Aviation Medicine

AvMed- Aviation Medicine is concerned with the health and safety of aviators. The goal of this page is to share the resources that combines all factors related to occupational, environmental and the physiology of aviators. AvMed contributes to the mitigation and management of health risks that helps the aviator to keep themselves fit and safeguard their licenses.

Following are few resources that creates awareness of different health parameters and challenges that we aviators may encounter in our professional journey. Awareness of these medical challenges will help us to mitigate these challenges and thereby guide us to lead a hale and healthy life.

OBESITY & COMMERCIAL AIRCREW

1) Obesity is generally defined as an excess concentration of body fat or adipose tissue. Obesity and overweight are terms often used interchangeably, but they do not necessarily represent the same situation. Some individuals may be overweight but not obese, while obese individuals are overweight to a certain defined degree.

2) Defining obesity is not a difficult task, but measuring obesity can be difficult & controversial.

3) The medical implications of obesity are more of a cause for concern for the employer than the regulatory body, in view of the nature of the disability & its ability to cause acute incapacitation.

4) Overweight and obese individuals are at increased risk for many diseases and health conditions, including hypertension, dyslipidemia, Type 2 diabetes mellitus, coronary heart disease, stroke, gallbladder disease, osteoarthritis, sleep apnea etc.

5) Body Mass Index (BMI):

BMI is defined as the weight (in kilograms) divided by the square of the height in meters (kg/m2).

6) A significant weight gain or change of weight parameters over a period of time may be important in assessing the clinical implications of obese or overweight aircrew & its impact on their overall health.

7) Recommended for assessment of overweight commercial aircrew, which does not have any other associated clinical disability.

8) BMI 25-29.9: Blood Sugar F & PP (after 75 gm of oral glucose load) & Lipid Profile once in two years, in addition to the mandatory tests at specified age

9) BMI 30-34.9 or WHR > 0.9 for men & 0.85 for women: Blood Sugar F & PP (after 75 gm of oral glucose load), Lipid Profile once a year, in addition to the mandatory tests at specified age

10) BMI 35 & above Blood Sugar F & PP (after 75 gm of oral glucose load), Lipid profile, once in six months, in addition to the mandatory tests at specified age.

HYPERTENSION

Normal Blood Pressure:

1) A blood pressure recording of 140/ 90 mm of Hg will be accepted as the upper limit of normal.

Confirmation of Hypertension:

1) The confirmation of the diagnosis of hypertension may be done by 24h Ambulatory BP Monitoring.

2) The Pilot will be declared temporarily unfit for flying for 04 weeks and advised next review at IAM/AFCME only.

3) The following investigations will be done-

Routine haemogram, Urine routine exam including microscopic examination, ECG resting, X- Ray Chest/(Postero-Anterior View), Complete biochemical profile [Blood Sugar (Fasting and 2 hours after 75 g of oral Glucose), Urea, Uric acid Creatinine  and Cholesterol with lipid profile, USG Abdomen, Fundoscopy, Echocardiography.

Disposal Of Flight Crew:

1) If Ambulatory BP recordings are within normal limits, the flight crew will be  declared fit for unrestricted flying.

2) In case the flight crew is confirmed to have hypertension, will be placed under observation as temporary unfit for flying duties for 04 weeks.

       a) He/She will under go investigations and treatment under his own/company doctor.

       b) After 04 Wks of stabilisation of treatment he will now take appointment with AFCME/IAM/MEC East for review.

3)Flight Crew with well controlled BP without drugs will be given unrestricted P1 Status.

       a) All medicals there after to be conducted at AFCME/IAM/MEC (E)

4) Flight Crew with well controlled BP with  drugs will be given “Fit for all flying duties except instructional duties and trainer captain in flight” (P2 Status).

       a) All medicals there after to be conducted at AFCME/IAM/MEC (E)

       b) Fitness to P1 Status will be given by next medicals depending on control of BP.

5) Flight crew with uncontrolled hypertension or those who have target organ involvement will be recommended unfit for flying duties unless the situation reverses.

OPHTHALMOLOGY (Eye Sight)

1) The function of the eyes and their adnexa shall be normal. There shall be no active pathological condition, acute or chronic, nor any sequelae of surgery or trauma of the eyes or their adnexa likely to reduce proper visual function to an extent that would interfere with the safe exercise of the applicant’s licence and rating privileges.

2) The following ophthalmological conditions are disqualifying for initial issue medical examinations: History/evidence of recurrent keratitis/Keratoconus Macular degeneration/Hereditary degeneration which interferes with visual acuity and/or visual fields/Retinitis Pigmentosa/Retinal Detachment/Retinal vascular disorders with exudates or neovascularisation/Optic neuritis and optic atrophy/Central Serous Retinopathy/Glaucoma/Any intraocular surgery/Manifest squint.

3) Distant visual acuity with or without correction shall be 6/9 or better in each eye separately and binocular visual acuity shall be 6/6 or better. No limits apply to uncorrected visual acuity. Where this standard of visual acuity can be obtained only with correcting lenses, the applicant may be assessed as fit provided that: such correcting lenses are worn during the exercise of the privileges of the licence or rating applied. For correction the refractive error (the amount of correction) must not exceed +5.00 diopters of long sight or -6.00 diopters of short sight. This is in the most ametropic meridian (taking into account any astigmatism). Astigmatism must not exceed 2.00 diopters. The difference in correction between each eye (anisometropia) must not be more than 2.00 diopters.

4)Near Vision– On the standard near vision eye chart you must be able to read the N5 print between 30 and 50 cm and the N14 print at 100 cm, with or without correction.

5) Contact Lenses– Contact lenses must be monofocal, nontinted and for distant vision only.

6) Eye surgery- Modern Kerato-refractive Surgery. Prospective aircrew aspirants and trained flight crew having undergone modern kerato-refractive surgery (PRK, LASIK, LASEK, Epi-LASIK, Femto-second LASIK etc.) will be considered for medical fitness for flying on a case-to-case basis. Such cases will be examined only after a minimum period of six months after such a procedure. Medical fitness for initial issue of licence may be considered for such cases, if the visual requirements for the license category are met with stable corneal topography and refraction done at 6 months post procedure and no post-surgical complications like corneal opacity interfering with vision

7) Color Vision– Will be tested for normal color vision with Ishihara Test Plates. If found difficulty in reading Ishihara Test Plates will be subjected to lantern test to identify the aviation colors. On successful completion of lantern test will be cleared as Color defective safe.

8) Eye Function– Must have normal fields of vision. Must not suffer from double vision. Any degree of heterophoria (eye muscle imbalance) in excess of: 8Δ exo, 10Δ eso or 2Δ hyperphoria – measured at 6 m or 12Δ exo, 8Δ eso or 1Δ hyperphoria – measured at 33 cm will require further evaluation by an eye specialist. There must be no acute or chronic disease in either eye or surrounding structures.

Lattice Degeneration (LD) and retinal holes:

1) On detection of Lattice Degeneration or retinal holes, during initial or renewal medical, the civil aircrew are to be made temporary unfit and asked to report with opinion of vitreoretinal surgeon. If the reports brings out no high risk features requiring prophylactic treatment, the civil aircrew may be considered fit. If advised treatment and treated adequately by cryotherapy/laser photocoagulation, the civil aircrew may be considered fit four weeks after the procedure.

Cataract Surgery and Intra-Ocular Lens Implantation with Monofocal Intraocular Lenses:

1) Flight crew having undergone cataract surgery where such surgery is performed by phaco-emulsification, medical fitness with the limitation, ‘Fit to Fly as PIC with QEP’ may be considered after four weeks of surgery if there are no post-surgical complications, vision is stable and within acceptable limits. Such crew may be upgraded to PIC status 12 weeks after surgery, if there are no post-surgical complications, vision is stable and within acceptable limits, with contact lenses or spectacle.

2) Cataract Surgery by a Full Incision. Cases that have undergone full cataract incision will be kept in non-flying status for a period of six months.

3) Thereafter, ‘Fit to Fly as PIC with QEP’ will be given for three months depending on the clinical status. Nine months post-operatively, PIC status may be considered if there are no postsurgical complications, vision is stable and within acceptable limits, with contact lenses or spectacles.

HEARING ASSESSMENT.

1) Applicants for Class 1 Medical Assessments shall be tested by pure-tone audiometry at first issue of the Assessment, not less than once every five years up to the age of 40 years, and thereafter not less than once every two years.

2) The ability to hear conversational speech when tested with each ear at a distance of 2 meters from and with his back turned towards the medical examiner. Otorhino-laryngology. This test is done at every medical examination for both professional and private pilots.

3) The audiogram is a test where you signify that you have heard sounds at different frequencies.

Perfect hearing is measured as nil loss of hearing (0 decibel – 0 dB) at that particular frequency.

Decreased hearing is shown as a decibel loss (10, 20, 30, 40 decibels) at a particular frequency.

The required hearing levels and the maximum allowable losses are listed below:

_____________________

l  Frequency  l  Allowable loss l

----------------------------

l  500 Hz           l          35 dB            l

----------------------------

l  1000 Hz         l          35 dB            l

----------------------------

l  2000 Hz        l          35 dB            l

----------------------------

l  3000 Hz        l          50 dB            l

----------------------------

The Class 1 Medical Assessment : Hearing requirements

1) The applicant, when tested on a pure-tone audiometer, shall not have a hearing loss, in either ear separately, of more than 35 dB at any of the frequencies 500, 1000 or 2000 Hz, or more than 50 dB at 3000 Hz.

2) An applicant with a hearing loss greater than the above may be declared fit provided that the applicant has normal hearing performance against a background noise that reproduces or simulates the masking properties of flight deck noise upon speech and beacon signals.

 AVIATION AND CARDIOVASCULAR RISK

1) Aviation is involved with risk of event. Airframes have a predicted number of hours of “life” and engines have a “time before overhaul”. This proscription attempts to reduce the possibility of failure to a predetermined target level in the interest of safety.

2) The same applies to the heart of a pilot. At a young age the probability of a cardiovascular event is very remote. In the four decades from age 30–34 to 70–74 years, cardiovascular

mortality increases by a factor of 100.

3) Electrocardiogram – (ECG)– measures the electrical impulses passing through your heart. It can show disorders of the heart rhythm or of the conduction of the impulses, and sometimes it can show a lack of blood supplying the heart muscle.

4) For Disposal of cases of Ischaemic heart diseases refer AIC circular AIC12-2017.

RESPIRATORY SYSTEM

Pulmonary tuberculosis:

1)  Active pulmonary tuberculosis shall be assessed as unfit.

2) Quiescent or healed lesions which are known to be tuberculous, or are presumably tuberculous in origin, may be assessed as fit.

Chronic obstructive pulmonary disease (COPD):

1)  Chronic obstructive pulmonary disease (COPD) is a heterogeneous condition, combining features of emphysema and chronic bronchitis. Emphysema is characterized by destruction of the parenchyma of the lungs. Chronic bronchitis is characterized by inflammation of the airways.

2) Chronic obstructive pulmonary disease shall be assessed as unfit unless the applicant’s condition has been investigated and evaluated in accordance with best medical practice and is assessed not likely to interfere with the safe exercise of the applicant’s licence or rating privileges.

Bronchial Asthma:

1) Bronchial asthma is caused by airway inflammation and characterized by recurring acute attacks of wheezing, coughing and shortness of breath. Between attacks the patient is frequently asymptomatic and often has normal pulmonary function.

2) Asthma causing significant symptoms or likely to cause incapacitating symptoms during normal or emergency operations shall be assessed as unfit.

Pneumothorax:

1) The primary form of spontaneous pneumothorax is most common in young, healthy males between 20 and 30 years of age and occurs not infrequently in the pilot population.

2) In the case of an initial applicant, a history of spontaneous pneumothorax need not be disqualifying provided that the applicant has had only one attack with complete clinical recovery, and that the medical investigation has revealed no evidence of predisposing disease such as bullous emphysema.

Post-operative effects of thoracic surgery:

1) In general, such cases should not be assessed as fit until four to six months have elapsed following major surgical procedures. The aeromedical decision should be made by the medical assessor and based on a thorough investigation and evaluation in accordance with best medical practice.

DIGESTIVE SYSTEM

GASTRITIS:

1) An important aetiological factor, often encountered in applicants with a history of gastritis, is the use or abuse of alcohol as well as habitual use or misuse of “over-the-counter” pain-relieving drugs such as asprin.

PEPTIC ULCER:

2)  Pilots with uncomplicated peptic ulcer should be considered as unfit for all aviation duties during any period of clinical activity sufficient to warrant treatment beyond simple dietary control.

3) The general criteria for medical fitness are that an applicant with a history of uncomplicated peptic ulcer be symptom-free on a suitable diet and that there is endoscopic evidence of the ulcer healing.

4) Irregular work schedules and eating habits of flight crews on duty need to be considered as a complicating factor.

GASTRO-OESOPHAGEAL REFLUX DISEASE:

1) Gastro-oesophageal reflux disease (GERD) is a common disease in which the acid content of the stomach is regurgitated up into the oesophagus.

2) The primary symptoms of uncomplicated GERD are heartburn, regurgitation and nausea. The condition is chronic; once it begins, it is usually lifelong.

3) Medical certification may be considered in cases where the frequency and intensity of episodes are low, where complications such as oesophagitis, oesophageal ulcer, strictures, bleeding, and Barrett’s oesophagus1 are absent, and where the medication prescribed has no significant side effects.

PANCREATITIS:

1) This condition, unless very mild, is disqualifying for aviation duties.

ULCERATIVE COLITIS AND CROHN’S DISEASE:

1) The primary symptoms of ulcerative colitis are abdominal pain, bloody diarrhoea and weight loss. The course of the disease is characterised by frequent exacerbations and many, often severe, complications including anaemia, and a high frequency of colonic

carcinoma. Medical treatment is often unsatisfactory, and many patients will require surgery (colectomy).

2) Crohn’s disease is usually more severe with a poor quality of life for most patients regardless of treatment.

3) For both conditions, an assessment as unfit is the rule.

URINARY SYSTEM

RENAL CALCULUS DISEASE:

1) Urinary calculi can arise from anywhere along the urinary tract, with clinical manifestations varying with size, configuration, nature and location of calculi. Small stones (< 5 mm) with smooth contours can be expected to pass spontaneously, albeit with potentially incapacitating symptoms such as severe pain, nausea, profuse sweating (diaphoresis), or shock, all of which are clearly incompatible with safe flying.

2) Larger stones typically require surgical intervention. 

3)All treatment including conservative management aimed at encouraging the natural passage of the stone, surgery, and extracorporeal shock wave lithotripsy will necessitate grounding until recovery.

MUSCULOSKELETAL SYSTEM

BACK PROBLEMS:

1) Back problems are commonly occurring and present a special case. Instability and muscular weakness are strong indications for shoulder harness support.

2) Any stiffness of hips will also increase back strain with prolonged sitting and pedal usage. Neck motion and stability must be present.

Cervical spine:

1) A neck motion of 45° (side to side) will in most cases provide enough lateral vision for flight safety; it is unlikely that a pilot with less motion ability will move shoulders and torso in flight sufficiently to compensate for lack of neck motion.

Lumbar spine:

1) Lower back pain is a common complaint among flight crew members. It may be accompanied by pain radiating to the legs in the distribution of the sciatic nerve.

2)  Medical fitness for aviation duties should be based on the degree of functional recovery and risk of recurrence that might cause sudden incapacity.

Syncope:

1) Syncope is defined as loss of consciousness and postural tone due to global cerebral hypoperfusion, followed by spontaneous recovery. In near-syncope or pre-syncope, consciousness is compromised but preserved.

2) Syncope is mostly benign and often situational. Medical certification is appropriate when the benign nature of the event has been identified and potentially serious mechanisms of syncope have been considered and excluded.

3) A three-month period might be appropriate when one or two fully explained benign events have occurred over time, whereas multiple recurrent episodes requiring treatment may warrant a six- to twelve-month period of observation before medical certification is considered.

4) Restriction to multi-crew operations.

MALIGNANT DISEASE

Every applicant who has been treated for malignant disease will need an individual assessment before exercising licence privileges.

PRIMARY TREATMENT FOR MALIGNANT DISEASE:

Surgery:

1)  Surgery is the commonest primary treatment for malignant disease and is frequently the only treatment. A return to flying, from the purely surgical aspect, depends on the extent of the surgical operation, and this can be conveniently broken down into minor,

intermediate and major surgery.

2) The medical assessor may consider earlier recertification if recovery is complete, the applicant is asymptomatic, and there is a minimal risk of complications.

Radiotherapy

1) Radiotherapy treatment for malignant disease is usually given as an intensive course. Most courses are intensive, there is little time to fly the many patients undergoing radiotherapy suffer non-specific systemic effects (tiredness, malaise and nausea) which make it

inadvisable for any pilot to fly whilst receiving such treatment.

Minimum periods of unfitness after surgery:

1)Minor Surgery One week Unfitness

2) Intermediate Surgery Four weeks Unfitness

3)Major Surgery Twelve weeks Unfitness

Chemotherapy :

1) Pilots should be assessed as unfit during any period of treatment with cytotoxic chemical agents.

2)After treatment of malignancy, however, the prognosis improves with recurrence-free time after the original episode. Thus to consider the full range of certification possibilities, from “certificate refused” to “unrestricted Class 1”, and including Class 2 certification for private flying, acceptable incapacitation risk levels have to be defined.

For further information read (ICAO Manual DOC8984 )

https://www.icao.int/publications/pages/publication.aspx?docnum=8984