Have you ever made major mistakes and owned up to them.

I had the opportunity to relieve a subordinate team leader several years ago. He had provided plenty of cause, but I declined instead taking the soft approach with the hope that my charm as a leader would reform somebody who was clearly a marginal performer and not a leader in any way into something more useful. Subsequently, his team was involved in a mishap with a civilian watercraft which resulted in personal injury. An outside independent investigation assigned 90 plus percent of the blame to the operator of the civilian watercraft, but the question was asked "why was this team where it was; doing what it was doing; instead of being on station doing their job?"

My boss set the example by accepting responsibility when our parent command demanded an answer so when the internal conversation started the table was set to for me to say "This guy works for me, and I knew he was a substandard leader prone to cutting corners. It's on me." I had to claim it. It was my failure and I had to own it. It didn't mean the fallout was easy to endure (or particularly helpful for my career), but it was a necessary personal growth opportunity. It has made subsequent failures (all much, much smaller and less serious in scope thank God) easier to claim.

Acknowledging our faults is far more important they calling attention to our successes.

I've made mistakes that could have gotten people in trouble had I not owned up to them, not major mistakes or major trouble but I have forgotten to call a soldier on comp time for CQ to tell him about the next days formation, etc...and I've always owned up to it. 

As for whether it raises or lowers my standing in my subordinates eyes, I'd hope they'd see it for what it is, a Man who is not impervious to mistakes but will take responsibility for his shortcomings.  I'd hope it sets an example for them to follow.

I have made many mistakes during my career, any good leader will be the 1st to admit they have or they are not a true leader, because the only way you learn to grow and progress in your career via knowledge and experience is by learning from your mistakes, it is what makes you a better leader and allows you to teach and mentor your subordinates as well.

I have always been one to very quickly own up to errors on my part as not only a way for me to learn and better myself, but always to show my Soldiers that they can trust me to be honest and straight with them on everything by leading from the front, part of that is accepting responsibility for not only your actions but for things that could or should fall under your realm as a leader. I have many times taken the hits for my Soldiers shortcoming on certain taskings, because if my instructions had possibly been clearer or better enforced, the mistake that may have occurred wouldn't have. I have shown many of my junior NCOs over the years that if you can accept responsibility it not only makes you a better leader to your Soldiers, but also makes you look very good and reliable to your superiors as they have a much stronger trust in you to be honest and integrity driven in doing your job and will do your best to accomplish any mission to what is required and to the best of your abilities.

If you can't accept and own up to your mistakes, then you will be a piss poor leader in the end because no one from subordinate to peer to superior will trust you or have any faith in you at all, it is not always about the politics as many think it can be.