A Mk-76 Tale

Let me introduce you to the Mark 76 Practice Bomb. More commonly referred to as the Mk-76, the bomb is the mainstay of Navy flight training.
First thing to know is that the Mk-76 is not really a bomb, although it could kill you and it will put significant holes in things it is hurled at, generally at around 500 knots or so, from a fast flying Navy jet. The Mk-76 is blue, as is all inert practice ordinance. The movie buffs among you will instantly recall Tom Cruise in the movie Top Gun (I know, TOPGUN, all one word, all caps) preflighting his completely worthless in combat blue Sidewinders before going face to face with the dreaded enemy Migs.

The Mk-76 is only about 2 feet long, weighs 25 pounds, has a fat little front body and a set of fins welded to that body. The center of the bomb body and fins is hollow, there is a charge in the nose that goes off when the bomb impacts and the point of impact is marked by the white smoke from the charge. At night there is a visible flash.  The AF version of the Mk-76 is the BDU-33, it’s zackly the same bomb.

Naval aviators can spend a considerable amount of time on the practice range dropping Mk-76’s, they don’t cost a lot of taxpayer dollars and don’t blow the target to smithereens like a 500 pounder might.
I have a tale (that’s not a typo) attached to the Mk-76, and a lesson that I learned. The lesson is going to come first in this story: don’t aggravate the troops, and in particular do not cross Navy Chiefs. Ever. Things happen.
My first squadron was the A-6 RAG, and my tour there as a very junior officer (I was Mr. Vice at the annual Dining In 2 times, or was it 3?) brought me in contact with the best officers in the fleet–and occasionally some who might have thought they were the best.

My initial encounter with Lcdr. Ring Knocker (like Dragnet, the names have been changed to protect the innocent, if any) occurred whilst I was still a lowly RAG staff Enswine and not yet in the driver seat of the Intruder. No slight intended here for Lex or other graduates of the Highest of the Military Institutes of Learning On an East Coast River, but Knocker was the epitome of perceived status given by virtue of a certain diploma and ring followed by reasonable performance in the aviation world followed by promotion followed by…a bit of Headous Largeous, a curious affliction that may infect some, although the victim of such a disease rarely detects the symptoms in himself. HL can sometimes be diagnosed in fighter pilots, where confidence in their chosen arena is of the utmost importance–we must remember that second place is dead–and uncommon in the ranks of the attack community.

The HL symptoms were revealed when Knocker and I were working on some project or other and I asked a question of him, he supplied the answer, and I mentioned that gee, I didn’t know that.

The response was That’s why you’re an ensign and I’M a LCDR! Followed by Hohohohahaha.

I must admit that this small blustery event had no effect on me, when you are at the bottom of the command heap it seems that you do know very little, although it may show a lack of couth for others superior to point out such a deficiency. Whatever. Lcdr. Knocker moved on to a fleet squadron a few months later and I forgot about him.

Fast forward a couple of years and now I have advanced a bit, I’ve finished the RAG, am no longer an Enswine and have risen to the heady height of Lieutenant Junior Grade, thank you, and have arrived in my first squadron. I’m a nugget, a full fledged nugget.

Knocker is in my new squadron. We, the squadron, are at Navy Fallon on a weapons det, meaning we are there to refine our tactics and bombing before going to sea and maybe having to drop bombs on targets that shoot back.

And I’m going to the target today with a load of 12 Mk-76’s to practice system boresight bombing in the latest and greatest iteration of the Intruder, the A-6E. I’ll be flying on the wing of my lead for this event, Knocker. He is one of several Lcdr’s in the squadron, and from the muted comments at the back of the ready room from time to time I have already formed an opinion that perhaps, just perhaps, Knocker has ruffled a few junior officer feathers with his personality and is still afflicted with the HL syndrome. What I did not know was that Knocker had somehow, some way, also irked one or two maintenance chiefs. Irked them big time.

OK, the stage is set, a little bit about how to use the boresight system bombing in the Ugly. The pilot sets up a 40 degree dive at the target, 500 knots or so, put the luminous piper in the gunsight on the target, depresses and holds the commit button on the stick, and then commences a 4G pull up. The computer figures out the wind, bomb ballistics, distance to target, aircraft speed, dive angle, applies the current rate of interest on a 10 year CD (just kidding), blah, blah, blah, then lets go of the bomb at the precise point needed to put the bomb on the target. Beats the heck out of the old way–figure out a mil setting, dial it in on the manual gunsight, and try to put the fixed pipper on target, compensating for whatever wind you think is swirling about. At exactly the right dive angle, altitude, and airspeed, with the pipper on the target, the pilot hits the pickle button, pauses, and then commences the pull up. A well tuned boresight system was just plain wunnerful, it made things so much simpler.
Knocker conducted a thorough brief, and as we left the ready room to don our flight togs, I committed to the standard bet with Knocker, a buck a bomb. Best hit of each run. Could be a total of $12 on the line, but usually only about 4 or 5 bucks ended up changing pockets in the end.

Then down the stairs to maintenance spaces to review the aircraft logs and system performance of our assigned jets. I noted with some pleasure that the bombing stats from the previous flight were good, my jet was a sweet bomber. Knocker, on the other hand, was standing next to me and looking at the stats for his plane, which were not quite so good. He looked over at the logs for my jet, and said Tell you what, yours is the better bomber, so we are going to switch planes. He swapped the logs and proceeded to study the maintenance record of what was now his sweet bomber. I stood silent, not really able to come up with a suitable remark. My trusty BN and I traded glances and a shrug of the shoulders, then checked the paperwork on what was now our jet.

Knocker finished his review and looked at the two of us. He grinned. RHIP, he said. HL had him in its clutches. His BN said nothing.

The four of us headed out to the flight line, our jets were parked side by side, waiting in the morning sun. The jets were new, they really looked good.
I finished my preflight walk around quickly and settled into the cockpit, my BN was already strapped in and checking out his system set up.

This is when the Maintenance Chief climbed up the ladder and stood on the top steps at eye level with me. He said Mr. B, do you have any bets on the bombing for this hop? Yes I do, Chief, a buck a bomb.

Well, says he, you’re going to win. Chief, I replied, I’m going to give it my best, thanks for the vote of confidence.

No, no, says the Chief. You are GOING TO WIN, says he. Look over there, he says, and leans back a little so I can see Knocker’s jet next to us. Knocker had just finished preflighting the starboard wing and moved around the jet to finish up on the port side. After he was out of sight, another Chief, who had been standing quietly under the starboard wing, moved over underneath the weapons rack where 6 Mk-76’s were hanging.

He looked over at us, and then reached up and grabbed the tail fins of the closest bomb. And twisted. Hard. Put his whole body weight into it. Bent the fins. The bomb was not going to follow a predictable path on its way to the earth. No way.

Then did the same on the other 5 bombs. The tail fins were going in multiple directions. He looked at the Chief next to me and smiled. The Maintenance Chief says to me, The other 6 on the port side will be adjusted as well. Have a nice flight, he says, and steps down to the ground, folds the boarding ladder into place, latches it, and gives me a thumbs up.

Whatever Knocker had done to get on the non sunshine side of the folks who run the show is still a mystery to me. Must have been that HL thing.
Off we went to the target, it’s a really clear sunny day in the Nevada desert, our pair of Intruders was cleared hot on the target and we went at it.
When lead’s first bomb hit 1200′ at 7 o’clock you know there was an eruption of sorts in Knocker’s cockpit. My BN and I erupted as well, a fit of laughter and giggles as we followed in our dive and scored a 50′ hit.

It got worse, or better, depending on which cockpit you were in. Lead’s second hit was somewhere in Nevada, and his remaining bombs followed suit, run after run, until all 12 blue bombs were gone. Gone all over the place, in no particular predictable order at all. One or two actually got close to the center ring, but that was purely by accident of dispersal. The safest place in Nevada when Lead was dropping his bombs was the Bull’s Eye.

I had a good day, my BN tuned up the system well on the way to the target, and we had a respectable 2 digit average, pretty good for a nugget.

We cleaned Knocker’s clock, would have given him a run for his money even if he’d been armed with the straightest bombs ever built. But he wasn’t.
Join up and RTB were uneventful, all the way back my BN and I were thinking of the free beers we were going to consume that evening.

After landing and shut down, Knocker was out of his cockpit and on the way to the maintenance spaces at a brisk pace, he was there for several minutes before I walked in the door. When I walked in, Knocker was in the midst of angrily describing how poorly the boresight system had worked for him. The first one hit 1200′ short, says he, and the next one was 1000′ short, so I fudged the system a bit on the next run and put the pipper long about the same amount. That one hit about 900′ at 3 o’clock. So I tried putting the pipper at 9 o’clock and that one….

The chiefs and system tech guys listened earnestly and asked what the pilot and BN thought might be the problem, the two of them had an idea or two, something about system velocities and ballistic calculations being out of whack, even though the readouts in flight looked good. Knocker said he wanted an extensive check conducted on the black boxes.  He wrote all this out, cataloging the erratic hits, and then he and his BN clomped up the stairs to the ready room. My BN and I were still standing at the maintenance desk submitting our flight data when the door at the top of the stairs closed.

And the poker-faced maintenance crew burst into muffled laughter. They tried hard not to be too loud. Backs were slapped, stomachs were held while doubled over with glee, and some laughed so hard there were tears in their eyes. My BN and I stood there just smiling, not joining in wholeheartedly because we had no idea what the original sin was at the root of all this. But we were getting an education.

HL is a dreadful thing, never let it get out of hand and aggravate the troops. Particularly Chiefs. Things happen.

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