Bell 407 Hard Landing Germany

[muermel]

A Bell 407 registration D-HEAB did a hard landing after "technical difficulties with the engine". Seems like the pilot autorotated into a field, the pilot was unharmed. The helicopter sure seems to be in a lot worse state.

https://www.hna.de/lokales/hofgeismar/hofgeismar-ort73038/notgelandeter-helikopter-schwere-schaeden-sichtbar-6522304.html

Aircraft was on it's way from Assen/ NL to Ingolstadt (Bavaria) and the pilot was the only occupant. The accident site is roughly 5 NM north of Kassel-Calden (EDVK) where the pilot was headed to refuel.

Lucky guy I'd say :ok:

[albatross]

Glad he made it...sorry about the tailboom chop.

[Flyting]

Definately not a hard landing... Skids aren't bent at all.

[gulliBell]

Nice wide open area to autorotate into. Looks like the toe of the skids may have dug in causing the thing to rock forward and chop off the tail. This will be an expensive repair. Hopefully for the pilot it's not a case of engine failure due to fuel exhaustion.

[whoknows idont]

Maybe not so wide open as he closely avoided the wires... You don't see the wires in any of the other pictures so they must be pretty close to the resting position of the A/C...

[212man]

What's the white bracket on the rear underside?

[whoknows idont]

I'd say that's a camera mount.

[Bell_ringer]

From the close up pic of the cowling, the floor under the main gearbox appears to have sagged which would indicate some vertical energy. Unless my pre-coffee state is causing me to see things.

Edit: Post coffee just noticed it is an optical illusion created by the support for the camera mount.

[HeliHenri]

.
Brazil,same day, same type, 5 POB, they didn't have the same luck :(

The Bell 407 crashed and caught fire

https://aviation-safety.net/wikibase/wiki.php?id=188411


http://i0.wp.com/www.cavok.com.br/blog/wp-content/uploads/2016/06/IMG_5573.jpg

[mickjoebill]

There is a side mount and a nose camera mount fitted.


Mickjoebill

[212man]

Thanks WKID and MJB.

Of course we don't see ANFI on these single engine threads!

[whoknows idont]

Of course we don't see ANFI on these single engine threads!

Strange, isn't it? :E

[Loki696]

What I heard is that the machine left early from the Dutch TT and did not film the GP 2 and also not the main event of the TT the GP 1.

[krypton_john]

Given we don't know the cause of these crashes, why would you expect anFI for anyone else to comment?

Petty stuff around a serious issue IYAM. :-\

[AnFI]

ooh i see i get a mention again 212 and idontknow

was there a problem? we don't know the cause (the guy presumably ran out of fuel) but we know he autorotated successfully as far as the current mandated (inadequate under EASA) stardard requires

[gulliBell]

I guess the definition of a successful autorotation is one where you're able to get out and walk away unharmed after the event. In which case this one would be successful. It's just a shame to see all that damage when the forced landing area options seem 8/8 flat level for as far as the eye can see.

When I read engine failure 5 minutes out from the refuelling stop screams volumes to me.

[canausheli]

I wonder how much they had to pay the farmer for the damage to his crop, good looking heads.

[Bell_ringer]

I find it difficult to believe that someone wouldn't opt to put it down in a field and take their medicine rather than carry on.
A 407 isn't complex and missing the amber caution, which would be lit for almost 30 minutes, and not seeing the fuel guage drop to two-digits and below seems unusual.

It would be interesting to see what recent maintenance may have been performed.

[hueyracer]

So far, it is only a rumor that was brought up here in this forum by other users...

Yes-running out of fuel was the first thing coming into my mind as well when i read the post.....but that does not mean anything...

I am curious to see what the investigation finds out.....

I have mentioned this in another post before:
I put an aircraft down 5 klicks away from an airfield once (with still enough fuel in it to go all the way, just due to the weather with strong headwind, the light came on early, and i did not want to risk it)...

The struggle i had to go through with the authorities in Germany is unbelievable, and it led me to the conclusion that i´d rather risk autorotating it somewhere next time (which of course i will not do)...

The whole aviation industry, but especially the authorities are f*#*# up!

[chopjock]

When I read engine failure 5 minutes out from the refuelling stop screams volumes to me.

So he had a full tank then?

[gulliBell]

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.

[evil7]

Hallo Gentlemen,

Just to clarify. The aircraft was about to make a fuel stop in Kassel but didn't make it there.
This statement is not meant to imply anything!

[AnFI]

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

[LRP]

it's a little different at the bottom when the engine isn't at idle...just sayin.

[oleary]

No, it is not.

[Bell_ringer]

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.

[hueyracer]

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...

[212man]

it's a little different at the bottom when the engine isn't at idle...just sayin.

Because why, exactly?

[hueyracer]

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........

[212man]

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.


That's like say a car engine drives the wheels when the clutch is depressed fully! Unless, the Nr/N2 needles aren't split in which case it's potentially not true autorotation ('Flight Idle Glide').

[hueyracer]

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...

[oleary]

212man is right. :8

[krypton_john]

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
?

[mickjoebill]

Rumours from that part of the world is that it was engine chip light followed by engine out.


Mickjoebill

[RVDT]

it's a little different at the bottom when the engine isn't at idle...just sayin.

Correct.

Because why, exactly?

Read Ray Prouty's books again - if you haven't already.

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. :cool:

[212man]

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...

Well, I rather hoped you might explain it to me then you might get an idea of what I'm talking about!

A freewheel is a form of clutch. Clutches are used de-couple shafts. Not much more to say really.......

[AnFI]

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. http://cdn.pprune.org/images/smilies/cool.gif"

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.

[Bell_ringer]

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. :uhoh:

[Paul Cantrell]

On the subject of autorotating while light, AnFI said:

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?

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! :confused:

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... :eek:

Of course the best thing is to just land before the darn thing flames out...

[Reely340]

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. :sad:

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?

[Salusa]

From an engineering perspective, in single engine high inertia (206L3+) we always set up auto revs as close to "operational weight and performance " as possible.

It can be a wide margin with fuel burn, cargo internal/hook, high to low altitude etc. On long line in hover pretty much down to walking away rather than saving the aircraft and all credit to those that do.

Better to overspeed light weight with high RPM and recognise and control early than go down heavy with low RPM was philosophy...

Doesn't matter after engine failure if overspeed, overtorque , boom strike etc, walk away is the best result.

Different subject, but would rather be in a wagon with a bloke that's gone from single to twin rather than other way round. No offence, just my own opinion. Subject just reminded me...

[Salusa]

Clarification, light is better, heavy bad