Moggy’s Tunaboat Helicopter Manual Ch.3-E “Runaway Blades “
Posted on September 12, 2009
The Luck o’ the Irish, put (maybe excessively) to the test!
PART 3 “Moggy’s Tuna Manual ” “Handling your helicopter “
Chapter 3-E RUNAWAY BLADES
Runaway blades, or ‘rogue blades’ are one of every helicopter pilot’s worst nightmares.
You tend to hear all sorts of stories, and it’s hard to know what’s fact and what’s fiction. Until it happens to you, and then you know exactly! So this is where I have to tell you a story against myself, in the hope I illustrate a few points!
I was working a couple of months’ relief on a different boat, for a pilot who had gone sick. So I had a new deck helper. A lad from the Philippines. You know you’re only there temporarily, and it’s easy to fall into the trap of not training your deck helper exactly the way you like it. You sort of assume a bit.
Well, I had made the point to him that he should never leave the helideck until the blades were tied down. I had made the point several times. But his fear of me was nothing compared with the fear he had of his captain. If I landed and the ship was not in the middle of a set, sure, he’d stay and help me tie down the blades. If the ship however happened, at the moment of my arrival, to be in the middle of a set, with the nets coming in, the chances were he’d attach the belly hook, wind in the cable, wait until I wasn’t looking, and scarper! Disaster lies awaiting there!
The day came… when I was landing back, with the ship heading straight for an ominous black cloud.
I didn’t like the look of it. I landed, and my observer, who was the captain, was -as usual- gone like a light. I checked to see if my deck helper was waiting to help me with the blades, and he was. I breathed a sigh of relief, and waited for things to cool down a bit in my hard working turbine. In the Hughes 500 I like a three minute cool down. After one minute, the black cloud was getting so black and so close, I decided to hurry up. I rolled the throttle off, watched the TOT, and a few seconds later some big rain drops started to bomb the windscreen. For some reason I looked around, just in time to see my helper look up at the sky, hold his hand out, palm up, the way people do when it starts raining… then he turned… and ran!
I was not pleased! Now I was totally on my own on the helideck, rotors spinning, both doors off, heavy, heavy drops beginning to really get going, and the wind picking up alarmingly. Approaching across the sea I could see the tell-tale signs of a very strong wind. The sea sort of…. goes funny in a particular way. Where as you’ve still got a regular wave pattern around the ship, when a ‘gust front’ is approaching the wave pattern changes. The color changes. And… you just know. Now I was hauling on the rotor brake, becoming very alarmed. The Hughes manual warns you not to over do the rotor brake (you can damage the strap pack) but I hauled pretty hard! It took an eternity, but I got the blades stopped.
Just in time!
If… my helper had been there, just one blade sock on would have prevented the whole sorry saga that was about to unfold.
I leaped out, and legged it over to where the blade socks were stored. Grabbed them, and sprinted back over to the machine. (You can’t ‘lock’ the rotor brake on. It’s designed to prevent stupid pilots from firing up with the brake locked on, and doing all sorts of damage)
With that, the gust hit. And I mean, it hit! From practically nothing, we must have gone up through thirty five to fifty plus knots.
Instantly, seconds before I could grab the nearest stationary blade, it was gone.
I had no idea that a gust could ‘spin up’ a Hughes rotor system that fast! The blades were turning like the machine was starting up on its own! Blade/tail boom strike imminent!
I leaped into the cockpit, and hauled on the rotor brake, and it is hard to describe the horrible fear I felt. I was convinced I was about to have a tailboom strike. Once the rotor system goes out of kilter after such a tailboom strike, there is no knowing where the blades will end up going, or what kind of ungodly damage they can do.
I was petrified.
The blades stopped, for the second time, and now the rain had also arrived. With no doors on, within seconds the water was deluging into the cockpit. Once again I let go of the rotor brake, and shot out the door, blade sock in hand, to grab the stationary blade. A great plan.
Son of a bitch…! I never even came close. It was gone, and by the time I was frantically hauling on the rotor brake once again, that blade had passed over my head a whole bunch of times.
It was that fast!
I was soaked, and being lashed by water coming in the door and through the cockpit. What the hell was I to do??
The thought crossed my mind to switch on the electrics, and call down to the bridge on the radio, but everything was saturated. Rivers of water were flowing across the instrument panel and the radio stack, and it just didn’t seem a good idea!
Holding on to the rotor brake, I half climbed out of the cockpit, onto the float, and looked up and across at my blades.
Just in time to see the “into wind ” blade stand up vertically!
Gawd! Damn! Damn! FUKKIT….!
By now I was no longer just scared. I was convinced any second that the vertical blade would crash over backwards across the rotor head, and I could only guess at the damage that was already being done to the strap packs.
There is this sick, sick feeling in your stomach…
My brain was racing, and I yelled at the top of my voice.
“HELP!!! HELP!!! SOMEBODY!!!! HELPPPPP!!!!! “
With the noise of the wind and rain, and the ship’s engines, it was futile. Even if somebody had been out on the deck below, they would never have heard me. As it was, they were all comfortably inside, sheltering from the rain. Don’t you love a helper who legs it, leaving the pilot to tie down the machine, and put the blade socks on, and put both doors back on.
I distinctly remember thinking “This can’t possibly get any worse! “, and, of course, BOY!, was I wrong.
You’ll love this: and this is no exaggeration. It’s ‘gospel’, it’s exactly what happened…
While I was standing on the left float, holding onto the rotor brake, staring in open mouthed horror at the vertical rotor blade, a ferocious gust positively slammed the helicopter across the helideck, and rotated her -tail first- through 45 degrees, until the belly cable went tight! She ‘weather vaned’ ! I was still standing on the left float!
Note this: Without the belly cable, or if the belly cable had failed, I would have gone straight over the side into the stormy sea, still standing on the left float, worrying about the blasted vertical rotor blade! Jump off? Dream on! It happened way, way too darn fast… Even if I had jumped, the machine would have just clouted me and swept me with it.
I know I debated getting off at that stage, and abandoning the helicopter, and just letting events unfold.
The fact that I stayed for the fight owes less to courage than to pure stupidity!
I eased off a fraction on the rotor brake, the rotors turned thirty degrees or so, and the vertical blade smacked back down with a crash and a shock that made me wince. And there I stood, for twenty minutes…! Every so often the blade furthest into wind would start to rear up, and I would release the rotor brake and try and keep it down.
After twenty minutes, the ship came out of the black cloud, the sun came out, blue sky appeared, the wind abated, and I put the blade socks on, and then the four tie downs, followed by the two doors.
Then I climbed up and looked at the strap pack!
(waft in music…. Ride of the Valkyries…the Devil’s March….. Apocalypse Now…. For a Few Dollars More….)
Then I marched down to the bridge!
SPLOSH! SPLOSH! SPLOSH!
Captain Chan is a great man, and he just took one look at me and he knew something bad had happened. He told me later it wasn’t so much the soaking wet and bedraggled aspect of the ghostly apparition, but rather the fact that I was still white as a sheet!
I dragged him… and everybody else…. and my helper (by the throat) up to the helideck, where everybody just sort of stared at the highly unusual position of the helicopter…. the fact that the WIND had parked it there, and not the humble pilot, impressed everybody.
If that belly cable had failed… I’d have been drowned. Nobody would have heard me.
I didn’t cover myself with glory that day, but I sure learned a lot. Now, on this ship, I insist I have help until the blade socks are on, and my observer, who heard the story, stays and helps my helper. That means there are three of us to make sure the machine gets secured nice and quick. I’ve also become much more wary of black clouds. I might delay a start up, and coming back from a trip, I’ll certainly ask the ship to move if they are parked up right beside a micro burst or a heavy downpour.
In many ways, this was one of those ‘coming out’ experiences for me as an offshore pilot. I learned so much respect and caution right there and then. It was one of perhaps a few dozen experiences in my helicopter career which I would unhesitatingly list ( I must do that one day) as “pivotal “. And I mean “pivotal ” in the sense that it changed my attitude forever.
Remember the “potential gust area ” where you are at risk extends several miles out from such a nice ‘black cloud’.
It will surprise you. Watch the surface of the sea for clues. If in doubt, sit it out. Think twice before you decide you can beat an approaching squall line. Many, many an offshore pilot has learned the lesson I learned the $$$$ expensive way, incurring serious damage. Tailboom strikes are very expensive, nearly always avoidable, and there have been lots and lots with Hughes 500’s in the tuna fields. Don’t think a Bell 47 is immune! A wrench tuna head told me how a Bell 47 blade he was trying to tie down physically lifted him right off his feet. He could not control it.
There are some powerful forces at work there.
The risk of blade sailing is at its highest when your rotor is really slowing down. On a Hughes 500, the big danger area is below 100 rotor rpm. You are losing your gyroscopic ‘rigidity in space’.
I frequently brief passengers in detail about this.
I have seen the results of tailboom strikes, and the results can be ugly. I have a long, sad story to tell later in this manual about one of my pilots (with an inoperative rotor brake) who would not listen to me on this subject, and disobeyed repeated direct orders not to even attempt to fly. I knew sooner or later he might not be able to shut her down safely. But wise-ass thought he knew better. Subsequently he did a whole lot of damage. I fired him.
Remember you don’t have to shut down straight away after landing. Nothing says you can’t keep ’em spinning.
It may be a much safer and smarter thing to do. I’ve done it. Not often, but a few times. Most tuna heads who have been out there for a while, will tell you they’ve done the same on occasions. Just waiting until it was safe to shut down. If they were low on fuel, they’d get the helper to fuel her up, carefully! Then, maybe twenty minutes later, with the wind reduced, or with the ship out of the gust area, then they have then shut down! Pretty clued up, some of these guys!
Rather burn some fuel than risk a tailboom strike.
These guys will also tell you to watch out especially for gusts coming from the left side of the helicopter. Why?
Because such a gust will tend to make the rotor blade ‘dip’ as it crosses the tailboom, making a tailboom strike more likely.
Sounds reasonable. Bring this up in a bar, with a gaggle of tuna heads, and you’re pretty well guaranteed a decent argument…. I once listened (in amusement) to some dude protesting that it wasn’t so much that the rotor blade ‘dipped’, but more that the blade ‘could not rise’ fast enough. What-ever…. Just be aware.
I’ve mentioned blades spinning up, and flying vertically. The third problem is that sometimes when you’re about to fire up, you look out and realize that the into-wind blade seems really high, whilst the opposite blade seems really low. I don’t like that, and I’ll unstrap, climb out, and level the blades before I start up. That’s just me. trying to look after the equipment. One tuna head shook his head, and totally dismissed that. He reckons it ‘makes no difference’, the blades will level themselves ‘real quick’. Well, he’s entitled to his opinion. But what if they do whack your sodding tail boom?
Now you’re going to be embarrassed ‘real quick’….
Here in the Gulf of Mexico, a lot of us are very wary of being caught out. Every year, there are costly accidents or incidents involving well meaning pilots, who fall victim to sudden gusts of wind, whilst parked -turning and burning- on a helideck. You will often hear it said that operations manuals (the ‘Bibles’ of many helicopter companies) are written in blood. That’s a sad, but true statement. When ever somebody gets killed, or seriously hurt, the event will get analyzed and cross analyzed, and you have a pretty good chance some of the ‘fall out’ will go into print, and work its way into the operations manual. The trouble is, these dry, almost legalistic passages, drawn up in terse and spartan lawyer’s language, don’t even begin to paint the full technicolor picture for newbie pilots. For that, in my mind, you need the addition of rambling prose from wacky dudes like me, who have been out there, and committed lots of innocent mistakes, frightened themselves silly, and are back to talk about them. The “30-30 rule ” is one such example. I will talk about that in a later chapter. I firmly believe we have a lot of control over our destiny as offshore pilots. I’ve seen accidents, where the pilots where exonerated from any and all blame. It was all put down to ‘a sudden gust’ that came ‘out of no where’. I have wondered a few times how much of these conclusions were for public (customer) consumption. I have asked myself if those conclusions are telling us that in the exact same circumstances ANY pilot, no matter how experienced, would have fallen victim to disaster. If that was the case, then our profession would be a version of Russian Roulette. Keep on trucking, hope for the best, and if your number’s up, well, tough cheddar! Hmmm….
I don’t see it that way. Sure, if the blades fall off in flight (an almost unheard of event) then it’s probably time to discover Jesus. In a hurry. But for most other cases, I believe in peddling like the devil. Listening, reading, putting a lot of thought into it, and exercising every conceivable caution. And learning from your experiences.
Flying helicopters is beautiful. Absolutely wonderful. An art form. It’s not some demented version of Russian Roulette.
Consider the day I had three customers on board. Preparing to take off from an offshore platform. All I was doing was rolling the throttle on. Perfectly normal. No rush, no hurry. All normal. I was only doing what I had done thousands of times before. The wind was brisk, but not particularly strong. Twenty knots maybe. No biggie.
Next thing…. I weathervaned through 40 degrees! Slick deck, lack of non-grease paint, combined with being turned out of wind to keep my tail rotor clear of the stairs…. all factors (individually harmless) perfectly coordinated together to scare the BeJayzus out of everybody. Had I done anything in violation of the operations manual? No! Was I therefore an innocent, helpless victim of Fate? Hell, no! Because it ain’t ever going to happen to me again! Next time I’ll recognize the build up to that particular scenario before it bites me!
Runaway blades are a problem, and they can cost a lot of money. You can cost your company fifty thousand to a hundred thousand dollars in a heart beat. But these accidents are not random, cruel, unavoidable handouts from some fickle and mischievous mistress of Fate. They are mostly easily enough preventable, if you’re clued up to the dangers, and willing to be stubborn as a mule if the ship won’t cooperate!
I was with a captain who could be just a dogged old fool. When he copped an attitude, he was unmovable. Stubborn. He had a reputation amongst tuna pilots. Unfortunately for him, he came up against a pilot, who was just another dogged old fool. And when he copped an attitude, he was unmovable. Stubborn.
That pilot was me.
I arrived back to the ship, in my beautiful Hughes 500, (my baby), and Idiot Features was parked hard up against a big black storm cell. Not fishing, no nets out, just lolly-gagging. The sea clearly showed the ferocity of the winds coming out of that ugly monster, and I wasn’t going to mess with it. I asked for the ship to move. I know the request was relayed to him instantly. It was early on in our relationship, and to him, I was probably just another tiresome pilot. He ignored it.
Becoming more and more cross, I orbited. And watched my fuel go down. And down. Now I was pissed. My observer knew it, and I know he was telling the ship. No response. In the end, I had no choice. I battled my way in, spitting blood, and landed on a ‘crazy’ deck. They put the belly hook on, and the observer helped in attaching the four tie downs. But now what? We were rolling like a drunken turd, spray was lashing us, and the wind gusts were violently erratic, with a humongous gust spread. Ranging from twenty knots up to forty or fifty or even more. I was damned if I was going to shut down in that lot. I was maintaining 100% rpm, and I was not going to even roll the throttle off. Now they were motioning for me to cut the engine and shut down. Ha! Fat chance. I liked my boss, (he treated and paid me well), ($7,000 a month), I loved my helicopter, and I was looking after my equipment. End of story. I gesticulated angrily, jabbing a finger at the Big Black Goliath towering over us, and then jerked my thumb vehemently towards open waters, away from that nonsense.
The game went on in this manner. Every so often a concerned crew member would come up to the helideck, and motion me to shut down. Poor dude would be sent packing by a livid pilot, with a face like a Great White Shark, (all gnashing TEETH sort of thing), and go and report back to Herr Kapitan.
Pretty soon I was running out of gas. The refined oil-derived type. (not the Irish temper derived type).
I still was not going to shut down. Now it was personal.
You want to play games?
I’ll give you games.
I locked the controls down as tight as I possibly could. Still ‘turning and burning’. Then I climbed out on the wet, wildly rolling, slippery deck, and checked the tie downs were as tight as they could go. Then… I made my way across to the fuel hose, rolled it out, and started re-fueling my little darling. Ha! I’ll sit here all day, if I have to, burning YOUR fuel, that YOU are paying for, and I’ll sit here all NIGHT long as well, if you want!
Instantly, I think the hose had barely started pumping fuel, black smoke rose up from the chimney stack, and the ship’s engines erupted into life. I looked around. He was up in the crow’s mast, watching me! All the time, probably.
The ship moved away, and soon we were clear. Then… I shut down.
After that, once they discovered that, firstly, I was a determined SOB, and secondly, that I was really skilled at spotting logs and fish (most pilots don’t bother), then the attitudes towards me changed dramatically. Soon I could do no wrong, there was lots of free beer, and I got what I required for the safest possible operations.
I worry in the middle of the night, when the weather is rough, and I’m scared that maybe a blade sock will come off, and the blade will stand up vertically. I have been known to set my alarm clock for 1 a.m.and again for 3 a.m. and go up to the helideck to check up.
(Medal, please, Boss!)
Purse seiner captains who have not had a helicopter before… sometimes don’t think! I got a bit testy one day when I had to explain that rough weather that is ‘no problem without a helicopter’ becomes a ‘BIG problem WITH a helicopter’.
That was the morning after I had wearily climbed the ladder leading up to the helideck at three a.m., only to have a massive wave break over me as I reached the top of the ladder. It knocked me flying ten feet down to the deck below, and this ladder is at the back of the helideck. I lay there stunned for a while. Just think of what the poor helicopter was suffering! My baby! That was simply a horrendous night. Dangerous as well. I got soaked through, and it’s real scary watching waves break over the windscreen! I was convinced it was going to get smashed. I was real miffed the next day, and I didn’t care if it showed. It’s no fun fiddling about trying to get a blade sock back over the tip of your rotor blade, near to the deck edge, when it’s pitch dark, lashing rain, slippery, and the deck is ‘wild’. If you fall overboard…
Purse seiner captains need to be a bit smart when they are carrying a helicopter, or it will get destroyed in heavy seas. It’s happened! The question then is: who pays the bill! Sometimes… I pity tuna helicopter owners, and I admire their nerves. In practice, if the weather is rough, I put more tension on the blade sock ropes. I really double check the knots, and I make sure the bellyhook is tight. And the four tie-downs are ratcheted tight!
A ‘sprat fish head’ read this chapter in draft form, identified with it wholeheartedly, and pointed something out I’d never sat down and thought about.
A very efficient windmill!
It’s the tail rotor that’s doing most of the driving! Like a windmill, it catches the full force of the wind, and drives the rotor system. Another contribution gratefully received. I wonder does all the driving force come from the tail rotor, or most of it, or what. Hm. Ideas?
In a way, in theory, you might think that ‘tying down the tail rotor’ and ‘to hell with the main blades’ would stop the problem, but I imagine that there would be some horrendous stresses imposed on couplings and drive shaft bearings.
All the wrong places. Nobody does it on any helicopter, to my knowledge. And unsecured blades will fly up vertically if you’re really unlucky, and bang up and down on the droop stops. I’ve found a cracked droop stop ring before.
The same ‘anchovy tuna pilot’ told me a grand story -after only two Pepsi’s- about being towed behind a motorboat after a succesful landing with pop-out floats in the sea off the Great Barrier Reef. He said the waves ended up driving the tail rotor, whilst they were under tow. That was not part of the grand plan. Then that spun up the blades. Then the blades went vertical, whilst spinning around. I guess they were spinning slowly enough that centrifugal force had not yet overcome the tendency to stand up vertically? Bizarre. That I would have liked to have seen…. from a safe distance.
One of my old bosses has a nice four foot section of rotor blade propped up in his office by way of a souvenir. It came and visited him while he was sitting in the cockpit. Now I know why he always wears brown overalls. That was the result of an attempted start up in a howling gale.
The Royal Air Force Air/Sea Rescue Unit in Scotland will sometimes fire up inside of a closed hangar. When everything is spinning merrily, they slide open the hangar doors, and tow the girl out! I wonder what they say to the Tower. “Rescue One request clearance to exit hangar… “?
Kind of neat. Not quite as good fun as James Bond flying his BD aircraft through a hangar, but warming up in that direction anyway!
Last edited by Francis Meyrick on February 28, 2014, 1:47 pm