Tornado GR.1 auto-land question...
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The aircraft had variable wingsweep. The furthest aft position was 67 wing (degrees of sweep) designed for supersonic flight. It was possible for the wings to get stuck in 67 wing which would lead to a difficult approach. With an approach speed of 240kts and the nose so high that it was almost impossible to see the runway until very late on the approach. As threeput has said, very uncomfortable for the GIB who could see nothing of the airfield until touchdown. Auto ILS could fly this approach very well and would put Biggles at 100ft exactly in the right place.
He's a shot comparing the Tornado in the 3 cleared wing sweep positions. 67, 45 and 25.
You don't see it from this angle but the front aircraft will be very 'nose up' in comparison to the rear aircraft to maintain level flight. Of course, this assumes they are all flying at the same airspeed and this wasn't a very clever planned overtake!
You don't see it from this angle but the front aircraft will be very 'nose up' in comparison to the rear aircraft to maintain level flight. Of course, this assumes they are all flying at the same airspeed and this wasn't a very clever planned overtake!
Last edited by Stuff; 31st Oct 2013 at 10:05.
Fair point. I was hoping to avoid the pedants pointing out that it'll happily fly at any angle it's just issues with fatigue counters that mean you aren't meant to do so which is why I added the "cleared" only to forget the 63/67 spangle 
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67 wing approaches from the back seat in the F3 were interesting, but made much easier by the dodge of using the HUD video on one of the TV/Tabs in the rear cockpit. What was quite tricky was flying rear seat IFR approaches on the standby ADI in the early F2s; it was mounted on the pedestal panel, directly in front of the base of the stick - made for a a curious and busy scan.....
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Fair point. I was hoping to avoid the pedants pointing out that it'll happily fly at any angle it's just issues with fatigue counters that mean you aren't meant to do so which is why I added the "cleared" only to forget the 63/67 spangle
S41
IIRC it triggered on speed and only scheduled between 25,45,(63/67) something in the back of my mind tells me it might also have gone to 58, someone certainly fitted a fatigue meter for 58 so it must have been there for a reason.
The problem was that once the movement had been triggered then it would complete before any further movement was possible so if, for instance, you were in 45 wing and accelerated beyond the trigger point the wings would begin to move to 67. Lets say you then immediately roll and pull hard into a turn bleeding the speed off, the wings will merrily continue to move to 67 before deciding that actually you did want 45 and starting their sweep forward again. By this point you had completed your turn, rolled wings level and accelerated and the wing moved back to 67 yet again.
The thinking was that by having it manually operated you could "think ahead" and know if moving the wings now was a good idea or not.
The problem was that once the movement had been triggered then it would complete before any further movement was possible so if, for instance, you were in 45 wing and accelerated beyond the trigger point the wings would begin to move to 67. Lets say you then immediately roll and pull hard into a turn bleeding the speed off, the wings will merrily continue to move to 67 before deciding that actually you did want 45 and starting their sweep forward again. By this point you had completed your turn, rolled wings level and accelerated and the wing moved back to 67 yet again.
The thinking was that by having it manually operated you could "think ahead" and know if moving the wings now was a good idea or not.
...and to give the navs something to do before the radar arrived.
"Wings!"
"Manoeuvres!"
And, yes, rear seat swept wing approaches on the IRET were a barrel of laughs. Come to think of it, a bit like a normal F4 rear seat approach.
"Wings!"
"Manoeuvres!"
And, yes, rear seat swept wing approaches on the IRET were a barrel of laughs. Come to think of it, a bit like a normal F4 rear seat approach.
There were a couple of reasons why auto approaches were not cleared. Firstly, the gains on the AFDS control laws varied with rad alt value and therefore if the rad alt locked up to the landing gear the gains were wrong for the distance from touchdown and some very speactacular divergent oscillations could develop on both localiser and glideslope. Note that the current radalts in the GR4 do not have this problem and so if someone pays money a clearance it could be re-investigated. The second problem was that when on the localiser the AFDS would try to match the aircraft's heading, rather than track, to the QDM set in the course window on the HSI. Therefore, in a crosswind the aircraft would offset downwind. This was ironinc as the same company had moded this function correctly on the Jaguar ILS flight director and, so I have been told, on the Lightning. This would not have been a show stopper although a crosswind limit for coupled approaches would probably have been needed.
With respect to auto wing sweep and auto manouvres on the F3, both systems received a very strong recommendation from A Sqn at Boscombe Down but the F3 OEU at Coningsby said 'NO' because 'they could do better than the auotmatics'! It was pointed out that, as 1000+ hour QWIs, they probably could but that new first tourists would have a significant reduction in workload if the systems were incorporated. After much wrangling the OEU agreed to recommend the use of the system but by then one or two finacial years had passed and it transpired that the test sets for the equipment had never been procured. In order to then release the money for these, other projects would have had to be cancelled or delayed and, based on priorites, the AWSMDS system was just inhibited. As for functionality, it did select 58 wing, and the CAS/IMN at which the wings swept was a function of of underwing fuel tank fit. One very useful feature of the automatic manoeuvres was that in 25 wing above 350 KCAS only the slats extended and the 25 MVR and 25 CRS g limits then became the same (all to do with flutter). The comments made previously about there being a problem in that once the wings started to move they had to travel fully is not quite correct because at any time the wings could be selected manually to any position which immediately disconnected the AWS; reselecting the AWS was then just a single push of one button. This was often done by just pressing the clutch lever on the wing swqeep handle on a 25 wing 'bug out' when you did not want the wings going to 45 wing at 0.73M but wanted to maintain 25 wing to just under 0.8M then pitch back into the fight.
And please, before you start Boscombe bashing, get your facts straight!
With respect to auto wing sweep and auto manouvres on the F3, both systems received a very strong recommendation from A Sqn at Boscombe Down but the F3 OEU at Coningsby said 'NO' because 'they could do better than the auotmatics'! It was pointed out that, as 1000+ hour QWIs, they probably could but that new first tourists would have a significant reduction in workload if the systems were incorporated. After much wrangling the OEU agreed to recommend the use of the system but by then one or two finacial years had passed and it transpired that the test sets for the equipment had never been procured. In order to then release the money for these, other projects would have had to be cancelled or delayed and, based on priorites, the AWSMDS system was just inhibited. As for functionality, it did select 58 wing, and the CAS/IMN at which the wings swept was a function of of underwing fuel tank fit. One very useful feature of the automatic manoeuvres was that in 25 wing above 350 KCAS only the slats extended and the 25 MVR and 25 CRS g limits then became the same (all to do with flutter). The comments made previously about there being a problem in that once the wings started to move they had to travel fully is not quite correct because at any time the wings could be selected manually to any position which immediately disconnected the AWS; reselecting the AWS was then just a single push of one button. This was often done by just pressing the clutch lever on the wing swqeep handle on a 25 wing 'bug out' when you did not want the wings going to 45 wing at 0.73M but wanted to maintain 25 wing to just under 0.8M then pitch back into the fight.
And please, before you start Boscombe bashing, get your facts straight!
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From an outsiders perspective, after working in the Ivory Tower for over 34 years, I witnessed 2 locked in 67 swept landings. At a certain secret soon to be closed Scottish base, this occurrence brought everyone out of their respective offices etc.
Watching an F-3 approach at an alarmingly huge speed, nose pointing up certainly had our hearts pumping. Inside the cockpit, heartbeats would have been at alarming numbers I`m sure.
Thankfully, both landings were successful and neither required RHAG`s to arrest their speed. Reverse thrust was always preferred over a hook engagement from my experience in the F-3 world, although the GR fleet used more cable stops.
The many years of controlling swept approaches meant that these two occasions had a happy ending. I wonder if the Tiffy has any different and unusual approaches other than flapless and single engine?
Watching an F-3 approach at an alarmingly huge speed, nose pointing up certainly had our hearts pumping. Inside the cockpit, heartbeats would have been at alarming numbers I`m sure.
Thankfully, both landings were successful and neither required RHAG`s to arrest their speed. Reverse thrust was always preferred over a hook engagement from my experience in the F-3 world, although the GR fleet used more cable stops.
The many years of controlling swept approaches meant that these two occasions had a happy ending. I wonder if the Tiffy has any different and unusual approaches other than flapless and single engine?
A little thread drift here but it sounds like this auto wing sweep function was / is quite different than that on the F14.
I believe that system was normally totally automatic throughout a continuously variable range based on AOA ?
Of course manual intervention was allowed at any time.
I stand to be corrected.
I believe that system was normally totally automatic throughout a continuously variable range based on AOA ?
Of course manual intervention was allowed at any time.
I stand to be corrected.
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The main reason why an approach end RHAG engagement was not used with wings fully swept back is that the maximum safe engaging speed for the RHAG at any weight was 160 Knots. Engagements did take place above them speeds and were usually successful however hooks and cables did break sometimes. The accepted industry standard is an absolute maximum of 190 Knots on any arresting cable although, again there have been faster.
Quite right, AGS. The plan would be to land and use thrust-reverse and then brakes to kill the speed and then lower the hook for a departure end engagement if required. Thing is that the TR and brakes did such a good job that the overrun wasn't usually needed - except in the sim.
I believe that you would have to go back to the Lightning to find a RAF fast jet
that was capable of auto land.
that was capable of auto land.
However, auto ILS and autothrottle were fitted, but the landing was manual.
Full autoland requires the installation of Cat3 ILS. which gives localiser guidance down to, and along, the runway. RAF airfields in the Lightning days has offset localisers.
Originally Posted by Courtney Mil
Quite right, AGS. The plan would be to land and use thrust-reverse and then brakes to kill the speed and then lower the hook for a departure end engagement if required. Thing is that the TR and brakes did such a good job that the overrun wasn't usually needed - except in the sim.
Last edited by just another jocky; 1st Nov 2013 at 12:48.