Helicopter down outside Leicester City Football Club

[Old Farang]

Originally Posted by DOUBLE BOGEY

I hesitate to say this, but if it is a TR Drive/Low power Hard over, he seems to take a long time to react. Many rotations under near hover power before the descent takes place.

This has been bothering me also. I have not flown helicopters for years, and the old things that I used to flap around in did not have such luxuries as an auto pilot, in fact I thought it was the latest thing when one of them had electric cyclic trim.
But it has been posted by people that should know that the A/P would probably be engaged, at least in attitude mode. The way that thing spun around it is almost like it was being driven. Surely, such an experienced pilot would have had the collective down long before the spin developed to the extent shown on the video. Is it possible that this is related to switching the A/P to full authority, or whatever the change is called, as he started to transition?

[jeepys]

The autopilot will only have max 10% authority.

[Unregistered_]

As someone else suggested earlier, but now I can't find it, it looks to me like they possibly climbed vertically and backwards then attempted rotation - with a reasonable tailwind.
Had something let go at that power setting in essentially an OGE hover, the immediate 'snap rotations' would be more evident I would have thought. The rotations came on relatively slowly I thought - consistent with running out of T/R authority. Started spinning with no T/R authority - dumped the collective and never recovered.
Did we get an answer how a potentially heavy AW169 behaves in a high power OGE downwind hover?

[GeeRam]

Originally Posted by Simplythebeast

Looking at that, I dont think it is something off the helicopter. It is travelling much too fast and more likely to be something flying past or being blown past, much closer to the camera.

I don't think it's an object at all, looks to be light reflection/refraction on the lens as the camera tracks up into the stadium lights...?

[Old Farang]

Originally Posted by jeepys

The autopilot will only have max 10% authority.

Ok, assuming that it is not faulty.

[Nige321]

Originally Posted by Flying Bull

If you watch the video you can see something fast going down from the helicopter to the lower left in the video. Seconds after that the turn starts
Part from helicopter?

It's an insect lit by the stadium lights. Another at 1:02. You see them all the time on CCTV. Really annoying when they trigger motion sensors to start recording... Already discussed...

[strake]

It's an insect lit by the stadium lights.

Playing that video at quarter speed, I respectfully disagree. The insects on my CCTV don't behave in that manner and there is always more of them. That 'particle' initially appears suddenly at 46.2s at the back of the aircraft, disappears for less than 100th of a second then appears again moving at speed to the left and down. Looking at what is happening to the aircraft and admittedly drawing a speculative conclusion of where the problem might lie, one has to question the odds of a lone insect appearing to fly across the screen emanating from that position at that exact time?

[Slowclimb]

Originally Posted by Unregistered_

As someone else suggested earlier, but now I can't find it, it looks to me like they possibly climbed vertically and backwards then attempted rotation - with a reasonable tailwind.
Had something let go at that power setting in essentially an OGE hover, the immediate 'snap rotations' would be more evident I would have thought. The rotations came on relatively slowly I thought - consistent with running out of T/R authority. Started spinning with no T/R authority - dumped the collective and never recovered.
Did we get an answer how a potentially heavy AW169 behaves in a high power OGE downwind hover?

The aircraft had a headwind. It was pointing north, in a northerly wind.

There was a brisk low-level flow on Saturday evening; I’m sure part of the reason for the highish climb was to clear all the shear before transitioning.

[dmba]

I assume they scoured the pitch for any parts that might have fallen?

[Nige321]

Originally Posted by strake

Playing that video at quarter speed, I respectfully disagree. The insects on my CCTV don't behave in that manner and there is always more of them. That 'particle' initially appears suddenly at 46.2s at the back of the aircraft, disappears for less than 100th of a second then appears again moving at speed to the left and down. Looking at what is happening to the aircraft and admittedly drawing a speculative conclusion of where the problem might lie, one has to question the odds of a lone insect appearing to fly across the screen emanating from that position at that exact time?

Have it your way.
Insects on my night time CCTV ALWAYS act like that.
I just stepped through the frames, blobs of light at 0.52, 0.53, 0.57, 1.02, 1.05, 1.06
Some of them flitting in all directions...

[strake]

Have it your way.

Please understand, I mean no disrespect to anyone's views, it's just an observation.

[XN593]

Anti-collision light

In the YouTube video the anti-collision light is clearly visible as are it's reflections under the main rotors. As control is lost the light seems to extinguish. Is it just me and my phone?

[Slowclimb]

The speck moves too fast to be anything but an insect in the foreground. Its sudden appearance could’ve been when it flew into the light cone from the floods, or simply near enough to the camera to be seen.

Some observations; after just the first half of rotation, it looks like the rotation was so rapid the resulting g-forces would’ve made positive control extremely difficult. Also, the aircraft rapidly built up a very high rate of descent. So thrust was lost from the main rotor one way or another.

It looks like the transition was above 300’, so sound would have been at least a second behind what you see.

[Fareastdriver]

Surely, such an experienced pilot would have had the collective down long before the spin developed to the extent shown on the video.

Here is a cameraman's last shot taken in 1960. Later on an external shot shows you what happened.

How fast are your reactions to a tail rotor failure at low speed.

You Tube

That was at about 1,000ft. Try it at 300.

[aox]

Originally Posted by Slowclimb

It looks like the transition was above 300’, so sound would have been at least a second behind what you see.

speed of sound about 330 metres per second, not feet

[stagger]

Originally Posted by Mitchaa

It moves too quickly and if it was part of a blade it would have embedded itself into the grass on the pitch and suspect it would have already been mentioned in the media if that was the case. As there are many similar light flashes throughout the video, I would say these are probably insects.

When thinking about what these specks might be - it is worth noting that this didn't happen during summer. It was a dark, cold evening - you won't find too many insects flying around in these conditions.

[Pittsextra]

Saw this & final report..

You Tube

https://www.fomento.gob.es/recursos_...boletin_03.pdf

[Nige321]

Originally Posted by stagger

When thinking about what these specks might be - it is worth noting that this didn't happen during summer. It was a dark, cold evening - you won't find too many insects flying around in these conditions.

So why is my CCTV motion detection triggered all night long by... Insects...

[ShyTorque]

Originally Posted by DOUBLE BOGEY

I hesitate to say this, but if it is a TR Drive/Low power Hard over, he seems to take a long time to react. Many rotations under near hover power before the descent takes place.

Have you personally experienced this particular failure, or practiced it in a simulator? Thirty years ago I was a QHI involved in a full motion helicopter simulator project for the UK military and was part of a team (of two) tasked to expand the then current teaching on tail rotor malfunctions, which was woefully inadequate. We did some practical test flying (hours costed by MOD on behalf of Boscombe Down) and developed a syllabus. We then began teaching both "ab initio" and experienced squadron pilots alike. I saw many highly experienced pilots fail to arrest the yaw rate in time, despite being pre-briefed and pre-warned that the T/R was about to malfunction. Bear in mind that this was in a simulator lesson doing nothing but tail rotor malfunctions.

Given that it takes a second or two to diagnose the failure in the real case, the pilot probably did as well as anyone could have in the circumstances. Note the slight pause in the yaw rate - it's likely that full opposite pedal was applied in an attempt to stop the yaw, probably a pilot response.Then once the tail rotor blades produced no more effective thrust, round it went again at an increased rate of yaw. Once a rapid fuselage spin develops, response to cyclic inputs may not be what is normally expected and that effective rotor rpm is reduced.

Other things that could cause a sudden yaw are a gust of wind, an autopilot/SAS malfunction, or an inadvertent foot touching a yaw pedal. Dumping the lever and chopping the engines would be an inappropriate immediate response.

This unfortunate pilot probably experienced a T/R drive failure at the most critical stage of flight imaginable. I say "probably" because AAIB haven't yet released initial findings and I am quite possibly wrong; obviously I'm only an amateur compared to some experts here.

[jeepys]

[QUOTE=Pittsextra;10297639]Saw this & final report..

You Tube

https://www.fomento.gob.es/recursos_...boletin_03.pdf[/QUOTE

Does it mention in the report TR failure?