Hawker Hunter Crash at Shoreham Airshow
Pittsextra,
Pontius is spot on. From the speeds at which looping manoeuvres are entered in aircraft such as the Hunter you do not have to worry about what pitch attitude you will be at following the first 300 ft of the pull up. My point was one that the pilot had not exceeded his DA minima, not that he had extra parameters that he had to monitor during the initial pull-up.
With respect to 1/4 clover type manoeuvres in an aircraft of the speed category of the Hunter, if you start as you suggest at less than 60 degrees nose up there will be a significant reduction in the apex height for a given g/pitch rate flown during the pull up; it also means that you will probably reach the apex not quite wings level or you will have to roll through more than 90 deg to achieve wings level. I have no experience of flying these manoeuvres in light aeroplanes and therefore if you do I defer to you knowledge in this category. However, in the category B, C and G aircraft that I display I frequently fly 1/4 clovers and I start to roll at about 80 deg nose up such that the roll is symmetrical about the vertical line. I think that this looks neater and it minimises the reduction in apex height.
Please note that my comment regarding 60 deg nose up as the definition of the start of an aerobatic manoeuvre is a worst case figure promulgated by some regulators; others use 90 deg whilst some are not prescriptive to that extent at all.
Finally, your public profile gives no clues as to your experience but, from your comments, I doubt that you have any fast jet display experience so perhaps it would be better to ask questions here, which will be politely answered, rather than making statements that are invalid.
Pontius is spot on. From the speeds at which looping manoeuvres are entered in aircraft such as the Hunter you do not have to worry about what pitch attitude you will be at following the first 300 ft of the pull up. My point was one that the pilot had not exceeded his DA minima, not that he had extra parameters that he had to monitor during the initial pull-up.
With respect to 1/4 clover type manoeuvres in an aircraft of the speed category of the Hunter, if you start as you suggest at less than 60 degrees nose up there will be a significant reduction in the apex height for a given g/pitch rate flown during the pull up; it also means that you will probably reach the apex not quite wings level or you will have to roll through more than 90 deg to achieve wings level. I have no experience of flying these manoeuvres in light aeroplanes and therefore if you do I defer to you knowledge in this category. However, in the category B, C and G aircraft that I display I frequently fly 1/4 clovers and I start to roll at about 80 deg nose up such that the roll is symmetrical about the vertical line. I think that this looks neater and it minimises the reduction in apex height.
Please note that my comment regarding 60 deg nose up as the definition of the start of an aerobatic manoeuvre is a worst case figure promulgated by some regulators; others use 90 deg whilst some are not prescriptive to that extent at all.
Finally, your public profile gives no clues as to your experience but, from your comments, I doubt that you have any fast jet display experience so perhaps it would be better to ask questions here, which will be politely answered, rather than making statements that are invalid.
CM - no no I'm not trying to be smart with the words... I just read that you thought item 1 of a previous posters view was irrelevant, you used the term physics. Now of course given we are talking about an actual event that had to be actually flown I took it that you were making your reply relevant.
100ft to 500ft talking no time... Depends how quickly you pull and actually we can see from the video it takes time. Of course you could argue perspective of the camera but then you'd have to square that same argument for the people who oversee these things... From the ground.
I'd like to think we can agree that this system is less than perfect.
100ft to 500ft talking no time... Depends how quickly you pull and actually we can see from the video it takes time. Of course you could argue perspective of the camera but then you'd have to square that same argument for the people who oversee these things... From the ground.
I'd like to think we can agree that this system is less than perfect.
In fact without being horrid the act of rolling an aircraft accurately has been demonstrated with this pilot not to be simple.
What's the saying? one swallow doesn't make a summer. Your statement above is in fact being 'horrid' and potentially libellous. It (deliberately?) misses the point that the Pilot in question has previously won awards for aerobatic flying in competition, has flown close formation aerobatics (including rolls), and implies the way you've written it that the pilot has difficulty to adequately fly a roll. His previous experience indicates otherwise.
LOM - a 1/4 clover flown the way you describe would seem to me specific to your class or type of aircraft. It wouldn't be a way to fly it (80deg nose up before rolling) in competition aerobatics, so i'm not sure how much practice or focus that gets. Is that technique something that is of focus?
The film I see it seems he starts rolling prior to your target of 80deg, you could use that same film to take a view on the rate of pitch up and height gain. Could you not?
The film I see it seems he starts rolling prior to your target of 80deg, you could use that same film to take a view on the rate of pitch up and height gain. Could you not?
Pittsextra,
My post does say quite clearly that my technique refers to displaying specific categories of aircraft including Cat G (which covers the Hunter) and I did say that I have no experience of flying these manoeuvres in light aircraft. Also, competition aerobatics is not the same as display flying and so not really relevant here.
I made no comment on the attitude at which the roll was commenced in the accident manoeuvre. Again, I just stated my technique. The apparent angle at which the roll appears to commenced on a video recording may be influenced by camera position but without photogrammetry analysis it is difficult to be precise as to the angle. However, I am sure that you will agree that for a given pitch rate and airspeed during the pull-up for a 1/4 clover, the lower the pitch attitude on starting the roll then the lower will be the apex height; this is just geometry and not type specific.
My post does say quite clearly that my technique refers to displaying specific categories of aircraft including Cat G (which covers the Hunter) and I did say that I have no experience of flying these manoeuvres in light aircraft. Also, competition aerobatics is not the same as display flying and so not really relevant here.
I made no comment on the attitude at which the roll was commenced in the accident manoeuvre. Again, I just stated my technique. The apparent angle at which the roll appears to commenced on a video recording may be influenced by camera position but without photogrammetry analysis it is difficult to be precise as to the angle. However, I am sure that you will agree that for a given pitch rate and airspeed during the pull-up for a 1/4 clover, the lower the pitch attitude on starting the roll then the lower will be the apex height; this is just geometry and not type specific.
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DaveUnwin
No, certainly not.
It was just a general observation.
I've never served so know only about 10 people behind usernames in this forum. However, if one reads a forum regularly, I think it's possible to discern with reasonable accuracy which posters' contributions to various discussions merit closer consideration.
An example, chosen simply because he has posted this morning: I respected LOMCEVAK's contributions years before I got to know him in real life, and when his profile didn't disclose as much as it does now.
Looking at someone's previous posts can be very revealing, particularly in accident threads which always seem to bring all sorts out of the woodwork - not just in this forum.
In many instances it reveals that they have no relevant expertise or experience, but that doesn't deter them from sounding off.
mopardave
I'm in that category.
What puzzles me is why some in our category don't just read and learn, and ask questions where necessary, rather than posting worthless opinions and sometimes arguing with those who clearly have expertise and experience in the relevant field.
BTW, Was the 'chip' comment aimed at me FL?
It was just a general observation.
I've never served so know only about 10 people behind usernames in this forum. However, if one reads a forum regularly, I think it's possible to discern with reasonable accuracy which posters' contributions to various discussions merit closer consideration.
An example, chosen simply because he has posted this morning: I respected LOMCEVAK's contributions years before I got to know him in real life, and when his profile didn't disclose as much as it does now.
Looking at someone's previous posts can be very revealing, particularly in accident threads which always seem to bring all sorts out of the woodwork - not just in this forum.
In many instances it reveals that they have no relevant expertise or experience, but that doesn't deter them from sounding off.
mopardave
those just genuinely interested in what you gents got up to.
What puzzles me is why some in our category don't just read and learn, and ask questions where necessary, rather than posting worthless opinions and sometimes arguing with those who clearly have expertise and experience in the relevant field.
Very well said, FL! 
How do you think a Hunter is going to pitch over 60 degrees in less than 400 feet?
Once again you are throwing in more and more baseless and ill-informed points without ever coming back to your previous ones when they are shown to be incorrect.
For the benefit of those who may have missed it before, would you mind stating your Miltary, Hunter and Display experience?
Originally Posted by Pitts
Does he throw it away if he does pull too quickly and achieves this visually judged 60deg pitch up at 300, 400, 450ft?
Once again you are throwing in more and more baseless and ill-informed points without ever coming back to your previous ones when they are shown to be incorrect.
For the benefit of those who may have missed it before, would you mind stating your Miltary, Hunter and Display experience?
I don't own this space under my name. I should have leased it while I still could
FL- I intended no criticism of your experience or indeed, that of your colleagues. My point was that after very non-scientific research on previous 'case celebre' ranging from tube and bus bombers, street terrorists and child abuse accusations . . . . To expect any jury to be 100% ignorant of such reporting would be hopeful in the extremet.
It would be near 100% in the early days after an event but suggest for any given event you will find a huge percentage ignorant of any later developments. Some 'massive' media coverage can actually anaesthesise many potential jurors. You cite Cliff Richard. I remember his song Living Doll and Batchelor Boy but other than that I have no interest.
Pittsextra,
Could you please post a link to the video that you have viewed to assess the pitch attitude at which the roll was commenced.
Your response to CM's first point is not an answer to his question and I am not clear about the point that you are trying to make. I am really mystified as to why you continue to be so argumentative in a discussion regarding subject matter (swept wing jet display flying) in which I suspect you have no experience. There are many aspects of aviation about which I know nothing and if I ever get drawn into discussions about them I very quickly hold my hand up, apologise and exit!
Could you please post a link to the video that you have viewed to assess the pitch attitude at which the roll was commenced.
Your response to CM's first point is not an answer to his question and I am not clear about the point that you are trying to make. I am really mystified as to why you continue to be so argumentative in a discussion regarding subject matter (swept wing jet display flying) in which I suspect you have no experience. There are many aspects of aviation about which I know nothing and if I ever get drawn into discussions about them I very quickly hold my hand up, apologise and exit!
A quick post as it's half time.
Hang on, Pitts. You are posting just to make arguments that you then try to change.
You asked,
I asked you how a Hunter would reach 60 degrees of pitch in less than 400 feet so you come back with,
I think you are confusing the relevance of pitch angle as a measure of aerobatic manoeuvre (thus minimum separation distance) with pitch angle to perform the manoeuvre.
Again, for the benefit of those who may have missed it before, would you mind stating your Military, Hunter and Display experience?
Hang on, Pitts. You are posting just to make arguments that you then try to change.
You asked,
Originally Posted by Pitts
Does he throw it away if he does pull too quickly and achieves this visually judged 60deg pitch up at 300, 400, 450ft?
Originally Posted by Pitts
Yep if that's how you start the figure but I don't see it pitched to 60deg before it commences the rolling element of the figure.
Again, for the benefit of those who may have missed it before, would you mind stating your Military, Hunter and Display experience?
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Petition
Ask Civil Aviation Authority to rethink their charges to the 2016 Airshow season
6,438 signatures at time of this posting
Ask Civil Aviation Authority to rethink their charges to the 2016 Airshow season
6,438 signatures at time of this posting
Yeah, Squib. It's an interesting move by the CAA. All the talk of improving safety when all they seem to be doing is raising their charges.
ATC, yes, we've noticed.
ATC, yes, we've noticed.
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PittsExtra, I wouldn't mind so much, but your attitude here is detracting from the discussion. I think, given your lack of credentials, you are boxing above your weight. I for one would be very happy if you stayed here, but with a little less of the attitude that you can talk authoritatively about aviation matters you appear not to grasp fully. Just tone it down a bit, answer questions and stop trying to prove your knowledge.
Following on from Lomcevak's point, I too would like to see the video that shows the pitch angle below 60 degrees whilst rolling. Thank you.
Following on from Lomcevak's point, I too would like to see the video that shows the pitch angle below 60 degrees whilst rolling. Thank you.
Last edited by Mach Two; 6th Feb 2016 at 16:42.
I really don't understand why some of you are giving PE a hard time. Those of us who have been posting on prune for some time are already well aware that he preceded the Wright Brothers by seven good years.
Sorry gentlemen had some snacks and a sponge down in a corner....
It moves on a pace.
OK lets put down some ground here. I'm expressing a view, I don't claim to be an expert in anything but then this is a public global forum and actually I don't see what I've ever written on PPRuNe is so contentious.
Yes I've commented upon some accidents and actually those who seem to know my postings will see that I posted upon this one when I suggested that actually you could see things in the accident via the video. In fact I used the term 1/4 clover only to spend 4 or 5 pages getting flamed for saying so! At least we agree its a 1/4 clover now!
So to some points of reply and I'll retire to my corner. I accept the criticism and my confusion re my comments re: pitch and height. In post No.1070 my comments/questions to Lomcevak were generic, in that I was talking display flying in general given any rules / regulations are unlikely to be type specific. Unless they are and please direct me appropriately.
So CM in answer to your post 1086 sure you can be right. My reply re: the rolling element is that because the figure being flown is a 1/4 clover which has rolling and looping then it isn't only pitch angle that is relevant. However actually my view is that this blurring of when is an aerobatic figure relevant is not clear and I don't know where that is written. After all it really means that the bottom 59deg of the entry and exit of a loop is never aerobatic. My view is that that argument becomes weak if there is no clear break between maneauvers. But thats my view, happy to be pointed in the direction of something that clarifies.
I was using this video as a ref: https://www.youtube.com/watch?v=vw75lBTZO2E
I think its rolling by 12secs. Again my view.
On the point re: angles & heights as reflected by Lomcevak in post 1078 no doubt angles and heights require more detailed analysis to be 100% but of course the people on the ground in supervision have no such equipment nor do they have time and so clearly any system needs to be unambiguous and able to be judged simply. Your system may work and be relevant for Cat G aircraft but of course there are other aircraft covered by the same umbrella/framework of rules. Or are they not?
I don't think I've hidden from any points? In fact actually there are many points I've asked that have been left hanging and whilst my skin is thick enough and to in reply to FLawyer. Yes I've commented upon some accidents although tell me what is your opinion on those that I have? What parts have irritated you so much?
I don't fly a mil. jet and I don't have time in a Hunter, there is nowhere I have said that I have. Although are we now saying that unless you do anything said is invalid? Does that apply to any accident? Anyone else commented upon an accident which involves a type they have no time on? PPRuNe would have some thin threads if they did. Crikey it would be pretty limiting to those reviewing the regulations for air displays wouldn't it!
It moves on a pace.
OK lets put down some ground here. I'm expressing a view, I don't claim to be an expert in anything but then this is a public global forum and actually I don't see what I've ever written on PPRuNe is so contentious.
Yes I've commented upon some accidents and actually those who seem to know my postings will see that I posted upon this one when I suggested that actually you could see things in the accident via the video. In fact I used the term 1/4 clover only to spend 4 or 5 pages getting flamed for saying so! At least we agree its a 1/4 clover now!
So to some points of reply and I'll retire to my corner. I accept the criticism and my confusion re my comments re: pitch and height. In post No.1070 my comments/questions to Lomcevak were generic, in that I was talking display flying in general given any rules / regulations are unlikely to be type specific. Unless they are and please direct me appropriately.
So CM in answer to your post 1086 sure you can be right. My reply re: the rolling element is that because the figure being flown is a 1/4 clover which has rolling and looping then it isn't only pitch angle that is relevant. However actually my view is that this blurring of when is an aerobatic figure relevant is not clear and I don't know where that is written. After all it really means that the bottom 59deg of the entry and exit of a loop is never aerobatic. My view is that that argument becomes weak if there is no clear break between maneauvers. But thats my view, happy to be pointed in the direction of something that clarifies.
I was using this video as a ref: https://www.youtube.com/watch?v=vw75lBTZO2E
I think its rolling by 12secs. Again my view.
On the point re: angles & heights as reflected by Lomcevak in post 1078 no doubt angles and heights require more detailed analysis to be 100% but of course the people on the ground in supervision have no such equipment nor do they have time and so clearly any system needs to be unambiguous and able to be judged simply. Your system may work and be relevant for Cat G aircraft but of course there are other aircraft covered by the same umbrella/framework of rules. Or are they not?
I don't think I've hidden from any points? In fact actually there are many points I've asked that have been left hanging and whilst my skin is thick enough and to in reply to FLawyer. Yes I've commented upon some accidents although tell me what is your opinion on those that I have? What parts have irritated you so much?
I don't fly a mil. jet and I don't have time in a Hunter, there is nowhere I have said that I have. Although are we now saying that unless you do anything said is invalid? Does that apply to any accident? Anyone else commented upon an accident which involves a type they have no time on? PPRuNe would have some thin threads if they did. Crikey it would be pretty limiting to those reviewing the regulations for air displays wouldn't it!
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Pitts,
Good. I'm glad you've decided to listen.
That is because you haven't been listening to what people here have been telling you for the past five months.
Now let's carry on better.
Good. I'm glad you've decided to listen.
actually I don't see what I've ever written on PPRuNe is so contentious.
Now let's carry on better.
Mach - fair enough. Just to clarify another thing and again if this isn't the same aircraft pilot happy to be told otherwise but here is the link to the film at Bray where the rolling element is on the down line.
https://www.youtube.com/watch?v=0P2TV2HZUss
https://www.youtube.com/watch?v=0P2TV2HZUss
Gents,
I think that I may be guilty of introducing a red herring by mentioning 60 deg of pitch for defining an aerobatic manoeuvre. I have done a bit more digging and actually the worst case is a FAA definition which states 60 deg of bank and 30 deg of pitch (with a few caveats); that is what must have prompted me a use the number 60 but incorrectly. The old military flying regs, JSP318 (happy days!) specified 90 deg of pitch or bank. I cannot find any actual numbers in CAP403 and am not actually aware of anything in the ANO (but if there is I would be interested to know). So let's not get hung up on hard numbers. Being pragmatic, there is no more risk in pulling up into a loop from a low height than there is from performing a wings level pass at the same height and, air display rules permitting, I usually pull up from my flypast minima and am quite content if someone does this during a DA renewal.
One item to consider when viewing the video clip that Pittsextra has linked to is that if you view a loop from directly abeam the aircraft at pull-up then by the time it is in the vertical you will view some of its topside and it may appear that it has rolled towards you. Therefore, from this aspect it may appear to have started rolling before it actually has. I am not saying that Pittsextra's judgement is incorrect or invalid, just that I would not actually put a figure on the pitch attitude based solely on a video from just that single aspect. Although not relevant here there is another visual illusion when viewing a loop head on in that the aircraft will appear to have a reduction in pitch rate when close to the vertical because the apparent length of the aircraft, the rate of change of which gives the visual cue of apparent pitch rate, is a function of sine pitch attitude and therefore even for a constant pitch rate the rate of change of apparent aircraft length is non-linear.
I think that I may be guilty of introducing a red herring by mentioning 60 deg of pitch for defining an aerobatic manoeuvre. I have done a bit more digging and actually the worst case is a FAA definition which states 60 deg of bank and 30 deg of pitch (with a few caveats); that is what must have prompted me a use the number 60 but incorrectly. The old military flying regs, JSP318 (happy days!) specified 90 deg of pitch or bank. I cannot find any actual numbers in CAP403 and am not actually aware of anything in the ANO (but if there is I would be interested to know). So let's not get hung up on hard numbers. Being pragmatic, there is no more risk in pulling up into a loop from a low height than there is from performing a wings level pass at the same height and, air display rules permitting, I usually pull up from my flypast minima and am quite content if someone does this during a DA renewal.
One item to consider when viewing the video clip that Pittsextra has linked to is that if you view a loop from directly abeam the aircraft at pull-up then by the time it is in the vertical you will view some of its topside and it may appear that it has rolled towards you. Therefore, from this aspect it may appear to have started rolling before it actually has. I am not saying that Pittsextra's judgement is incorrect or invalid, just that I would not actually put a figure on the pitch attitude based solely on a video from just that single aspect. Although not relevant here there is another visual illusion when viewing a loop head on in that the aircraft will appear to have a reduction in pitch rate when close to the vertical because the apparent length of the aircraft, the rate of change of which gives the visual cue of apparent pitch rate, is a function of sine pitch attitude and therefore even for a constant pitch rate the rate of change of apparent aircraft length is non-linear.