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aerolearner
14th Aug 2017, 22:49
An Agusta-built B206 crashed yesterday while landing on a plateau near the Gran Sasso massif in Central Italy.

Among the crew of three, two crewmembers got minor injuries.

Could it be another case of LTE/LTA? To my untrained eye, the direction of the dust after the crash would suggest that the approach was being carried out with some tailwind.

https://www.youtube.com/watch?v=DKpN-IrDaLI

DKpN-IrDaLI

https://www.youtube.com/watch?v=Ukr7BRGvysE (zoomed in a bit)

Ukr7BRGvysE

L'Aquila, si ribalta elicottero dei vigili del fuoco: due feriti (http://www.ilmessaggero.it/abruzzo/aquila_vigili_fuoco_incidente-2616590.html)

Vertical Freedom
15th Aug 2017, 02:29
Pilot mode.......disengaged :{

BOBAKAT
15th Aug 2017, 03:39
Could it be another case of LTE/LTA? To my untrained eye, the direction of the dust after the crash would suggest that the approach was being carried out with some tailwind.



"As long as you do not see big branches like my face move, there is no wind ... That is what my instructor said to me when he teaching me approach flat and in power downwind ... in Alouette 3. .. :ok:

the coyote
15th Aug 2017, 04:28
I fail to understand why the pilot didn't roll the throttle off and cushion it onto the ground. Poor training I guess.

15th Aug 2017, 07:42
Next to no wind judging by the lack of movement of the grass - so the next question is 'What DA and AUM were they at?'

SuperF
15th Aug 2017, 08:57
next to no wind... is actually a very light tailwind, came in too high, probably heavy. with a wind that light you should be able to land downwind in a JR, even a B2 with the "small" tail rotor, however you should finish your approach at a hover in ground effect.

aerolearner
15th Aug 2017, 10:16
SP, thanks for fixing the Youtube links! :}

Here is the location:
Google Maps (https://www.google.com/maps/@42.4101006,13.7637682,3a,48.5y,144.44h,98.25t/data=!3m6!1e1!3m4!1supl8vu6hgJaXSSSpWL1_dg!2e0!7i13312!8i665 6)
The landing zone was in the inside of the 90° turn of the road in the middle of the map, so the elevation is approx 1480m.
Local map with elevation (http://geoportale.regione.abruzzo.it/Cartanet/viewer?sharedViewId=1502786096113)
According to the local meteo data, I would guesstimate the temperature was 15-20°C and there wasn't much humidity.

Three persons on board, possibly with equipment, since the helicopter was supposed to help ground crews fighting a forest fire nearby.
The helicopter had taken off from the airport in Pescara, approx 40 km away, so the fuel tanks might have been more on the "Full" side.

haihio
15th Aug 2017, 10:50
The fire brigade in Italy hardly flies at all, they struggle with budget cuts and so on, the pilots are just about current, so I don't expect high piloting standards from them.....

15th Aug 2017, 11:18
So, at about 4850' amsl, assuming 1013.2 at sea level, that would give about 6000' DA at 15 deg and 6500' at 20 deg.

The very light tailwind may have been a minor contributory factor but it begs the question of handling skills - not making an approach to an IGE hover - and performance calcs - how heavy were they for what they were trying to do?

As aerolearner questions in his OP - was it LTA/E caused by an inadequate TR?

rotorfan
15th Aug 2017, 16:46
I'm very low time, and have no 206 time. I'm not understanding this 206 LTE/LTA phenomenon. The video suggests to me a very light tailwind, as the dust cloud from the wreck moves away slowly. When I trained in the R22, I had a couple of times where we were hovering downwind, and doing a pedal turn resulted in the ship really rotating quickly. My instructor pushed me hard not to let the aircraft rotate quickly. But, I also observed that the ship would stop itself nicely when the wind came on the nose and the vertical fin helped with stability. Later, while building solo time, I would practice pedal turns in 15-20 knots, common in the midwest US, and had no problem with control. So, my question about the video is if the pilot in this case gave it full pedal when the helicopter started to rotate, would that not stop the rotation, or is the TR so underpowered that it just can't stop the rotation? As light as the wind appears, I wouldn't expect the fin to help much when the heading is upwind again.

Hedski
15th Aug 2017, 18:20
It doesn't necessarily stop the rotation depending on various factors. If you google 'loss of tail rotor effectiveness' and find the appropriate links there are good descriptions out there. B206 is one of the worst aircraft to suffer the phenomenon and also incur height loss as a result. The US Army were losing many 206/OH58's at Fort Rucker due to a lack of appreciation of it until they researched back in the 70's.