This is probably my favorite thing about being a vegan on the go - airplane food. Not the food itself, but the look on my seat mate's face when he unwraps his colorless breakfast sandwich and gazes longingly at my specially prepared fruit plate :)
Be sure to request a special meal up to 72 hours in advance of your flight. Some airlines might be able to submit a late request, but once you are less than 24 hours from your departure time, there is simply not enough time to notify the crew and to get your special meal on board.
Also, please be understanding if they do not have a special meal for you when you haven't requested it. There are times when, as vegans, we have to be flexible and I have found that it is much easier for everyone involved if you take any mishaps with a positive attitude. I am working on a post now about packing your own vegan snack bag ;)
Here is a summary of Airline Meal Descriptive terms thanks to HappyCow*:
Vegetarian Meal (VGML) - Also known as Vegan, this meal is totally free of any animal products or by-products such as eggs or dairy products. It contains one or more of these ingredients: all types of vegetables and fresh fruit. It does NOT contain any type of meat, fish, or animal products or by-products.
Vegetarian Lacto-Ovo Meal (VLML) - This is a Vegetarian Meal that may also contain eggs and dairy products. It contains one or more of these ingredients: vegetables, fresh fruit, eggs, dairy products, and pulses. It does NOT contain any type of fish or meat.
Vegetarian Oriental Meal (VOML) - This is a Vegetarian Meal (VGML) [presumably therefore vegan] that is also prepared Chinese or Oriental-style.
Asian Vegetarian Meal (AVML) - This meal is available for vegetarian passengers. It is usually aromatic and spicy, and incorporates flavors from the Indian sub-continent. It contains one or more of these ingredients: all types of vegetables, fresh fruit and milk products. It does NOT contain any type of meat, fish or eggs.
Vegetarian Jain Meal (VJML) - This meal is for members of the Jain community who are pure vegetarians. It is prepared with a selection of Indian condiments. It contains one or more of these ingredients: fresh fruit and stem vegetables that grow above the ground. It does NOT contain: animal products and by-products, and any root vegetables such as onions, mushrooms, ginger, garlic, potatoes, carrots, beets, radishes, etc.
Raw Vegetable Meal (RVML) - This meal consists exclusively of raw vegetables and salads.
Fruit Platter (FPML) - This meal may be ordered for dietary reasons. It may also be ordered by members of certain communities who eat only fruit while fasting. It contains one or more of these ingredients: seasonal fresh fruit.
Hindu Meal (HNML) - This meal is available for members of the Hindu community who are not strictly vegetarian and eat meat, fish, eggs, and dairy products. It may contain one or more of these ingredients: lamb, chicken, fish, eggs, milk, and dairy products. It does NOT contain beef.
*(these terms may be used differently by various airlines so please confirm for yourself when reserving a meal)