French MP and billionaire Olivier Dassault dies in helicopter crash

[Carbon Bootprint]

French MP and billionaire Olivier Dassault has died in a helicopter crash in north-western France.

The accident occurred on Sunday evening in Normandy where he had a holiday home, according to police sources.

In his tribute, President Emanuel Macron said Dassault, 69, loved France and his death would be "a great loss".

Dassault was the son of industrialist Serge Dassault, whose group builds Rafale war planes and owns Le Figaro newspaper.

Full story on the Beeb. (https://www.bbc.com/news/world-europe-56313271?xtor=AL-72-%5Bpartner%5D-%5Bbbc.news.twitter%5D-%5Bheadline%5D-%5Bnews%5D-%5Bbizdev%5D-%5Bisapi%5D&at_custom1=%5Bpost+type%5D&at_campaign=64&at_custom3=%40BBCWorld&at_custom2=twitter&at_custom4=8AC6B684-7F75-11EB-BA25-A3E84744363C&at_medium=custom7)

[piesupper]

https://on.rt.com/b3a8

[Del Prado]

Le décès d'Olivier Dassault et du pilote a été confirmé dimanche par Delphine Mienniel, procureur de la République de Lisieux, qui s'est rendu sur place. Le Bureau d'Enquêtes et d'Analyses pour la Sécurité de l'Aviation civile a indiqué dans un tweet que l'appareil, un Aérospatiale AS350 Écureuil, s'était écrasé «au décollage», effectué «depuis un terrain privé».

The Bureau of Investigation and Analysis for Civil Aviation Safety said in a tweet that the aircraft, an Aerospatiale AS350 Squirrel, had crashed "on takeoff", carried out "from private land".

[ApolloHeli]

Reported as F-GIBM (AS 350 B). Weather at nearby Deauville (LFRG):
METAR LFRG 071800Z AUTO 03008KT CAVOK 03/M02 Q1023 NOSIG=
METAR LFRG 071730Z AUTO 02008KT CAVOK 04/M03 Q1023 NOSIG=
METAR LFRG 071700Z AUTO 01008KT CAVOK 05/M02 Q1023 NOSIG=
METAR LFRG 071630Z AUTO 01010KT 340V040 CAVOK 06/M02 Q1023 NOSIG=
METAR LFRG 071600Z AUTO 02008KT 340V050 CAVOK 06/M02 Q1023 NOSIG=

[172510]

His own AS 350 B reg F-GIBM .

[cavuman1]

Now, at last, le Petit Prince has some fine company along with Monsieur Antoine de Saint-Exupery....

- Edvard

https://cimg1.ibsrv.net/gimg/pprune.org-vbulletin/343x429/littleprince_0951b494ced7385da6d96c7c7c5803c5d02cd858.jpg

[atakacs]

Still baffled by the number of extremely wealthy people giving their life to rotorcrafts over the years..

[nomorehelosforme]

Once again another VVIP flight with a single pilot, why do people with all the money in the world keep doing this!!!

That said there have been many in-depth discussions on here regarding 2 pilot operations that have had some grim outcomes

More information here,

https://aviation-safety.net/wikibase/248616

[atakacs]

Well we don't know if it played a role but I'd agree that if you can afford 2 pilot + dual turbine seems a prudent approach to those flying contraptions.

[havick]

Two pilot ops have killed just as many fancy passengers.

[Gustaf2]

Man another wealthy guy dead in a helicopter crash :/

[filejw]

Still baffled by the number of extremely wealthy people giving their life to rotorcrafts over the years..
Helicopter generally are flown in more risk exposure environments and have many more critical parts than fixed wing aircraft. Just the nature of the beast so to speak and I assume most of the people who own and or use helicopters know the increased risk. I remember in 1970 an old US Army pilot telling me helicopter accident losses in Vietnam almost the same as those lost in combat.

[helonorth]

Well we don't know if it played a role but I'd agree that if you can afford 2 pilot + dual turbine seems a prudent approach to those flying contraptions.
This only seems to kill twice as many pilots.

[gulliBell]

Photo of emergency services responding on a very dark night. I think they'll wrap this investigation up quite quickly. Probably nothing new here.

[lederhosen]

Olivier Dassault was an extremely accomplished pilot, graduate of the French Air Force academy and rated on many aircraft. I don't know for sure, but I would be very surprised if he was not rated on his own helicopter. Someone else I knew always flew his own turbine helicopter with with another pilot, basically two crew operations.

[skadi]

Photo of emergency services responding on a very dark night. I think they'll wrap this investigation up quite quickly. Probably nothing new here.

The crash happend during daylight before sunset around 18:00 LCL, SS 18:50
According to the S/N the AS350 was built in the early eighties!

Skadi

[ApolloHeli]

Photo of emergency services responding on a very dark night. I think they'll wrap this investigation up quite quickly. Probably nothing new here.
It was CAVOK, about 10kts of wind and more than an hour before official night. Disorientation would be a stretch here.

[4468]

Olivier Dassault was an extremely accomplished pilot, graduate of the French Air Force academy and rated on many aircraft. I don't know for sure, but I would be very surprised if he was not rated on his own helicopter. Someone else I knew always flew his own turbine helicopter with with another pilot, basically two crew operations.

One can only imagine what having the billionaire aircraft owner and pilot’s employer as an actual crew member might do to CRM and/or any decision making process? 😳

Not a situation I’d like to be in.

[skadi]

One can only imagine what having the billionaire aircraft owner and pilot’s employer as an actual crew member might do to CRM and/or any decision making process? 😳

Not a situation I’d like to be in.

It was a chartered helicopter:

https://www.abchelico.com/#3

skadi

[alicopter]

It was a chartered helicopter:

https://www.abchelico.com/#3

skadi
The machine operator is Dolijet and "D assault Oli vier" is the sole shares owner, surely that makes it his own.... They hit a tree on take off...
May they rest in peace, both of them and thank you Mr Dassault for such contributions to a shared passion, Aviation.

[alicopter]

Olivier Dassault was an extremely accomplished pilot, graduate of the French Air Force academy and rated on many aircraft. I don't know for sure, but I would be very surprised if he was not rated on his own helicopter. Someone else I knew always flew his own turbine helicopter with with another pilot, basically two crew operations.
I think I know who you are refering to when mentioning your friend flying with a pro in the left seat... it is an insurance imposition and Show-Business requirement.

[lederhosen]

Alicopter beat me to it regarding ownership through Dolijet. But I would be surprised if he and I are thinking of the same person regarding always flying with another pilot, although the point about insurance is a good one. Tragic ending, but what an aviation life Dassault had. I cannot think of any other billionaires who were Air Force fighter pilots....role model for my next life! By the way some of the speculation and opinion passed off as gospel on this short thread has been up there with PPRune's best traditions.

[172510]

many in-depth discussions on here regarding 2 pilot operations that have had some grim outcomes

I think that what makes the difference is not a second pilot, but the discipline of an AOC operation.

[lederhosen]

But is that not what abchelico would be offering? it seems that Dassault owned the machine through Dolijet and quite probably had it managed and chartered out through abc with an AOC. We will find out soon enough what licence the other pilot had and what the currency and experience of both occupants was. But the Leicester City owner's very public crash and the one taking off in the Bahamas at night are but two examples where having two pilots and an AOC did not make a difference.

[172510]

From many newsfeeds
Une pale de l'appareil a "heurté un arbre", a aussi précisé la procureure.
(The coroner said the rotor hit a tree)

[CDG1]

Ouest France posted an update with more details (translated)

The first elements of the investigation indicate that "the takeoff was atypical. There is no evidence yet to confirm that the helicopter was not in the same location as usual. But instead of taking off at 90 degrees, rising off the ground at a right angle, the helicopter instead took off at a 45-degree angle and struck the branch of a tree. One blade was sectioned and the occupants of the helicopter were ejected. "
A blade from the craft, which "was not recent", "hit a tree," the prosecutor also said.
...
The pilot, Jean-Claude Bedeau, was born on February 25, 1947 (74 years old) in Paris. “He had had a career as an airline pilot. "

-50%
https://www.ouest-france.fr/normandie/touques-14800/mort-d-olivier-dassault-dans-un-crash-d-helicoptere-le-decollage-s-est-fait-de-facon-atypique-7179059

[172510]

But is that not what abchelico would be offering? it seems that Dassault owned the machine through Dolijet and quite probably had it managed and chartered out through abc with an AOC.
Typical owner deal is that the aircraft may be used by the AOC holder when the owner does not need it. When the owner needs it is then still operated by the AOC holder but as a private flight (ORO.AOC.125 explained here https://xcaviation.wordpress.com/2018/07/16/preparation-et-vol-ifr/ if you read French ) and so part CAT regs are not mandatory anymore, the ops manual can be as simple as "just use part NCC/NCO regs" . In that case the pilots were too old anyway to fly under part CAT operation

We will find out soon enough what licence the other pilot had and what the currency and experience of both occupants was. But the Leicester City owner's very public crash and the one taking off in the Bahamas at night are but two examples where having two pilots and an AOC did not make a difference.
Isn't the accident you are referring to due to a mechanical failure of the tail rotor?(*) Anyway there is no way to be 100% sure that there won't be any accident ever, I'm just convinced that the discipline of a part CAT operation does increase safety a lot compared to part NCC/NCO operation. The fact that all the paperwork of the flight must be stored and available for inspection and is actually inspected, the mandatory line checks, the currency of the crew , the event reporting system etc.
The 74 years old pilot was certainly not as current as a part CAT pilot.
(*)EDIT Yes it was according to AAIB preliminary report. At 0 speed and low height, no crew can do much when such a thing happens . Standard procedure does not work at low height/speed, and the failure has no reason to happen at a reasonable speed.

[lederhosen]

The 74 year old pilot (if confirmed) does suggest a private flight. My experience of this kind of operation was the owner (who was type rated) choosing to have a professional pilot along at all times. The professional pilot of course flew other charter operations single pilot. Appears to be a different case here. Two very experienced aviators down and a sad way to go.

There is quite a lot of (also unconfirmed) speculation in the French press which does indeed paint a somewhat different picture. Dassault had apparently acquired the helicopter quite recently and was said to be taking instruction from the other pilot, who was an ex Air France captain. The ground was wet, leading to the aircraft landing in a less than ideal position for the subsequent takeoff. Who was flying at the time of the takeoff is unclear and may be hard to ascertain. In any case the takeoff was reported to be unusual and different from previous departures with the blades then impacting a tree. Whether the late hour, and concerns about completing the flight by nightfall played a role were also considered. One view was that there were an unfortunate set of circumstances leading up to the crash.

[Hot and Hi]

Once again another VVIP flight with a single pilot, why do people with all the money in the world keep doing this!!!


Maybe it has to do with the feeling of guilt? The social pressure to not use and display your wealth to any real advantage.

Not a stranger on these pages.

[atakacs]

Rumor mill has that they indeed landed (and departed) from an unusual spot as the ground was soaked.
Also the flight was probably illegal as there is a curfew in France at 1800. All VFR flights are to terminate before that.

[malabo]

Missed the part supporting the statement of “two very experienced aviators” in the context of a helicopter accident. Was this area “confined” - in the Canadian context of the word, not Texan, and if so what was their relevant experience in such an operation. Experience flying off a runway is irrelevant.

[[email protected]]

The France 3 article linked on the Aviation Safety Net page shows a map of the approximate crash location - on one side of the road is a large house with an oblong field surrounded by trees - the talk of taking off in an unusual direction may be lifting out of that area across the field instead of down it.

It wouldn't take much of a drift in that case to get too close to the trees either ahead or behind and a TR or MR strike could easily have disastrous consequences.

[Michael Gee]

Still no picture of incident !

[172510]

Rumor mill has that they indeed landed (and departed) from an unusual spot as the ground was soaked.
Also the flight was probably illegal as there is a curfew in France at 1800. All VFR flights are to terminate before that.
VFR flight are not treated differently than IFR flights.
There are seven ways to leave home legally
Art. 4.-I.-Tout déplacement de personne hors de son lieu de résidence est interdit entre 20 heures et 6 heures du matin à l'exception des déplacements pour les motifs suivants, (...)
« 1° Déplacements à destination ou en provenance :
« a) Du lieu d'exercice ou de recherche d'une activité professionnelle et déplacements professionnels ne pouvant être différés ;
« b) Des établissements ou services d'accueil de mineurs, d'enseignement ou de formation pour adultes mentionnés aux articles 32 à 35 du présent décret ;
« c) Du lieu d'organisation d'un examen ou d'un concours ;
« 2° Déplacements pour des consultations, examens et soins ne pouvant être assurés à distance et ne pouvant être différés ou pour l'achat de produits de santé ;
« 3° Déplacements pour motif familial impérieux, pour l'assistance aux personnes vulnérables ou précaires ou pour la garde d'enfants ;
« 4° Déplacements des personnes en situation de handicap et, le cas échéant, de leur accompagnant ;
« 5° Déplacements pour répondre à une convocation judiciaire ou administrative ;
« 6° Déplacements pour participer à des missions d'intérêt général sur demande de l'autorité administrative ;
« 7° Déplacements liés à des transferts ou transits vers ou depuis des gares ou aéroports dans le cadre de déplacements de longue distance ;

[Del Prado]

172510,

1800-0600. there are a couple of extra exceptions on the attestation de déplacement dérogatoire now too.

[McGowan]

This is why I don't look at pprune any more.
So many armchair experts. You were not in the aircraft, you do not have any idea what was going on, wild guesses as to what the dynamic was between the pilot and owner are just bull****.
All of this does nothing to help. let investigators do their jobs, they know what they are doing and all of this speculation does nothing for the families of those killed.

[nomorehelosforme]

This is why I don't look at pprune any more.
So many armchair experts. You were not in the aircraft, you do not have any idea what was going on, wild guesses as to what the dynamic was between the pilot and owner are just bull****.
All of this does nothing to help. let investigators do their jobs, they know what they are doing and all of this speculation does nothing for the families of those killed.

Sir with respect,

If this is the reason you no longer look at PPRuNe it maybe time to hang up your boots and delete your profile....Agreed some ‘rumours and speculation’ on this site often are full of BS but when you look through that you will see the many many discussions that are extremely beneficial for many users on this site.

Maybe time for you to sit back in your armchair and read a good novel... hopefully nothing to do with aviation!!!!

[OvertHawk]

This is why I don't look at pprune any more.
.

And yet here you are...

[CDG1]

Ouest France (Touques)
10/03/2021
Translated https://translate.google.com/

Death of Olivier Dassault near Deauville. The helicopter, "broken in two", was evacuated
.... snip
At the crash site, the helicopter, which struck a tree on takeoff and "was snapped in half with the tail on one side and the cockpit on the other," was removed on Tuesday (March 9). "The debris were evacuated and transported to the Bureau of Investigation and Analysis (BEA) at Le Bourget," said Procurator Delphine Mienniel.
-50%
https://www.ouest-france.fr/normandie/touques-14800/mort-d-olivier-dassault-pres-de-deauville-l-helicoptere-a-ete-evacue-et-les-autopsies-realisees-7181407

BEA Twitter link (with pictures)
https://twitter.com/BEA_Aero/status/1369028680006197250?ref_src=twsrc%5Etfw%7Ctwcamp%5Etweetembe d%7Ctwterm%5E1369028680006197250%7Ctwgr%5E%7Ctwcon%5Es1_&ref_url=https%3A%2F%2Fwww.ouest-france.fr%2Fnormandie%2Ftouques-14800%2Fmort-d-olivier-dassault-pres-de-deauville-l-helicoptere-a-ete-evacue-et-les-autopsies-realisees-7181407

RIP 2

[EvaDestruction]

Still baffled by the number of extremely wealthy people giving their life to rotorcrafts over the years..

Fate is the hunter. The Lord giveth, and the Lord taketh.

[DOUBLE BOGEY]

So far that’s Trees - 2, Rich People - 0.

Trees appear to be the common denominator! All trees need to be removed.

[172510]

Full report here

https://bea.aero/fileadmin/user_upload/BEA2021-0089_22_02_final.pdf

Yea, trees. Report is worth reading. Espcially this part:
Dans le cas de verres solaires sans correction optique, la diminution de la quantité
de lumière transmise à la rétine conduit à l’augmentation du diamètre pupillaire
ce qui diminue la capacité d’adaptation à la distance de l’objet. Les indices élevés
fréquemment adoptés par les pilotes, généralement 3, pour ne pas être éblouis,
accroissent l’obscurité des zones les moins éclairées, comme le panneau des
instruments ou bien, comme ici, la zone ombragée de l’arbre le plus élevé. Pour
les pilotes soumis à la mention VML, l’utilisation de verres solaires non corrigés
est proscrite.
De nombreux travaux ont également été menés sur le vieillissement et ses
conséquences. L’une des capacités la plus impactée par le vieillissement est la vision,
et certains essais montrent le caractère contraignant du contraste. La sensibilité au
contraste est un élément fondamental de la vision des motifs et fait référence à la
capacité de discriminer des variations de luminance dans une image.
L’acuité visuelle, c’est-à-dire la capacité à discriminer les détails fins d’un objet
à 100 % de contraste, va naturellement diminuer. Stable jusqu’à environ 40 ans,
l’acuité visuelle diminue de façon linéaire au-delà puis la diminution s’accentue
après 70 ans. Cette diminution s’accentue en situation de faible contraste et de faible
luminosité.
La sensibilité lumineuse en condition scotopique diminue avec l’âge, se traduisant
par un allongement du temps d’adaptation à l’obscurité.


Mr Dassault, who held a full ATPL(A), had no helicopter license and flew his helicopter dual with an instructor, who himself had retired from an airplane pilot career, and kept himself busy flying helicopters.

[The Nr Fairy]

The English version of the report is at https://bea.aero/fileadmin/user_upload/BEA2021-0089.en.1.pdf, and the section that @172510 refers to reads:

In the case of sunglasses without an optical correction, the reduction in the quantity of light transmitted to the retina leads to an increase in the pupil diameter which reduces the capacity of adaptation to the distance of the object. The high indexes frequently adopted by pilots, generally 3, to avoid being dazzled, increase the darkness of the least lit areas, such as the instrument panel or, as here, the shaded area of the tallest tree. For pilots subject to the VML limitation, the wearing of uncorrected sunglasses is prohibited.

Much work has also been done on ageing and its consequences. One of the abilities the most impacted by ageing is vision, and some trials show the nullifying character of contrast. The sensitivity to contrast is a fundamental part of pattern vision and refers to the ability to discriminate variations in luminance in an image.

Visual acuity, the ability to discriminate fine details in an object with 100% contrast, will naturally decrease. Stable until reaching an age of around 40 years, visual acuity decreases linearly after that, with the decrease becoming more pronounced after the age of 70 years. This decrease is accentuated in low contrast and low light situations.

Light sensitivity in scotopic conditions decreases with age, resulting in a longer adaptation time to darkness.

Natural ageing progressively modifies the neurophysiological, perceptual and cognitive aspects of vision.

[172510]

The one thing I had not in mind, is that even if your visual acuity is at 100% thanks to your glasses, your sensitivity to contrast can be poor before you know it.

[[email protected]]

I think that is most noticeable when you try to read in different light conditions with and without glasses - my correction for reading is between 1.5 and 2 dioptres but I can read unaided in bright conditions because of the high contrast - as soon as the light levels reduce from that I have to reach for my glasses.

If you artificially reduce your light levels with sunglasses, down goes your contrast.

[[email protected]]

This paragraph made me pay attentionWhen the distance vision is relatively preserved, certain subjects think that they can omit wearing glasses, except if they are forced to do so by necessity (reading on-board documents or instruments for pilots). This choice, made here by the pilot, necessarily implies accepting the significant deterioration of the near vision and intermediate vision. The result of this is that, unlike a subject who does not need such a correction, it is more difficult to detect and identify an apparently moving object which may "enter" the field of vision. Thus the monitoring of the flight parameters and outside obstacles during the takeoff may have been slowed down by the adaptation time caused by the alternation between intermediate and distant vision.

[blind pew]

I’m 73, have the start of cataracts which affect my sight in bright light. I ride a motorcycle with far too much power at silly speeds in the south of France generally in the morning before it gets too hot. The loss of vision from bright sunlight to shade is incredible. To counteract the brief periods of semi blindness I look at the road surface ..important as a diesel spillage is game over.
Evening paragliding is more difficult and I sacrifice looking at my instruments with corrected dark Polaroid glasses and avoid situations where conflicting traffic is up sun. (Often by landing and waiting until others have as well).
My wife hasn’t driven for decades at night as women have more cones than rods..the former are for colour perception whilst the latter work in low light.
‘It’s about understanding your limits like look out at junctions wrt cyclists and the width of the windscreen pillars.

[whoknows idont]

I’m 73, have the start of cataracts which affect my sight in bright light. I ride a motorcycle with far too much power at silly speeds in the south of France (...)
‘It’s about understanding your limits (...)

:D Brilliant!

[MechEngr]

I think that is most noticeable when you try to read in different light conditions with and without glasses - my correction for reading is between 1.5 and 2 dioptres but I can read unaided in bright conditions because of the high contrast - as soon as the light levels reduce from that I have to reach for my glasses.

If you artificially reduce your light levels with sunglasses, down goes your contrast.

The main effect of brighter light is to allow/cause the pupils to contract, reducing the effect of off-axis distortions in the lens and cornea. The ultimate limit is diffraction limits in pinhole apertures where the interference of the light causes spreading at the edge of the pinhole. There are gag glasses made that are opaque black plastic for the "lenses" with many small holes for light to pass through. When conditions are bright enough they work quite well.

I guess one could call the problem "contrast" but the real effect is optical aberration / blurring / smearing of the image not being focused on a one-to-one correspondence between the scene and the retina.

I still recall in my 40s standing up in the cube farm from a long day at the computer monitor and noting that everything more than 20 feet or so was a bit blurry, like a fog had rolled in - the lenses were no longer elastic enough to flatten out rapidly when the lens muscles relaxed. Now my lenses appear to be stiff enough the little muscles that should deform them no longer can. At least I can see well enough in the distance, though there is some correctable astigmatism that is annoying. As long as there are no highway eye charts and I have cheap readers to see the speedometer I am still good to drive.

That "adaptation time" in the report is, I think, the time required for the elastic capsule of the lens to change shape as the muscles squeeze or release it. At the age mentioned, I suspect that adaptation time is approaching infinity.

[Two's in]

The eyesight and visual perception only became issues because a thorough appreciation of the HLS and its hazards was either not completed or not completed fully. If visual acuity, ambient light levels and a low sun were critical factors for safe operation, the HLS was not within the acceptable risk envelope for the pilot(s). Sadly, still nothing remotely unique about this tragic accident.

[212man]

https://bea.aero/en/investigation-reports/notified-events/detail/accident-to-the-airbus-as350-registered-f-gibm-on-07-03-2021-at-touques/
Yes - as the previous 8 posts are discussing

[pax britanica]

What a very very interesting and informative post concernign the vsioin degradation issues (being just past70 myself) . As to rich people in helicopters perhaps many such are less risk averse than most of us perhaps they consider their time more valuable than their life.

[topradio]

Much discussion as to why rich people expose themselves to risk as if, by dint of them being wealthy, their life is somehow more valuable than the rest of us

Nobody sets out kill themselves but at the same time we all want to live a life and doing things that present an elevated risk makes some feel even more alive

I suppose they could wrap themselves up in cotton wool but the grim reaper will still get them in the end

[Hot and Hi]

The eyesight and visual perception only became issues because a thorough appreciation of the HLS and its hazards was either not completed or not completed fully. If visual acuity, ambient light levels and a low sun were critical factors for safe operation, the HLS was not within the acceptable risk envelope for the pilot(s). Sadly, still nothing remotely unique about this tragic accident.
I fully agree. The age-related, natural degradation of vision to the maximum is a contribution factor. It may have had no influence at all.

What we see is informal (illegal) training, complacency because they had landed there numerous times. And compete absence of risk assessment. Not blasting the pilots. Can happen to all of us. But don't blame it on my eyesight!

What happened to the good old Triple-S? Sun, surface, slope. A good reminder that this not only applies to the confined *landings*. But also to take-offs. The pilots may have totally forgotten about the presence of the trees (not because they looked, and couldn't see the trees due to old age, but because they didn't look):

The [horizontal] distance travelled by the helicopter from the point of take-off to the point of impact with the tree branches, of approximately 8.50 m, suggests that, irrespective of a possible drift of the helicopter, it was probably deliberately put into forward flight in order to start horizontal acceleration. The helicopter’s manoeuvre with a nose-down attitude, observed by a witness, is in line with this hypothesis of the helicopter deliberately being put into forward flight.


https://bea.aero/fileadmin/user_upload/BEA2021-0089.en.1.pdf - Page 38

[[email protected]]

An old guy without a huge amount of helicopter experience (est 1400 hours in the report), in a confined area without his glasses on giving illegal instruction to another old guy with negligible helicopter time in poor light conditions - what could possibly go wrong with that?

I think the eyesight factor is a major cause, in part because he couldn't see the trees ahead but primarily because he didn't notice the drift during the vertical climb - basic scanning to a lateral marker would have picked this up straight away.

5 S recce is great but picking good markers is even more important.

If the 'passenger' in the LHS was flying the departure, all the major obstacles were on the other side of the aircraft where the instructor was sitting and his inexperience would make a drift in a vertical climb quite likely without verbal or physical intervention from the instructor.

If the instructor was flying the departure the his proximity to the obstacles would, in my mind, have led him to drift deliberately left in the vertical climb - presuming he could actually see the obstacles well enough.

Either way, a very avoidable accident with tragic consequences.

[Hot and Hi]

Another point: According to the investigation the two pilots (or passengers, we don't know) were already fatally injured before the impact with the ground:

1.16.1 Separation of tail boom and seats
The collision of the main rotor blades with the tree branches led to an instantaneous and violent overtorque on the main rotor hub.

[...]

The accelerations generated during the overtorque on the main rotor hub exceeded the lateral accelerations which could be borne by the two front seats, leading to them being torn from the helicopter cabin floor.


1.15 Survival aspects
The results of the autopsy showed that the internal injuries received by the two people on board, due to the acceleration experienced by their bodies when the main rotor collided with the trees followed by the rotation of the airframe about its yaw axis left no chance of survival.



It was also noted that the damage occurred during a single rotation of the rotor. Very different from gently grazing a few leaves with the rotor tips. These mishap pilots must have gone full in.

Damage resulting from the collision with the branches was identified on the red and yellow blades over a length of around 2.60 m from the blade tips. The red blade had at least seven points of damage, the yellow blade had suffered at least one impact while the blue blade did not seem to have suffered an impact.

The distribution of the damage on the main rotor blades tends to show that it occurred during a single rotation of the rotor. A succession of impacts over several rotations would probably not have left the blue blade without visible impact marks.

[SLFMS]

[QUOTE=Hot and Hi;11460155]Another point: According to the investigation the two pilots (or passengers, we don't know) were already fatally injured before the impact with the ground:

This is surprising, I can’t quite get my head around this one. That is one hell on an acceleration to kill a human that quickly. Is it possible it’s a translation issue? It just does not quite sound right.

[OvertHawk]

If the main rotor blades were significantly damaged the out of balance forces would produce massive lateral G-loads that would be well beyond what a human neck and spine could cope with.

It has happened in past accidents where blades have been damaged or separated - the lateral g-load can be massive and immediate.

[[email protected]]

Especially considering the age of the pilots - reduced muscle strength and bone density in your 70's

[SLFMS]

If the main rotor blades were significantly damaged the out of balance forces would produce massive lateral G-loads that would be well beyond what a human neck and spine could cope with.

It has happened in past accidents where blades have been damaged or separated - the lateral g-load can be massive and immediate.


Interesting I don’t know enough about those forces to comment other than to say I’m surprised. It would be interesting to know the potential G values involved and how they separated injuries from the aircraft hitting the ground.


It is a good comment you make about the age of the crew Crab.

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If the lateral forces from shock loading the transmission were enough to snap off the tail boom then they probably calculated what would be experienced a similar distance forward of the rotor mast where the pilots were sitting.

[MechEngr]

The lateral forces are in any direction that aren't rotational or vertical, so the distance doesn't matter. What does matter is how much centrifugal imbalance there is from damage to the rotor blade. The helicopter body is set to orbit in opposition to the offset of the rotor CG. If that offset is 0 there is no shaking.

I doubt the blade itself is strong enough to kick-back over it's length**, but losing 2.6m will lose a lot of the most heavily accelerated mass and that will result in an unbalanced tension load the blade is certainly strong enough to withstand.

**This is in contrast to the kickback of hitting a baseball with a bat far off the "sweet spot" and having the resulting vibration hurt the batter's hands. In that case the bat is very sturdy compared to the squishy hands. The helicopter situation is like spinning while holding two heavy buckets by strings and cutting one of the strings. The person doing the spinning is very likely to fall over.

[OvertHawk]

I'm reminded of the accident to G-BJVX in the Southern North Sea in the early 2000's where much research was done into the out of balance forces that would have been experienced when a sizeable portion of one of the main blades separated in flight resulting in the separation of the transmission from the fuselage and loss of the aircraft.

https://assets.publishing.service.gov.uk/media/5422fe4240f0b6134200089f/G-BJVX_Pub_version_inc_annexes.pdf

[212man]

I'm reminded of the accident to G-BJVX in the Southern North Sea in the early 2000's where much research was done into the out of balance forces that would have been experienced when a sizeable portion of one of the main blades separated in flight resulting in the separation of the transmission from the fuselage and loss of the aircraft.

https://assets.publishing.service.gov.uk/media/5422fe4240f0b6134200089f/G-BJVX_Pub_version_inc_annexes.pdf
At the time there was a lot of talk that the occupants died instantly from broken necks due to the lateral imbalance, the autopsy report suggested otherwise:
The pathologist concluded that everyone had died from multiple
injuries consistent with a high vertical impact loading with some forward
motion

(Which I already knew, but highlight for others)

[OvertHawk]

I was also aware of that 212 - I was more highlighting the research carried out into the imbalance of forces that took place when the bladed failed.

OH

[RVDT]

Not imbalance - sudden stoppage.

Page 56 in the report gives an insight?

[RatherBeFlying]

These days, plastic lenses incorporate UV protection. I have a yellow tint on my glasses to make it easier to see cloud wisps and haze domes - and keep my pupil diameter down for better acuity.

My opthalmologist has been muttering about cataracts for over a decade, but they're not bad enough for the op yet.

Contrast is a biggie. Rigging my glider on a nice sunny day, underneath the turtledeck is a black hole.
​​

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The lateral forces are in any direction that aren't rotational or vertical, so the distance doesn't matter. What does matter is how much centrifugal imbalance there is from damage to the rotor blade. The helicopter body is set to orbit in opposition to the offset of the rotor CG. If that offset is 0 there is no shaking.

I doubt the blade itself is strong enough to kick-back over it's length**, but losing 2.6m will lose a lot of the most heavily accelerated mass and that will result in an unbalanced tension load the blade is certainly strong enough to withstand.

**This is in contrast to the kickback of hitting a baseball with a bat far off the "sweet spot" and having the resulting vibration hurt the batter's hands. In that case the bat is very sturdy compared to the squishy hands. The helicopter situation is like spinning while holding two heavy buckets by strings and cutting one of the strings. The person doing the spinning is very likely to fall over.
Appendix 2, page 48 et seq discusses their methodology in calculating the 'overtorque' caused by blade impact resulting in tail separations and seat failure

[212man]

On balance - no pun intended - I doubts this level of investigation would have taken place for a regular AS350 accident