Seeing the amount of questions that we get every hour (which is not very much), I would like to request all the highly respected and reputed users to relax for sometime, after a question is asked! Your answers are truly very very good and helpful, but somewhere they are preventing the new users to submit good answers. We don't have many questions left for us to answer, when the experience and expertise of reputed users is there! Can you please leave the question unanswered for some time say about 24 hours, before posting some very good answer, if you feel that some question has not been answered properly, in order to promote new users' interest as well!I Hope you understand what I mean to say! I salute to the work you have done in making Aviation.SE a success that it is today!
Aside from maybe having less practice, new users aren't at a disadvantage in posting answers. Everyone has an equal opportunity to answer new questions. Posting good answers quickly is also part of earning reputation and should not be discouraged.
If you feel that you could also post a good answer with new information, you should feel free to post it, even if there are already other good answers. Multiple answers are encouraged and help to improve the quality overall. Although the first answers tend to have some advantage, there is no reason an answer adding good information that is posted later shouldn't be voted up as well.
I know I have had other users beat me to answering questions that I could have answered very well, but that is part of having a site where anyone is free to answer any time. The good news is that since this is a site with lower question traffic, your posts are more likely to get more attention even if you don't get them in right after the question has been posted.
In addition to the other two responses:
It would be unfair to the person asking the question.
When people post their questions, they want answers as soon as possible. If the community decides not answer a question for some time, it will make people (similar to your reason) stop asking questions as sometimes they need to wait a long time to get answers.
Many times it happened (and I have witnessed it) that a new user has written an excellent answer, with no other answers coming even close to it (example).
Several times it happened (and I have witnessed it) that an OP has accepted an answer and later on (even after a question is no longer active), and new answer is posted, and then OP unaccepts the previously accepted answer and accepts the new one. An example is this question. It had an accepted answer for over a year, and then a new one came and got accepted.
If you answer an old question, it will get in the active list again, and your answer will get a lot of attention. If you are presenting something which others have not, then you will be appreciated anyway. An example is this question. It was posted on August 4th, and got an answer (10 votes) just after an hour. After two months, it got another answer (24 votes).
With a global audience, there will always be this possibility that some people would be left out in answering questions.
You should never be hesitant, even if you find one or more answers to any question, to add an answer if you feel that the existing ones have missed even a tiny aspect.
But remember that all the rep here, and all the badges here are just here, on this site alone. Even if you have seen this, it is always a lesson and a reminder to focus on real life stuff.
Why should we not let users answer questions? All users are welcome to answer questions, even if they are brand new to the website. You can always answer a question, whether or not it has 2, 5 or even 10 answers. If you have something valuable to say, then by all means say it!
There are many "new" users that have large interests. If people would like to answer a question, then they will. There is nothing stopping you. Nothing prevents a well thought out answer, as long as it is clear, concise and to the point.