Patent Publication Number: US-2019185178-A1

Title: Apparatus and methods for a portable avionics system to provide flight information in a general aviation aircraft

Description:
BACKGROUND 
     Field 
     The present disclosure relates generally to avionic sensor systems, and more specifically to portable avionics systems using head mounted displays. 
     Background 
     The Federal Aviation Administration (FAA) defines a Loss of Control (LOC) accident as an unintended departure of an aircraft from its controlled flight. According to the FAA, factors contributing to LOC are a pilot&#39;s failure to recognize an aerodynamic stall or spin and a pilot&#39;s failure to maintain airspeed. Due to a large number of reported general aviation (GA) pilot and passenger fatalities, both the FAA and National Transportation Safety Board (NTSB) have encouraged the general aviation community to seek ways to improve pilot awareness. 
     Technologies relating to improving pilot awareness and safety include avionics and avionics systems. Avionics pertains to electronic systems used on an aircraft to perform functions relating to aircraft control and to aviation flight procedure. For instance, the avionics in the cockpit of a commercial airline includes electronic communication systems, electronic collision avoidance systems, electronic navigation systems, and the like. 
     SUMMARY 
     Several aspects of a portable avionics system for providing flight information in a general aviation aircraft will be described more fully hereinafter with reference to a portable sensor pod and to a head mounted display system. 
     In one aspect a portable avionics system for displaying aircraft specific flight information for a plurality of general aviation aircraft types comprises a portable sensor pod and a head mounted display (HMD) system. The portable sensor pod comprises at least one sensor; and the head mounted display system comprises a hardware box and a wearable display. The portable sensor pod is configured to convert sensor data from the at least one sensor into pod output data. The hardware box is configured to receive the pod output data and to convert the pod output data into the aircraft specific flight information; and the wearable display is configured to display the aircraft specific flight information. 
     The portable sensor pod can be configured to convert the sensor data from the at least one sensor into the pod output data based upon a predetermined formula. The predetermined formula can be calibrated for the plurality of general aviation aircraft types. 
     The portable sensor pod can further comprise a sensor pod circuit. The sensor pod circuit can comprise a transducer and a wireless transmitter. The transducer can be configured to receive the sensor data from the at last one sensor and to provide a transducer output signal proportional to the sensor data. The wireless transmitter can be configured to transmit the pod output data. The pod output data can comprise a digital representation of the transducer output signal. 
     The sensor pod circuit can further comprise a microcontroller. The microcontroller can be configured to convert the transducer output signal into the digital representation of the transducer output signal based upon a predetermined formula. The predetermined formula can be calibrated for the plurality of general aviation aircraft types. 
     The portable sensor pod can further comprise a flange section and an aerodynamically streamlined attachable container section. The flange section can be configured for permanent mounting to the underside of a wing of the aircraft. The attachable container section can comprise a nose cone section and a body section. The attachable container section can be attached to the flange section with a removable pin. 
     The flange section, the nose cone section, and the body section can be additively manufactured. The flange section can be mounted to the underside of the wing of the general aviation aircraft using an adhesive. The body section and the nose cone section can be sealed together to form the attachable container section. 
     The hardware box can comprise a wireless receiver and at least one processor. The wireless receiver can be configured to receive the pod output data; and the at least one processor can be configured to convert the pod output data into the aircraft specific flight information. The wearable display can be a wearable display lens. 
     The at least one sensor can comprise a first pitot tube; and the aircraft specific flight information can comprise airspeed. The at least one sensor can comprise a second pitot tube; and the aircraft specific flight information can comprise angle of attack 
     In another aspect, a method of displaying flight information for a plurality of general aviation aircraft comprises: attaching a portable sensor pod to a select one of the plurality general aviation aircraft types; measuring sensor data using the portable sensor pod; converting the sensor data to pod output data using the portable sensor pod; wirelessly receiving the pod output data at a head mounted display (HMD) system; converting the pod output data into aircraft specific flight information using a hardware box; and displaying the aircraft specific flight information on a wearable display. 
     Converting the sensor data to the pod output data using the portable sensor pod can comprise using a microcontroller to convert the sensor data to the pod output data based on a predetermined formula. The predetermined formula can be calibrated for the plurality of general aviation aircraft types. 
     Attaching the portable sensor pod to the select one of the plurality of general aviation aircraft types can further comprise: permanently mounting a flange section of the portable sensor pod under a wing of the select one of the plurality of general aviation aircraft types; sealing a sensor pod circuit and at least one sensor in an aerodynamically streamlined attachable container section; and attaching the attachable container section to the flange section with a removable pin. The attachable container section can comprise a nose cone section and a body section. The flange section, the nose cone section, and the body section can be additively manufactured. 
     Permanently mounting the flange section of the portable sensor pod under a wing of the select one of the general aviation aircraft types can comprise mounting the flange section of the portable sensor pod using an adhesive. 
     Converting the sensor data to the pod output data using the portable sensor pod can comprise: receiving the sensor data from the at last one sensor; providing a transducer output signal proportional to the sensor data; converting the transducer output signal based on a predetermined formula; and wirelessly transmitting the pod output data. The pod output data can comprising a digital representation of the transducer output signal. 
     Converting the pod output data into aircraft specific flight information using a hardware box can comprise: wirelessly receiving the pod output data; and converting the pod output data into the aircraft specific flight information. 
     The at least one sensor can comprise a first pitot tube and a second pitot tube; and the aircraft specific flight information can comprise airspeed and angle of attack. 
     In another aspect, a portable avionics system for displaying aircraft specific flight information for a plurality of general aviation aircraft types comprises: an attaching means, a sensing means, a first converting means, a receiving means, a second converting means, and a displaying means. The attaching means is for attaching a portable sensor pod to a select one of the plurality general aviation aircraft types. The sensing means is for measuring sensor data using the portable sensor pod. The first converting means is for converting the sensor data to pod output data using the portable sensor pod. The receiving means is for wirelessly receiving the pod output data at a head mounted display (HMD) system. The second converting means is for converting the pod output data into aircraft specific flight information; and the displaying means is for displaying the aircraft specific flight information on a wearable display. 
     In another aspect an avionics system for conveying aircraft specific flight information for a plurality of general aviation aircraft types comprises an avionics sensor hub and an avionics warning system. The avionics sensor hub comprises at least one sensor and is configured to provide hub output data. The avionics warning system comprises a hardware box and a plurality of warning devices. The hardware box is configured to receive the hub output data and to convert the hub output data into the aircraft specific flight information. The plurality of warning devices are configured to convey the aircraft specific flight information. 
     The avionics sensor hub can be a portable sensor pod configured to convert sensor data from the at least one sensor into the hub output data. 
     The plurality of warning devices can comprise a wearable display configured to display the aircraft specific flight information. The plurality of warning devices can comprise a light emitting diode (LED) strip configured to display light in response to the aircraft specific flight information. The plurality of warning devices can comprise a stick shaker configured to shake in response to the aircraft specific flight information. The plurality of warning devices can comprise an audible device configured to provide sound in response to the aircraft specific flight information. 
     The hardware box can comprise a wireless receiver and a processor. The wireless receiver can be configured to receive the hub output data. The processor can be configured to convert the hub output data into the aircraft specific flight information. 
     It will be understood that other aspects relating to the portable avionics for providing flight information will become readily apparent to those skilled in the art from the following detailed description, wherein it is shown and described only several embodiments by way of illustration. As will be appreciated by those skilled in the art, both electronic hardware and mechanical implementations can be realized with other embodiments without departing from the invention. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not as restrictive. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Various aspects of apparatus and methods for providing flight information via a portable sensor pod to a head mounted display system will now be presented in the detailed description by way of example, and not by way of limitation, in the accompanying drawings, wherein: 
         FIG. 1  illustrates a general aviation aircraft using a portable avionics system according to an embodiment. 
         FIG. 2A  illustrates a portable sensor pod attached to a first type of general aviation aircraft according to aspects presented herein. 
         FIG. 2B  illustrates the portable sensor pod attached to a second type of general aviation aircraft according to aspects presented herein. 
         FIG. 3A  illustrates a side view perspective of a separated flange, body, and nose cone for a portable sensor pod according to aspects presented herein. 
         FIG. 3B  illustrates a side view of a flange and an attachable container according to aspects presented herein. 
         FIG. 3C  illustrates a bottom view perspective of a portable sensor pod according to aspects presented herein. 
         FIG. 3D  illustrates a side view perspective of a portable sensor pod including an airspeed pitot tube sensor and angle of attack pitot tube sensor according to aspects presented herein. 
         FIG. 4A  illustrates a side view perspective of a head mounted display (HMD) system according to aspects presented herein. 
         FIG. 4B  illustrates a front view of the head mounted display system according to the example of  FIG. 4A . 
         FIG. 5A  illustrates an eyepiece display region of a head mounted display system according to aspects presented herein. 
         FIG. 5B  illustrates flight information displayed in the eyepiece display region of the example of  FIG. 5A . 
         FIG. 6A  illustrates a system block diagram of the sensors and sensor pod circuit within a portable sensor pod according to a first example. 
         FIG. 6B  illustrates a system block diagram of the sensors and sensor pod circuit within a portable sensor pod according to a second example. 
         FIG. 6C  illustrates a system block diagram of the sensors and sensor pod circuit within a portable sensor pod according to a third example. 
         FIG. 7A  illustrates a system block diagram of the display and hardware within a head mounted display system according to a first example. 
         FIG. 7B  illustrates a system block diagram of the display and hardware within a head mounted display system according to a second example. 
         FIG. 8  conceptually illustrates a method of using a portable avionics system according to aspects presented herein. 
         FIG. 9  conceptually illustrates a flow graph corresponding to measuring air data using a portable sensor pod according to aspects presented herein. 
         FIG. 10  conceptually illustrates a method of using a head mounted display system according to aspects presented herein. 
         FIG. 11  illustrates a functional system block diagram of the portable avionics system for measuring air data according to aspects presented herein. 
         FIG. 12  illustrates a method for calibrating airspeed data for a type of general aviation aircraft according to aspects presented herein. 
         FIG. 13  illustrates a method for operating avionics hardware of the portable avionics system for measuring air data according to aspects presented herein. 
         FIG. 14A  illustrates a system block diagram of a portable avionics system using a hardware box according to aspects presented herein. 
         FIG. 14B  illustrates a system block diagram of a general avionics system using a hardware box according to aspects presented herein. 
     
    
    
     DETAILED DESCRIPTION 
     The detailed description set forth below in connection with the drawings is intended to provide a description of exemplary embodiments of portable avionics relating to providing flight information using portable sensor pods and head mounted display systems. Further, it is not intended to represent the only embodiments in which the invention may be practiced. The term “exemplary” used throughout this disclosure means “serving as an example, instance, or illustration,” and should not necessarily be construed as preferred or advantageous over other embodiments presented in this disclosure. The detailed description includes specific details for the purpose of providing a thorough and complete disclosure that fully conveys the scope of the invention to those skilled in the art. However, the invention may be practiced without these specific details. In some instances, well-known structures and components may be shown in block diagram form, or omitted entirely, in order to avoid obscuring the various concepts presented throughout this disclosure. 
     The National Transportation Safety Board (NTSB) has identified prevention of loss of control (LOC) as a top priority of the General Aviation (GA) community. Loss of control incidents account for an unacceptably high percentage of fatalities. According to the NTSB, between the years 2008 to 2014 nearly forty-eight percent of fatal fixed-wing GA accidents in the United States resulted from pilots losing control of their aircraft. The FAA recognizes pilot distraction and loss of situational awareness as one of the largest contributing factors to the high rates of LOC incidents, citing stalls to be the most common end result. Stalls are most common where they are also most deadly: during maneuvers and pattern flight. 
     While there are many ways to curb the occurrence of LOC incidents with training and briefing, one of the NTSB&#39;s suggestions is to install technology that improves the pilot&#39;s awareness. Although avionics displays and electronic flight instrument systems (EFIS) have been developed to enhance the interpretation of the data being taken by sensors and to consolidate flight data, affordable avionics to readily display essential flight information have not yet been developed for the general aviation pilot. And while there may be applications of advanced avionics display systems for the military or commercial airline industry, these advanced avionics systems are not readily deployed in a general aviation aircraft. Accordingly, there is a need for an avionics system which readily displays essential flight information to a general aviation pilot. Further, there is a need for an avionics system which can be easily implemented in a general aviation aircraft. 
     Apparatus and methods for a portable avionics system to provide flight information in a general aviation aircraft are described herein. The portable avionics system includes a portable sensor pod and a head mounted display system. The portable sensor pod houses sensors and solid state components in a portable container, thereby allowing the pod to be ported to a plurality of general aviation aircraft. The head mounted display system includes a hardware box in wireless communication with the portable sensor pod. Sensor data from the portable sensor pod is transmitted to the head mounted display system and processed so that essential flight information becomes readily available on a wearable display. The wearable display conveys essential flight data to a general aviation pilot without interfering with the pilot&#39;s vision. 
       FIG. 1A  illustrates a general aviation (GA) aircraft  100  using a portable avionics system  102  according to an embodiment. The GA aircraft  100  can be a civilian aircraft, such as a light sport propeller aircraft, for use by a general aviation pilot. The avionics system  102  includes a portable sensor pod  104  and a head mounted display system  106 . Prior to takeoff the portable sensor pod  104  can be removably attached to a secure location, such as a tie down location or a preinstalled attachment point, at the underside of a wing  110 ; and a general aviation pilot can wear all or part of the head mounted display system  106 . The portable sensor pod  104  can probe aerodynamic and/or air data from outside the cockpit  112  and convert the probed sensor data into sensor pod data for transmission to the head mounted display system  106  inside the cockpit  112 . 
     The sensor pod data can be transmitted to the head mounted display system  106  via a radio frequency (RF) carrier. For example, Bluetooth® (a registered trademark of Bluetooth Special Interest Group (SIG) technologies; hereinafter referred to as Bluetooth) and Bluetooth technology can be used to allow the portable sensor pod  104  to wirelessly communicate with the head mounted display system  106 . In other examples, WiFi or other wireless communication technologies may be employed. Upon flight completion, the portable sensor pod  104  can be removed for recharging and/or for porting to a different type of general aviation aircraft. 
     The portable avionics system  102  can advantageously be used to constantly provide flight data, including essential flight data, to a general aviation pilot during flight without distracting the pilot. In some embodiments, the portable avionics system  102  can be used to constantly provide flight data within the general aviation pilot&#39;s field of regard and/or field of view on a wearable display and/or lens. For instance, essential flight data including airspeed and/or angle of attack (AOA) can be provided to the general aviation pilot on a wearable display so the pilot will always be aware of these essential flight parameters even while scanning outside of the cockpit  112 . As general aviation pilots and those of skill in the art can appreciate, constantly being aware of airspeed and angle of attack flight information can be essential in preventing accidental stalls. 
     As illustrated on the general aviation aircraft  100  of  FIG. 1A , the portable sensor pod  104  can be small and have a small form factor to advantageously mount to a plurality of general aviation aircrafts. Having a small form factor, the portable sensor pod  104  can be mounted so as to have a negligible effect and/or no effect on the aerodynamic properties of the general aviation aircraft  100 . 
     Also, the portable sensor pod  104  can be an independent unit. For instance, it can use a rechargeable battery to serve as a power source, independent of the electrical power source in the general aviation aircraft  100 . Being both portable and having wireless capability, the portable sensor pod  104  can be mounted to the wing  110  with either small and/or no modification to the general aviation aircraft  100 . However, in other embodiments a power source from the general aviation aircraft  100  may be used to provide power and/or battery charge to the portable sensor pod  104 . 
     In some embodiments the portable sensor pod  104  can be calibrated in advance for a plurality of general aviation aircraft types. As one skilled in the art can appreciate, there are many types, models, and variations of aircraft and general aviation aircraft. In the disclosure herein a general aviation aircraft type can mean the general aircraft type, manufacture, characteristics, and/or model which may affect aerodynamic flight behavior in a way that requires the calibration of avionic sensors. For instance, a Cessna  172 , which has one type of wingspan, may be distinguished from a Piper Cherokee which has another type of wingspan. In the disclosure herein, “general aviation aircraft” can also be referred to by the terms “aircraft”, “airplane”, and/or “aviation aircraft.” Additionally, the term “portable sensor pod” can also be referred to by the term “pod”, “sensor pod”, and/or “portable pod.” 
       FIG. 2A  illustrates a portable sensor pod  104  attached to a first type of general aviation aircraft  200   a  according to an embodiment.  FIG. 2B  illustrates the portable sensor pod  104  attached to a second type of general aviation aircraft according to another embodiment. As illustrated in  FIG. 2A , the general aviation aircraft  200   a  has a different wingspan and aerodynamic profile than that of the general aviation aircraft  200   b.  An avionics system using the portable sensor pod  104  can be calibrated with preset and/or predetermined aircraft dependent calibration data and/or formulas. In this way the sensor pod  104  can be mounted to the wing  110   a  of general aviation aircraft  200   a  so that essential calibrated flight data is readily displayed to a general aviation pilot in the cockpit  112   a  via a head mounted display system. 
     Similarly, by virtue of the preset aircraft calibration, the portable sensor pod  104  can also be mounted to the wing  110   b  of general aviation aircraft  200   b  so that essential calibrated flight data is readily displayed to a general aviation pilot in the cockpit  112   b  via a head mounted display system. 
       FIG. 3A  illustrates a side view perspective of a separated flange  302 , body  304 , and nose cone  306  for a portable sensor pod according to an embodiment.  FIG. 3B  illustrates a side view  330  of a flange  302  and an attachable container  332  according to an embodiment; and  FIG. 3C  illustrates a bottom view perspective  340  of a portable sensor pod according to an embodiment. 
     The flange  302  has a top surface  310 , a support section  311 , a flange connector section  314 , and a flange attachment hole  312 . The body  304  is a hollow section with a notch  316 , a body attachment hole  318 , and a utility hole  320 . The nose cone  306  has an interior surface  326 , a first tab  322 , and a second tab  324 . 
     The flange  302 , body  304 , and the nose cone  306  can be manufactured to be aerodynamically streamlined so that there is negligible and/or no aerodynamic load interference. In some embodiments the flange  302 , body  304 , and the nose cone  306  can be additively manufactured, e.g., using a three dimensional (3D) printer. Avionics including hardware circuits, sensor pod circuits, power supplies, batteries, and sensors, can be installed inside hollow portions of the body  304  and nose cone  306 . The first tab  322  and the second tab  324  can then be inserted into the body  304  to secure the body  304  to the nose cone  306  prior to sealing the body  304  and the nose cone  306  together. Body  305  may have a corresponding recess or notch that is configured to receive the first tab  322  and the second tab  324  of the nose cone. 
     As illustrated in  FIG. 3B , the sealed body  304  and the nose cone  306  can form the attachable container  332  which may attach to the flange  302  with a pin or similar attachment device. The top surface  310  of the flange  302  may be attached to a part of an aviation aircraft with an adhesive to advantageously make for an easy portable installation before flight and uninstallation after flight for the user. Additionally, the utility notch  320  can be used to mount a hardware switch to operate as an on/off switch to enable or disable the installed avionics and hardware circuits. 
     As shown in  FIGS. 3A-C , the flange connector section  314  can be inserted into the notch  316  so that the flange attachment hole  312  aligns with the body attachment hole  318  to form an alignment hole  341 . In this way a pin or similar attachment device such as a rivet may be inserted to secure the flange  302  to the attachable container  332 . 
     As shown in  FIG. 3C , the attachable container  332  can include a pitot hole  342  and a pitot hole  344 ; and  FIG. 3D  illustrates a side view perspective  350  of a portable sensor pod including an airspeed pitot tube  352  and angle of attack pitot tube  354  according to an embodiment. As shown in  FIG. 3C  and  FIG. 3D , the airspeed pitot tube  352  can be inserted into the pitot hole  342 ; and the angle of attack pitot tube  354  can be inserted into the pitot hole  344  at an installment angle with respect to the airspeed pitot tube  352 . The installment angle can be any angle of magnitude greater than 0 degrees; for instance, in some embodiments the installment angle may be 30 degrees, and in other embodiments the installment angle may be 45 degrees. 
     During flight, the airspeed pitot tube  352  can probe air data having a first flow vector angled directly in line with an airplane&#39;s geometric heading; and the angle of attack pitot tube  354  can probe air data having a second flow vector rotated by the installment angle with respect to the first vector flow. As will be further disclosed herein, the probed air data from the airspeed pitot tube  352  can advantageously be used to provide airspeed; and the probed air data from both the airspeed pitot tube  352  and angle of attack pitot  354  can be used to provide angle of attack. 
     Although the embodiment of  FIGS. 3A-D  describes a portable sensor pod using a flange  302  for mounting the attachable container  332  to an aircraft, other configurations are possible. For instance, in some embodiments an attachable container may be attached to other parts of an aircraft, such as to a tie-down anchor point. Also, within the disclosure herein “attaching a portable sensor pod” can also refer to “attaching the attachable container of the portable sensor pod.” 
     In addition, although the attachable container  332  is shown to have two pitot holes  342  and  344 , other attachable container configurations are possible. For instance, an attachable container may have greater or fewer than two pitot holes to hold greater or fewer pitot tubes (also referred to as static pitot tube systems). In some embodiments the attachable container  332  may have only an airspeed pitot tube  352 , and in some embodiments the attachable container  332  may include an additional side slip pitot tube for probing air data having a third flow vector. The third flow vector may be used to provide additional flight information such as aircraft sideslip. In other embodiments additional sensors including proximity sensors and/or global positioning system (GPS) sensors can be sealed within or outside the attachable container  332  to probe additional aspects of flight. 
       FIG. 4A  illustrates a side view perspective of a head mounted display (HMD) system  106  according to an embodiment. The HMD system  106  includes a hardware box  402 , a signal cable  404 , and a display module  406  with a display  408  for displaying flight information at an eyepiece  410 .  FIG. 4B  illustrates a front view of the head mounted display system  106  according to the embodiment of  FIG. 4A . The hardware box  402  can comprise hardware and/or avionics for wirelessly receiving and for processing data from the portable sensor pod. A function of the hardware box  402  can be to convert wirelessly received data into flight information for display via the display module  406  with the display  408 . The display  408  can be an organic light emitting diode (OLED); and the hardware box  402  can be a computer, a mobile device, a tablet, or similar system comprising hardware for receiving wireless signals and performing signal processing operations to display flight information at the eyepiece  410 . 
     In some embodiments the hardware box  402  can be conveniently attached to a wearable device, such as a hat, headband, glasses, helmet, etc. In other embodiments, the hardware box  402  may be placed in a small pouch for attachment to a piece of clothing or behind a hat. The signal cable  404  can be a high definition multimedia interface (HDMI) cable for carrying HDMI signals to the display module  406 . The eyepiece  410  can include glasses, sunglasses, eyepieces, and the like. In some embodiments the display module  406  can comprise a commercial off the shelf (COTS) component. For instance, the display module  406  can be part of a Vufine® HDMI compatible wearable display which may attach to glasses, headbands, hats, and other head apparel. (Vufine® is a registered trademark of Vufine, Inc. of Sunnyvale, Calif. 94086; hereinafter referred to as Vufine.) 
       FIG. 5A  illustrates an eyepiece display region  502  of a head mounted display system according to an embodiment; and  FIG. 5B  illustrates flight information  504  displayed in the eyepiece display region  502  of the embodiment of  FIG. 5A . The head mounted display system can be the HMD system  106  of  FIGS. 4A-B  configured to display essential flight data on the eyepiece  410 . As shown in the embodiment of  FIGS. 5A-B , the flight information  504  conveys airspeed (120 kts) in knots (kts) within the eyepiece display region  502 . 
     As shown in  FIG. 5A , the eyepiece display region  502  can be a small region of the eyepiece  410 . The eyepiece display region  502  can be positioned at any location on either the left or right eyepiece so that the flight information occupies a small zone in the pilot&#39;s field of regard. In this way essential information can be constantly and promptly conveyed to a general aviation pilot even while the pilot is looking outside of the cockpit. In some embodiments angle of attack can also be conveyed within the display region  502 . Angle of attack can be conveyed in numeric form and/or in symbolic form. In other embodiments additional flight information including rate of descent and/or climb can also be represented in symbolic form. Symbolic information can be conveyed with colors to immediately distinguish dangerous situations, like unsafe airspeed and/or unsafe angles of attack. In other embodiments angle of attack can be conveyed via a sound warning system, such as a stall warning indicator, within the cockpit. 
       FIG. 6A  illustrates a system block diagram  600   a  of the sensors  602   a  and sensor pod circuit  603  within a portable sensor pod according to a first embodiment. The system block diagram  600   a  shows the sensors  602   a,  the sensor pod circuit  603 , and an antenna  610   a.  The system block diagram can represent the avionics and/or hardware system components which may be sealed inside an attachable container  332  as described in the discussion of  FIGS. 3A-D . 
     The sensors  602   a  can comprise air data sensors  612  and aviation sensors  613 . Examples of air data sensors  612  may include pitot-static systems, which can be also be referred to as “pitot tubes” and/or “differential barometers.” As one of ordinary skill in the art can appreciate, the pitot tubes can be used to probe and measure differential pressure between static and total impact pressure. For instance, the airspeed pitot tube  352  can probe and provide a differential pressure between the total impact pressure along the first flow vector and the static pressure. Examples of aviation sensors  613  may include an altimeter, compass, GPS, and/or attitude determination sensor. For instance, an ultrasonic ground proximity sensor, for assisting a pilot with flare timing, can be installed at the bottom of the attachable container  332 . 
     As illustrated the sensor pod circuit  603  includes transducers  604 , a microcontroller  606 , and an RF module  608   a.  The transducers  604  can be used to convert non-electrical signals into analog signals. For instance, the transducers  604  can include a piezoresistive pressure transducer for converting differential pressure P from the air data sensors  612  into a transducer output signal S T . The transducer output signal S T  can be an analog signal which is then coupled to an analog input of the microcontroller  606 . Also, the aviation sensors  613  can provide sensor output signals S AV , which may be either digital and/or analog signals and which may be coupled to digital and/or analog inputs of the microcontroller  606 . 
     As one of ordinary skill in the art can appreciate, the microcontroller  606  can be configured to process the signals S T  and S AV  to provide an output signal or vector of output signals S 1  to the RF module  608   a.  For instance, the microcontroller  606  can be programmed to provide digital data S 1  in a serialized format to the RF module  608   a.  The microcontroller  606  can also be programmed with instructions including preset data and/or predetermined formulas to account for an aircraft&#39;s characteristics. For instance, aircraft specific calibration data for the sensors  602   a  can be programmed into the memory and/or into predetermined formula instructions within the microcontroller  606 . Having preset data and/or predetermined formulas programmed into the microcontroller  606  can advantageously allow a pilot to attach the attachable container  332  to multiple aircraft types without having to perform an initial calibration flight test. 
     The RF module  608   a  can transmit pod output data via antenna  610 . The pod output data can comprise digital information including the digital data S 1 . In some embodiments the antenna  610  can be fully integrated into the RF module  608   a.    
       FIG. 6B  illustrates a system block diagram  600   b  of the sensors  602   b  and sensor pod circuit  603  within a portable sensor pod according to a second embodiment. The system block diagram  600   b  is similar to the system block diagram  600   a,  except it uses sensors  602   b.  The system block diagram  600   b  can represent avionics within the portable sensor pod enclosure of  FIG. 3D  configured for probing airspeed and angle of attack. Sensors  602   b  include the air data sensors  612  which comprises an airspeed pitot tube  614  and an angle of attack (AOA) pitot tube  616 . 
     The airspeed pitot tube  614  and the angle of attack pitot tube  616  can be system block diagrams of the airspeed pitot tube  352  and the angle of attack pitot tube  354  of  FIG. 3D . The airspeed pitot tube  614  provides a differential pressure P IAS  to a transducer  618 , which converts differential pressure P IAS  into a proportional analog signal S IAS . Similarly, the angle of attack pitot tube  616  provides a differential pressure P AOA  to a transducer  620 , which converts differential pressure P AOA  into a proportional analog signal S AOA . 
     The microcontroller  606  can receive the analog signals S IAS  and S AOA  and convert them into the digital data S 1 . The microcontroller  606  can convert both of the analog signals S IAS  and S AOA  to airspeed data based on a predetermined formula, which can be calibrated for multiple aircraft types. 
       FIG. 6C  illustrates a system block diagram  600   c  of the sensors  602   b  and sensor pod circuit  623  within a portable sensor pod according to a third embodiment. The system block diagram  600   c  is similar to the system block diagram  600   b,  except it uses sensor pod circuit  623 ; also, sensor pod circuit  623  is similar to sensor pod circuit  603  except the RF module  608   a  is replaced with a Bluetooth module  628  having serial data RX/TX input ports. As shown in  FIG. 6C , the processor/controller can have serial data output ports TX/RX coupled to the RX/TX input ports of the Bluetooth module  628 . 
     As one of ordinary skill in the art can appreciate,  FIGS. 6A-C  show system level diagrams which can be realized with circuit components. In addition, a circuit level realization can include additional components, connections, and/or features which are not conveyed at the system level. For instance, a circuit realization of  FIG. 6C  can include an on/off switch; in addition the circuit realization can include power management modules and components such as step-up converters, low dropout regulators, and/or rechargeable batteries. 
     Additionally, as one of ordinary skill in the art can appreciate, the microcontroller  606  can be realized with a microcontroller such as the Arduino/Nano. The Arduino/Nano can be preprogrammed with calibration data and/or a predetermined air data (airspeed) formula so that the system represented by  FIGS. 6A-6C  can be attached to a plurality of aviation aircraft types. 
       FIG. 7A  illustrates a system block diagram  700   a  of the display  704  and hardware components  702  within a head mounted display system according to a first embodiment. The system block diagram  700   a  also illustrates an antenna  701  which wirelessly receives the pod output data from a sensor pod circuit as described above in the discussion of  FIGS. 6A-C . The system block diagram  700   a  can also represent the avionics and/or hardware system components corresponding to the head mounted display system  106  described above. 
     The hardware components  702  include an RF module  706 , a processor  708 , and data storage  710 . The hardware components  702  and antenna  701  can represent some or all of the components within the hardware box  402 . For instance, the processor  708 , antenna  701 , and RF module  706  can be components realized within a laptop, tablet and/or similar computer system, such as Raspberry Pi Zero W. As one skilled in the art can appreciate, a Raspberry Pi Zero performs the functions of a computer including both WiFi and Bluetooth. In addition, the data storage  710  can refer to both internal and external removable data storage such as a secure digital (SD) card and/or a removable hard drive. 
     The hardware components  702  can perform processing calculations and smoothing algorithms. For instance, program instructions can be stored into the data storage  710  and accessed to perform angle of attack calculations based on the received pod output data. When the pod output data has information from an airspeed pitot tube  352  and an angle of attack pitot tube  354 , angle of attack can be calculated by solving a system of two equations and two unknowns to estimate the angle of attack. In addition flight information including flight path and aircraft flight pattern can be stored into the data storage  710  for later retrieval. The stored flight information can advantageously assist a pilot to objectively learn from prior flight patterns. 
     In addition to performing processing calculations, the hardware components  702  may convert and/or format signals to be compatible with the display  704 . For instance, when the display  704  is an HDMI display, the signals S DIS  may be provided in HDMI format.  FIG. 7B  illustrates a system block diagram  700   b  of the display  704  and hardware components  702  within a head mounted display system according to a second embodiment. The system block diagram  700   b  can represent an integrated realization of the hardware components  702  and display  704 . For instance, the hardware components  702  and display  704  can be fully integrated into the lens and/or surrounding lens frame. Alternatively, the system block diagram  700   b  can represent an integrated realization wherein the display  704  is integrated with the hardware components  702  inside the hardware box  402 . 
       FIG. 8  conceptually illustrates a method  800  of using a portable avionics system (e.g.,  102 ) according to an embodiment. The method  800  comprises six operations  802 ,  804 ,  806 ,  808 ,  810 , and  812  which can be executed in sequence. The first operation  802  can correspond to attaching the portable sensor pod  104  to a general aviation aircraft wing. The portable sensor pod  104  can comprise a sensor pod circuit with a microcontroller  606 , and the microcontroller  606  can use a predetermined formula with sensor calibration data corresponding to the general aviation aircraft. The next operation  804  can correspond to measuring sensor data. For instance, air data from the airspeed pitot tube  352  and air data from the angle of attack pitot tube  354  can be measured. 
     The following operation  806  can correspond to converting the sensor data using the predetermined formula. For instance, the microcontroller  606  of  FIG. 6C  can convert analog signals S IAS  and S AOA  into pod output data; and the pod output data can correspond to the digital data S 1  provided to and transmitted via the RF module  608   a  (or Bluetooth module  608   b ). 
     Next, operation  808  can correspond to receiving the pod output data at a hardware box  402  of an HMD system  106 . As described above, the pod output data may be received via wireless communication between an HMD system  106  and the portable sensor pod  104 . Then operation  810  can correspond to converting the received pod output data into aircraft specific flight information S DIS . And finally, operation  812  can correspond to transmitting and/or displaying the aircraft specific flight information S DIS  on a display  704 . 
       FIG. 9  conceptually illustrates a flow graph  900  corresponding to measuring air data using a portable sensor pod (e.g.,  104 ,  330 ,  340 ,  600   a,    600   b,    600   c ) according to an embodiment. The method  900  includes a first operation path  902  in parallel with a second operation path  904 . The first operation path  902  includes a probe operation  910  corresponding to probing air data using the airspeed pitot tube  352  and an operation  912  corresponding to converting the probe data into an analog signal S IAS . At operation  910  the airspeed pitot tube probe  352  probes a differential pressure relating to indicated airspeed (IAS); and at operation  912  a transducer, such as a piezoresistive pressure transducer, converts the differential pressure into the analog signal S IAS , which can then be provided to a microcontroller (e.g microcontroller  606 ). 
     The second operation path includes a probe operation  914  corresponding to probing air data using the angle of attack pitot tube  354  and an operation  916  corresponding to converting the probe data into an analog signal S AOA . At operation  914  the angle of attack pitot tube probe  354  probes a differential pressure based on the installment angle (e.g. 30 degrees) relative to the airspeed pitot tube probe  352 ; and at operation  916  another transducer, such as a piezoresistive pressure transducer, converts the differential pressure into the analog signal S AOA , which can then be provided to the microcontroller  606 . 
     Next, at operation  906  the analog signals S IAS  and S AOA  can be processed using the microcontroller  606  based a predetermined formula. The predetermined formula can be programmed into the microcontroller  606  for the type of aircraft. Next, at operation  908  the pod output data can be transmitted via wireless carrier (e.g. Bluetooth) so that it can be received by an HMD system. 
       FIG. 10  conceptually illustrates a method  1000  of using a head mounted display system (e.g.,  106 ,  500 ,  700   a,    700   b ) according to an embodiment. The method  1000  comprises four operations  1002 ,  1004 ,  1006 , and  1008  which can be operated in sequence. First, in operation  1002  the pod output data is received by the head mounted display system. With reference to  FIG. 7A , operation  1002  can correspond to receiving the pod sensor data via the antenna  701  and RF module  706  within the hardware components  702 . Then at operation  1004  the received pod output data can be processed by the hardware box. Operation  1004  can correspond to using the hardware components  702  for processing calculations and smoothing algorithms. For instance, angle of attack can be calculated by the hardware box at operation  1004 . Next, operation  1006  can correspond to using the hardware components  702  to format the processed data for conveying as flight information on display  704 ; and finally operation  1008  can correspond to displaying the flight information on display  704 . 
       FIG. 11  illustrates a functional system block diagram  1100  of the portable avionics system (e.g.,  102 ) for measuring air data according to an embodiment. Block  1102  can correspond to a high level block diagram of air data measurements within the portable sensor pod  104 ; and block  1104  can correspond to a high level block diagram of operations within the HMD system  106 . Additionally, as shown in the system block diagram  1100 , the portable sensor pod  104  and HMD system  106  are in wireless communication via Bluetooth  1120 . 
     Block  1102  may include operations  1106  and  1008 . Operation  1106  can correspond to measuring air data with the airspeed pitot tube  352  and the angle of attack pitot tube  354 . In addition, operation  1106  can include the step of converting sensor data (differential pressure) into an analog signal (e.g. an analog voltage) using a piezoresistive pressure transducer. Block  1108  can also correspond to using a microcontroller  606  to convert the analog signals into digital data S 1 , which can be communicated via Bluetooth  1120  as pod output data. The microcontroller can perform calculations and corrections to the analog signals by using a predetermined formula; and the digital data S 1  can comprise calibrated airspeed values, in digital format, based on the predetermined formula. 
     Block  1104  may include system blocks  1110 ,  1112 , and  1114 . System block  1112  can be a computer, tablet, a Raspberry Pi, and/or other wireless device which can wirelessly communicate via Bluetooth  1120 . The system block  1112  can perform operations including processing calculations and smoothing algorithms. The system block  1110  can be removable data storage for storing flight information data processed by system block  1112 . System block  1114  can be an HDMI display capable of displaying flight information in HDMI format. 
       FIG. 12  illustrates a method  1200  for calibrating airspeed data for a type of general aviation aircraft according to an embodiment. The method  1200  includes steps  1202 ,  1204 ,  1206 , and  1208  which can be performed in sequence to obtain calibration data. The calibration data can in turn be used to create and/or augment the predetermined formula for use within the microcontroller  606 . At step  1202  an airspeed pitot tube  352  is placed into portable sensor pod  104  and the portable sensor pod  104  is attached to the aircraft. At step  1204  an airspeed calibration data point can be measured. The following step  1206  is a decision step which can determine if enough calibration points have been measured. If the calibration still requires additional data points, the decision loop can return to step  1204 . If the calibration data points meet the calibration requirements, then the method  1200  continues to step  1208 . In step  1208  data is stored and/or preprogrammed into the portable sensor pod for using with multiple types of aircraft. In other embodiments, a fixed number of calibration points (e.g. four data points) can be measured. 
       FIG. 13  illustrates a method  1300  for operating avionics hardware of the portable avionics system (e.g.,  102 ) for measuring air data according to an embodiment. Method  1300  can apply to a portable avionics system using a head mounted display system and portable sensor pod. The method  1300  uses steps which can be performed to maintain a short duty cycle when polling portable sensor pod sensors, including the airspeed pitot tube  352  and the angle of attack pitot tube  354 . Method  1300  can constantly check accuracy of the sensor outputs. A function of method  1300  can be to ensure that a pilot receives accurate information by checking the integrity of the portable sensor pod sensors before every flight and by checking the plausibility its sensors readouts based on previous outputs. For instance, before every flight the method  1300  can perform steps to check the integrity of the airspeed pitot tube  352  and the angle of attack pitot tube  354 . 
     As shown in  FIG. 13 , method  1300  may include twelve logical steps  1302 ,  1304 ,  1306 ,  1308 ,  1310 ,  1312 ,  1314 ,  1316 ,  1318 ,  1320 ,  1322 , and  1324 . Steps  1302 ,  1304 , and  1306  can comprise hardware and setup initialization procedures. For instance, step  1302  can apply to enabling electrical power to the head mounted display system  106  and to the portable sensor pod  104 . At  1302 , a pod and HMD may be turned on, where HMD can refer to an HMD system and/or hardware box of an HMD system. At  1304 , an offset of a pitot tube may be found at the sensor pod, and the identified offset may be checked for discrepancies. At  1304 , the sensor pod and HMD may establish communication with each other. For example, the pod may connect with the HMD via a handshake procedure, e.g., a Bluetooth handshake procedure. 
     Step  1308  can be a loop initialization point, where the main loop comprises steps  1308 ,  1310 ,  1312 ,  1314 ,  1316 , and  1318 . Step  1308  may begin once a connection is established between the pod and the HMD. Steps  1310  and  1316  are decision steps having local decision making loops. For instance, step  1310  can be used to determine if a wireless (e.g., Bluetooth) connection is broken and to execute step  1320  to reconnect the pod and HMB in response to determining that the connection is broken. If the connection is determined to be maintained at  1310 , the analog output from the sensors, e.g., pitot tubes, may be read at  1312 . For example, the analog output from the sensors may be read a predetermined number of times, e.g., N times. Then, at  1314 , the analog signals may be processed, e.g., into IAS data. Step  1316  can be used to execute step  1322  if there are errors in the data. Thus, at  1316 , a determination may be made as to whether the processed output makes sense, e.g., falls within an expected range or meets threshold. If an error is identified in the data at  1316 , then, a notification of inaccurate data may be communicated from the pod to the HMD at  1322 . The receipt of the error notification at the HMD may cause an error notification to be displayed to the user at the HMD. If no errors are detected at  1316 , then the pod may transmit the processed data to the HMD. The HMD may then use the processed data to present a display of avionic information to the user at the display portion of the HMD. 
     By way of example, an element, or any portion of an element, or any combination of elements may be implemented as a “processing system” that includes one or more processors. Examples of processors include microprocessors, microcontrollers, graphics processing units (GPUs), central processing units (CPUs), application processors, digital signal processors (DSPs), reduced instruction set computing (RISC) processors, systems on a chip (SoC), baseband processors, field programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functionality described throughout this disclosure. One or more processors in the processing system may execute software. Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software components, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. 
     Accordingly, in one or more example embodiments, the functions described may be implemented in hardware, software, or any combination thereof. If implemented in software, the functions may be stored on or encoded as one or more instructions or code on a computer-readable medium. Computer-readable media includes computer storage media. Storage media may be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise a random-access memory (RAM), a read-only memory (ROM), an electrically erasable programmable ROM (EEPROM), optical disk storage, magnetic disk storage, other magnetic storage devices, combinations of the aforementioned types of computer-readable media, or any other medium that can be used to store computer executable code in the form of instructions or data structures that can be accessed by a computer. 
     The above sub-processes represent non-exhaustive examples of specific techniques to accomplish objectives described in this disclosure, It will be appreciated by those skilled in the art upon perusal of this disclosure that other sub-processes or techniques may be implemented that are equally suitable and that do not depart from the principles of this disclosure. 
       FIG. 14A  illustrates a system block diagram of a portable avionics system  1400  using a hardware box  1404  according to aspects presented herein. Like the portable avionics system  102  described above, the portable avionics system  1400  includes a portable sensor pod  1402  and an HMD  1406  coupled to the hardware box  1404 . Also, the portable sensor pod  1402 , the HMD  1406 , and the hardware box  1404  can be similar to the portable sensor pod  104  and corresponding HMD system  106  with hardware box  402 . However, unlike the portable avionics system  102 , the portable avionics system  1400  includes light emitting diode (LED) strips  1408 , speakers with auxiliary inputs  1410 , a shaker  1412 , and peripheral devices  1414 . The LED strips  1408 , speakers with auxiliary strips  1410 , shaker  1412 , and peripheral devices  1414  can be part of a network of displays (warning devices) to augment the display features of the HMD  1406 . 
     As shown in  FIG. 14A , the portable sensor pod  1402  is electrically coupled to the hardware box  1404  via a wireless and/or wired interface. For instance, the hardware box  1404  can communicate with the portable sensor pod  1402  via Bluetooth as described above with respect to the portable avionics system  102 . Also, the HMD  1406 , the LED strips  1408 , the speakers with auxiliary inputs  1410 , the shaker  1412 , and the peripheral devices  1414  can be electrically coupled to the hardware box  1404  via a wireless and/or wired interface. For instance, the HMD  1406  can communicate with the hardware box  1404  using Bluetooth and/or HDMI cables as discussed above; and the speakers with auxiliary inputs  1410  can connect via a universal serial bus (USB) cable and/or via a WiFi interface. 
     The LED strips  1408  can be used to light the interior of the cockpit in distinct colors to indicate the safety of the pilot. Similar to the display in the HMD system  106  and the HMD  1406 , red can indicate an extremely dangerous situation while no illumination can indicate a healthy state. Other examples can be based on a variable degree of severity; LED colors can be used to indicate a variable degree of safety and/or peril the pilot may experience during flight. 
     The LED strips  1408  can be placed inside and/or outside the cockpit in a variety of ways and in a variety of general aviation aircraft. For instance, in a Cessna  152 , which has a dashboard-like avionics panel, the LED strips  1408  can be lined or placed across the front top of the avionics panel. Alternatively, and additionally, the LED strips  1408  can be arranged to line the outsides of windows on the interior of the cockpit. The LED strips may be wirelessly coupled to the hardware box and in wireless communication with the components of the hardware box such that the components in the hardware box can wirelessly control the operation of the lights. 
     The speakers with auxiliary (AUX) inputs  1410  can be used inside the cockpit to verbally warn (“yell” at) the pilot when the pilot reaches an unsafe aircraft attitude. As one of ordinary skill in the art can appreciate, pilots can use headsets when they operate an aircraft; headsets can comprise AUX inputs and/or outputs for music and for recording. The AUX outputs provide audio output to a pilot. Additionally, conversations and transmissions made by the pilot can be recorded by the hardware box  1404  to provide “black box” functionality. The speakers with auxiliary (AUX) inputs  1410  can be wirelessly connected to the hardware box  1404  . In some embodiments they can be positioned behind the pilot&#39;s head. The power supply for the speakers, and similarly for the lights, can be self-contained and/or powered by the airplane&#39;s power supply. 
     The shaker  1412  can be a stick/yoke shaker, may be a haptic device that can be attached to the yoke/stick of the aircraft and wirelessly connected to hardware box  1404 , to bring tactile functionality and to alert the pilot of a dangerous situation. 
     Alternatively, and additionally, the shaker  1412  can be implemented and used in a variety of ways and applications. For instance, the shaker  1412  can be positioned to shake the pilot&#39;s seat to alert the pilot of a dangerous situation. The shaker may be positionable in other locations, as well. For example, the shaker may be worn by the pilot. 
     Also, the shaker  1412  can be implemented using vibration functions of portable technology like phones, smart watches, smart device, or other wearable, many of which have small motors that serve to vibrate. The hardware box may form a wireless communication link with such devices and use the vibration or other motion function of the device to alert the pilot when the components of the hardware box detect a dangerous situation. For example, when used as part of a smart watch, the shaker  1412  can alert a pilot via the smart watch&#39;s internal motors. 
     In other embodiments, the peripheral devices  1414  can include devices such as smart phones and/or watches with additional display functionality. 
     Although the portable avionics system  1400  shows the hardware box  1404  as being connected to a network of displays including an HMD  1406 , LED strips  1408 , speakers with AUX inputs  1410 , a shaker  1412 , and peripheral devices  1414 , other configurations having greater or fewer displays are possible. For instance, in some embodiments the portable avionics system  1400  can include just the HMD  1406  and the LED strips  1408 . 
     As one of ordinary skill in the art can appreciate, traditional avionics systems may include a central avionics panel. Advantageously, the hardware box  1404  can function as a central computer performing the processing for a network of displays. The network displays, including the HMD  1406 , LED strips  1408 , speakers with AUX inputs  1410 , shaker  1412 , and/or peripheral devices  1414  can be positioned on and/or away from the central avionics panel so as to provide additional alerts to the pilot. 
       FIG. 14B  illustrates a system block diagram of a general avionics system  1450  using a hardware box  1404  according to aspects presented herein. The general avionics system  1450  is similar to the portable avionics system  1400  except the portable sensor pod is replaced with a general avionics system  1420 . The avionics system  1420  can be a preinstalled and/or preexisting avionics system within the aircraft. The avionics system  1420  can be coupled to hardware box  1404  via Bluetooth and/or wired interface. 
     The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these exemplary embodiments presented throughout this disclosure will be readily apparent to those skilled in the art, and the concepts disclosed herein may be applied to using other types of avionic sensors and/or head mounted displays. Additionally, the concepts may be applied to other forms of aircraft and transport vehicles. 
     Thus, the claims are not intended to be limited to the exemplary embodiments presented throughout the disclosure, but are to be accorded the full scope consistent with the language claims. All structural and functional equivalents to the elements of the exemplary embodiments described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. No claim element is to be construed under the provisions of 35 U.S.C. § 112(f), or analogous law in applicable jurisdictions, unless the element is expressly recited using the phrase “means for” or, in the case of a method claim, the element is recited using the phrase “step for.”