Helicopter dunker training

Helicopter dunker training at Pensicola NAS.
Our National Guard Medevac unit was activated in November of 2003 to provide helicopter medevac support for active Army installations on the eastern part of the United States. Since our unit flew Viet Nam era Huey helicopters which were considered obsolete in the active Army, they were not able to deploy overseas. This made our unit only available to do stateside deployments so that the over used Active duty medevac units could recover after long deployments. After completing the initial training that the active Army inflicts on the National Guard upon activation, our unit began flight training to assume the mission.

One of the places our unit was tasked to provide medevac support for was the Ranger training camp in Florida. This location involved flying over large areas of water along the Florida coast and our crews needed to be trained in underwater helicopter egress procedures in case we landed in the water. The Navy has been doing this since before World War II and they have established a training program to teach this subject very well. Only the aircrews that were assigned to work rotations in Florida were required to complete "Dunker" training at Pensacola Naval Air Station. This training lasted one day, but it was packed with many different skills needed to survive a water event.



I went with Leroy (another pilot) and Shannon (a flight medic). We drove in a van from Fort Benning GA, to Pensacola, Fl. The drive was pretty calm. The medic (Shannon) was really nervous because she thought her swimming skills were not that strong. Since we were aware of a couple of crew members who failed to complete Dunker training, they were not allowed pull duty at Florida Ranger Camp. Leroy was always calm. Regardless of how dangerous or tedious, his demeanor was always the same.

We arrived at a specialized swimming pool on Pensacola's main road, parked and headed inside. We had driven down in our civilian clothes so we had to change into our flight gear when we got there. You were expected to swim wearing flight suits, survival vests, boots and helmets. The Navy used their own training helmets for the pool because the salt water normally destroyed the electronic equipment in the helmet.

While getting dressed for the class, there was an Army staff sergeant there who was to become an instructor for the Army program. He kept telling our nervous medic that it was easy and there was nothing to be worried about. Telling her training was easy only created a feeling inadequacy when once she started to struggle. I wasn't too worried about the training because I used to be a really good swimmer when I was younger and I used to scuba dive back in the Marine Corps.

We had a brief class in a briefing room about what to expect in the training. There were several tests you had to pass during each phase of training or you were not allowed to continue. One of the things discussed in the briefing was how all helicopters have the heavier parts near the top. The engine, transmission and rotor blades are all on the top of the aircraft. Once the aircraft settles into the water, that weight causes the aircraft to flip upside down. Another thing that they stressed is how you should not unbuckle your seatbelt until after the aircraft is done filling with water. All that water rushing into the cockpit creates a current that can pull you out of your seat and deposit you somewhere in the back of the aircraft. If this happens, you can end up disoriented to the point where you might not be able to the exit.

The first task was just a swim test. You were required to swim a couple of lengths of the pool, followed by treading water for several minutes. The pool was filled with salt water which denser than fresh water and makes you more buoyant. Although I was confident in my swimming skills, it is much more difficult than I expected wearing a flight suit, boots and helmet. Treading water was more difficult than I expected as the added drag of the uniform tires you out quickly and I often struggled to keep my head afloat.

The next hurdle to overcome was learning how to use the Helicopter Emergency Egress Device (HEEDs) bottle. This was a very tiny air tank that was strapped to your survival vest that only gives you a few breaths of air to escape the sinking helicopter. Although it sounds pretty simple to use, the stress of waiting for the helicopter flip upside down and fill up with water before unbuckling your seatbelt can cause you to panic and you only get two breaths. The key is to learn to calm down to get more air out of the bottle. The Navy cadre had this chair made from PVC pipe with Styrofoam floats on the sides to keep it buoyant. Under the surface of the water (about 4 feet deep) was a PVC cage like setup that was about as large as a refrigerator box. On the far end of the box was a gate that you had to open to escape. This whole set up was about 10 to 15 yards from the edge of the pool. The routine was to hold the HEEDs mouth piece between your teeth, keep one hand on the seat belt and the other on the chair. The cadre would flip the chair completely upside down. After you stopped moving you were allowed to release your seat belt, swim underwater to the end of the box, unlatch the gate and then swim underwater 15 yards to touch the edge of the pool without surfacing. It looked pretty easy watching from the water's edge. Putting this into practice turned out to be more difficult! Being flipped upside down without being able to hold my nose caught me off guard! The salt water rushed up into my sinuses and I had to fight the urge to surface to clear the water from my nose. The discomfort in my sinuses was a distraction that made it difficult to reach the other side of the box. On the second attempt I managed to clear the door, but I ran out of air swimming underwater to the edge of the pool and I had to surface just short! I had to repeat the whole thing again! The instructor said that a trick to use to go just a little further was to exhale just a little bit of air from your lungs but hold off inhaling ... it will fool your body to push on for just a little further. Sure enough, it worked the second time around. The instructor explained the dangers of shallow water blackout. This is when you hold your breath to the point where your body passes out just a foot or two from the surface due to oxygen starvation. For safety purposes the cadre had a person stationed close to the pools edge in case someone needed assistance.

Our medic, Shannon was struggling with the HEEDs training. Many of her first attempts would end with her surfacing in a fit of coughing. As all the other people attending the course finished this phase of training, they were allowed to leave for lunch. Shannon asked the instructors if she could keep trying. They told her that as long as she doesn't quit, they would keep letting her try. It took her 12 attempts, but in the end she was able to get through the whole thing. I have to admit, I was extremely impressed with her drive. She demonstrated willpower to overcome this difficulty that many others would have given up.

We were instructed to eat light a light lunch as we were going to be swimming in the deep end for the second half of the course. When we returned, the next challenge was just to tread water or float in the deep end for 2 minutes. The cadre started off with a demonstration consisting of throwing an empty flight suit, boots, helmet and survival vest into the water. Every piece floated to the surface. They did this to reject the excuse that the weight of your gear would pull you to the bottom. The cadre suggested a technique to use the foam in your helmet as a floatation device. By laying back and pressing your head into the Styrofoam lined helmet, you could pretty much relax and float your way through the 2 minutes. I tried this trick, but I found myself very slowly sinking below the water's surface. I kept telling myself to relax; you'll come back to the surface in good time. When I felt the urgency to get a breath of air, I found that I was too far below the water's surface to just casually stoke my arms to get my head above the water. After repeating this a few times, I began to struggle. There was safety divers scattered around the students for those who struggled. After a minute and a half I noticed that all three safety divers were surrounding me and ignoring all the other swimmers. I asked, "Why are all of you looking at me?" One of them answered, "You're the only one having trouble." I looked around and sure enough, everyone else was just floating there calm and serine. Damn!

At the end of the two minute float the cadre had produced two inflatable survival rafts. They were huge! They looked like they came out of a commercial air liner. The thought occurred to me that I never really knew exactly how big the raft was that we kept in the center of the floor of our aircraft. We practiced climbing into the raft. The first time we had to pull ourselves into the raft without help. That was very difficult to do when you are exhausted from treading water. Then we practiced pulling someone pretending to be unconscious into the raft. This required so much effort that I have to admit that if it were the real thing, I would really have to like that guy.

The last part of the training was the actual dunker. This was one big monster! The training device was a fiberglass helicopter cockpit that was suspended from the ceiling with a chain and hoist. There were two front seats with a Plexiglas windshield and doors on both sides with large windows. In the back there was a cargo section that resembled the inside of a large helicopter with bench seats and large windows. They would let this thing fall about 2 to 3 feet to simulate the impact. Despite the short fall it was still pretty jarring. As the cockpit filled up with water, an electric motor would quickly rotate the whole thing inverted. You had to sit there patiently while the whole thing sank upside-down before attempting to find an exit. Once you surfaced, you had to tread water for at least 1 minute. There was only 4 in the group, so we were rotated through the seat positions. I did my first one in the front left seat and all we had to go is go out our own door after it sank.
On my second dunking, I sat in the right seat but I was required to exit out the left door to simulate my door being jammed. Right before the second dunk, a cadre member popped his head into the cockpit and asked if the aircraft that I flew had seats that "stroked." I answered no. He turned and asked Leroy the same question, but he answered yes. I was surprised at Leroy's answer because we flew the same aircraft. I didn't want to embarrass Leroy by correcting him in front of the cadre, but then the guy flipped a toggle on the side of his seat and left. In newer model helicopters the seat is designed to slide downward on spring loaded rails to absorb some of the impact of a crash. This design was to minimize the injury to the pilot's spine upon impact. This system was referred to as a "Stroking "seat. This is a common feature in modern helicopters like Blackhawks and Apaches, but the concept wasn't around when they built the Huey. When the training device hit the water, Leroy's seat suddenly dropped about 10 inches and his knees pressed up against his gut. Leroy could not get his seatbelt unbuckled because his knees were in the way. I quickly undid my seatbelt and I vaguely remember using his nose as a handhold to pull myself out of his window. The safety diver had to reach in and release his belt.
I surfaced and waited in embarrassment for Leroy to the surface.

The last two dunks were done with us wearing goggles that had black plastic in place of the lenses to simulate doing all this in the dark. I recall that this was some of the best training I have ever gone through. Before I went through "Dunker" training, I never really gave any thought about flying over water ... now I feel no shame about circumnavigating around small ponds or lakes.

When the training was done, the school sold commemorative tee shirts that had a graphic of the dunker device and slogan that read, "panic in a can." Now I know where the military slang "been there, done that, got the tee shirt" came from.