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Dynamic Rollover


cburg

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This is not "technically" a case of dynamic rollover which we typically associate with a helicopter lifting off the ground.

 

We are taught to get the helicopter into a stable hover BEFORE doing anything else. This is for a reason. We are taught to hover at a specific height. This is for a reason. We are taught to hover POINTING IN the direction the helicopter is moving. This is also for a reason.

 

In the video, the EC120 pilot lifts off but never really gets it stabilized. He starts an immediate pedal turn and then begins to hover taxi away from the crowd. But it's not a good hover. He's going too fast and his hover height is erratic. We can conclude that the PIC is horribly weak in skill level. As the ship gets out to the grass runway, we see it start to move sideways in relation to his heading. At five feet this would have been no big deal. At one foot it's a Big Deal. Sure enough, he catches the back of the skid and over she goes!

 

I've said repeatedly that helicopters are incredibly easy to crash. You go from what you think is controlled flight into the "accident zone" in the blink of an eye. It's over before you know what happened, or have time to react.

 

Even at my advanced age and experience level, I always, always, ALWAYS lift off to a hover and then STOP! I take a breath, look around, check that everything is alright. *THEN* I do whatever comes next. I never just "pull and go" like I see so many, many pilots do. Pull and turn and we're outta here! That's bad form, fellas. Bad form. Lift off, GET IT STABILIZED, do a pretakeoff check ("hover hang", gauges in the green, lights out, area clear) and then go aviating. Unless someone is shooting at you, there is...or should be...no rush to get airborne.

 

The EC120 in the video wasn't dynamic rollover. It was dumbass rollover.

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Like many arguments reduced to black and white with no shades of grey allowed, I disagree with a requirement to stop at a stable hover. But, it's not wrong in all conditions and it is best practice.

 

How long must one hold the stable hover? A second? Two? Thirty? 0.00001 seconds? However long it takes if you're doing it. Again, it is best practice.

 

How high should the hover be if the dictate were accepted? 36 inches? 48 inches? A foot? Five feet? An inch? If I break ground stable and at power, why shouldn't I continue the takeoff? Suppose a takeoff from the ground is appropriate for whatever conditions? (Per my GOM, for instance)

 

How would catching a stable hover have changed the outcome in this event? It wouldn't have, the skid was caught, upsetting the helo, well after that portion of the flight.

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Wally, like a lot of other old-timers I learned to fly in a Franklin-powered Bell 47G that barely had enough power to hover with me and an instructor onboard. And so running takeoffs and no-hover takeoffs were our specialty. You got everything set *before* pulling pitch, and then when you did pull you were pretty much committed to going.

 

But turbines have spoiled us (at least, us sea level pilots). Nowadays, if I can't hover, I ain't going, period. Simply put, if I'm too heavy to hover I am seriously overweight.

 

I agree with you that sometimes a takeoff directly from the ground is appropriate. Lifting off from a beach or snowy field come to mind. Done both. In neither case do you want to be hovering around for an extended period of time.

 

But for the other 99% of all normal operations, like taking off from a big grass airport, it is "best practice" to get it into a stable hover before doing anything else. I mean what's the rush? Looking back on my career, which includes some 50,000+ takeoffs and landings (and that's no exaggeration), I can count on one hand the number of times when I felt it was better to immediately initiate the takeoff from the ground. I'm just not a fan of the "pull-and-go" technique.

 

How high should the hover be? Well, that might vary. Offshore for PHI on a hot, windless August day, I might only get two feet out of that old Bolkow. Scary, but doable. Whatever the circumstances, you should certainly hover high enough to ensure that you won't snag a skid while you're hovering around for departure. I guess being able to accurately hold a constant hover height goes hand in hand with this. The pilot in the above video did neither. Now, in his defense the terrain was sloped. But we hold our hover height in relation to the terrain. And if the terrain is undulating, then we vary our hover height to compensate. Or we stay well above the highest point, and accept the fact that it might be a little "too high" for the low points. Oh well.

 

It's sad that the pilot in the video trashed a perfectly good EC120. If only he'd had better instructors who demanded more attention to detail.

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Three Conditions Required:

1.) Pivot Point - Roll Over on Level Ground (Takeoff)
2.) Rolling motion - Rolling Downslope (Takeoff or Landing)
3.) Exceeding the critical angle

Between 1992 and 2003 75% of all rollover accidents occurred on level ground. Additionally, 75% of all rollovers were to the right (tail rotor thrust) (US Army FLIGHTFAX 2003).

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I heard it was a pilot letting a student pilot do some flying at an airshow "take a ride in helo" event. Sadly a spectator was killed because of this stupidity. Hit in the head by a flying piece of the rotor blade.

 

Similar thing happened in this video (

) where a student pilot was allowed to take the controls. Training should be done without passengers on board or spectators watching... Ultimately it's the fault of the PIC for poor judgement. Until that pilot is certificated everything is on the instructor or PIC. You instructors out there, feel free to use cerebral shock therapy if your student has any side translation. Arrest that motion and stabilize the damn hover!

 

The EC-120 and EC-130 (what I fly) have particularly pronounced translating tendencies but nothing that is difficult to control. I'm not sure why that is, perhaps a feature of the ducted fan tail rotor (fenestron). I remember stepping into the EC-130 from the R44 and finding my self having to learn to hover again. There is a lot different about that aircraft. Fortunately I had an instructor who would flog me for the slightest lapse in hover control in both aircraft.

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The Robinson Helicopter community underwent a number of these type rollovers and RHC came out with a notice back in 1982.

 

Mostly caused by poor training, poor piloting technique, and/or lack of situational awareness, ending in the helicopter literally being flown into the ground.

 

Notice SN-9

 

To avoid a dynamic rollover:

 

1) Always practice hovering autorotation’s into the wind and never when the wind is gusty or over 10 knots.

 

2) Never hover close to fences, sprinklers, bushes, runway lights or other obstacles a skid could catch on.

 

3) Always use a two-step liftoff. Pull in just enough collective to be light on the skids and feel for equilibrium, then gently lift the helicopter into the air.

 

4) Do not practice hovering maneuvers close to the ground. Keep the skids at least five feet above the ground when practicing sideward or rearward flight.

 

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Edited by iChris
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I hope that Nearly Retired doesn't mind if I coat tail on his comments.

 

When lifting off a hard surface the chances of getting into trouble with an other than a slow controlled liftoff is minimal.

 

Sometimes skids or gear can freeze on one side of a hard surface, setting you up for disaster with a quick pickup.

 

It is rare, but some line workers will tiedown skids or wheels on aircraft parked overnight. If not untied before pickup...

 

When landing on softer surfaces, the chances of a quick pickup being immediately regretted goes up substantially.

 

It's also a good idea to get light and yaw the helo before pickup if there is any doubt.

 

Thanks for the previous replies, especially NR's which was the muse for mine.

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NR said, “The EC120 in the video wasn't dynamic rollover. It was dumbass rollover.” and I completely agree. Additionally, the same can be said for the L crash as well. However, when the discussion swirls around the Dynamic Rollover “technical” aspect, we seem to lose focus of the true cause… These crashes happened simply because there were people on the controls who shouldn’t have been. Additionally, if we review other threads like “Needing some advice” and “building turbine time in experimental??” you can see the reasoning behind what is said by the experienced folks and thus why employers are somewhat particular about who they hire. That is, employers are particular because they know, anyone can fly a helicopter and, ANYONE includes dumbasses……

Edited by Spike
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pilot#476398:

If I had a nickle for every time a CFI has told me I'm too high while hovering around...!

 

 

It's true that CFI's don't want you hovering around too high in case of the dreaded engine failure. But their message should really be, "Pick a hover height and maintain it...and make that hover height 3 to 5 feet!"

 

Me, I don't care what altitude another pilot hovers at - as long as it's not 50 feet. I'd rather see a pilot hover a "little" on the high side than be on the down low. I mean...well, nevermind. You know what I mean.

 

I know I'm beating a dead horse here, but too many pilots minimize the value of getting into a stabilized hover at the "proper" height before initiating the takeoff. The LongRanger crash video is a prime example. Whoever was on the controls was clearly *not* in control. Either he/she didn't know how to hover, or didn't want to waste time/effort in getting it stable first. So off they went! Everybody's always in a hurry. "Let's just get this thing going!" I can envision the hapless *real* PIC in that ship, suddenly realizing he's made a horrible mistake in letting the other guy fly...his hands lunging for the controls in a futile effort to prevent the inevitable as the left-front skid dug in. I can clearly imagine the sick feeling of, "Oh, no..." in his gut.

 

Oopsie!

 

Now then again, we all enjoy a good nose-low, pitot-in-the-dirt type of takeoff. So thrilling! But that's kind of an advanced maneuver that should be left to pilots who actually know what they're doing. Which doesn't include me; I hate that sh*t. If *YOU* on the other hand are going to try such shenanagins, please start from a high enough altitude and DON"T LET THE GODDAM SHIP SETTLE, which is pretty hard to do when you're looking at a bubble full of gravel as you fall off the so-called, mythical "ground cushion" with your tail way up in the air like that.

 

And then...! Just recently I was watching some U-toob video footage of some guys hopping sightseeing rides in a...well...let's not say where or in a what. Every takeoff filmed showed the helicopter popping into the air and immediately initiating a takeoff. I watched the video with amusement, going, "Kids...they'll learn." Hopefully they won't learn the hard way. My message to them? Hey guys, non-aviators who ride in helicopters are fascinated by our ability to hover. They get all giggity about it. It's amazing to them. So fer cryin' out loud, let them experience it! I know you're in a hurry...I know this. But would it kill yous to just sit there for a couple of seconds in a hover before yanking and going? Answer- no, it wouldn't kill you. But *not* doing that might!

 

 

 

 

 

 

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damn. Scary stuff. Sad. Don't you HATE watching that. (Yes, hollering at the screen) (sucking air through teeth) (wondering about their instructors)

 

For what it's worth: (probably not-a-lot)

 

1) I like the two step pickup. A) get light B) Ease her up. C) Controls responding normally. D) no sideways drift. That's the way I used to teach it.

 

2) I like S-L-O-W. I agree, Take your T-I-M-E. I think our passengers like it as well. Maybe because I am so S-L-O-W, but I like S-L-O-W. I watch nippy guys all the time, who scare me. Then again, I like to use ALL the take-off distance available, even if it means a lengthy hover taxy.

 

3) I would caution against the assumption that only "dumb-asses" achieve dynamic roll-overs.

It's a constant hazard, as long as you fly helicopters. Not just for low-timers or the poorly trained.

 

I would respectfully suggest that it's a whole lot easier to do than you might think.

 

Especially, if you have watched these videos, and read the comments, and if you're thinking:

 

"THAT WOULD NEVER HAPPEN TO ME++++ ('cos I'm so frickin' GOOD)"

 

then you might just... pause... re-think.

 

If you're feeling all judgmental, I would offer the caution that Karma is... Karma.

 

Humility is good. "There for the grace of God... go I " (or: "ROLL I...") :rolleyes:

 

Of Helicopters and Humans (22) "Sounds like a stupid thing to do".

Edited by Francis Meyrick
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From the videos posted, IF I was behind the controls, during the exact same moment, it wouldn’t have happened (and, if you believe, well… If it were me… it might’ve, possibly could’ve, cuz ya know what, ya never know…. Steer clear of flying helicopters….) Does this mean I believe I’m immune from DR? Hell no (and please, -really?)….. However, define the cause and no, it wasn’t because the skid contacted the ground. That was a result, not the cause.. Both crashes displayed ignorance in the basic principles of responsible airmanship. Simply put, both were negligent operations and the owners should be held accountable for their actions. Flying helicopters has no room for touchy-feely philosophies. It's far too unforgiving...

 

[The 120] Hovering laterally inches off the ground, faster than a brisk walking pace, across a grassy field…..

 

[The L] Prior to lifing off the ground, the machine yaws significantly to the right then to the left. Once airborne and only inches off the ground, transitioning from a hard surface to a field, left skid low….

 

The most junior helicopter pilot should be able to explain the dangers AND corrective actions for the above 2 paragraphs (scenarios) and yet these were million dollar machines supposedly operated by responsible individuals….

 

Just because you can get a license to fly a helicopter, doesn’t necessary mean you should……

Edited by Spike
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(Ho-hummm...)

Okay, I'll bite... :P (day 1 of 7 off...)

 

@Spike...

 

 

(and, if you believe, well… If it were me… it might’ve, possibly could’ve, cuz ya know what, ya never know….

This is obviously deep and meaningful, (heck, it may even have spiritual connotations), but I confess I don't have a clue what you're saying here.

 

 

Does this mean I believe I’m immune from DR? Hell no (and please, -really?)…..

OH, I liked that. Juicy. Are we giving with the one hand here, and quickly taking back with the other? Are we mouthing the inevitable (required) platitude, but instantly backing it up with quiet scorn at the suggestion? I mean, ah mean... really?

( ME? are you kidding??) :angry:

 

 

Flying helicopters has no room for touchy-feely philosophies.

Maybe. Maybe not. But it does have room for ALL helicopter pilots, at ALL skill levels, at ALL experience levels, to periodically take (their own) little step back, and ask themselves a few personal, private questions. Like: "Am I really that good? Or maybe just average? Maybe a bit complacent even? Lemme try harder - today".

 

Some of us, in quiet corners, still reminisce about a certain haughty, furiously judgmental, hot tempered screamer, who worked as a training pilot somewhere in this world. He affected all sorts of people with his temper tantrums, and affected and influenced careers. His organization had experienced a very expensive rash. It's caused by pilots trying to take off in a twin engined choppy, with one engine still at idle. It burns up the live engine. Now, it takes four omissions from proper checklist procedure to accomplish this little trick. Our hero, El Capitan, him of the Immaculate Conception, sitting in screaming judgment of all those "dumb-asses" below him, well, he became the FIFTEENTH certified engine burner-upper. He couldn't take the egg on face, and resigned. Ran away. Wasted a great learning & teaching opportunity, and a chance at humility.

 

So, Spikey-baby. This, respectfully, is my point:

 

We don't need you to tell us what a dumb-ass, dozy, cretinous, Mickey Mouse, fu#@d up performance we all saw in those two videos. We can see that for ourselves.

What we need to find is answers to some vexing questions. If you pour scorn on what happened there, you basically dismiss the relevance of those abortions to the average pilot. See? STUPID! DUMB-ASS! Does NOT APPLY to US, because we're SMART. (really...)

 

Hold it. It IS relevant. To all of us. The pilot at the controls did not become a pilot in a vacuum. Who was his instructor? What supervision did he have in his early, formative stages? What did he SEE more experienced pilots DO, maybe all the time, that HE was trying to COPY??

Is there a COLLECTIVE GUILT applicable here?

 

You see my point? Not just ONE certifiable 'dumb-ass', but a whole klutz of 'dumb-asses' or at least, at-risk behavior in evidence around that pilot all day long.

 

I'll stick up for both those pilots. (First, I'll beat 'em black and blue, and kick them all around the flight line). But then, I'll defend them. They were NOT acting in ISOLATION. They were a product of an environment. A product of a CULTURE.

 

And PART of that culture is an attitude that gets on my tits:

 

Basically: "THEY ARE DUMB-ASSES and you can file that one away under STUPID and go back to your daily grind..."

 

Wrong. Flat out wrong. There are much more complex forces and influences at work here. Much more serious signs of a sick ENVIRONMENT, and a problematic CULTURE.

 

I still maintain: "there for the grace of God, go I." Maybe I was the instructor, maybe I was a local pilot with a cavalier flying style (who impressed our accident pilot so much, that HE wanted to be cool as well), etc, etc.

 

This kind of PUDDING PERFORMANCE is relevant to all of us. What can we do today to make our flying helicopters SAFER.

 

Arrrrr..... that was fun,

 

Mogster :)

 

(touchy-feeley philosopher) (where's my toast, honey?)

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(Ho-hummm...)

Okay, I'll bite... :P (day 1 of 7 off...)

 

@Spike...

 

This is obviously deep and meaningful, (heck, it may even have spiritual connotations), but I confess I don't have a clue what you're saying here.

 

OH, I liked that. Juicy. Are we giving with the one hand here, and quickly taking back with the other? Are we mouthing the inevitable (required) platitude, but instantly backing it up with quiet scorn at the suggestion? I mean, ah mean... really?

( ME? are you kidding??) :angry:

 

Maybe. Maybe not. But it does have room for ALL helicopter pilots, at ALL skill levels, at ALL experience levels, to periodically take (their own) little step back, and ask themselves a few personal, private questions. Like: "Am I really that good? Or maybe just average? Maybe a bit complacent even? Lemme try harder - today".

 

Some of us, in quiet corners, still reminisce about a certain haughty, furiously judgmental, hot tempered screamer, who worked as a training pilot somewhere in this world. He affected all sorts of people with his temper tantrums, and affected and influenced careers. His organization had experienced a very expensive rash. It's caused by pilots trying to take off in a twin engined choppy, with one engine still at idle. It burns up the live engine. Now, it takes four omissions from proper checklist procedure to accomplish this little trick. Our hero, El Capitan, him of the Immaculate Conception, sitting in screaming judgment of all those "dumb-asses" below him, well, he became the FIFTEENTH certified engine burner-upper. He couldn't take the egg on face, and resigned. Ran away. Wasted a great learning & teaching opportunity, and a chance at humility.

 

So, Spikey-baby. This, respectfully, is my point:

 

We don't need you to tell us what a dumb-ass, dozy, cretinous, Mickey Mouse, fu#@d up performance we all saw in those two videos. We can see that for ourselves.

What we need to find is answers to some vexing questions. If you pour scorn on what happened there, you basically dismiss the relevance of those abortions to the average pilot. See? STUPID! DUMB-ASS! Does NOT APPLY to US, because we're SMART. (really...)

 

Hold it. It IS relevant. To all of us. The pilot at the controls did not become a pilot in a vacuum. Who was his instructor? What supervision did he have in his early, formative stages? What did he SEE more experienced pilots DO, maybe all the time, that HE was trying to COPY??

Is there a COLLECTIVE GUILT applicable here?

 

You see my point? Not just ONE certifiable 'dumb-ass', but a whole klutz of 'dumb-asses' or at least, at-risk behavior in evidence around that pilot all day long.

 

I'll stick up for both those pilots. (First, I'll beat 'em black and blue, and kick them all around the flight line). But then, I'll defend them. They were NOT acting in ISOLATION. They were a product of an environment. A product of a CULTURE.

 

And PART of that culture is an attitude that gets on my tits:

 

Basically: "THEY ARE DUMB-ASSES and you can file that one away under STUPID and go back to your daily grind..."

 

Wrong. Flat out wrong. There are much more complex forces and influences at work here. Much more serious signs of a sick ENVIRONMENT, and a problematic CULTURE.

 

I still maintain: "there for the grace of God, go I." Maybe I was the instructor, maybe I was a local pilot with a cavalier flying style (who impressed our accident pilot so much, that HE wanted to be cool as well), etc, etc.

 

This kind of PUDDING PERFORMANCE is relevant to all of us. What can we do today to make our flying helicopters SAFER.

 

Arrrrr..... that was fun,

 

Mogster :)

 

(touchy-feeley philosopher) (where's my toast, honey?)

 

Sorry pal, not even in the park…… And if you please, stop ministering my posts in order to fill the next box in the thread….

 

Furthermore, IMHO, it’s rather insulting to say, on one hand, someone is being judgmental but on the other hand, this is how “I” do “it” ultimately suggesting, this is the best way to do “it” because it’s “how” “I” did it as an instructor…..

 

And, if it the mistakes were so obvious on the video, then why did the discussion go into a tit-for-tat “pick-up” lesson? Why? Because of the usual impulse of pilots to state the obvious in order to achieve self-importance (illustrated by the number of time one says “I”). This is a common theme on all helo-centric forums and no, I’m not immune. However, “I” call it like “I” see it. In all countries, certificates are simply bought subsequently resulting in the videos depicted above and in the case of the 120, apparently someone lost their life over it… That is, the day the life of the unfortunate victim was sealed was the day the pilot became a certified pilot….. Sad, truly sad…… Just because you can, doesn’t mean you should….

 

If the goal is to prevent this type of thing from happening again, one must start at the beginning and not at the middle of the issue. AGAIN, define the cause in order to change the result. If we only attempt to change the result (on our way to achieving self-importance), we miss the opportunity to fix the cause. AGAIN, in the videos it’s obvious “what” had happened (no f’n sh*t Frank). However, it’s the “why” it happened for which this tread seems to ignore (BTW, you said you were a cop once. Did you not learn, regardless of your feelings are, that there are dumbasses in this world?).

 

It’s easy to stand on the box and declare to know the answers but the reality is, if you’re not in the ballpark, the culture can’t change…. Attacking me won’t change anything either because it’s far to simple to do….

Edited by Spike
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Who was the instructor of the dumbass that washed a brand new freshly painted helicopter with Scotch Brite pads and ruined it? Like someone mentioned earlier..."Just because you can get a license to fly a helicopter, doesn’t necessarily mean you should……"

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