Pitch Lock……

I’ve waited a while to write about this as I wanted to put some space between the event and the commentary. A lot of readers are probably already familiar with the basics, namely the tragic loss of LT Steve Zilberman, USN of Columbus, Ohio, in an aircraft mishap in the North Arabian sea. The aircraft was returning from an Airborne Command and Control mission over Afghanistan when it developed problems, and the crew had to bail out.

The details of what caused the mishap are still under investigation – but it appears as if LT Zilberman found himself in the position of flying the aircraft in order to keep it in a stable configuration while his crew bailed out. What I think has not been accurately told-except within the service community is how truly frightening it had to be for him and the rest of his crew and how much of a debt of gratitude the rest of us owe this young man for his courageous actions on that horrible day.

I want you to remember this statement as I work through this post; its meaning will become apparent in a couple of paragraphs:

The new propeller is quieter, with less vibration on the airframe and equipment. It provides a little more SHP. It is virtually impossible to pitchlock, since the 8 blades can feather with loss of hydraulic oil pressure. One of the interesting performance attributes of the new prop is the reduced noise inside the airplane. The pilots and crew are able to hear noises they have never heard before. But the problem is, they don’t know if these noises have always been there and they were unable to hear them because of the noise of the old props, or if the new noises are related to the new props

There is that word again: pitch lock. What does it mean? Let me explain. In a turboprop aircraft, the jet engine it has turns at a constant RPM or 100%. When you add power by moving the throttles forward, the engine is not turning any faster. What is happening is that the propellers are changing their pitch to take a larger “bite” of air and thus “pull” the aircraft through the air faster. The changing of the pitch of the propeller is accomplished normally through a hydraulic system in aircraft like the E-2, where the propellers are big, and the engine nacelle is too.

The E-2 used to have a four-bladed prop. It was similar to the C-130 in some ways and has a variant of the P-3 engine attached to it. The decision was made to go to an eight-blade propeller in order to reduce vibration and noise, as was stated above. It was also supposed to be easier to maintain since now-individual blades could be changed right on the flight deck-whereas under the “old” system I grew up with,a prop change was a major evolution that require the aircraft to be moved to the hangar bay, the new prop “built-up” and balanced, and then the aircraft had to do a low and high power turn on the flight deck and a Functional Check Flight. If you have ever served on an aircraft carrier-you will know that stringing together that series of events is never easy.

If the hydraulic fluid that moves the propeller to its desired pitch is lost or is in the process of being pumped overboard ( e.g., as in a leak), there is a set of teeth that will engage with each other to lock the aircraft propeller into whatever pitch it failed at. It has to be that way because otherwise, the propeller would randomly pitch as it moved through the slipstream.  That is bad. C-2s and E-2s have a pitch lock system built into the propellers to “help” the pilot if a propeller loses hydraulic fluid. Unlike the T-34, which has a spring assembly that will drive the prop to feather in the event of a failure, the C-2 and E-2 need hydraulic pressure inside the prop to drive the prop to feather. The pitch lock system is supposed to prevent the prop from going to flat pitch in the event that all the prop fluid is lost.

At least that is how it is supposed to work-however if this happens at a low power setting, the prop is going to be at an angle just shy of being perpendicular to the slipstream. E-2 pilots refer to it as flying with a barn door attached to the aircraft. During my time in the community-probably after a fire ( which was a big deal when I was coming into my command tour, as the community had had several), this was the most feared emergency there was. Because the pilot always faced a dilemma, when and if he could shut the engine down and could he get back aboard if he did? Not to mention that if the aircraft pitchlocks at a low blade angle, the ability to control the aircraft becomes sporting – to say the least.

So now, lets return to the situation that the VAW-121 aircraft found itself in that day:

So after one engine lost oil pressure and then failed completely; after one propeller couldn’t be adjusted to balance the plane; after it was clear that there was no way to safely land, Zilberman ordered his crew to bail out.

He manually kept the Hawkeye stable as it plummeted toward the water, which allowed the three other men to escape.

Time ran out before he could follow.

Zilberman, 31, was declared dead three days later.

On Thursday, more than 250 sailors, officers, aviators, and friends gathered to pay tribute to Zilberman at the Norfolk Naval Station chapel.

His widow, Katrina, was presented the Distinguished Flying Cross that her husband was awarded posthumously.

My stomach hurts just thinking about it. What I hope to make you understand is just how gut-wrenching this whole sequence of events had to be and the real courage and presence of mind it took to do this.

When you bail out of an E-2, there is no ejection seat. You strap into the seat, release from it with the parachute attached to your back via a torso harness, and then you have to shuffle about 20 feet to the main cabin door and roll out of the hatch.

The pilots? They have a few things to do to get ready for that. Level the wings ( if they can), call the ship,  broadcast their position——oh, and as an extra added bonus,  deal with the emergency that put them in extremis, to begin with.

I want you to think about it, the LT, as the Plane Commander- had to know he was in a bad situation. So did the rest of the crew.  For him to get out, he would have to set the auto-pilot and then hope that he could get the distance to the door before the aircraft most probably forced the auto-pilot to kick offline and then,  in all probability,  stall and depart controlled flight soon thereafter. In which case, the aircraft noses over, and getting to the door is the equivalent of climbing a flat wall with no handholds.

Assuming he had the altitude left to have time to do so.

And now remember this-he had to know all of these facts when he ordered the bailout.

But what about the ditching hatches,  you ask. ( There are three on the aircraft, two over the cockpit and one over the Air Control Officers seat). What about them? Besides the fact that it is doubtful, you can fit out them with a parachute on-there is this little matter of an eight-bladed mixer turning out there and the laws of inertia.  There is only one way out. Getting out of an E-2 that was sitting still on deck when we practiced bailouts was hard.  Out of balanced flight, with the pilots working to maintain control?

Terrifying.

Yet this young man did it-and three men are alive today because of him. There can be no question of his devotion to his duty and his courage. He’s a hero in every sense of the word-and the Navy and the United States have suffered a terrible loss.

Questions can and should be asked, however, about the system that put this crew in that gut-wrenching situation that day. I’ve got three, to be precise.

One: This is the third major prop-related mishap in the past two years. This is a known problem.  It begs the question of what is being done in terms of training, and more importantly, material solutions to fix what appears to be a big issue with a system that “wasn’t supposed to work this way.” Sorry, I kind of keep thinking of watching  a similar situation play out in the early 1990s with respect to fires on the aircraft.  Go back and ask someone who was in the community about how many aircraft were lost in a three-year period. And more importantly – why are not flag officers in the Naval Air Systems command screaming bloody murder about this?

Maybe they are-the skeptic in my mind kind of doubts it-I’ve seen this drama before.

Two: Why is the US Navy-after some 50 + years of being in the jet age and the advances that have taken place in propulsion systems, still operating aircraft with propellers on the carrier? Jet engines don’t pitch lock-more importantly; they would have provided some definite tactical advantages for the E-2 in the current operational environments it is operating in. Better dash to station, the ability to accelerate to more reasonable airspeeds for the coming innovation of air refueling to the E-2, and most importantly – it would eliminate a huge hazard to personnel operating on the flight deck.

When I got to my first fleet squadron, they were just two months away from an incident where a blue shirt got chopped to smithereens by a turning propeller when he turned the wrong way after removing a huffer hose. Kid was 20 years old. In the intervening 30 years, I can think of at least two other similar mishaps and five others where the propeller struck something metal on the flight deck, sending shrapnel through the skin of the aircraft.

Jet engines have their hazards too-I know this, but they also have their advantages.

Three: In conjunction with item two-why, after some forty years, has there not been a redesign of the crew placement in the aircraft to potentially allow the possible installation of ejection seats?  The dome is a problem. I know-but ask yourself this, not every AEW aircraft is using a rotodome anymore. Phased arrays are the wave of the future.  And perhaps the dome could be moved slightly and the weight compensated for to allow for an ejection seat.

This is a pipe dream, I know – because even as I write this, I can think of about five or six really insurmountable challenges from an engineering standpoint. At the same time – there have been marvelous advances in aircraft design, and there were during my time several unique attempts to convince the Navy to adopt a new airframe for the AEW mission. I was on the record as being in favor of that. I can also tell you that it was never considered a popular position-the P-3 community was not the only community that was fixated on one type of platform for its mission.

So let me state it again-I believe strongly that the E-2 could be redesigned into a twin-engine jet aircraft with the crew positions lined up like the Prowler or S-3 ( with canopies too!) and with the advances in avionics, could still have the radar work in a manner to perform its mission. It probably would have looked like a “stretch” S-3. I remain convinced it could have been done.

It would cost a little bit of money to be sure-and that was something the leadership of Naval Aviation could not abide. There were, after all, boatloads of Hornets to buy and JSF.

Most of us, most of the time, live in blissful ignorance of what a small, elite, heroic group of Americans are doing for us night and day. As we speak, all over the globe, American Sailors, submariners and aviators are doing something very dangerous. ‘People say, Well, it can’t be too dangerous because there are no wrecks.’

But the reason we don’t have more accidents is that these are superb professionals; the fact that they master the dangers does not mean that the dangers aren’t real. Right now, somewhere around the world, young men (and women) are landing … aircraft on … pitching decks … at night! You can’t pay people to do that: they do it out of love of country, of adventure, of the challenge. We all benefit from it, and the very fact that we don’t have to think about it tells you how superbly they’re doing their job — living on the edge of dangers so the rest of us need not think about, let alone experience, danger.”-George Will.