Fast Jet Display Safety

[Wingless Walrus]

Whilst watching a video of the tragic fatal loss in September 2017 of an Italian Air Force Typhoon at an air display, I wondered if there could be a system developed for use during display flying that could have avoided such a crash and fatality. The crash does not appear to be a failure of the aircraft but due to pilot incapicitation or error. In watching this tragedy a couple of things came to mind: -

1) The aircraft systems had data that if utilised would show that the crash was approaching.
2) A fast jet pilot on the ground would probably have seen that crash coming a significant time before it happened.
3) A ground based system comparing the intended display with the actual display (e.g. via radar or onboard GPS data, inertial, etc.) would be able to spot significant deviations from the intended display and generate warnings.

With all of todays technology could not a system be produced around these points that could have avoided the crash and fatality? Both onboard and ground based systems. * I stress that these systems would only be used for display flying *.

A)
ONBOARD SYSTEM (Automatic initiation of crash avoidance or of crew escape)
The aircraft systems know what the aircraft is doing and what it is capable of doing. Put this data together with knowledge of where the ground is and that is the basis of a ground avoidance system.

Once the aircraft detects that a crash inducing position is fast approaching, would it be acceptable to have automatic initiation of recovery to a safe attitude?
If a crash is unavoidable, is it acceptable to have the aircraft automatically initiate ejection at the last second?

B)
GROUND BASED SYSTEM (Monitoring of air display and generation of warnings)
Pilot on the ground acts as observer and can command the display pilot to abort any manoeuvre.
This could be assisted by utilising point 3), a ground based system displaying warnings of deviations from the intended display (height, speed, etc.).

I have no experience of flying or of air display procedures and requirements. It just seems doubly tragic to see a pilot killed in such a way while surrounded by technology that potentially could have been utilised to have saved him.

The history of pilots staying with a doomed aircraft in a bid to save it goes back to the dawn of aviation and will continue until the end.
With advanced fast jets being both highly sophisticated and immensely expensive is it now not viable to spend the money to utilise the technology to make an advanced safety system to avoid these tragedies.

It would be of great help to get comments from fast jet pilots on the viability of such systems.

[Wensleydale]

With advanced fast jets being both highly sophisticated and immensely expensive is it now not viable to spend the money to utilise the technology to make an advanced safety system to avoid these tragedies.


...or indeed stop display flying.

[Pontius Navigator]

Wingless Walrus, without close scrutiny, much of what you say is true and has merit. However Google Mulhouse Crash.

I think that answers the question.

[Timelord]

I doubt that anyone would pay to write special software JUST for displays so you would have to work with normal flight envelope protection. As PN says this probably caused the Mulhouse accident. More recently I heard of a pilot displaying a modern fast jet who was demonstrating a dirty slow speed pass at low level past the crowd. The software decided that he was too slow, so what did it do? Lowered the nose!

[Mr. Vice]

Companies that make fighter aircraft put their efforts in to making the most lethal aircraft they can within their budget. Why would they spend a certain amount of their budget on protecting display pilots when it is not required in the mission set or the aircraft requirements. Yes it would make display flying safer, of that there is no doubt. Would it sell more fighters or give it the edge in some kind of competition? Almost certainly not, so they take that money and put it in to developing better sensors,weapons and avionics for fighting.

Display flying is a by product of fighter design. Love it or hate it, it is the way Business works.

Cheers,

Mr Vice.

[tartare]

Wouldn't that automatic fly-up software thingy that the Swedish use and the Spams have tried do the job?
Or are most airshow sequences inside it's "...don't do that, I'm taking over control..." envelope?

[KKoran]

Might as well have the safety system fly the display.

[rcsa]

That manoeuvre starts going wrong the moment the pilot decides to pull a loop without enough altitude.

KKoran is spot on. Sadly, by the time my kids have kids, I suspect that most national air forces will compose of a tame, and heavily protected historic flight, and a deployable force of UAVs in every role from A2A, through strike and recce, to transport. We are in the last decade or two of fast jets being flown with humans in the driving seat. Why bother writing software to protect against incompetence?

[Runaway Gun]

How does one pull a loop without enough altitude?

[AnglianAV8R]

How does one pull a loop without enough altitude?

By starting to pull up into the loop from a height that would result in a heavy landing/arrival ?

It's basic stuff, surely. Or, am I misunderstanding the question?

[Peter G-W]

By starting to pull up into the loop from a height that would result in a heavy landing/arrival ?

It's basic stuff, surely. Or, am I misunderstanding the question?

I’m with Runaway Gun on this one. It’s basic stuff, for sure.

[AnglianAV8R]

I’m with Runaway Gun on this one. It’s basic stuff, for sure.

Ah, perhaps I misunderstood the tone of his question. Maybe he meant " How on earth does anyone consciously pull into a loop from a height that makes it impossible" ?
If so, I concur. The sky is perfectly safe, so long as you keep away from the edge.

[rcsa]

If so, I concur. The sky is perfectly safe, so long as you keep away from the edge.

That's the truth. Nicely put.
Watch the video. https://www.youtube.com/watch?v=8d8zSCIvByk

Even as a low-hours Cessna driver, I can tell it's going to go horribly wrong from about 00.20. And I bet the poor pilot knew it from before that.

[Treble one]

I saw this with horror at the time, and wondered why no ejection attempt was made (incapacitation excepted)? I accept that the sink rate may have been outside of the seat parameters, but surely it was worth taking the chance? Given the obvious alternative. I'm not aware of any BOI findings on this incident-it may be covered in there. Apologies if this is the case.

[Treble one]

I doubt that anyone would pay to write special software JUST for displays so you would have to work with normal flight envelope protection. As PN says this probably caused the Mulhouse accident. More recently I heard of a pilot displaying a modern fast jet who was demonstrating a dirty slow speed pass at low level past the crowd. The software decided that he was too slow, so what did it do? Lowered the nose!
I believe that on certain FJ displays now, the undercarriage is lowered during their high alpha low speed passes, to prevent the automatic systems kicking in to lower the nose, as the computer thinks the aircraft is in landing configuration and hence wont activate the flight envelope protection system.

[fantom]

As my Boscombe tp mate said: looping at low altitude is very dangerous. Think about it, it starts at low level and fast. The loop is entered with much stick-pulling and unless the top half has the same (or less) radius, you will crash. It's the top half that will kill you.

[phil9560]

Simple-enter the loop at 5000 feet.Never failed me yet.Bit dull for folks on the ground though.

[dook]

It's called proper training and situational awareness. Technology is not required.

I didn't have any in my jet display days.

[phil9560]

Funnily enough Dook a Lightning pilot talked me through my first loop from the front seat of a Chipmunk in 1984.All went well until I felt the stick wrenched from my hands as I almost entered a second loop at about 90 knots.Didn't know where the hell I was :rolleyes:

[Green Flash]

It's the top half that will kill you.
You are right there fantom. A couple of us were the closest people to 'that' Typhoon loop at RIAT. Between us, maybe 60 years of watching displays and as he started to pull over the top we both turned on our heels and ran, quite sure that we would hear an awefull noise and feel the heat. We didn't, thankfully, but even before he had reached the critical point we just knew it was going to end in tears. We were about 20' out in our estimationand the pilot walked away.

[dook]

Funnily enough Dook a Lightning pilot talked me through....

Would you be kind enough to PM his name to me ?

edit: my display base height was 500ft and in serious competition work all manoeuvres had to be commenced and finished at that height. It is also worth noting that the exit speed from any manoeuvre must be the entry speed for the next since any delay will incur penalties.

[LOMCEVAK]

Wingless Walrus,

I do not believe that your suggestions are feasible for a few reasons:
- The aircraft does not know what the intended manoeuvre is at any time. At the apex of a looping manoeuvre, how does it know whether the pilot is planning to fly a downward 1/2 loop or to pull onto a down 45 deg line then roll erect and pull out? The latter manoeuvre can be flown safely from an apex height considerably lower than that required for a downward half loop. Therefore, an automatic recovery system would either prevent the pilot flying a 1/2 Cuban 8 (1/2 horizontal 8 in RAF terms) or would allow him to crash from a loop. Similarly, if at, say, 500 ft a level high g turn was flown to roll out to the inverted and then an inverted pass flown, how would it sense that as being different to the top of a loop? In a barrel roll, you may be in a wings level inverted attitude at the apex but there is no safety gate to account for getting too steep nose down during the second half. You could never derive an infallible algorithm.
- Although the military tend to use fixed sequences for displays, this is not, in my opinion, always the safest option because it can result in a pilot feeling pressured into flying a marginal manoeuvre rather than changing the sequence and flying a safer one. Therefore, ground based observation is not infallible because the observer will not know precisely what the pilot is planning to do next. Also, assimilation of the flight data when off board takes time and by the time an unsafe manoeuvre has been identified it may be too late to implement a safe escape manoeuvre.
- Automatic initiation of a recovery manoeuvre or automatic ejection initiation could result in the aircraft being placed on a vector towards the crowd which, whilst potentially saving the pilot's life, may endanger bystanders whose safety is paramount.

Low level loops can be flown safely, as some Boscombe tps do frequently (fantom, PM me if you wish!!!). I am with dook that it is all about proper training and situational awareness. Automation in displays - I wonder how large the crowd would be for a UAV display?

[Runaway Gun]

It's not the entry altitude that will kill you, it's generally the lack of entry speed (and what you do over the top). Press-on-itus often 'forces' the pilot to do attempt it at 'just a few knots' lower than their usual speed, with disastrous consequences.

[Rhymenoceros]

Some interesting comments and I certainly agree with Lomcevak and Dook - Automation has proven on multiple occasions to not be the answer. Instead training, situational awareness and most importantly understanding of the individual aircrafts performance is key.

Low level aerobatics are in my view not dangerous; they simply expose you to more risk. If that risk is managed via the above, then technically one could initiate a loop (for example) from takeoff - assuming it was sensible based on the aircraft performance available.

One must first differentiate between “competition” aerobatics and display aerobatics. In competition the expectation is a ‘perfect’ loop - a constant radius, where the entry and exit speeds are the same. Skill in flying this manoeuvre is key. A slight error could result in recovery below the start height. If the margin isn’t there you will crash and thus why competition aerobatics are not generally flown at low altitudes below 500ft. Display aerobatics are not scored. A flying display should be flown to show off the aircraft, not the pilots skill. Manoeuvres need not be textbook, simply safe and ideally pleasing to those watching. As such, a loop will probably not have a constant radius - the first half flown to achieve altitude in excess of the minimum required to complete and the second half flown to make advantage of the assistance of gravity to increase turn radius and pitch rate. On the way back down, once assured that the loop can be completed safely, the radius can be gradually increased thus allowing energy to be regained and the pull managed to arrive back at the start altitude. Not all aircraft can do this, hence it is important to know the limits of the machine. A chipmunk for example will generally lose altitude in a loop. That’s not to say it can’t be done - it can, but not ending with the same energy package that you started with. In stark contrast a typhoon can execute a loop from extremely low speed / energy - it has the thrust to gain the required altitude over the apex and the pitch authority on the way back down to successfully complete the manoeuvre. However that type of loop is not the same as a competition manoeuvre, rather than prescribing a circle in the sky it will instead be more of an ‘egg’ shape.

Ultimate performance is not however, the be all and end all. Regardless of whether doing low level aerobatics in a tiger moth or an F22, energy must be managed correctly. There is always talk of too low to complete, too slow, didn’t make gate height etc. This is usually not the full story - it is almost always just energy mismanagement. The video above is a sad example. The manoeuvre (which was not a loop) was not conducted from too low or too slow and probably had the required gate altitude to complete. It was the mismanagement of the energy state of the aircraft that resulted in the accident. I will caveat that I do not know the details - I have simply seen the film and as a fast-jet aviator, understand how modern aircraft fly.

An aircrafts wing will only fly to a certain angle of attack, exceed that and under loaded flight (ie greater than 0g) it will stall. Simple aerodynamics. A modern fighter aircraft can usually exceed 30 alpha before this occurs compared to a chipmunk which is a fraction of that value. However you cannot always just pull to max performance alpha that will give you minimum radius - if you have excess airspeed you may encounter the load limit first. In a modern fighter, the load limit is effectively the G-Limiter. If you can remove that then you as a human become the limiter (ie. maintaining consciousness) or the structural integrity of the aircraft. Whilst i believe the typhoon in the video may have had the altitude to recover from the split-s he executes, he has far too much energy in the form of airspeed. On the way down the aircraft is max performing but due to either being g-limited (I assume in the region of +9g) or physiologically limited, it cannot achieve the radius of turn required from the planned gate height.

My stab at explaining some of the characteristics of aircraft performance barely scratch the surface of what is a very complex subject. We as humans will always error. The key is to learn from others and strive not to keep repeating the mistakes made in the past.

[Argonautical]

I remember years ago watching a USAF F-15 display in the UK somewhere.The actual aircraft was an F-15B and the American commentator said the back seat was occupied by a safety pilot.

[dook]

Suspect the commentator was talking through the other end of his body.

[Argonautical]

Dook, you suspect wrong. The commentator was a member of the USAF F-15 display team.

[Wingless Walrus]

I have enjoyed reading the comments made here, very helpful and interesting. It got me thinking more about the issue, I have summarised some views against a summary of the main points made in other comments.

Summary of main points so far: -

1) stop display flying

A valid and logical option for the defence ministries (who fund the purchase of the assets) and the armed forces (who have just lost two very precious assets, the pilot and fighter while entertaining kids eating ice cream on the beach).

Public air displays generate a great deal of public interest and support for the armed forces and its hard to put a value on that. Public support could translate into political support, e.g. politicians will be more wary of how they treat armed forces if they are popoular in the mind of the public. A future prime minister may come from one of those kids watching air displays.

Regardless of the merits I dont ever see display flying being stopped. If Ramstein & Shoreham didnt stop them probably nothing will.
I have not seen many displays in the flesh, but those I did gave a spectacular and deep impact. They grab the attention of nearly every person from every walk of life.

2) automatic systems can cause crashes, dangerous to rely on them too much

The Mulhouse crash in 1988 of the new fly by wire A320 that flew into tree's on its first public demonstration was not due to system failure according to the recent articles by an aviation journalist last month. These articles are below and it is well worth also reading the comments made. It was aircrew error and misunderstanding of how the fly-by-wire worked that led to aircrew blaming the system.
* I am on less than 10 post so I cannot include web adresses; look on the website 'fearoflanding' (.com) and search for the articles:
Thirty Years Since Air France Flight 296
Too Slow, Too Low and Obstacles Ahead: Air France flight 296

Regardless of the cause, this airliner crash was 30 years ago when fly-by-wire was new on airliners but was already flying on fast jets.
I take the point that automatic flight systems can fail. However with careful design and development they are incredibly reliable and capable systems.

Typhoon proves this point, it could not fly without them; it is unstable and relies on the flight control computers to keep control of it in every speck of its huge flight envelope and in every conceivable configuration. By comparison, ground avoidance is a far easier requirement to meet for automatic flight systems.

3) Its too expensive to develop a system

For the flight control designers to add a display ground avoidance function to their already comprehensive task of designing a system to fully control the aircraft in all configurations in all parts of the flight envelope, is easily possible. Typhoon is already half way there; it has an automatic recovery function that when selected automatically recovers the aircraft to a safe attitude.

A small dedicated team could have designed a ground avoidance function (at least offering some protection if not total protection), grabbing information from the main flight controls team already in place. A similar sized team could test and develop the software using simulators topping off with aircraft tests piggy backed onto the existing flight test programme. Lets say that would cost £10million.

This system could have been fitted to all aircraft, so that is sharing £10million between the four countries making the Typhoon. You could also sell the ground avoidance system to export customers and for use on other aircraft.

Cost of one Typhoon is about £75million (£110million by some estimates)
Cost of Italian test pilot killed is well over £4million
- £4million to train and get to squadron
- over one thousand hours of fast jet flying @£15k per hour roughly?
- Graduation from test pilot school?

TOTAL COST = well in excess of £79million, maybe as high as £140million.

Saving that one Typhoon from crashing would have made a ground avoidance system worth it many times over. Even a limited ground avoidance system would have been able to see that crash coming and at least warn the pilot if not initiate recovery. A ground avoidance system could possibly prevent future Typhoon losses/fatalities, especially if utilised not just in air displays. The link below lists Typhoon crashes to date and possibly had there been at least some warning of the approaching unavoidable crash more pilots may have ejected and been saved?
* I am on less than 10 post so I cannot include web addresses; visit 'fighterjetsworld' (.com) and earch for web page:
Crash Videos of Eurofighter Typhoon List of All Eurofighter Typhoon Crash So far

4) its not feasible / aircraft cannot know what the intended manoeuvre is and so the system cannot work

I think that the Tornado IDS had a terrain following system that was in effect a ground avoidance system, consisting of a ski slope curve projected ahead of the aircraft. When terrain broke through the ski slope the aircraft pulled up to clear the ski slope from the terrain.

Maybe a system using some form of 3D ski slope volume constructed around the aircraft, representing the max manoeuvre ability of the aircraft from its current position, could determine if the aircraft was approaching a position from which it is not possible to avoid the ground with any manoeuvre. This does not require to know the intended manoeuvres but only the aircraft position, aircraft max manoeuvre capability and where the ground is.

5) It would make the display boring (i.e. system flying display)

If the display was flown correctly the system would never kick-in. There would be no observable difference in the display, it would still be a pilot flying the aircraft to its liimits. Even if a mistake was made the system would only kick-in to avoid a crash condition, not to catch non-dangerous mistakes.

6) Fast jets are soon to be replaced by unmanned aircraft, not worth investing now in an avoidance system

If those unmanned aircraft are going to fly displays, why not fit a ground avoidance system?
If it crashes that is still a very valuable asset lost. At some point there will be UAV's doing combat at low level. Such an UAV will benefit from a ground avoidance system.

7) No need for safety systems as long as pilots fly right i.e. dont make mistakes

History shows that pilots do rarely make mistakes despite them being highly trained and highly professional. Rare as they are, when they happen they cost highly prized assets in pilot and machinery.

8) ground based observation is not infallible because the observer will not know precisely what the pilot is planning to do next.

Unless the display went exactly to plan I cant see a way around that problem. Coupled with the time lag between seeing a problem and relaying it to the display pilot, probably no practical advantage could be had.

A previous comment mentioned a two seat F-15 air display with a second pilot acting as an additional safety mechanism in the aircraft. If that was effective should displays use twin seat aircraft? Doesnt have the same thrill factor for onlookers, though.

I guess that some displays are cutting things so fine that even a second pilot would not have time to take control and recover; possibly end up with two dead pilots instead of one.

9) such a system could result in the aircraft being placed on a vector towards the crowd, i.e. could jeopardise crowd safety

That is a fundamental problem but not impossible to solve. The system could be programmed with the crowd locations and permissable corridors to operate in.

*
It is technically possible to make a ground avoidance system and it is financially viable to make such a system. The system may have limits but if it saves one pilot/aircraft it will pay for itself.

Such a system would be useful for truly autonomous UAVs, especially in combat roles.

I wonder if the reason it hasnt been done is that it has never been put in the aircraft requirements given to industry?

[flighthappens]

some variants of F-16 already have Auto-GCAS(Ground Collision Avoidance System). It has been credited with saving lives and airframes.

It can be done and from what I understand it has already “paid for itself”.

it has been integrated into Bk40/42/50/52 Vipers for a few years; they have flown displays since then; it probably has no or limited effect on their displays.

[tartare]

Yep - that's the system I was thinking of.
There's some video somewhere on web of it doing a 6 or 7g flyup after a Viper driver suffered G-LOC...

Here it is:- 9.1g on the dial!
https://www.youtube.com/watch?v=WkZGL7RQBVw

[EAP86]

WW I'm pretty sure Typhoon was designed with an auto-recovery mode within the FCS. It was designed against the risks arising from GLOC during normal military flying. Its a while since I had any direct knowledge but I'm sure someone who knows about its current status will be along soon.

EAP

[flighthappens]

WW I'm pretty sure Typhoon was designed with an auto-recovery mode within the FCS. It was designed against the risks arising from GLOC during normal military flying. Its a while since I had any direct knowledge but I'm sure someone who knows about its current status will be along soon.

EAP

Typhoon FCS has no auto recovery protection from GLOC. The aircraft can recover itself from pilot disorientation, however this function is pilot activated to enter/exit, certainly not automatic.

[Pontius Navigator]

To answer just some points, I agree about Mulhouse but the point was not a systems failure but a pilot failure using a system. Perhaps not typical.

Air shows are undoubtedly popular with many regular visitors over the years and some visiting many in one year. Adding them all up however and the numbers are minute. They are really preaching to the converted. The established shows are so few that most people don't have access. The free seaside shows are popular but I don't know how they cover costs.

An attempt to start a new show at Abingdon to attract the Londoners was an abject failure on so many levels. I think Lincolnshire has dropped off the circuit now so what Military shows remain?

[Wingless Walrus]

Comments on USA using Auto-GCAS (Ground Collision Avoidance System) are spot on.
Good articles on websites below:
F-35 To Incorporate Automatic Ground Collision Avoidance System
https://www.f35.com/news/detail/f-35-to-incorporate-automatic-ground-collision-avoidance-system
What Exactly Is Auto GCAS?
https://fightersweep.com/3955/exactly-auto-gcas/

The Typhoon does have an automatic recovery system that is initiated by the pilot (the button was on the panel in front of the stick). When activated by the pilot the aircraft recovers itself.

Air shows preaching to the converted is a good point. As impressive as they are, there is not the public interest there used to be. I remember air shows being on TV when I was a kid, but I don't see them anymore.

That is the ground avoidance system question answered. What about automatic ejection systems? Probably by the time such a system could be reliably developed, pilots will no longer be in the aircraft?

[CAEBr]

The Typhoon does have an automatic recovery system that is initiated by the pilot (the button was on the panel in front of the stick). When activated by the pilot the aircraft recovers itself.

That's all very well, but is likely to be of limited use in display flying. as the pilot has to realise that he has lost control, or at least needs assistance to recover the aircraft. You then need to have sufficient height to allow the system to recover the aircraft. In a number of airshow accidents involving vertical manoeuvres running out of height, the pilot has invariably been flying the aircraft to the limit of its performance in attempting to complete the manoeuvre, often tragically coupled with not acting soon enough to use the ejection seat. An auto recovery system would not be able to do any better.

Medium to high altitude manoeuvring is obviously different and the automatic recovery system could be utilised - but that's not display flying, at least for a year or two until the CAA/MAA raise the minimum height and give all spectators binoculars........

[Wingless Walrus]

That's all very well, but is likely to be of limited use in display flying. as the pilot has to realise that he has lost control, or at least needs assistance to recover the aircraft.

Yes I agree. See my earlier comment (#28 point 3). Some comments about Typhoon were unsure whether the system was activated in response to GLOC or manually selected.

[Bing]

What about automatic ejection systems? Probably by the time such a system could be reliably developed, pilots will no longer be in the aircraft?

Didn't the Yak-38 Forger have one of those?

[tartare]

Yes - it did.
https://www.flightglobal.com/FlightPDFArchive/1986/1986%20-%200458.PDF

[NutLoose]

I do not think the UK really has a problem with airshow crashes bar the last couple of high profile ones, the Shoreham crash was caused by entering a manoeuvre too low that it was impossible to recover from, righty or wrongly the main difference in that incident was members of the public not involved with the show died and they hadn't agreed in the terms of sale to accepting ones own liability, the strange outcome of all of this was the display line was moved away from the crowds who had accepted that burden to further areas outside the perimeter of the site, where those that haven't accepted it are more at risk.

Don't most Russian fighters also have a button to put it back into straight and level flight if it all goes pear shaped.

[NutLoose]

The Stuka incidentally had an automatic recovery system in case the pilot blacked out in a dive.

Junkers Ju 87 Stuka (http://www.aviation-history.com/junkers/ju87.html)

[LOMCEVAK]

Wingless Walrus,
Points related to yours above:
- It is highly unlikely that a database update of crowd positions and obstacles at the display site for loading into a display aircraft could be done in enough detail and within the required timescales for it to give the risk mitigation levels that you seek.
- Minimum altitude loss requires a wings level pull-out. If an automated escape manoeuvre had to achieve a specified ground track in order to avoid the crowd or obstacles then a turn would inevitably be required to achieve this. This would increase the overall height loss and, therefore, the algorithm to decide when to initiate the manoeuvre automatically would be, I suspect, too complicated to be feasible.
- If I fly on an erect down 45 line at a safe height and fly a 360 degree roll, the automatic recovery system should not trigger. However, if I stop the roll inverted and immediately pull full back stick the high pitch rates achievable by modern fighters would almost certainly be able to beat any recovery algorithm that actually allowed the pilot to fly even safe manoeuvres and a ground impact would occur.
- When would the automatic recovery mode disengage and hand control back to the pilot? What would the power setting be at that point? If the recovery was at the g limit and the pilot was not expecting it then he/she could GLOC. Even if GLOC did not occur the pilot could be very disorientated. Disengaging is one aspect that you have not considered and I believe would be a major safety concern which could result in the system causing an accident.
- The Tornado TFR system controlled to a maximum turn rate of 7 deg/sec and left the aircraft in an open loop climb after 2 secs. This is a very limited manoeuvre envelope and not analogous to display manoeuvres.

The comments regarding a 'safety pilot' in the rear seat of the F-15 display are interesting. Without knowing the CRM aspects of how this was flown, I suspect that the rear cockpit pilot was calling out airspeeds on the way up, altitudes on the way down, and may have confirmed correct engine performance. Having displayed 2 seat aircraft, this is what my navigators did and it was very useful.

Rgds

L

[Onceapilot]

The Stuka incidentally had an automatic recovery system in case the pilot blacked out in a dive.

Junkers Ju 87 Stuka (http://www.aviation-history.com/junkers/ju87.html)

Yes, it did. However, this was a rudimentary system that merely coupled a link between the operation of the (very effective) dive brakes and a pre-set elevator nose down trim bias and, a reset of those settings upon a signal from the contact altimeter. The recovery was therefore, more of a simple automated function. If the pilot mis-set the contact altimeter (baro), recovery might not be achieved...depending upon the error! :oh:

OAP

[EAP86]

Typhoon FCS has no auto recovery protection from GLOC. The aircraft can recover itself from pilot disorientation, however this function is pilot activated to enter/exit, certainly not automatic.

Thanks for the correction. It was a while ago. I think there was some discussion wrt GLOC but the difficulty was establishing that it was actually taking place. Some form of physiological measurement/feedback seems to be essential but you can probably imagine the aircrew response to some of the more invasive techniques :hmm:

EAP

[Just This Once...]

- If I fly on an erect down 45 line at a safe height and fly a 360 degree roll, the automatic recovery system should not trigger. However, if I stop the roll inverted and immediately pull full back stick the high pitch rates achievable by modern fighters would almost certainly be able to beat any recovery algorithm

A number of years ago we (the UK) did look at protection system that moved away from a recovery algorithm to a dynamic flight envelope protection system. The idea behind it was to prevent or frustrate any manoeuvre that could not be manually (or automatically) recovered from.

In the example you give above the system would allow the 'roll inverted' bit but limit/frustrate/prevent the worrisome pitch input. Alternatively if you had pitched-up hard first and then rolled the system would push back in roll when the lift vector became ominous. In a way it was more akin to SPILS intervention on the Tornado (physically harder to pull back with increasing AoA) but in all axes with terrain/aircraft/store limit awareness. In the sim environment you could still deliberately crash it but you had to work really hard to do so. For the Douglas Adams fans think 'throwing-yourself-at-the-ground-but-missing' - I think that line made it into the TP report....

The original idea behind the programme was to eliminate the alarms and overt interventions used with traditional GCAS whilst providing care-free handling, without ever fully-seizing control from a pilot operating at the limits of achievable flight. Without a platform customer I guess the details are archived at dstl or with whatever DEC-TA morphed into.

[Wingless Walrus]

A number of years ago we (the UK) did look at protection system that moved away from a recovery algorithm to a dynamic flight envelope protection system. The idea behind it was to prevent or frustrate any manoeuvre that could not be manually (or automatically) recovered from.
...
The original idea behind the programme was to eliminate the alarms and overt interventions used with traditional GCAS whilst providing care-free handling, without ever fully-seizing control from a pilot operating at the limits of achievable flight. Without a platform customer I guess the details are archived at dstl or with whatever DEC-TA morphed into.

That systems could have saved the Italian Typhoon and pilot lost. The Typhoon already has an automatic recovery function but is pilot selected. Had your system been developed and linked to the existing auto-recovery function that would have made an effective system.

I wonder if automatic ground/air collision systems will be on the next UK fighter and will the UK develop it or buy it from the USAF?

[Wingless Walrus]

LOMCEVAK
- the auto-GCAS appears to be a very capable ground avoidance system (as mentioned by other comments here).
It has already saved several fast jets and pilots. Some good clips on YT and good information on it in links in comment #34. Also the link below for Wright Patterson Air Force base. The USAF is also developing an ACAS (Air Collision Avoidance System).
- Automatic Collision Avoidance Technology (ACAT)
https://www.wpafb.af.mil/Welcome/Fact-Sheets/Display/Article/1578307/afrl-automatic-collision-avoidance-technology-acat/

The following description from The Aviationist: -

The Auto-GCAS (Automatic Ground-Collision Avoidance System) is an automatic system that, once installed and activated on a plane, monitors the flight parameters: to make it simple, when predictive algorithms and computer software determine that altitude, speed, attitude, GPS position, terrain are such that the CFIT [Controlled Flight Into Terrain] is imminent, the A-GCAS automatically (without pilot initiation) sends inputs to the flight controls to recover the plane.

[just another jocky]

LOMCEVAK


The Auto-GCAS (Automatic Ground-Collision Avoidance System) is an automatic system that, once installed and activated on a plane, monitors the flight parameters: to make it simple, when predictive algorithms and computer software determine that altitude, speed, attitude, GPS position, terrain are such that the CFIT [Controlled Flight Into Terrain] is imminent, the A-GCAS automatically (without pilot initiation) sends inputs to the flight controls to recover the plane.

Unless you have the gear down...:confused:

[Wingless Walrus]

Unless you have the gear down...:confused:

It would be ironic if a jet fitted with auto-GCAS crashed because it ran out of fuel because the auto-GCAS would not let the aircraft land!

I suspect they have these problems solved; they have paid particular attention to using the system in all flight regimes without unwanted behaviour. They are aiming for a very comprehensive system of collision avoidance.

Reading some of the links mentioned previously, one of the main objectives was to also avoid nuisance warnings and behaviour. It seems a very sophisticated system. It doesnt kick-in until almost the last second of decision making (I think in one event the time quoted was 0.8 sec from being too late to do anything) and the system aims for a 5G pull-out.

In essence they are building a system that replicates the pilot thought process, since the pilot is the current most sophisticated anti-collision system. At some some point the artificial intelligence will be as good as the pilot, then its time to put Cylons in the jets.

[LOMCEVAK]

Wingless Walrus,

With your conviction for the incorporation of auto-GCAS for display flying, I am curious to know what you propose re my earlier point regarding when the system would disengage and return control authority to the pilot and the potential for it inducing GLOC.

When displaying a high performance aircraft, the aim is to demonstrate its maximum performance when safe to do so and to transition between such manoeuvres in a safe manner which, invariably, will not be flown at maximum performance. Any automatic GCAS will have to have safety margins built in, and I feel that g onset rates and peak g would have to be reduced from the ultimate capability of the aircraft such that GLOC would not be induced upon a pilot who was unprepared for the automated and unannounced high g manoeuvre. Therefore, in a display I suspect that there would be nuisance intrusions occurring when the automatic system would effectively terminate the display unnecessarily. Personally, I would not be prepared to display an aircraft that had such a system.

The key to display safety is to pick a pilot who has the correct attitude and to train him properly. This training must be done by someone with the requisite experience, not just of senior military rank. And I suspect that this paragraph may open up a whole new topic for discussion!

[dook]

The key to display safety is to pick a pilot who has the correct attitude and to train him properly. This training must be done by someone with the requisite experience, not just of senior military rank.

Well put - I'm with you.

[Wingless Walrus]

LOMCEVAK,
it will take someone far more knowledgeable than me to make any decision on any system to be used on any aircraft for anything. I only make the point that those far more suitable than me, i.e. the USAF and others, have gone down the path of creating an automatic ground collision avoidance system (and air collision avoidance system) that even with its current limits has saved aircraft and pilots.

I have no idea what actual parameters are used in this system for those criteria you mention. The system in its current state of development has already recovered aircraft and saved pilots that other wise would have crashed. Whatever the values of those criteria used, they are saving the aircraft and pilot. This includes cases of recovering the aircraft after the pilot has suffered GLOC.

What the system current limitations are I dont know, but it is still in ongoing development. A system goal is for use in air-air combat training/exercises to avoid ground and air collisions. That is a very dynamic and unpredictable environment. I would imagine such a system could be made of use for display flying too.
Below is a summary of your points raised previously and my thoughts.

- crowd location
Does not the pilot also need to know these in advance for the same reasons of planning the display? The Italian Typhoon was at the coast; an approximation could have been made that the beachline was the boundary between crowd and recovery area; that would have been enough to save that pilot and Typhoon.

- minimum altitude loss
Does this not also apply to a human pilot? Computers can think and act faster than a human pilot; unstable aircraft can be flown by computers that a human pilot could never control.

- rolling at 45 deg nose down
See comment #44; the current auto-GCAS appears to be able to cope with high pitch rates (system flown on F-16; see also links in comments #34 & #46); computers can sense and react faster than any human pilot, it only requires the right algorithm/method.The system makes a decision as to whether the aircraft is approaching a point from which any recovery is impossible (as a human pilot would) and then reacts at the last second to avoid it.

- When would automatic recovery mode disengage and hand control back
I dont know the criteria exactly but it is being done by the current auto-GCAS which has saved aircraft and pilots in state of with/without GLOC. The Typhoon has an auto-recovery system, pilot selected, which can recover the aircraft and hand control back to the pilot in a satisfactory manner. Automatic recovery and handing control back to pilots who have/have not suffered GLOC is successfully implemented in some current systems.

- Tornado TFR
I mentioned this only as an example of a simple ground avoidance system; the auto-GCAS is extremely sophisticated, much more than the Tornado TFR and it is still developing. Had the Italian Typhoon been fitted with the current auto-GCAS it probably would never have crashed. Current auto-GCAS may not be perfect, but it is saving lives and even a modified limited auto-GCAS could have probably saved that Typhoon, whether it was pilot error or GLOC.

I am guessing that to display pilots auto-GCAS seems the equivalent of stabiliser wheels on a bike. Auto-GCAS is being fitted to the F-35 5 years earlier than planned (from 2019). I am guessing that soon we will see an F-35 at an air display using auto-GCAS to some extent; either modified, limted or fully functional.