Bell 407 Hard Landing Germany
I read it as he was heading towards his refuelling stop. But I don't know.
@Bell_ringer: totally believable as it's happened time and time again before (Channel 10 in Perth, and others). It's a human factors thing that some pilots will take the risk and press on with low fuel when so close to destination, save any embarrassment. If only for another 20L of gas and nobody would ever know.
@Bell_ringer: totally believable as it's happened time and time again before (Channel 10 in Perth, and others). It's a human factors thing that some pilots will take the risk and press on with low fuel when so close to destination, save any embarrassment. If only for another 20L of gas and nobody would ever know.
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but it does in the balance of probability
and a fuel empty 407 should be a doddle to autorotate, modern training does not require better than that for some reasons to do with the chance of engine failure being so remote as to not warrant it
but really its a general skill level that should be present
and a fuel empty 407 should be a doddle to autorotate, modern training does not require better than that for some reasons to do with the chance of engine failure being so remote as to not warrant it
but really its a general skill level that should be present
Something worth considering is that an auto onto soft, furrowed farm soil may not be as forgiving as you would expect - plenty of opportunity for the skids to dig in.
If the machine noses over there is also opportunity for the wirestrike kit on the chin to dig in, though this is more probable on low skids - same occurred to a local 206 not that long ago.
If the machine noses over there is also opportunity for the wirestrike kit on the chin to dig in, though this is more probable on low skids - same occurred to a local 206 not that long ago.
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Can´t see anything wrong with this....
Yes-most of the pprunians would have autorotated it onto a small track, and would have been able to park it nice and parallel in a way that not even a single leaf would have been bent......
Jokes aside:
An unexpected autorotation is always a reason for some adrenalin rushing through veins-Mayday-call (if one has the time for that AND does remember), looking for a field, controlling rpm-flare, cushion-down.
The whole thing probably happened in less than 60 seconds...the pilot walked away unharmed....so i´d like to say "well done"..
Autorotating into crops is always a bit of an unknown-one cannot see the surface, and its more difficult to judge the exact skid height......
Until the reason for this emergency is made public, i recommend to stop any kind of "pilot bashing"....and save that for later...
Yes-most of the pprunians would have autorotated it onto a small track, and would have been able to park it nice and parallel in a way that not even a single leaf would have been bent......
Jokes aside:
An unexpected autorotation is always a reason for some adrenalin rushing through veins-Mayday-call (if one has the time for that AND does remember), looking for a field, controlling rpm-flare, cushion-down.
The whole thing probably happened in less than 60 seconds...the pilot walked away unharmed....so i´d like to say "well done"..
Autorotating into crops is always a bit of an unknown-one cannot see the surface, and its more difficult to judge the exact skid height......
Until the reason for this emergency is made public, i recommend to stop any kind of "pilot bashing"....and save that for later...
it's a little different at the bottom when the engine isn't at idle...just sayin.
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He is right-even when in idle, the engine will still drive the rotor system-though at a much lower speed, but preventing a total drop in rpm.
Plus many people underestimate the different stress levels produced by the total absence of noise........
Plus many people underestimate the different stress levels produced by the total absence of noise........
He is right-even when in idle, the engine will still drive the rotor system-though at a much lower speed, but preventing a total drop in rpm.
There's reduced ground effect over long grass (and water, and other energy dissipating surfaces) so the landing will be harder, if all other things are equal.
And surely once the needles are split it makes no difference if the engine is at 0%, idle or whatever - assuming you're not going to attempt to get power recovery and re-match them
?
And surely once the needles are split it makes no difference if the engine is at 0%, idle or whatever - assuming you're not going to attempt to get power recovery and re-match them
?
it's a little different at the bottom when the engine isn't at idle...just sayin.
Because why, exactly?
Practice and reality can be quite different.
And while we are at it a "light" helicopter can be your worst nightmare.
Come back when you have had a think about it.
So explain to me how the freewheel-unit works, please?
I guess by describing this, you might get an idea of what i am talking about...
I guess by describing this, you might get an idea of what i am talking about...
A freewheel is a form of clutch. Clutches are used de-couple shafts. Not much more to say really.......
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RVDT:
"And while we are at it a "light" helicopter can be your worst nightmare.
Come back when you have had a think about it.
"
IMO being light is a huge advantage to acheiving an easy landing. So having thought about it for over 40yrs now could you please let me know why it can be my worst nightmare?
(are you worried that sufficient autorevs might not be acheived? i don't think that is significant as can be seen from the autorotating independant rotor system in Norway, a light helicopter doesn't need the same RPM that a heavy one needs, and you can wind up the revs as required in a flare anyway (sometimes special techniques required)
OR
Are you refering to the marginal conditions where you can get further (and stay up longer) with more weight due to more Potential Energy and a potentially increased efficiency
OR
is it something I'm missing? if so please help)
212 i think 'engine on' EOL is very slightly easier for cushioning ("at the bottom") if N2 is not far under Nr. as Nr droop catches N2 then the inertial contribution plus some marginal gas flow contribution makes a little (noticeable) help.
Engines can stop, its not really a large risk, relative to the other risks that in practice cause so much more death.
"And while we are at it a "light" helicopter can be your worst nightmare.
Come back when you have had a think about it.
"IMO being light is a huge advantage to acheiving an easy landing. So having thought about it for over 40yrs now could you please let me know why it can be my worst nightmare?
(are you worried that sufficient autorevs might not be acheived? i don't think that is significant as can be seen from the autorotating independant rotor system in Norway, a light helicopter doesn't need the same RPM that a heavy one needs, and you can wind up the revs as required in a flare anyway (sometimes special techniques required)
OR
Are you refering to the marginal conditions where you can get further (and stay up longer) with more weight due to more Potential Energy and a potentially increased efficiency
OR
is it something I'm missing? if so please help)
212 i think 'engine on' EOL is very slightly easier for cushioning ("at the bottom") if N2 is not far under Nr. as Nr droop catches N2 then the inertial contribution plus some marginal gas flow contribution makes a little (noticeable) help.
Engines can stop, its not really a large risk, relative to the other risks that in practice cause so much more death.
At flight idle NG,NP and (without the freewheeling unit) NR would be well below the minimum rpm required to sustain flight or to make a material difference to the experience. Apart from human stress factors, it's a largely academic discussion.
Back to the handbags ladies.
Back to the handbags ladies.
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On the subject of autorotating while light, AnFI said:
I'm more in the camp that it's more difficult to autorotate when light, although I've only been thinking about it for 30 years so maybe in the next 10 years I'll change my mind! 
Obviously this depends a lot of the model helicopter and how it's rigged. You can always bias the collective pitch rigging to favor light or heavy autorotations, and most of us want a compromise because we fly in both configurations.
Many years ago I flew an Enstrom F28a, arguably one of the easiest helicopters to autorotate. My typical planning had me getting back to base with minimum fuel, therefore at very low weight. At that weight in autorotation the Nr would be sitting at the bottom of the legal range which is a pretty typical way to rig a helicopter. The amount of pull available at the bottom was noticeably less than at higher weights, making it much harder to do a good touchdown than when heavier. It was difficult to get zero ground-run at those weights on a calm day.
I played with a bunch of techniques trying to get good landings on the F28a at minimum weights and really didn't arrive at any techniques that gave me as good a landing as when I was at a higher weight. At light weights a flare hard enough to increase RPM ends up ballooning the aircraft which obviously isn't good. I tried hard turns while flaring to load the rotor during the flare but that didn't work as well as I would have hoped. I did finally arrive at a technique that worked well enough, but it was definitely not as good as just adding a few hundred pounds to the weight of the aircraft!
The opposite is obviously true: landing at max weight you have a lot more vertical momentum to arrest, and it takes more Nr to do the final part of the landing, so you can again find it difficult to achieve a soft landing with minimum ground run.
On a low inertia machine you might not notice the weight difference as much because you pretty much accept that there is going to be ground run and you tend to use a less aggressive flare at the bottom, more to arrest the sink than worry about trying to kill all the forward speed.
On the F28 with oleos I'd still rather hold the flare longer and take a bit of a vertical impact because sliding on oleos is distinctly uncomfortable in my opinion (the forward tilt of the fuselage as you decelerate). On a rigid gear like a Bell it's comfortable to slide, but if the ground is rough and the skids dig in...
Of course the best thing is to just land before the darn thing flames out...
IMO being light is a huge advantage to acheiving an easy landing. So having thought about it for over 40yrs now could you please let me know why it can be my worst nightmare?
Obviously this depends a lot of the model helicopter and how it's rigged. You can always bias the collective pitch rigging to favor light or heavy autorotations, and most of us want a compromise because we fly in both configurations.
Many years ago I flew an Enstrom F28a, arguably one of the easiest helicopters to autorotate. My typical planning had me getting back to base with minimum fuel, therefore at very low weight. At that weight in autorotation the Nr would be sitting at the bottom of the legal range which is a pretty typical way to rig a helicopter. The amount of pull available at the bottom was noticeably less than at higher weights, making it much harder to do a good touchdown than when heavier. It was difficult to get zero ground-run at those weights on a calm day.
I played with a bunch of techniques trying to get good landings on the F28a at minimum weights and really didn't arrive at any techniques that gave me as good a landing as when I was at a higher weight. At light weights a flare hard enough to increase RPM ends up ballooning the aircraft which obviously isn't good. I tried hard turns while flaring to load the rotor during the flare but that didn't work as well as I would have hoped. I did finally arrive at a technique that worked well enough, but it was definitely not as good as just adding a few hundred pounds to the weight of the aircraft!
The opposite is obviously true: landing at max weight you have a lot more vertical momentum to arrest, and it takes more Nr to do the final part of the landing, so you can again find it difficult to achieve a soft landing with minimum ground run.
On a low inertia machine you might not notice the weight difference as much because you pretty much accept that there is going to be ground run and you tend to use a less aggressive flare at the bottom, more to arrest the sink than worry about trying to kill all the forward speed.
On the F28 with oleos I'd still rather hold the flare longer and take a bit of a vertical impact because sliding on oleos is distinctly uncomfortable in my opinion (the forward tilt of the fuselage as you decelerate). On a rigid gear like a Bell it's comfortable to slide, but if the ground is rough and the skids dig in...
Of course the best thing is to just land before the darn thing flames out...
Nice writeup, Paul. Scary consequences, though. As I'm not allowed (e.g. insurance would bail) to practize autorotation on the leased S300C, I've to resort to having the FI with me. With half an hour fuel and my 250 pounds I never ever could have the pitch fully down for more than ~4 second or the Nr would exceed top power-off end of the arc.
But if I digested your description, an unplanned/emergency autorotation w/o passenger might feel very different to the ones I legally can practize.
I therefore plead to mandate minimum insurance coverage to include praticing emergency maneouvres at an air field. How else should we be able to hone real world skills?
But if I digested your description, an unplanned/emergency autorotation w/o passenger might feel very different to the ones I legally can practize.
I therefore plead to mandate minimum insurance coverage to include praticing emergency maneouvres at an air field. How else should we be able to hone real world skills?