Author Topic: Shoreham Airshow aircraft crashes into A27 road  (Read 62481 times)

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Offline John Coloccia

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Re: Shoreham Airshow aircraft crashes into A27 road
« Reply #25 on: August 23, 2015, 03:05:49 pm »
Not the first time recovery from a low level loop at an airshow has ended badly - usually these things come down to pilot didn't reset altimeter before flight, or had it set to msl and but forgot and read it as field elevation.  Accidents happen, humans make mistakes.

That said, looks like really rather poor planning and too cramped area for an airshow with low level high speed aerobatics.

As I said above, it's a reverse half cuban he was performing, and not a loop as was stated by many news outlets.

Altimeter settings are set to MSL, and are adjusted according to the air pressure which is told to pilots by ATC, and it's also recorded on the ATIS. Altimeters are only set away from MSL if one is flying in on airways at a flight level, at which point it is set to 1013mB or 29.92 inches. Shoreham is next to the coast and is about 10ft above sea level, if that.

It's not much of a reverse half cuban, to be honest.  Never even came close to finishing his roll.  I would have to think that whatever went wrong happened pretty early.

re: altimeter calibration
Take it from someone who used to do aerobatic flying.  You worry a great deal about the altimeter if you're anywhere near the ground.


Reverse half cuban. As I said above, he climbed up, rolled inverted before pulling down. He then didn't make it out of the downwards line. Ran out of energy and went into an accelerated stall.

He never got to inverted.  That's why he started in the frame flying to the left, but recovery was flying away from us.  Watch the video again.  The entry to the 3/4 loop looks more like a wing over than a half roll. If there was any running out of energy, it looks like it happened very early.
 

Offline IO390

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Re: Shoreham Airshow aircraft crashes into A27 road
« Reply #26 on: August 23, 2015, 03:07:52 pm »
As I posted above, I was there and saw it. I described the entire flight.
 

kc3ase

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Re: Shoreham Airshow aircraft crashes into A27 road
« Reply #27 on: August 23, 2015, 03:18:36 pm »
I tried this on Xplane 10 a few times. Unfortunately, the closest model I have is the much newer F-4. I find that even with the F-4 running at near stall speed and then going into the climb if the loop is too small the plane stalls in the vertical ascent which one wing may lose lift first. It's hard to tell if the video point is actually a stable horizon image. If it is it does appear one wing loses lift and then the plane teeters a bit.

Either way once the stall happens you can't recover because you aren't high enough to trade altitude for speed.

Steps
1) Fly at 130 knots with full flaps.
2) Throttle pull in the flaps and go into the vertical climb of the loop.
3) I find that an aggressive tight loop is around 2250-2500 ft / ~750 meters peak. If I try to do it tighter and only go to 2000 ft the plane stalls in the ascent and although look likes it's still under control it has not enough airspeed or altitude to ever recover lift.

Also I did this completely on instruments. If I try to do it without I crash every time because I have to idea where I am. Even then it's hard because when the horizon disappears it's like being blind. I guess if you do this all the time you kinda know where you are or should be. But I normally try to fly with a horizon  :-+

From the original video it looks as though he is trying to trade altitude for speed as the descent seems to appear controlled and straight down in order to recover speed and regain lift later but it never happened and he was trying to find the clearest place possible to put it down. But without lift you can't control the plane. To me this looks like what has happened because the plane has not much lift at all near the crash point as it appears to be descending 20 feet or more per second.
« Last Edit: August 23, 2015, 04:07:49 pm by kc3ase »
 

Offline John Coloccia

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Re: Shoreham Airshow aircraft crashes into A27 road
« Reply #28 on: August 23, 2015, 03:25:28 pm »
As I posted above, I was there and saw it. I described the entire flight.

The video is clear as day.  He got through about 90 degrees of a roll, not even close to 180. That aimed him right at the camera, which I'm assuming is in the audience, at the top and you would generally never do that on purpose.  That's why he's flying across the scene to the left at the beginning of the maneuver, and towards/away from the camera at the end. You may remember it differently, but there's no question what actually happened. Just watch the stupid video and see for yourself.

For all we know, he may have been trying to get through a full loop and aborted, or any number of different things could have happened, but it's hard to believe this is a case of a half reverse cuban just starting too low.  I  hate to assume with so little information, but it seems pretty likely that something became botched up with plane, pilot or both very early on.

« Last Edit: August 23, 2015, 03:30:06 pm by John Coloccia »
 

Offline G0HZU

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Re: Shoreham Airshow aircraft crashes into A27 road
« Reply #29 on: August 23, 2015, 03:25:50 pm »
I searched for this Hunter's serial number WV372 on youtube and found this:



I reckon this is the same plane (but don't know if it's the same pilot) and you can perhaps see what was meant to happen with this manoeuvre at 1:30 onwards in this video.

I'm guessing this video will be in the media soon. Especially if it's the same pilot.
 

Offline IO390

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Re: Shoreham Airshow aircraft crashes into A27 road
« Reply #30 on: August 23, 2015, 03:38:05 pm »
Looking back at the video, you are quite right. I've watched it quite a few times before but I think I skipped the first bit. It also looked different from where I was. The angle of the video is a bit more clear.

The video was taken from Mill Hill and that's not near the airport. The airport is on the other side of the road from where the camera was.

Note that I said I may be wrong on some things, knowing that he was attempting a full loop makes more sense as I remember I was expecting him to roll out at the top, having completed a normal half cuban. One could see that he was way too low to do the full loop.

So yes, I was totally wrong there. But you're also correct that he was simply too low. The height of the hill that the video was taken from is 300ft, and hence my estimation that he wasn't above 1500ft at the start of the downwards leg.
 

Offline G0HZU

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Re: Shoreham Airshow aircraft crashes into A27 road
« Reply #31 on: August 23, 2015, 03:48:36 pm »
If you watch the Shuttleworth video in my previous post you can see that the plane was able to climb and power through a big wide inverted loop. But at Shoreham the plane wilted as it approached the peak of the inverted loop and you can see it was in serious trouble because it couldn't power through the inverted loop. So it lost momentum and wilted down sideways and fell like a leaf from a tree and ended up in a different flight direction downwards.
« Last Edit: August 23, 2015, 03:50:23 pm by G0HZU »
 

kc3ase

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Re: Shoreham Airshow aircraft crashes into A27 road
« Reply #32 on: August 23, 2015, 03:50:38 pm »
I searched for this Hunter's serial number WV372 on youtube and found this:



I reckon this is the same plane (but don't know if it's the same pilot) and you can perhaps see what was meant to happen with this manoeuvre at 1:30 onwards in this video.

I'm guessing this video will be in the media soon. Especially if it's the same pilot.

Nice video link. It appears this aircraft is at much more airspeed than the crash video on entry to the loop.
 

Offline Jeroen3

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Re: Shoreham Airshow aircraft crashes into A27 road
« Reply #33 on: August 23, 2015, 06:06:52 pm »
 

Offline John Coloccia

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Re: Shoreham Airshow aircraft crashes into A27 road
« Reply #34 on: August 23, 2015, 06:19:50 pm »
It also looked different from where I was. The angle of the video is a bit more clear.


I figured that was the case. Based on your name I assumed you were a pilot too and probably knew what you were talking about :)

Hopefully Andy Hill will survive and give some insight on what happened. If not, it will just probably get marked as "pilot error". I don't know how it is in Europe, but in the US a plane could get hit by a watermelon that fell from an alien spacecraft, and the NTSB would list the root cause as, "Failure of PIC to anticipate watermelons falling from alien spacecraft."
 

kc3ase

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Re: Shoreham Airshow aircraft crashes into A27 road
« Reply #35 on: August 23, 2015, 10:30:11 pm »
My original thought about airspeed may be incorrect. It's hard to determine the perspective and distance in the video but based on the trees where I think the aircraft is I'm estimating an entry fly by speed of 300 knots before going into the loop. I thought someone had indicated the flaps were out during entry. At this speed that doesn't seem like it's necessary.

So I go back to the video tape for more detailed analysis.

Assume 300 knots entry.
11 sec 10 degree climb
12 sec 45 deg
14 sec 60 deg
15 sec 80 deg - plane starts to roll left
21 sec 70 deg
22 sec 65 deg - plane now inverted
24 sec 0 deg inverted

from the camera angle which started on a port side view and I would have figured would remain a port side view it became a top view of the aircraft. No afterburner is shown on the vertical ascent. Something isn't right at the 15 sec point. The plane is likely too long in a high angle position without afterburner and losing airspeed quickly.

Who knows how to calculate g forces based on angle and speed assuming constant speed to make it easy?

Did the pilot black out due to G forces? (I think this is probably not likely. I think at even an angle of 90 degrees at <Mach 1+ there is only about 5 G's)

Did the flight suit fail?

Equipment failure?

Anyway this video shows a lot just in itself. So, I'll try again @ EGKA and see if I can pick anything up from the simulator with the wrong plane but just for experiment purpose.


« Last Edit: August 23, 2015, 10:39:52 pm by kc3ase »
 

Online Howardlong

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Re: Shoreham Airshow aircraft crashes into A27 road
« Reply #36 on: August 23, 2015, 11:06:24 pm »
Extending flaps is standard on this a/c during a loop.

AAIB will give a factual account of the incident based on evidence, there is no subjectivity in it, but there are often several contributing factors. Typically in aviation, there is a Swiss cheese analogy, where it is a combination of events that cause such tragedies.

FWIW, I did much of my instrument rating training at Shoreham. Nice airfield on a sunny day, but not so nice when cloud base is low and you're heading North knowing that the Downs are somewhere in front, and hopefully below you. Very sad what happened.
« Last Edit: August 23, 2015, 11:27:23 pm by Howardlong »
 

Offline sleemanj

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Re: Shoreham Airshow aircraft crashes into A27 road
« Reply #37 on: August 23, 2015, 11:55:43 pm »
Altimeter settings are set to MSL, and are adjusted according to the air pressure which is told to pilots by ATC,

In aerobatic, qfe is commonly used (height above field), for safety, doing mental calculations to determine your agl when operating over such a small local area, close to the ground, fast, while under pressure doesn't make much sense, set qfe and read it directly.

Qfe is also often set by gliders.  Microlights (ultralights) historically, but not so common now.
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kc3ase

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Re: Shoreham Airshow aircraft crashes into A27 road
« Reply #38 on: August 23, 2015, 11:56:24 pm »
Extending flaps is standard on this a/c during a loop.

AAIB will give a factual account of the incident based on evidence, there is no subjectivity in it, but there are often several contributing factors. Typically in aviation, there is a Swiss cheese analogy, where it is a combination of events that cause such tragedies.

FWIW, I did much of my instrument rating training at Shoreham. Nice airfield on a sunny day, but not so nice when cloud base is low and you're heading North knowing that the Downs are somewhere in front, and hopefully below you. Very sad what happened.

Are the flaps extended that you can see in this video? I don't know this aircraft well enough to see if they are.
 

Offline cimmo

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Re: Shoreham Airshow aircraft crashes into A27 road
« Reply #39 on: August 24, 2015, 12:57:28 am »
No afterburner is shown on the vertical ascent.
The Hunter's engine is not fitted with an afterburner.

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Online EEVblog

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Re: Shoreham Airshow aircraft crashes into A27 road
« Reply #40 on: August 24, 2015, 01:12:40 am »
and how did they get this shot?


From looking at the crash video posted again, I  don't see how this shot was physically possible.
There doesn't appear to be a hill or overpass on the left side of the plane as it comes in.
And all those people in that ditch watching doesn't add up.
A stock photo?
 

Offline ccs46

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Re: Shoreham Airshow aircraft crashes into A27 road
« Reply #41 on: August 24, 2015, 01:26:26 am »
and how did they get this shot?


From looking at the crash video posted again, I  don't see how this shot was physically possible.
There doesn't appear to be a hill or overpass on the left side of the plane as it comes in.
And all those people in that ditch watching doesn't add up.
A stock photo?
I'm thinking it is a movie set. I bet that picture has nothing to do with the crash.
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Offline TheElectricChicken

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Re: Shoreham Airshow aircraft crashes into A27 road
« Reply #42 on: August 24, 2015, 01:56:20 am »
From looking at the crash video posted again, I  don't see how this shot was physically possible.
There doesn't appear to be a hill or overpass on the left side of the plane as it comes in.
And all those people in that ditch watching doesn't add up.
A stock photo?

It's a real image. I'm good at spotting fakes. Also a cameraman and photographer. The image may seem to be fooling you because it's something that your eyes are not used to looking at. If you look at the depth of the subject matter, that is a huge elongated area of the ground that has been imaged. So it's simply a very long-range lens that is being used for that image. Look carefully at the perspective of the image, the bus, the vehicles, the long length of road, the VERY long length. Not an image that can be taken with anything but a big-arse telephoto lens. A few grand at least.

Also, people watch airshows ! and that is the only place that they can stand without being run over by cars. It's all good and above-board. TheElectricChicken gives this image his peck of approval. The photographer doesn't need to be very high, especially given the depth of the subject material. Looking at a hill through a telephoto looks just like this. Think distance from camera to target.
 

Online EEVblog

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Re: Shoreham Airshow aircraft crashes into A27 road
« Reply #43 on: August 24, 2015, 02:05:24 am »
It's a real image. I'm good at spotting fakes. Also a cameraman and photographer. The image may seem to be fooling you because it's something that your eyes are not used to looking at. If you look at the depth of the subject matter, that is a huge elongated area of the ground that has been imaged. So it's simply a very long-range lens that is being used for that image. Look carefully at the perspective of the image, the bus, the vehicles, the long length of road, the VERY long length. Not an image that can be taken with anything but a big-arse telephoto lens. A few grand at least.

Also, people watch airshows ! and that is the only place that they can stand without being run over by cars. It's all good and above-board. TheElectricChicken gives this image his peck of approval. The photographer doesn't need to be very high, especially given the depth of the subject material. Looking at a hill through a telephoto looks just like this. Think distance from camera to target.

Yes, I understand all that, I'm not saying it's faked, but it just doesn't seems right, the camera is on the left side of the plane, the North side of the A27. Seems pretty flat to me. Nor do I see that bend in the road, on the map it seems pretty straight.
Perhaps I need to consult the map of the place better, I could certainly be wrong. It just didn't seem to add up at first glance as a pic of the plane moment before impact into the presumably A27 below it.
https://www.google.com.au/maps/place/Brighton+City+Airport/@50.8394853,-0.3025439,1630m/data=!3m1!1e3!4m2!3m1!1s0x487599ef6cb32407:0x3dd527ac04e875c!6m1!1e1

Here is a photo of the crash scene:

Can someone identify the exact spot on google maps?
« Last Edit: August 24, 2015, 02:12:33 am by EEVblog »
 

Offline TheElectricChicken

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Re: Shoreham Airshow aircraft crashes into A27 road
« Reply #44 on: August 24, 2015, 02:20:19 am »
easthill way portslade at 6km looks down, or thundersbarrow hill at 4km also looks down, but I have trouble because of the curve of the road.....
 

Offline TheElectricChicken

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Re: Shoreham Airshow aircraft crashes into A27 road
« Reply #45 on: August 24, 2015, 02:28:29 am »
Here is a photo of the crash scene:

Can someone identify the exact spot on google maps?

for this one, I place the camera at 2km, 80m above on an unnamed road bearing 60.
 

Offline TheElectricChicken

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Re: Shoreham Airshow aircraft crashes into A27 road
« Reply #46 on: August 24, 2015, 02:35:29 am »
Ok, for the photo you doubt, I place it for sure on mill hill 1.1 km bearing almost east and a smidgen of north. It all lines up perfectly. Everything about this photo is good. Everything about the location of the camera says it is correct. I'll make an image. h5
 

Offline TheElectricChicken

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Re: Shoreham Airshow aircraft crashes into A27 road
« Reply #47 on: August 24, 2015, 02:40:32 am »
here it is

 

Offline IanB

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Re: Shoreham Airshow aircraft crashes into A27 road
« Reply #48 on: August 24, 2015, 03:01:53 am »
Here is Google street view of the same location. The details all match up:

https://goo.gl/maps/evsVG
 

Online EEVblog

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Re: Shoreham Airshow aircraft crashes into A27 road
« Reply #49 on: August 24, 2015, 03:27:11 am »
Yep, ok, looks good now.
The people on the side of the road were standing here:
http://bit.ly/1KG8PDm
Would have crashed about 100m in front of them!
« Last Edit: August 24, 2015, 03:28:54 am by EEVblog »
 


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