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Oct
19
2020

Check that box, and fly it to the ground!

Posted 37 days ago ago by Admin

This true ordeal occurred on 14 April 2000, and was written by Chris Kruse, a retired U.S. Army and civilian medevac pilot:

St. Paul, MN

14 April 2000, 16:12 hrs.

Bell 222UT, N225LL

NTSB: CHI-000FA111

Sometimes life comes at you in small drips. At other times, like a fire hose stream. And still at other times, it resembles a water tower collapse.

Basics First

Helicopters are very curious but capable beasts. Unlike our airplane cousins, rotorcraft need to spin their wing or airfoil to create lift. The airplane relies on forward speed to flow air over their wings, creating that magic lift. We spin ours. To do that, there are multitudes of moving parts all working in concert. With that main rotor spinning above, a smaller rotor attached to the tail is needed to counteract the torque and keep the fuselage from spinning in the opposite direction.

The pilot uses his or her feet to control the tail rotor pitch. His or her left hand to control the pitch of the main rotor above, and the right hand to control the cyclic stick between our legs to steer the direction of the craft. To say all this is a rather busy endeavor is a total understatement. The helicopter demands your complete attention at all times. When things go south they usually do so in a big hurry. When the engine (or engines) fail, we can use the stored energy in those spinning rotors and a rapid descent to keep that rotor spinning adequately to do an emergency landing. That is autorotation. The only caveat is you have only that one chance to get it right. There’s no going around for a second try. Lose that stored rotor RPM and the lift all goes away. Everything stems from the main and tail rotor spinning at the proper speed to allow controlled flight.

Joining the Emergency Club

I had been an EMS helicopter pilot for years, and before that a US Army medevac pilot as well. All helicopter pilots can be separated into two distinct, but very different clubs: (1) those that have had emergencies, and (2) those still naively thinking they are immune.

My prior military service had ended with a medical discharge after injuries sustained in a helicopter rollover sequence following an engine failure over water. On that sunny May Day lady luck had cast no shadows on me. The near perfect autorotation ended with the left skid of our Huey pivoting on a submerged stump in the water, causing the rollover. Take that stump out of the equation, and the helicopter and its crew would still be at it today.

The violence associated with a main rotor striking the ground or water is indescribable. In the Huey, a 1,200 HP turbine engine is spinning a driveshaft at 6,600 RPM, into a transmission spinning a 48-foot diameter main rotor at 324 RPM. A tremendous amount of kinetic energy is suddenly interrupted causing mayhem simply beyond words. While I did recover from the injuries, the resulting blood clot in my right subclavian vein disqualified me from further military service. My naivety had been vigorously shaken from me that day. I had joined the “had emergency” club.

When I transitioned to my civilian career, the Bell 222UT seemed like a great alternative to the single-engine military Huey. Instead of one, now there were two turbine engines, about 750 HP a-piece and two redundant hydraulic systems. A reliable autopilot allowed single pilot instrument flying. Plenty of fuel capacity provided a solid two to three hours of endurance. FInally, a decent amount of payload to carry everything needed on a typical civilian medevac role. All of that working together would create typical cruise airspeeds of about 130-140 knots (about 150 MPH). Day, night, visual, and instrument flying were all allowed. We routinely carried a nurse and a paramedic. Along with them, and their associated life-saving equipment, we would still be several hundred pounds below max gross weight.

So when I entered the civilian medevac world, flying this machine, I felt I had made a good choice in terms of safety, redundancy, and survivability. And of course, my crash was behind me! That box had already been checked. Or so I thought…

Harrowing Second Emergency Club Initiation

On 14 April 2000, fortunately for the little one we transported and the medical team, that second back-to-back neonatal flight from Buffalo, Minnesota, went off without any drama. That is, no drama until after they were all dropped off safely at the Minneapolis Children’s Medical Center.

The next several minutes would impact us remaining crewmembers for the rest of our lives.

After assisting in the unloading of the baby and the hospital’s team members, Paramedic Bill Yoch rejoined me, sitting in the left front crew seat. I obviously sat in the pilot’s seat and after a normal run-up and before takeoff checks we left the hospital helipad. As we headed back to our home base at the St. Paul airport (KSTP), all appeared normal as I climbed the Bell 222 helicopter up to 1,000 feet above the ground and headed east. Thoughts of a lunch missed due to the two morning flights dominated our minds as we flew towards the airport, just a short five-minute flight. Until a sudden but slight metal-to-metal ‘tick’ sound was heard and felt, all looked routine. This would be the first and only warning I would receive of the pending mayhem that faced us shortly.

Captain Geoff Presson, an off-duty airline pilot from Rochester, New York, was doing his normal afternoon jog along the walkway of the high-bridge in downtown St. Paul. He heard an approaching helicopter and glanced up to see us just as we turned the downwind leg for the landing at St. Paul. A sudden loud engine surge and the subsequent backwards loop of the helicopter stopped him dead in his tracks. He glanced at his watch and believed he was about to witness a fatal helicopter accident.

After the ‘tick,’ Bill looked over at me and asked, “What the hell was that?” We heard a momentary engine surge simultaneously with the sound. I looked over everything available to me to verify systems and all appeared normal. I saw no indication of trouble on the multitude of gauges and warning lights before me. I momentarily thought of continuing the flight in an attempt to troubleshoot the issue. As I looked over to my right, with the downtown St. Paul Airport so close, I quickly abandoned that plan. Instead, heading back to my waiting mechanic seemed the more prudent idea. I had already contacted the tower for landing clearance and keyed the mike again to announce the state capital, a routine visual checkpoint that tower had requested us to announce as our arrival in their traffic pattern: “St. Paul tower, helicopter 225LL is the state capitol for bravo taxiway.” Tower acknowledged us and cleared us to land. After the right-turn to the downwind, I again keyed the mike. But before I could get the words out to read back their landing clearance, I heard and felt that weird ‘tick’ sound again. Immediately after that and to my horror, the cyclic stick between my legs suddenly went hard over to the full-aft position, dead solid and frozen.

St. Paul Tower Controller Robert Olson had glanced my way as I turned downwind after announcing the capital. Suddenly he heard a person screaming on the radio. He looked back at where he thought we should be and saw nothing. Unable to see us, and after repeated attempts at contacting us went unanswered, he queried a Minnesota State Patrol helicopter in the area to look for us. The screams continued over their radio frequency.

I was the scream heard on that radio. The sudden pitch up and inability to move any of the flight controls began the ultimate fight of my life and wouldn’t end for some 90 seconds according to Captain Presson’s watch.

Those next 90 seconds were going to be the longest seconds of my life and I knew we were in serious peril. The rotor system on the Bell 222, a teetering rotor system, is not designed for aerobatics. Similar in design to a Bell Huey or Cobra, it is known to catastrophically fail when exposed to violent low-G environments. As the helicopter pitched straight up, I remember thinking that if I could somehow just keep it from going over backwards, we might survive. This thought happened as the helicopter pitched over upside down in an inside loop.

Captain Geoff Presson watched in horror as our out-of-control helicopter went through a series of loops, weird immelmann turns, partial split-S’s, hammerhead type stalls, and partial rolls. He watched us struggle for control and was convinced it would end in disaster. We then disappeared out of his sight…

I struggled to move the cyclic and regain control of the ship. The initial inside loop resulted in a dive straight towards the ground. The Mississippi River was quickly filling the windshield view as I managed to arrest the dive and begin a climb, only a few hundred feet above the water. Looking right, I saw the tall downtown buildings pass by my side as the fight continued upwards.

The next 30 seconds gave me that exact view again and again. I was tiring very quickly and remember thinking: if you’re going to kill me, just get it over with! I then thought of my family and friends, and a vivid image suddenly was forefront in my mind. It was a dingy, flat barge anchored on that dark Mississippi River. A crane sat on that damn barge, and at the end of its cable the destroyed helicopter cabin emerged from the water with the lifeless bodies of Bill and I hanging from our belts. This imagined image reenergized me in a way I have trouble even expressing. A super-human determination to live overwhelmed me again, and I became determined not to ever quit. “Fly it to the ground” is the phrase I and every other aviator out there heard during training. My military flight instructor would allow you to get very close to disaster, and then offer the correcting words or actions to save the aircraft. Again these words flooded my mind, and I fought the continuing battle.

Bill was watching me struggle from his seat and with a similar will to survive, he tried to assist me in any way he could. He noticed that when I let go of the collective lever to use both hands on the cyclic, it would go uncommanded to the full up position on it’s own. The aircraft would then flip upside down. I would recover from the upset, and then use my left hand to reposition the collective again. My hands were bleeding from the collective and cyclic jumping around and me trying to grab them. The collective lever to my left controls the collective pitch of both main rotor blades, and also the engine governors to meet the demands of the system in regards to power. On this model helicopter, the two engine throttles protrude out at 90 degrees to the left at the end of this control stick. Pull up on that lever, you get more pitch in the blades and more engine power to make the helicopter climb. Lower it, and the opposite occurs. What happens next is somewhat of a mystery. I either told Bill to stabilize the collective, or he on his own did so. Regardless, when he did that he grabbed the collective at the point of those throttles. As he lowered the collective, he also rolled both engine throttles mostly off line, either all the way to flight idle, or at a minimum, to partial power. The timing of his lowering the collective lever was paramount. Had he done this action under a low- or zero-G environment, the result would have been that rotor system failure I talked of. Mast bumping would have torn the rotor right off the mast and the fight would have been abruptly over. As life goes sometimes, he did this while the helicopter was in a configuration that allowed it. I’ll take a little luck anytime.

What occurred as a result of Bill’s help was a small degree of returned control. I was now able to at least minimally control the attitude of the machine, but I also was now in a power-off autorotation. Power off, falling from the sky in a 7,000-pound helicopter with nearly 175 gallons of Jet-A fuel as well. But, at this point, being upright was a wonderful thing.

We had drifted south of the river, and were over Harriet Island. I frantically searched for an area large enough to do a run-on landing. Descending quickly, I scanned and just to our left saw a construction company’s parking lot, with a tall chain-link fence surrounding it. I planned on touching down within that parking lot, and skid the helicopter on the ground into that fence to arrest the ground run. At about 400-to-500 feet above the ground, I managed to turn the helicopter left and back into the wind. As I approached the parking lot, a man suddenly walked out into the exact spot I was aiming for. I remember yelling out loud, “Dude, I can’t do a thing for you; I hope you move!” I continued the approach. At about 200 feet, as I began to arrest the approach and slow down by adding aft cyclic, I quickly learned that the machine was going to have the last word. The aircraft pitched straight up and appeared to be going over backwards just one last time.

Very flammable Jet-A fuel: 1,100 pounds, 175 gallons. With two very hot, unhappy turbine engines, we were going to die in a flaming mess.

As the helicopter approached vertical again, the rotor started bleeding down its speed due to that reduced engine power settings. The familiar ‘whop-whop-whop’ of a slowing rotor filled our ears. This last loop failed at its apex, and slowly the helicopter’s pitch fell forward again. What filled the windshield now were high-tension power lines that were not seen before and now looming large and right in front of us. Every helicopter pilot’s DNA includes a strand dedicated to the avoidance of power lines. It’s inbred in every one of us, and there was no way I was going to go through all this and in the end be blamed for killing us by hitting power lines. I reached over to pull the collective and use the last energy available to jump over these lines and crash to the ground beyond them.

Just as I was about to increase collective, Bill yelled, “Hey, a flat roof over here!” I looked and right next to that construction company’s building was a mostly flat metal roof, and yes, immediately to our left! I quickly jammed in full left pedal and swung the cyclic left. The helicopter used its one remaining breath to make that last 180-degree turn, and then promptly fell the remaining 15 to 20 feet onto the rooftop.

The metal roof swayed deeply under the impact load of the helicopter’s fall. I briefly considered the likelihood of the roof failing, and the burning helicopter destroying it and us as well. And then the roof rebounded, damaged but intact. The roof acted like a huge pillow, absorbing the impact load from the helicopter’s fall. We then just sat there at flight idle, the blades turning happily, just like I had intentionally parked it there.

We stared out the windscreen in utter disbelief. There was no fire. The helicopter’s skids had collapsed. The tail boom was kinked; it otherwise looked intact.

After shutting down the engines I managed to crawl up and look inside one of the cowlings on the helicopter. All three hydraulic flight control servos were dangling in space, broken free of their mounts. I looked up at the helicopter mast. Numerous ‘witness marks’ consisting of very deep gouges were all over it, revealing the severe mast bumping that had entailed. Somehow it had all held together just long enough to bring us here. Here back to earth. Getting down from that look in the cowling, my knees buckled and I was unable to walk without help.

I know literally dozens of professional helicopter pilots who went an entire career, flying 10,00, 15,000, or even 20,000-plus hours without a single incident. Who possibly could have predicted that I would have to check that damn box not once, but twice? My measly 5,500 hours offered me two chances.

I guess lady luck was shining on me after all.