-Age
Age is a firm requirement. You either meet the minimum age requirement or you do not. Airlines won't waiver on this. The minimum allowable age for some U.S. airlines is 18, but most require you to be at least 20.
The age requirement is usually based on the age you will be upon graduation from training. So, if you are not at the minimum age at the time of your initial application, but will reach that age during training, you can still apply for the job.
With increased hiring now underway, airlines are constantly lowering their minimum age requirements in order to broaden their audience of prospective applicants. AirlineCareer.com updates these minimum qualification requirements on a regular basis (members only).
If you do not meet the minimum age requirement for a particular airline, you can still apply for another position within the airline as a reservationist or customer service agent, which usually have lower minimum age requirements. As an employee of the airline, you would greatly improve your chances of getting hired in the future since most airlines prefer to hire from within rather than take chances on unproven newcomers.
You could also spend this time improving your chances of becoming a flight attendant by taking enrichment courses (such as learning a second language) or getting experience in customer service outside of the airline industry. Customer service experience can be as complex as working as a Dell Technical Support Representative or as simple as working the drive-thru window at Taco Bell. It all counts.
Due to discrimination issues, there are no maximum age requirements. In fact, in every flight attendant class, there is always a small percentage of "older" new-hires. Because there is no age limit, many people are pursuing second careers as flight attendants - and are gladly accepted because of their experience and level of maturity. Do not ever think you are too old to apply for a flight attendant position. A recent class of 100 new hires at a major airline had 7 people between the ages of 40 and 49, 5 people between the ages of 50 and 59, and 1 person over 60!
-Height
Most flight attendants are between 5'2" and 5'9" tall. Outside of this normal range, certain airlines have minimum and maximum height requirements.
A very short person may have difficulty reaching the overhead compartments in an airplane, which are typically between 6' and 6'10" inches high. Some airlines have no minimum height requirement, but do require you to pass a reach test. The reach test is nothing more than a demonstration of your ability to reach all the necessary components inside an airplane's cabin.
You can perform a reach test on your own. Simply grab a tape measure, measure out a distance of 6'10" from the floor, and mark it on the wall. If you can reach the mark in bare feet, chances are you will pass any airline's reach test.
If you find you do not meet the minimum height requirement for any of the major airlines, do not let this discourage you. You can always apply to be a flight attendant for a commuter airline; commuter aircraft are much smaller, making height less critical.
Conversely, if you are a little on the tall side, most major airlines' maximum height requirement is right around 6’2". If you are taller than 6'2", keep in mind that you will be working in small galleys and may find it difficult to work 8-hour days in such a cramped environment.
Weight and Health
Airlines used to have stringent height-to-weight guidelines; however, due to a number of recent discrimination lawsuits, most airlines are simply looking for your height and weight to be proportional.
Today, it is more important to be in good shape than to look like a super model. Airlines need people with the necessary strength to open emergency doors, the agility to attend to passengers in sometimes cramped working conditions, and the stamina to survive 16-hour days. An overweight or out-of-shape person may not have the necessary strength, agility or stamina to perform. We recommend getting yourself into good physical shape before initial training.
The airlines also want healthy people. You will be in contact with thousands of passengers each week, both in the airport and in small airplane cabins (most with recycled air). You will need a strong immune system to ward off illness and a healthy body to bounce back from sometimes grueling 4-day trips. A history of personal illness, drug or alcohol abuse, or a bad family medical history could dissuade certain airlines from hiring you.
All airlines are required by law to administer comprehensive physicals to new-hires. Before applying, make sure you are in good health and drug-free. If you do not pass the physical, you will probably be dismissed by the airline.
If you have a known, uncorrected problem with your eyesight, see a doctor before the airline's medical exam. During the exam, you will undergo an eye test in which you must demonstrate 20/20 vision, either naturally or with corrective lenses.
Education
Virtually every airline requires that you have a high school degree or Government Equivalency Degree (G.E.D.) If you did not finish high school or have not passed the G.E.D., do not bother to apply for a job as a flight attendant. You absolutely won't get hired without a high school degree (or equivalent).
When you review each airline’s minimum hiring qualifications, you should realize that these are merely minimums. More is always better, especially when it comes to education. Just because you have a high school degree, do not expect to walk into an airline employment office, show your diploma and get hired. Many airlines look favorably upon applicants who have tried to better themselves by pursuing higher education. A recent study shows that over one-half of all flight attendants hired have at least one year of college under their belt, and over one-third have an Associate’s or Bachelor’s degree. A few even have Master’s degrees or Doctorate’s; these types of advanced degrees are certainly not required for the job, but will be helpful if you plan on pursuing a management or supervisory position someday.
Additionally, if you are lacking customer service experience, many airlines will overlook this "weakness" if you have a college education behind you. Hiring departments believe that college experience makes applicants more mature and better able to handle the many challenges and responsibilities that come with being a flight attendant.
Customer Service Experience
Customer service experience is typically not a firm requirement; meaning, you can usually apply without it. However, a lack of customer service experience makes getting hired that much more difficult. Customer service experience will give you a clear competitive advantage in your quest to become a flight attendant. Remember that you will be working in front of the public on a regular basis. From greeting, serving and assisting passengers to making announcements, you will always be representing the company in a customer service role. Because it is very important to project a positive image, airlines are very careful about selecting candidates who have experience working with the public.
Most people do not even realize that they have a customer service background. If you have ever worked in an environment in which you had to deal with the public on a regular basis, you have customer service experience. This can include working in a retail clothing store, waiting tables in a restaurant, answering telephones in a corporate environment, etc.
However, if you do not have any customer service experience, you should not despair. You may have a more difficult time than others who do, but it won't preclude you from landing the job, especially if you excel in other qualification areas. For example, the airlines will usually substitute a college education (even without a degree) for a lack of customer service experience.
taken from : AirlineCareer.com
