time continuum. The are many cautions concerning this flight mode:
Apart from activating the fast return switch when appropriate, the rest of the flight sequence proceeds as normal.