SEPECAT Jaguar
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The first time a Jaguar visited Bruggen the pilot hopped out and asked 2 or 3 of us interested bystanders to help push it into the hangar, which we did. That was when I realised that it was actually made of tin foil.
When the first sqn arrived, in '75, it was a reasonably warm summer and this played havoc with the cabin conditioning system. As result they couldn't fly until the outside air temperature dropped below a particular level, which normally occurred at about 5pm. The Jaguars would then get airborne - while we all sloped off to the bar and watched them doing circuits, circuits and more circuits as the Low Flying System was closed by then. We truly did feel sorry for them.
When the first sqn arrived, in '75, it was a reasonably warm summer and this played havoc with the cabin conditioning system. As result they couldn't fly until the outside air temperature dropped below a particular level, which normally occurred at about 5pm. The Jaguars would then get airborne - while we all sloped off to the bar and watched them doing circuits, circuits and more circuits as the Low Flying System was closed by then. We truly did feel sorry for them.
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Is the story true, that when you got the new RR motor that eliminated the exaust smoke, you found that there was a design problem with it, and every time you returned to flight idle, the engine cut out, and the only reason that nobody had picked up on it was that gcarbon deposits in the exhaust (which caused the smoke) had been keeping the engine ignited untill the fuel management system got its act together?
Matty
Matty
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Sounds like a load of S**te to me!!!
As anyone with even a basic knowledge of how a jet engine works will tell you that even a big roaring fire in your jet pipe will not keep the fire burning in a combustion chamber, ESPECIALLY if the engine has flamed out due to fuel starvation.
And quite how you think a flame would backtrack through two turbine stages and relight the engine with tons of pressurised air from a windmilling engine blowing in the opposite direction, is a mystery to me!
As anyone with even a basic knowledge of how a jet engine works will tell you that even a big roaring fire in your jet pipe will not keep the fire burning in a combustion chamber, ESPECIALLY if the engine has flamed out due to fuel starvation.
And quite how you think a flame would backtrack through two turbine stages and relight the engine with tons of pressurised air from a windmilling engine blowing in the opposite direction, is a mystery to me!
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Beautiful aircraft, and a real shame to see them going.
I'm highly surprised to see that nobody has any stories about their time on them though.
Must be the "Detachment Rules" mentality
Only jet I've worked on where the Microturbo/APU is louder than the actual engines!!
I'm highly surprised to see that nobody has any stories about their time on them though.
Must be the "Detachment Rules" mentality
Only jet I've worked on where the Microturbo/APU is louder than the actual engines!!
I suspect that there may be some enthusiasts reading this thread who know few facts on the Jaguar but have heard the stories! I have flown it for 20 years in the flight test environment but, sadly, not operationally. I have many flight test stories which could be prised out of me (stores clearances for Operation Granby, LGB Lateral Toss, FLIR/NVG trials, GR1B upgrade etc). However, as a starter I shall try to paint a brief picture of the Jaguar, and as it is just my personal opinion I am sure that there will be some interesting disagreements posted!
The Jaguar is an aircraft that needs to be understood to put it into context with the stories. It has a small, low aspect ratio wing with a high speed aerofoil and small engines which, especially in dry power, develop relatively low thrust. This leads to an optimum sustained turn speed of around 0.85 to 0.9M and a high corner speed (around 430 KIAS at mid sortie weights and low level). Combine this with a relatively low AoA limit, a tendency to depart with large lateral stick inputs at quite modest AoAs and an inertial autorotation mode that is triggered if you roll and push simultaneously, the Jaguar obviously is not an agile low speed combat machine! Nor does it have a high dry power maximum speed, rapid reheated acceleration from low speeds, a high dry power ceiling nor good take-off performance (especially at high OAT). Therefore, it is not surprising the F-4 squadrons were not impressed with the Jaguar as a replacement aircraft!
But, it definitely has its good points. Up to 480 KIAS, you can fly it very low (as evidenced in some of the threads relating to the Omani Jaguars) although at higher speeds it becomes a little oversensitive in pitch. With respect to "operational" low flying its flying qualities are far superior to the Tornado and Phantom (but not as good as the Buccaneer!). It is excellent for tracking in guns and rocket attacks and has a very good Laser Range and Marked Target Seeker system (LRMTS). Also, the maximum speed and g limit with a full weapons load, even at maximum weight, is considerably better than just about all other current RAF attack aircraft. And the nav/attack system has come a long way from the early days of NavWaSS, when it had an 8k computer and a moving map and HSI that froze when you selected weapon aiming, and a 5:1 geared HUD! In 1995, the GR1B became, I believe, the first RAF combat aircraft to have an integrated GPS/IN navigation system and the first RAF single-seat aircraft to carry a laser designator pod (TIALD). This was further developed into its current GR3/3A incarnation incorporating several more RAF "firsts"; a helmet mounted sight, a ground proximity warning system combined with obstacle warning and terrain separation cues in the HUD, and electronic emergency checklists and airfield approach plates on the cockpit multifunction displays. Please note that this is not a commercial for BAES as much of the work (including the whole GR1B upgrade) was not done by them!
But back to the bad news. The Jaguar does not, I believe, have enough pylons for stores carriage. When introduced into RAF service in 1974, there was little thought given to electronic warfare and PGMs were some way off. Therefore, on the four wing pylons and fuselage centreline pylon the Jaguar could carry two 1200 l fuel tanks and four 1000 lb bombs, which was a respectable load. But once it moved into the EW era and the outboard pylons were taken up with a chaff dispenser and active jamming pod, it was left with only one external fuel tank plus four unguided bombs (on tandem beams on the inboard pylons) or two 1000 lb LGBs, or two external fuel tanks plus two unguided bombs or one LGB on the centreline. Or, with a TIALD pod for a self-designation LGB attack, it could carry only one external tank and one LGB. Overall, the weapon load was becoming very small, despite an excellent capability for accurate delivery.
I hope that this has given a little meat to put on the bones of the apocryphal stories. Flight test stories to follow.
The Jaguar is an aircraft that needs to be understood to put it into context with the stories. It has a small, low aspect ratio wing with a high speed aerofoil and small engines which, especially in dry power, develop relatively low thrust. This leads to an optimum sustained turn speed of around 0.85 to 0.9M and a high corner speed (around 430 KIAS at mid sortie weights and low level). Combine this with a relatively low AoA limit, a tendency to depart with large lateral stick inputs at quite modest AoAs and an inertial autorotation mode that is triggered if you roll and push simultaneously, the Jaguar obviously is not an agile low speed combat machine! Nor does it have a high dry power maximum speed, rapid reheated acceleration from low speeds, a high dry power ceiling nor good take-off performance (especially at high OAT). Therefore, it is not surprising the F-4 squadrons were not impressed with the Jaguar as a replacement aircraft!
But, it definitely has its good points. Up to 480 KIAS, you can fly it very low (as evidenced in some of the threads relating to the Omani Jaguars) although at higher speeds it becomes a little oversensitive in pitch. With respect to "operational" low flying its flying qualities are far superior to the Tornado and Phantom (but not as good as the Buccaneer!). It is excellent for tracking in guns and rocket attacks and has a very good Laser Range and Marked Target Seeker system (LRMTS). Also, the maximum speed and g limit with a full weapons load, even at maximum weight, is considerably better than just about all other current RAF attack aircraft. And the nav/attack system has come a long way from the early days of NavWaSS, when it had an 8k computer and a moving map and HSI that froze when you selected weapon aiming, and a 5:1 geared HUD! In 1995, the GR1B became, I believe, the first RAF combat aircraft to have an integrated GPS/IN navigation system and the first RAF single-seat aircraft to carry a laser designator pod (TIALD). This was further developed into its current GR3/3A incarnation incorporating several more RAF "firsts"; a helmet mounted sight, a ground proximity warning system combined with obstacle warning and terrain separation cues in the HUD, and electronic emergency checklists and airfield approach plates on the cockpit multifunction displays. Please note that this is not a commercial for BAES as much of the work (including the whole GR1B upgrade) was not done by them!
But back to the bad news. The Jaguar does not, I believe, have enough pylons for stores carriage. When introduced into RAF service in 1974, there was little thought given to electronic warfare and PGMs were some way off. Therefore, on the four wing pylons and fuselage centreline pylon the Jaguar could carry two 1200 l fuel tanks and four 1000 lb bombs, which was a respectable load. But once it moved into the EW era and the outboard pylons were taken up with a chaff dispenser and active jamming pod, it was left with only one external fuel tank plus four unguided bombs (on tandem beams on the inboard pylons) or two 1000 lb LGBs, or two external fuel tanks plus two unguided bombs or one LGB on the centreline. Or, with a TIALD pod for a self-designation LGB attack, it could carry only one external tank and one LGB. Overall, the weapon load was becoming very small, despite an excellent capability for accurate delivery.
I hope that this has given a little meat to put on the bones of the apocryphal stories. Flight test stories to follow.
I have never had a Jaguar depart on me - yet! It is an aircraft that talks to the pilot; those that depart generally are not listening! 4 to 8 degrees AoA is life, and if it departs below 150 KIAS it has insufficient energy to actually spin (data from original spin trial). However, if the two-seater spins, it will not recover!
I have had a Tornado depart and spin on me - 340 KCAS into a fully developed spin in less than 2 seconds; departed at 21,000 ft, spin stopped at 10,000 ft, started to pull out at 8,000 ft, bottomed at 3,000 ft. But that is another story - and for another thread, another day.
Rgds
L
I have had a Tornado depart and spin on me - 340 KCAS into a fully developed spin in less than 2 seconds; departed at 21,000 ft, spin stopped at 10,000 ft, started to pull out at 8,000 ft, bottomed at 3,000 ft. But that is another story - and for another thread, another day.
Rgds
L
Last edited by LOMCEVAK; 4th Apr 2005 at 15:44.
LOMCEVAK,
My memory might be playing tricks but I'm sure that I saw film of a two seat Jaguar spinning over Lulworth Cove. I think it was on the excellent TV series Test Pilot which showed a course going through ETPS at Boscome Down.
It may have been the same programme but I also remember seeing a test pilot who held the record for the number of spins in a Jaguar. Perhaps that was you? p1
My memory might be playing tricks but I'm sure that I saw film of a two seat Jaguar spinning over Lulworth Cove. I think it was on the excellent TV series Test Pilot which showed a course going through ETPS at Boscome Down.
It may have been the same programme but I also remember seeing a test pilot who held the record for the number of spins in a Jaguar. Perhaps that was you? p1
An ex-RAF friend told me of his time on Jags in the desert, which has left him scarred for life.
Doing a bombing demo for the Powers That Be, one of the bombs detonated under his wing on release. The oxygen-rich cabin lit up rather well, and his first instinct was to put his hands over his face - imprints of his left hand are still visible after twenty something years.
Then he took one hand away to pull the manual pilot/aircraft interface separation handle and he departed what was left of the machine. Pictures of the explosion and ejection were published in various magazines but I can't find them on line.
In a huge change of lifestyle, he has gone from a machine that flew at over 400 knots and almost always landed at the place he took off from, to an aircraft that flies at 0 knots and NEVER lands where it took off. A hot-air balloon.
Doing a bombing demo for the Powers That Be, one of the bombs detonated under his wing on release. The oxygen-rich cabin lit up rather well, and his first instinct was to put his hands over his face - imprints of his left hand are still visible after twenty something years.
Then he took one hand away to pull the manual pilot/aircraft interface separation handle and he departed what was left of the machine. Pictures of the explosion and ejection were published in various magazines but I can't find them on line.
In a huge change of lifestyle, he has gone from a machine that flew at over 400 knots and almost always landed at the place he took off from, to an aircraft that flies at 0 knots and NEVER lands where it took off. A hot-air balloon.
Pulse 1,
If there were any shots of a Jaguar spinning on the "Test Pilot" series, they were archive material from the spin trial. The ETPS jet over Lulworth may have been rapid rolling but certainly was not spinning.
Unfortunately, I was not involved in the Jaguar spinning trial; it was before my time. However, I do have to declare some level of involvement in the BBC series! I think that the French had the lead on the spinning trial and that Jean-Marie Saget was the project pilot for it. However, several Warton and Boscombe Down pilots were involved. Boscombe Down did lose a T2 in a departure/spin accident in the mid1970's. Fortunately, both pilots ejected safely and I still see both of them fairly often. I think that they ended up in inertial autorotation and followed the recovery procedure that was recommended at the time. This did not work, and the proper recovery technique was discovered shortly afterwards!
If there were any shots of a Jaguar spinning on the "Test Pilot" series, they were archive material from the spin trial. The ETPS jet over Lulworth may have been rapid rolling but certainly was not spinning.
Unfortunately, I was not involved in the Jaguar spinning trial; it was before my time. However, I do have to declare some level of involvement in the BBC series! I think that the French had the lead on the spinning trial and that Jean-Marie Saget was the project pilot for it. However, several Warton and Boscombe Down pilots were involved. Boscombe Down did lose a T2 in a departure/spin accident in the mid1970's. Fortunately, both pilots ejected safely and I still see both of them fairly often. I think that they ended up in inertial autorotation and followed the recovery procedure that was recommended at the time. This did not work, and the proper recovery technique was discovered shortly afterwards!
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LOMCEVAK,
Although not related to the Jaguar, this article makes a good read about the Tornado spinning trials over Yorkshire.
Tornado Spinning Trial
Although not related to the Jaguar, this article makes a good read about the Tornado spinning trials over Yorkshire.
Tornado Spinning Trial
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Lomcevak
Thanks for a great description of Jaguar flying qualities. A couple of questions
1. What is HUD "gearing"?
2. Have you flown the Jaguar International variant? It had a significantly higher thrust engine - wonder how that effected the performance?
Thanks
Worf
Thanks for a great description of Jaguar flying qualities. A couple of questions
1. What is HUD "gearing"?
2. Have you flown the Jaguar International variant? It had a significantly higher thrust engine - wonder how that effected the performance?
Thanks
Worf
Razor61,
Thanks for that link. I think that, perhaps, a "Spinning Stories" thread would be interesting - I have a few! When I have time, I will start one, unless anyone else wishes to (hint!).
Worf,
HUD gearing is the relationship between the angle represented by two symbols in the HUD and the actual angular subtension between them. A "5:1" geared HUD, such as in the Jaguar GR1/1A/T2/2A (and Harrier GR3/T4 and some prototype Tornados) has markings in the HUD that represent climb and dive angles of zero, 30 deg, 60 deg and 90 deg. However, the actual angle between the horizon bar and, say, the 30 degree climb bar is only 6 degrees, hence 5:1. The reason that it was used (allegedly) was that early INs were not accurate enough to support 1:1 gearing. The big disadvantage is that you lose correlation between the HUD horizon line and the real horizon when not in level flight. However, it has the advantage that you do not get "laddering" (pitch ladder moving at too high a rate to interpret it) at high pitch rates, a problem that occurs in a 1:1 geared HUD. In fact, that is why the current Jaguar GR3A HUD only has 1:1 gearing within 30 degrees of the horizon. The pitch gearing is then blended to increase progressivley to 4.4:1 in the vertical. The heading scale in many fast jet aircraft HUDs is also geared (6:1 in most british HUDs) to prevent oversensitivity during heading control tasks, whereas most airliner HUDs have 1:1 heading scale gearing for greater accuracy on a low vis approach.
In answer to your second question, I have not flown the Jaguar International. However, the greatest difference in performance when flying the Jaguar is related to external stores carriage, the extra drag and weight both giving a significant degradation. A "clean" aircraft with no pylons is a totally different machine to one with even just two underwing fuel tanks plus three bare pylons. I suspect that these differences are more dramatic than those with the same stores configuration and different marks of engine.
Thanks for that link. I think that, perhaps, a "Spinning Stories" thread would be interesting - I have a few! When I have time, I will start one, unless anyone else wishes to (hint!).
Worf,
HUD gearing is the relationship between the angle represented by two symbols in the HUD and the actual angular subtension between them. A "5:1" geared HUD, such as in the Jaguar GR1/1A/T2/2A (and Harrier GR3/T4 and some prototype Tornados) has markings in the HUD that represent climb and dive angles of zero, 30 deg, 60 deg and 90 deg. However, the actual angle between the horizon bar and, say, the 30 degree climb bar is only 6 degrees, hence 5:1. The reason that it was used (allegedly) was that early INs were not accurate enough to support 1:1 gearing. The big disadvantage is that you lose correlation between the HUD horizon line and the real horizon when not in level flight. However, it has the advantage that you do not get "laddering" (pitch ladder moving at too high a rate to interpret it) at high pitch rates, a problem that occurs in a 1:1 geared HUD. In fact, that is why the current Jaguar GR3A HUD only has 1:1 gearing within 30 degrees of the horizon. The pitch gearing is then blended to increase progressivley to 4.4:1 in the vertical. The heading scale in many fast jet aircraft HUDs is also geared (6:1 in most british HUDs) to prevent oversensitivity during heading control tasks, whereas most airliner HUDs have 1:1 heading scale gearing for greater accuracy on a low vis approach.
In answer to your second question, I have not flown the Jaguar International. However, the greatest difference in performance when flying the Jaguar is related to external stores carriage, the extra drag and weight both giving a significant degradation. A "clean" aircraft with no pylons is a totally different machine to one with even just two underwing fuel tanks plus three bare pylons. I suspect that these differences are more dramatic than those with the same stores configuration and different marks of engine.
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Was there a 'big' marked difference in performance once the Jaguar GR3 got the mk106 engine replacement from the mk104?
Although i still don't think it was as powerful as the Jaguar International engine?
Although i still don't think it was as powerful as the Jaguar International engine?
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HUD Gearing
I'm sorry to be an insufferable thickie, but I'm not sure I understand HUD Gearing.
The Jaguar I flew in (T4) had a 5 deg pitch bar above the horizon line, about an inch as I viewed it. If that's a 5:1 geared HUD does that make it an actual angle of 25 degrees, or 1 degree.
Using Tan x = pitch seperation/nut seperation (my nut was about 20 inches from the HUD), I reckon that the angle subtended between the 5 deg pitch bar and horizon bar was about 2.8 degrees - assuming I remember the one inch thing properly. To get a 1:1 ratio, the bars would need to be about 1.75 inches apart, and to get a 5:1 ratio they'd need to be about 8.75 inches apart.
So, how badly have I mis-understood this all?
Blunty.
The Jaguar I flew in (T4) had a 5 deg pitch bar above the horizon line, about an inch as I viewed it. If that's a 5:1 geared HUD does that make it an actual angle of 25 degrees, or 1 degree.
Using Tan x = pitch seperation/nut seperation (my nut was about 20 inches from the HUD), I reckon that the angle subtended between the 5 deg pitch bar and horizon bar was about 2.8 degrees - assuming I remember the one inch thing properly. To get a 1:1 ratio, the bars would need to be about 1.75 inches apart, and to get a 5:1 ratio they'd need to be about 8.75 inches apart.
So, how badly have I mis-understood this all?
Blunty.
Last edited by BluntM8; 7th Apr 2005 at 15:14.
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There is an enormous difference in performance.
Mk 104's work,
Mk 106's enjoy eating jet pipes and turbines, and rarely work
The Mk 106 Engine is a bitsa, made up from three different marks of the RR/Turbomeca Adour.
The core of the engine is taken from the Adour Mk871, used in the T-45A Goshawk,
The reheat system is taken from the Adour Mk811, used in the Jaguar International variant,
And the ancilleries (Accessory pack, pipes, pumps, filter assy etc..) are taken directly from the Adour Mk104.
The primary considerations for the 106 were not increased power or economy, but enhanced flight safety and increased reliability (And it seems that they cocked that up on both accounts).
There was an increase in thrust, but this was a paltry 5%, to 5514 lbs dry, and 8245 lbs in reheat. This is however, largely negated by the additional weight of the newer engine
Mk 104's work,
Mk 106's enjoy eating jet pipes and turbines, and rarely work
The Mk 106 Engine is a bitsa, made up from three different marks of the RR/Turbomeca Adour.
The core of the engine is taken from the Adour Mk871, used in the T-45A Goshawk,
The reheat system is taken from the Adour Mk811, used in the Jaguar International variant,
And the ancilleries (Accessory pack, pipes, pumps, filter assy etc..) are taken directly from the Adour Mk104.
The primary considerations for the 106 were not increased power or economy, but enhanced flight safety and increased reliability (And it seems that they cocked that up on both accounts).
There was an increase in thrust, but this was a paltry 5%, to 5514 lbs dry, and 8245 lbs in reheat. This is however, largely negated by the additional weight of the newer engine