Many times large number of incentive and familiarization flights are offered to maintenance and operational support personnel during temporary duty (TDY) deployments. Flight surgeons play a crucial role in this process educating and medically clearing potential candidates. In this setting, the flight surgeon may be without their standard materials, computer, or other resources.
Hopefully, you will at least have access to the internet. And if so, use this resource to prepare your incentive and familiarization flyers!
ORIENTATION FLIGHT RATIONALE
All three branches of the US Armed Forces conduct orientation flights in certain aircraft to reward and motivate individuals (incentive flights), ensure a better understanding of a particular weapon system, or when the flight is determined to be in the best interest of the military. The regulations that direct orientation flight programs is DoD 4515.13-R and each service’s unique respective guidance. The USAF addresses authorization for these flights in AFI 11-401 and medical clearance for these flights in AFI 48-123.
Some of the various categories of these flights are:
- Distinguished Visitor (DV) Flights: Display weapons systems so individuals gain a better understanding of the aircraft and mission.
- Familiarization Flights: Familiarize individuals who normally have aviation-related responsibilities with aircraft and missions.
- Incentive Flights: Provide a visible reward to active duty or reserve military personnel for outstanding service and motivate others to attain similar performance levels.
- Spouse Orientation Flights: Familiarize military spouses with the unit aircraft and mission to enhance their understanding of the military member‘s role and contribution to the mission.
These types of flights can be on virtually any aircraft, from heavy transport planes to rotary wing helicopters. However, there is no bigger incentive for a young enlisted member (or operational support officer or even celebrities) to gain than a sortie in a fighter jet. Flying in a high-performance combat aircraft also happens to have the most serious aeromedical implications. Due to this fact, there are specific requirements for those selected for an orientation flight. Candidates must meet with a flight surgeon to review their medical history, perform an exam to ensure medical fitness, and provide a flight safety brief on pertinent aeromedical concepts. This last task can also be fulfilled by aerospace physiologists.
All of the remaining content below will serve as a resource for flight surgeons providing aeromedical education to orientation flyers. Although I don’t know Hayley, the below youtube video was made by flight medicine and physiologists at Hill AFB and although dated serves as a great introductory video for orientation flyers to watch.
AEROSPACE PHYSIOLOGY BRIEF FOR F-16 FAMILIARIZATION & INCENTIVE FLYERS
THE ORIENTATION FLIGHT HISTORY & PHYSICAL EXAM
- Past Medical History: All current and past medical conditions, surgical history, and medication use should be gathered. Inquiry of recent dental procedures should be discussed. The most significant body systems to inquire about are ENT, cardiac, and pulmonary health. Any noteworthy cardiac or respiratory disease could be a show-stopper. A recent upper respiratory or moderate to severe seasonal allergic rhinitis could put the flyer at risk of developing an ear or sinus block. Medical clearance for an orientation flight usually lasts 7-14 days in the USAF (some MAJCOMs have a supplemental guidance to limit the normal 14 day clearance to 7 days). For this reason, it is important to direct orientation flyers to report to the flight surgeon if they develop a new upper respiratory infection (common cold) or symptoms of seasonal allergies on the day of flight.
Physical Exam: The typical orientation physical exam is comprised of vital signs, anthropometric measurements, and a focused exam on the body systems described above. Anthropometric measurements ensure that the flyer will be within the ejection seat manufacturer’s parameters for safe ejection. These measurements are aircraft-specific. Measurements outside some parameters can be waived thru the flyer signing a consent that he or she assumes a higher risk for injury during ejection, which must then be approved by the appropriate waiver authority. The ‘butt-to-knee’ measurement is representative of the femur length and is not waiverable in USAF ejection seat aircraft due to the risk of longer legs not clearing the dashboard resulting in loss of limbs. Aside from auscultating the heart and lungs, it is vital that the flight surgeon visualizes movement of the tympanic membrane (eardrum) when the patient performs the valsalva maneuver during otoscopic ear exam. The flight surgeon will need to explain and demonstrate this maneuver before the exam if the patient is unfamiliar.
AEROMEDICAL TOPICS FOR FAMILIARIZATION & INCENTIVE FLYERS
- Helmet & Mask Discomfort and Fit: Fighter pilots in the USAF fly with the HGU-55/P helmet.
The importance of a comfortable fit for the helmet and mask should be briefly discussed. The fit should be snug to ensure adequate protection in event of blunt impact or ejection, but not painful. The mask should also be comfortable, but fit snugly enough to prohibit air escaping from the sides. A thorough explanation and demonstration of all life support equipment will be covered during fitting by life support/aircrew flight equipment (AFE) teams. Also direct the flyer to gain familiarity on mask removal and how to perform the Valsalva Maneuver thru the mask. For example, many of the USAF masks have soft plastic ports that allow the wearer to Valsalva, but only with both index fingers rather than pinching with the thumb and index of one hand.
23 Oct 2006 Surgeon General NOTAM – Cockpit Pressurization & Oxygen Delivery Systems: In 2006, a tragic incident involving an incentive flyer provoked the USAF Surgeon General to draft a Notice to Airman (NOTAM) for all personnel involved in medical clearances for orientation flyers. An incentive flyer inadvertently turned the oxygen regulator off and failed to either turn it back on or remove their mask, both of which would have corrected the problem. Instead the victim slowly suffocated and with no oxygen, was unable to tell the pilot that they were in distress. The finding from the investigation was that the mishap was caused by inadequate training on cabin pressurization and oxygen delivery systems in addition to other causes. Relate this story to the orientation flyer and briefly explain how cabin pressurization in aircraft functions. Explain how isobaric cabin pressurization schedules work and the importance of low-differential cabin pressures used by fighter aircraft. Emphasize to the flyer that wearing the mask is to prevent hypoxia in case of loss of cabin pressure and that removal of the mask is safe and necessary in the event that the oxygen delivery system fails.
Hypoxia & Hyperventilation: Explain how air density diminishes with elevation and with this change the partial pressure of oxygen. Relating common flight altitudes to the elevation of Mt Everest is immediately understood. A loss of cabin pressure can be either slow or rapid. Describe the differences between these two scenarios and the expected signals (condensation of water vapor, sudden explosive noise, abrupt temperature drop) associated with a rapid decompression. Time of useful consciousness at various altitudes is often surprising to untrained flyers and these specific values can be viewed in the table below. Describe the common signs and symptoms of hypoxia. The corrective action for hypoxia is to ‘gang load’ the oxygen regulator. Use the accompanying photo above as a visual aid to explain how this regulator is used and how to perform a P-R-I-C-E check prior to flight. Another discussion point can be to point out various commercial mishaps found to be caused by hypoxia in the cockpit, such as the 2005 crash of Helios Airways Flight 522. Lastly, mention that hyperventilation is an increased respiratory rate usually resulting from anxiety and can present with many of the same signs and symptoms of hypoxia. Hyperventilation is overcome by intentional slowing one’s breathing rate and should be considered if the flyer feels anxious in flight. The ‘4 of Spades’ video below is an entertaining way to demonstrate the serious consequence of experiencing hypoxia in flight and always gets a few laughs.
4 OF SPADES – USAF AIRCREW HYPOXIA TRAINING
- Upper Respiratory Illness, Seasonal Allergies and other ENT abnormalities: This should be covered during the history and physical exam, but orientation flyers should be reminded during this brief that they should present to the flight doc if they develop any of the above symptoms or illnesses on the day of their flight.
Trapped Gas & the Valsalva Maneuver: Briefly explain Boyles’ Law and the fact that gas expands with ascent and contracts with descent. Relate this physical property to normal human physiology and educate the orientation flyer on the areas of the body that may be affected (sinuses, middle ear, teeth, and GI tract). The valsalva maneuver should be described so that it can be properly demonstrated during exam. A brief description of ENT anatomy may be useful. Stress the physiology that normally allows the Eustachian Tube to spontaneously open during ascent as gas expands, but is resisted on descent which creates a vacuum effect in the middle ear, ultimately leading to barotrauma or hemotympanum if a maneuver to open the Eustachian tube is unsuccessful. Other modes of equilibrating pressures may also be discussed- the Toynbee Maneuver, Frenzel Maneuver, jaw thrusts, or drinking water.
- Motion Sickness & Vertigo: Describe the current medical understanding of motion sickness as a contradiction in conflicting sensory inputs to the visual, vestibular and tactile ‘seat of the pants’ receptors. Educate the flyer on a few common visual and vestibular types of disorientation experienced in flight. Provide tips to decrease the likelihood of motion sickness prior to flight, such as normal diet, good hydration & adequate rest. During flight they should restrict head and eye movements, focus on a fixed point in the distance, use the cooling system, and drop the mask if they begin feeling sick. I find that approximately 50% of orientation flyers get sick to the point of vomiting during flights in the F-16. I have also seen a few orientation flyers who developed intractable vomiting requiring anti-emetics and IV fluids after flight. Let them know how to contact you if this should happen. Most importantly, try to stress a positive anticipation of the flight without anxiety about getting sick. Don’t become a self-fulfilling prophecy. Always counsel the orientation flyer to bring a ‘sick sack’, which they pick up from AFE. Going ‘cold mic’ to prevent the pilot from overhearing emesis is encouraged, but not required. The pilot will likely appreciate this. Watch out for negative-G’s after vomiting, and tightly close that sick sack when full (see the video below on what NOT to do)!
BEWARE MOTION SICKNESS DURING NEGATIVE G’S
- Acceleration & Pulling G’s & The AGSM: The F-18 is limited to 7.5 G’s, the F-15 was designed to max out at 8 G’s, and the F-16 peaks at a whopping 9 G’s! Briefly describe the concept of ‘G-forces’ and/or show this video about G-forces in the US Navy’s Blue Angels demo team (who actually do not fly with G-suits!).
USN BLUE ANGELS ON G-FORCES & G-LOC:
A ‘G’ is as a unitless measure of the earth’s gravitational force exerted on all nearby objects and is defined in aviation as magnitudes of the earth’s gravity (1 G = 9.82 m/s^2). It is an accelerative force. One’s weight is literally multiplied by the number of G’s experienced (a 150 lbs male weighs 600 lbs at 4 G’s).
Explain the physiologic consequences of increased G-forces, before discussing how the aircraft design, AFE, and the anti-G straining maneuver mitigate this force to maintain consciousness. The body has evolved adaptive physiologic processes to compensate for the specific gravitational force that we are normally exposed to on terrestrial earth (1 G). The circulatory system is most sensitive to changes in gravity and when the number of G’s exceed the individual’s resting G-tolerance, the now ‘heavier’ blood is displaced in the direction of the gravitational pull. Many acrobatic and combat maneuvers aligns these forces parallel to the spine in the direction from cranium to toes (Gz-axis). If the G-forces in this direction exceed the heart and blood vessels’ ability to compensate (aka the cerebral blood pressure), intraorbital and intracerebral perfusion drops to negligible levels. In short, there is no blood perfusing the eye or brain.
The spectrum experienced by the flyer is a loss of peripheral vision (tunnel vision), then graying of the vision, total black out (inability to see, but still conscious) and finally the G-LOC (G-induced loss of consciousness). Obviously, this state must be avoided at all costs by those piloting any aircraft. Some aircraft have a seat that reclines (F-16). Although this may not have been designed to manipulate the G-force axis, it still does reduce the orientation of the G’s experienced by the pilot. Additionally, the G-suit removes some of the G’s experienced by the wearer when it inflates as G’s increase. The older USAF Standard CSU-13B/P G-Suit and USN’s Standard CWU 27/P are thought to compensate for 1.0 – 1.5 G’s, while the newer CSU-23/P, Advanced Technology Anti-G Suit (ATAGS) advertise up to 3 G’s of protection. The remaining G’s that the body experiences must be overcome by a maneuver that is used to displace blood from non-essential parts of the body to the eyes and brain, while maintaining sufficient cardiac output. This is called the Anti-G Straining Maneuver (AGSM) and must be explained and demonstrated to any orientation flyer. A more detailed explanation of this maneuver can be found at the link above.
There are two components to the AGSM:
- Isometric Muscle Contraction
- 3-Second Breathing Cycles
The videos below provide an entertaining and illustrative example of a proper AGSM, followed by the scary consequence of an absent or poor one, the notorious G-LOC.
EXAMPLE OF A STRONG AGSM AT SUSTAINED 9 G’S:
SCARY G-LOC IN THE CENTRIFUGE:
An orientation flight of any kind in a multi-million dollar fighter jet is a HUGE privilege and will likely prove to be one of the orientation flyer’s most memorable life experiences. This point should also be embraced by all fighter flight docs who get to fly on a regular basis, what a cool job! Remind the orientation flyer to be sure to pack a few important things for the flight:
- Sick Sack (in case of emesis)
- Hearing Protection (foamies)
- Piddle Pack (most fighter jets don’t have a bathroom!)
Be sure to tell the flyer candidate to have a blast, get a media pass to be able to bring a camera (to make an epic video like the one below) and remind them that he two most common questions they will likely be asked upon landing:
- Bro, how many G’s did you do!?
- Did you puke???
Hopefully, your answer to number 1 is “9 G’s!!!” and your answer to number two is not you holding up a full sick sack. Regardless, make sure you have a great time. Enjoy the Go-Pro video below from an incentive flight at Luke AFB.
GO PRO F-16 INCENTIVE FLIGHT FROM LUKE AFB