JetRanger crash Honolulu HI
John are you suggesting to disregard the HV chart in the RFM?
Of course there are obstacle/wind/terrain considerations that necessitate a steep approach for operational purposes in some instances, however I think Bell would disagree with your technique of flying well and truly in the shaded section of the HV chart for just about every approach.
** only talking about single engine aircraft here.
Of course there are obstacle/wind/terrain considerations that necessitate a steep approach for operational purposes in some instances, however I think Bell would disagree with your technique of flying well and truly in the shaded section of the HV chart for just about every approach.
** only talking about single engine aircraft here.
I recommended a steep approach such that a failure would leave the option of a successful autorotation, which is perfectly manageable within the recommended HV in the JetRanger Flight Manual.
That the approach chosen was too shallow is apparent from the flight path after the failure. Dragging a helicopter in to a landing spot on the backside of the power curve severely limits your options when Something Nasty Happens.
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I am from another school.....
For me, Steep approach mean lot of power available AND when you begin your speed reduction to land, your are "High", no power applied and very vulerable if anything happen.
Per sample : if the freewheel goes wrong at this time...your are ****** .
But i use it, i teach it, but only when needed
But i say it again, it's another school...
For me, Steep approach mean lot of power available AND when you begin your speed reduction to land, your are "High", no power applied and very vulerable if anything happen.
Per sample : if the freewheel goes wrong at this time...your are ****** .
But i use it, i teach it, but only when needed
But i say it again, it's another school...
Chaps,
All this talk of HV curves, surely nothing to prohibit entry to the HV curve unless local operating regulations prevent you from being in it.
The conditions the HV diagrams are built for are not those usually met on the approach, steep approaches provided an appropriate technique is used for the aircraft type may well be absolutely fine. Avoid going into the curve for departure but not necessarily on the approach (for commercial operations where I am from any way).
Some of the larger types have the HV curve in the limitations section at which point they must be respected.
Gary
All this talk of HV curves, surely nothing to prohibit entry to the HV curve unless local operating regulations prevent you from being in it.
The conditions the HV diagrams are built for are not those usually met on the approach, steep approaches provided an appropriate technique is used for the aircraft type may well be absolutely fine. Avoid going into the curve for departure but not necessarily on the approach (for commercial operations where I am from any way).
Some of the larger types have the HV curve in the limitations section at which point they must be respected.
Gary
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John Eacott said:
John, don't know if you were responding to my post about counting video frames or just responding to some of the people eyeballing it at full speed. You're certainly right that there are plenty of videos out there where the camera rate was close enough to the rotor RPM to cause illusions like stopped rotor systems.
In fact, that actually happens with the TR in this video: you can see that it appears stopped at first, the rotates slowly backward, and rotates slowly forward, etc. However you can tell that even when it appears to be moving backward that it is actually turning forward because the bottom blade appears bent forward due to the scanout of the video sensor.
Also, unlike the main rotor, the tail rotor is turning at a rate that is a multiple of the video capture speed. (2550 * 65% = 27 revolutions per second, very close to the 30 frames per second the capture unit was likely using. A 206 main rotor blade is turning at 6.5 revolutions per second at 100% Nr so this is unlikely to be aliased with any modern cell phone or video camera IMHO (with two blades you would be seeing 13 blades per second so if you were capturing at 15 frames per second you might get aliasing but I don't think any modern cell phone is capturing at that rate unless it's someone trying to capture at 4K, and you can easily tell 15 fps capture from the jerkiness of the video - note that lots of the "stopped MR" videos are 4 bladed where you're getting a 4x multiplier in the # of blades passing per second)
In any case, although the TR is showing these sorts of things in this video, the main rotor is turning slowly enough you can clearly watch the blade go round and round without it showing these sorts of video artifacts.
Then Arnie Madsen said:
That's what I was saying at first, it seemed weird to see the helicopter accelerate towards the surface when we would all expect a slow increase in vertical speed, like watching someone do a hovering auto. But when you realize he had only 65% Nr at the beginning of the video, it actually fits quite well. For whatever reason, he ran out of RPM fairly high up and the acceleration towards the surface was just gravity doing it's thing. We all expect to see a mush towards the ground because we're expecting flight RPM, but in this case he was already almost unpowered at the beginning of the video. Therefore I don't think it was anything like VRS - I think it was a classic case of running out of RPM because of loss of power.
Normally this is the part where I would lecture everybody about the importance of maintaining Nr right until impact "if you're gonna crash, crash with lots of RPM to pull right before impact". We had a bad fatal accident here in Boston a number of years back where a low time State Police pilot apparently stalled the rotor after an engine failure, the result being that they fell at the end of the sequence and were all killed. I immediately thought about that accident when I saw this video, but in reading people's comments I'm thinking there is a chance this was a deliberate decision on the part of the pilot:
A couple of people have mentioned that it was probably an emergency landing where he realized at the last second there were too many bystanders to make the landing where he planned and he ran out of options. That sounds pretty likely. Putting it right at the edge of the water certainly maximizes the chances of the water being shallow enabling everybody to get out of the aircraft (rather than mid channel, say). Maybe he used his RPM to get right next to the shore, rather than preserve it for a soft touchdown further from shore. A tough decision and one that I hope I don't have to ever make.
I'm hoping the pilot will be interviewed soon and and we'll get a first person account of exactly what was going on.
Rotor flicker/speed on a smartphone video is totally unreliable. Search for videos of stationary blades in flight, what you see on the video is unlikely to have any similarity to what actually happened.
In fact, that actually happens with the TR in this video: you can see that it appears stopped at first, the rotates slowly backward, and rotates slowly forward, etc. However you can tell that even when it appears to be moving backward that it is actually turning forward because the bottom blade appears bent forward due to the scanout of the video sensor.
Also, unlike the main rotor, the tail rotor is turning at a rate that is a multiple of the video capture speed. (2550 * 65% = 27 revolutions per second, very close to the 30 frames per second the capture unit was likely using. A 206 main rotor blade is turning at 6.5 revolutions per second at 100% Nr so this is unlikely to be aliased with any modern cell phone or video camera IMHO (with two blades you would be seeing 13 blades per second so if you were capturing at 15 frames per second you might get aliasing but I don't think any modern cell phone is capturing at that rate unless it's someone trying to capture at 4K, and you can easily tell 15 fps capture from the jerkiness of the video - note that lots of the "stopped MR" videos are 4 bladed where you're getting a 4x multiplier in the # of blades passing per second)
In any case, although the TR is showing these sorts of things in this video, the main rotor is turning slowly enough you can clearly watch the blade go round and round without it showing these sorts of video artifacts.
Then Arnie Madsen said:
I am just making guesses like everyone else and I keep leaning toward VRS because how else could it drop so fast .
VRS could also explain the rpm increase because of unloaded blades and unloaded engine during the VRS
As far as I can tell MR pitch was never reduced ... so if it was a shaft or sprague failure a 206 should have mushed down as MRRPM decayed , not the sudden drop we saw.
VRS could also explain the rpm increase because of unloaded blades and unloaded engine during the VRS
As far as I can tell MR pitch was never reduced ... so if it was a shaft or sprague failure a 206 should have mushed down as MRRPM decayed , not the sudden drop we saw.
Normally this is the part where I would lecture everybody about the importance of maintaining Nr right until impact "if you're gonna crash, crash with lots of RPM to pull right before impact". We had a bad fatal accident here in Boston a number of years back where a low time State Police pilot apparently stalled the rotor after an engine failure, the result being that they fell at the end of the sequence and were all killed. I immediately thought about that accident when I saw this video, but in reading people's comments I'm thinking there is a chance this was a deliberate decision on the part of the pilot:
A couple of people have mentioned that it was probably an emergency landing where he realized at the last second there were too many bystanders to make the landing where he planned and he ran out of options. That sounds pretty likely. Putting it right at the edge of the water certainly maximizes the chances of the water being shallow enabling everybody to get out of the aircraft (rather than mid channel, say). Maybe he used his RPM to get right next to the shore, rather than preserve it for a soft touchdown further from shore. A tough decision and one that I hope I don't have to ever make.
I'm hoping the pilot will be interviewed soon and and we'll get a first person account of exactly what was going on.
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No civilians land in the Pearl Harbor area on purpose. Joint Base Pearl Harbor Hickam is right next to Honlulu International Airport and typically the last area a tour flies over before returning to land.
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Tower Audio
The pilot said, "Tower, Chopper 8. I think I'm going down."
https://www.youtube.com/watch?v=MCKL...ature=youtu.be
https://www.youtube.com/watch?v=MCKL...ature=youtu.be
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Jeez, John, ...
... and I make the point long and loud to anyone who will listen: a steep approach is the only guard against losing power on short final that will assure a landing at the planned site for a single engine helicopter.
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Hmmmm, ...
John are you suggesting to disregard the HV chart in the RFM?
Of course there are obstacle/wind/terrain considerations that necessitate a steep approach for operational purposes in some instances, however I think Bell would disagree with your technique of flying well and truly in the shaded section of the HV chart for just about every approach.
Of course there are obstacle/wind/terrain considerations that necessitate a steep approach for operational purposes in some instances, however I think Bell would disagree with your technique of flying well and truly in the shaded section of the HV chart for just about every approach.
I would also note that many Canadian training pilots will cheerfully put a 55/58/204/206/205/500 in a 150' hover and wack the engine.
That said, if you do not need to increase risk - don't - fly outside the HV curve.
BOBAKAT:
Bobakat, I'm not exactly sure what you are getting at here. I don't know what you're teaching, but if *my* freewheeling unit or input drive shaft (or engine, or tail rotor) fails, I'd rather be steep with a little airspeed than shallow and slow. Autorotations (and by extension flat-pitch approaches) have been demonstrated in every certified helicopter at maximum gross weight. It does not take Chuck Aaron to perform this maneuver.
As it was lifted out of the water, the blades of the Hawaii 206 look absolutely undamaged, meaning that they were certainly not under power and turning very slowly when they hit the water. Considering that we hear the tail rotor turning at 100% rpm or perhaps more all the way through the descent, it indicates a disconnect between the main and tail rotors. *Something* very mechanically bad happened to that helicopter.
I am from another school.....
For me, Steep approach mean lot of power available AND when you begin your speed reduction to land, your are "High", no power applied and very vulerable if anything happen.
Per sample : if the freewheel goes wrong at this time...your are ****** .
For me, Steep approach mean lot of power available AND when you begin your speed reduction to land, your are "High", no power applied and very vulerable if anything happen.
Per sample : if the freewheel goes wrong at this time...your are ****** .
As it was lifted out of the water, the blades of the Hawaii 206 look absolutely undamaged, meaning that they were certainly not under power and turning very slowly when they hit the water. Considering that we hear the tail rotor turning at 100% rpm or perhaps more all the way through the descent, it indicates a disconnect between the main and tail rotors. *Something* very mechanically bad happened to that helicopter.
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@ FH1100 pilot
Sorry, i say again, we are helicopter pilot both, but not from the same "school". And i don't say you are wrong....i just explain some fact :
In europe (my school) :
Normal approach in Europe mean a slope between 3 and 5 °
For the FAA it's a "shallow approach".
For the FAA , the normal approach is under 13° .
"European Steep approach" begin above 5°
But is named "normal approach" By the FAA.
For the FAA, only above 13° slope it is a "Steep Approach.....
For me, to perform a steep approach and to maintain an acceptable rate of descent around 150 ft/mn, we reduce the speed at 2/3 of the normal speed approach.
For the FAA pilot, in "steep approach" they accept to have the rate of descent exceeding most of the time 300ft/mn.
I try the 2 method and i feel safer with "european Approach". Again, i don't say "you are wrong", i say, we are different...
Many post about "Settling with power" are posted by FAA pilot..... Why ? Easy, It is written in the FAA manual :
Steep Approach
A steep approach is used primarily when there are obstacles
in the approach path that are too high to allow a normal
approach. A steep approach permits entry into most confined
areas and is sometimes used to avoid areas of turbulence
around a pinnacle. An approach angle of approximately 13°
to 15° is considered a steep approach. [Figure 10-4] Caution
must be exercised to avoid the parameters for settling with
power
I drove for years on the right side of the road. Now for 10 years, i drive left side .... Nothing is wrong, just i moved from europe to Asia.
About the 206 crash, i explain just my opinion, but i say again : "i was not on board when the crash happened".
And maybe the T/R noise overspeed you are listen is the overspeed of the turbine runing free of charge ?
And sure, without free wheel, no more trust on the main and T/R. The blade of the T/R are destroyed ? As we see : no ...as the main rotor, for me they runing with a low speed at the impact..
And i am very surprised by the last audio posted there : the accident happen very quick on the vidéo and the pilot got the time to call the control and say : "i fall down" ?
Sorry, i say again, we are helicopter pilot both, but not from the same "school". And i don't say you are wrong....i just explain some fact :
In europe (my school) :
Normal approach in Europe mean a slope between 3 and 5 °
For the FAA it's a "shallow approach".
For the FAA , the normal approach is under 13° .
"European Steep approach" begin above 5°
But is named "normal approach" By the FAA.
For the FAA, only above 13° slope it is a "Steep Approach.....
For me, to perform a steep approach and to maintain an acceptable rate of descent around 150 ft/mn, we reduce the speed at 2/3 of the normal speed approach.
For the FAA pilot, in "steep approach" they accept to have the rate of descent exceeding most of the time 300ft/mn.
I try the 2 method and i feel safer with "european Approach". Again, i don't say "you are wrong", i say, we are different...
Many post about "Settling with power" are posted by FAA pilot..... Why ? Easy, It is written in the FAA manual :
Steep Approach
A steep approach is used primarily when there are obstacles
in the approach path that are too high to allow a normal
approach. A steep approach permits entry into most confined
areas and is sometimes used to avoid areas of turbulence
around a pinnacle. An approach angle of approximately 13°
to 15° is considered a steep approach. [Figure 10-4] Caution
must be exercised to avoid the parameters for settling with
power
I drove for years on the right side of the road. Now for 10 years, i drive left side .... Nothing is wrong, just i moved from europe to Asia.
About the 206 crash, i explain just my opinion, but i say again : "i was not on board when the crash happened".
And maybe the T/R noise overspeed you are listen is the overspeed of the turbine runing free of charge ?
And sure, without free wheel, no more trust on the main and T/R. The blade of the T/R are destroyed ? As we see : no ...as the main rotor, for me they runing with a low speed at the impact..
And i am very surprised by the last audio posted there : the accident happen very quick on the vidéo and the pilot got the time to call the control and say : "i fall down" ?
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The steep approach helps keep you in a safer position IF the engine quits on short final, but try steep slow approaches during summer in the mountains and you WILL have a lot of helicopters with pancaked skids.
But every approach is different, different locations, density altitudes, weights, etc. So there is never one perfect approach, the situation dictates what works best.
But every approach is different, different locations, density altitudes, weights, etc. So there is never one perfect approach, the situation dictates what works best.
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"What? Like coming to a hover at 500 ft agl in a Jet Box and then decending straight down?"
Sometimes yes, with a 150' line and 100ft. timber, I'll often do a 300' vertical descent in a 206B.
But at max gross with an internal load at high DA I'm making a smooth, shallow approach to the LZ, hard to arrest a fast descent rate in that scenario with a steep approach.
Sometimes yes, with a 150' line and 100ft. timber, I'll often do a 300' vertical descent in a 206B.
But at max gross with an internal load at high DA I'm making a smooth, shallow approach to the LZ, hard to arrest a fast descent rate in that scenario with a steep approach.
But at max gross with an internal load at high DA I'm making a smooth, shallow approach to the LZ, hard to arrest a fast descent rate in that scenario with a steep approach.
I recommended a steep approach such that a failure would leave the option of a successful autorotation, which is perfectly manageable within the recommended HV in the JetRanger Flight Manual.
That the approach chosen was too shallow is apparent from the flight path after the failure. Dragging a helicopter in to a landing spot on the backside of the power curve severely limits your options when Something Nasty Happens.
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But at max gross with an internal load at high DA I'm making a smooth, shallow approach to the LZ, hard to arrest a fast descent rate in that scenario with a steep approach.
I rest my case...
I rest my case...
hard to arrest a fast descent rate in that scenario with a steep approach.
It should be accomplished slowly, less than 200 ft/min descent rate and a slow walking pace forward with full In Ground Effect Hover power before you get below the demarcation line or before you descend below your "fly away point".
I mentioned in posts No's 7 & 9 that it appears to be an approach to a precautionary landing at a suitable open space.
Obviously might not be doable all the time, and WIRES may well be a factor if you don't have time to check properly, but all things being equal it's going to give you auto potential all the way down if power or drive are lost.
Maybe this is a little off-topic. It's funny that some pilots assume that a steep approach is necessarily a steep and fast approach. This is not the case. I flew a 206B for a rich guy - mainly out of his hunting camp and various dealerships that he owned. The sites we used were ALWAYS confined and we were ALWAYS heavy, both going in and coming out. There was no such thing as a "nice, gentle, shallow approach" to any of these places. The approaches often went beyond the FAA definition of "steep." Forty-five degrees was not uncommon.
You learn how to do it - learn how to ride the ETL burble all the way down. The 206 is great in this regard: Hold a cabin attitude that is just a degree or two below the horizon. As you come down into ground effect, simply raise the nose to the hover attitude (2 or 3 degrees above the horizon). Voila! The ship stops with hardly any power change at all. Very rewarding when done right.
Shallow approaches are for airplanes. In a helicopter I'll always take a steep approach over a shallow one. It might not always guarantee that I'll hit my intended spot if the engine quits, but I believe it's better than doing what the Hawaii 206 did.
You learn how to do it - learn how to ride the ETL burble all the way down. The 206 is great in this regard: Hold a cabin attitude that is just a degree or two below the horizon. As you come down into ground effect, simply raise the nose to the hover attitude (2 or 3 degrees above the horizon). Voila! The ship stops with hardly any power change at all. Very rewarding when done right.
Shallow approaches are for airplanes. In a helicopter I'll always take a steep approach over a shallow one. It might not always guarantee that I'll hit my intended spot if the engine quits, but I believe it's better than doing what the Hawaii 206 did.