Is the Tornado GR4 still supersonic?
 

I know the RAF states that the Tornado can go at M2.2 but with the airframe alterations on the GR4 (laser designators and changes to the air intakes?) can and does the aircraft still fly at supersonic speeds?

Thanks all.

what change to the intakes (assuming it isnt classified)?

I was under the impression that there had been an alteration or inhibiting of something called the 'variable geometry intake ramps' in the early 80's.

Although this could easily be a load of tosh.

The GR1 was designed, I think, with supersonic intakes which included hydraulic ramps which influenced the airflow into the engines at high speed. AFAIR, the 'RAMPS' were inhibited from the very early days. We used to do a supersonic run at TTTE (clean jets, not even pylons) but once you put tanks, ECM, CBLS or real weapons on there was not much need for supersonic ramps (bloody thing wanted to M1+ at Goose aand Nellis though :rolleyes: )

Supersonic intakes and the hydrailic ramp mechanisms seemed like a lot of unnecessary weight to carry round but it was probably more expensive to replace them.

So would a operational GR4 go over M1.0 ?

Surprisingly, I think everything above is correct!

The GR1/4 does not have functioning ramps. However, the ramps (if they were functioning) do not start to move until about M1.3 so don't actually make a difference until then.

A GR4 will still go super but as you hang more stuff off it it becomes harder and harder, until at some point it can't. Additionally many stores may have a VNE or MNE that limits the ac to a slower speed than it may be capable of. I guess a GR4 guy could give more details.

As an example from the F3 world the M fit tanks have a subsonic limit on them but definitely do go super (I've seen it, but not done it, honest!). The F3 also does have functioning ramps, and they have a noticeable affect as soon as they move - giving decent M1.3 onwards acceleration.
Even old, bent F3s can still get to Mach 2 with inboard pylons and stubs fitted. Clean ones certainly quicker, but of course that isnt allowed so noone has done it.:}

Hope that helps

Tricky. I suppose it depends on how fast you could 'really' go with a typical load as to whether the ramps would be necessary to keep the shock positioned upstream far enough of the compressor. If it naturally stayed in an OK posuition, no need for the ramps I guess.

By operational you mean with anywhere near standard, useful loadout and tank fit I think the answer would be no. And if it could, it wouldn't get very far before it needed a tanker!

Previously, IIRC the AICS (Air Intake Control System) was inhibited on GR1 after all the bits were put under the nose. These bits disturbed the airflow and imposed some limits. As F3s needed AICS, and GR1s didn't, I believe most were removed from GR1s to stock up the F3s.

But that was 10+ yrs ago. and the GR4 may be quite different in that respect.

sw

So when the BBC states that the Gr4 can 'fly at supersonic speeds', they are correct but only if lightly loaded?

A fixed geometry intake will only work efficiently at its design Mach no. At any off-design point, sub-critical or super-critical operation will occur when the oblique shock is not positioned on the cowl lip, because the shock angle depends on Mach no. For aircraft which operate over a wide range of Mach nos, the penalties imposed by a fixed geometry intakes can be unacceptable. :8

The Tornado was initially fitted with ramps (ie variable geometry intakes) to position the oblique shock wave on the cowl lip of the intake. They were indeed scheduled to work above Mach 1.3. The ramps were a pain in the ass because they frequently leaked hydraulic fluid and it was normally an arduous task to repair. As with everything, the cost of continually repairing the ramps outweighed the benefits of having them so we stopped having them.

Asking a question such as "can the GR4 go supersonic?" generates a million answers, the shortest of which is "yes!"

It will go supersonic in almost any fit at any level with reheat engaged. As has already been mentioned, each store has a mach / IAS speed limit - that does not mean that they cannot go supersonic when strapped to the jet, they just shouldn't.

Obviously, if you had to make a sharp exit, it would be bye bye to the stores and the clean jet would go supersonic and some (but I think that 2.2M is unrealistic at low level).

Thanks, this is the bit where I couldn't see what was happening.

It's obvious it's got to choke to get the pressure recovery but I just couldn't see how anyone could design an intake to choke in one place at all speeds without something moving. What I could see was a limited speed range with fixed geo.

Nicely explained.

ok, my point of view on this, being a tornado engineer. The GR4 can no longer go supersonic. in fact, i was carrying out the AICs inhibit mod at St Athan on the Gr1 in 1994. The Ramp actuators were removed and replaced with steel rods. The actual electrical system remained intact, and the CB's tripped.

However, there was a problem some years after, where the steel rods were causing cracks in the intake frames, so some gr's had actutors put back in, but the system is still inhibited. A GR is only capable of greater than 1.3M, with outboard stores removed, and as they never fly in that config, it is not required

You might even see some F3's with the outboard pylons, as part of the trial sead mod, these were also lim'd to subsonic, as the extra stress caused by the loads on the ends of the wing were too great.

UKMIL,
F3s had o/b pylons back in the mid 90s.
sw

Typical Canuck, I had to take a GR-4 (the XV Sqn air display spare) super at low level east of Leuchars on the way home from an airshow...:p

...yes, I complied with all the orders and it was authorized.;)

...Of course, it wasn't much ~1.05ish

HC

My, my, the short range subsonic bomber known as GR4 is clearly a huge advance over the real bombers we used to have...... Buccaneer and Vulcan.

Gout keeping you up? Wrong side of bed? Decided on early morning fishing trip? :bored:

yes they did, but not all, only a select few were comlpeted, and there is still one or two now, that have them fitted. i was involved with the Mod in the mid 90's fitting to outboard pylon links.

From Memory the whole point of the ramps was to maintain subsonic airflow over the compressor (0.5 mach I seem to remember as being the figure always quoted) regardless of Aircraft Mach. The ramp movement was scheduled using a small pitot probe in the intake itself sensing purely intake airspeed.

The intakes did this on the GR1 despite having the ramp cb's pulled because the unmodified intake profile was sufficent to slow the intake air down (upto, again from memory, about 1.5 Mach aircraft speed)

No idea about GR4 Ramps

I was led to believe (by BWOS) that, in the early 80s, the installation of the laser fairing on the GR1 made one of the engines (the right one? ) rather prone to surging at lowish Mach 1+ speeds (I don't know whether this figure was classified so I can't be more precise). Perhaps the FLIR fairing on the GR4 had the same effect on the other engine? Whatever, the TTTE Tornados, not being fitted with those fairings would not have had the same problem.

they did have a small impact, but the main thing with TTTE is they flew CLEAN, with no pylons

Perhaps I did not make myself clear. Regardless of whether TTTE Tornados flew with pylons or not, all I was trying to suggest was that,since they did not have laser fairings, they would not be prone to engine surges caused by such fairings. BTW, UK Mil, what is a "small fact"?

ukmil... wrong.

GR4... very definitely supersonic when stores removed.

:ok:

UK Mil

You say in your initial post that the GR4 will not go above Mach 1.3.....Surely, in anybody's language, that is definitely supersonic! Also, one of the benefits of hanging stores on the outboard pylons of an F3 was that it was determined to actually relieve stress on the wing. Perhaps some of the aerodynamicists will explain this.

Anorak removed!

UK MIL is generally in the ballpark.

After the introduction of the LRMTS (and associated reduction in Vne), active ramps only bought an extra nought point very small Mach, whether clean or not. Hardly worth the additional complexity and maintenance, so they were deleted.

Clean (or even with O/B stores) GRs are still supersonic.

kitwe

not an aerodynamicist but I'll have a go.
A weight of say 300kg at the end of the wing will require just 300kg of extra lift to maintain level flight. However, at the wing root, for say a 4m wing, the upward bending stresses will be reduced by 300x4 (1200)kg/metres.
Effect even greater under g.

Have I got this right boffins?

this one certainly isnt supersonic
http://newsimg.bbc.co.uk/media/image...ornado.203.jpg



meant as a bit of a giggle. was great to hear the crew were safe etc etc, go safely all of you.

L Peacock

Please check your PMs.

Ai, not bad, it's all about bending moments baby - more like mechanical engineering than aerodynamics though! I believe the effect is known as "nodal progression" and the outboard stores stop the ends of the wings flapping up and down like something that flaps up and down a lot :8

Incidently, the fuel in the wings helps to prevent torsional flexing so it remains in the wings for as long as possible to reduce fatigue.

Ukmil - are you sure you're a Tornado engineer? You sound more like a mechanic or technician if you were involved with inhibiting supersonic ramps... Anyway, you may find reading the Release to Service interesting - you can look up the speed limits for each different fit. In 10 fit (outboards but no tanks) it is supersonic and some!

Is the GR4 any slower than the GR1?
 

Just a quick note for what it's worth.
Back in Apr 1994, Goose Bay, with the Vicar in the back seat a couple of GR1 chaps got tapped by 2 CF-18s. Well the GR1 guys did the honourable thing and 'Ran away bravely!' Combat burner down a dry river bed with the Vicar twisted round in his seat shouting 'faster, faster!' When just before some kind of nodding PIO started the nose gunner saw 725 IAS in the HUD. Sorry, didn't have the capacity to select Mach. I guess the OAT was around 0 deg C.
I seem to recall the jets were in (would it be) B11 fit, ie 2 Hindenburger tanks, BOZ, ECM and 2 CBLS. Also seem to recall that Vmo in that fit was around 595 KIAS with the wings in 67.
Thank God I'm still alive! Thank God I'm out!!!!
Cheers... Max
ps Regards to Vicar, Cheese, Cas, Bunter, Sammy, JT, JP, Chaz and all the others unfortunate enough to be terrified by me!!:eek: :E

I can't be entirely sure about the GRs but the F3 was/is capable of speeds much higher than the RTS upper limits. Lack of engine thrust is not a problem with the F3 and it will still accelerate above 800kts IAS (clean).

Rumour hath it that some mate decided to have a go at the 'wot'll she do, mister' competition a few years ago in a F3. Full chat, pull to the vertical, establish a very gentle push as the thing passed FL lots - then it went a bit pear shaped. Double flame out, no pressurisation, battery power only.... But he got it down OK.

Then, so the rumour goes, Ba$tard Bill tried to hang him out to dry for grossly exceeding the RTS. Until, that is, someone happened to mention that surely Lightning reheat rotation take-offs were also outside the RTS and hadn't 'certain Air Officers' done such things when they were his age....

Whereupon it all went rather quiet....:cool:

All very technical and complicated, but why would you want to do those sorts of speeds, for any reason? When would it be either desirable or necessary for a Tonka operationally?

I think that B*ll had something to do with lifting and realigning a few roofs in the Farnborough area, around showtime one year and in an F4!

Respected and admired by all who do not know him well!

Samuel

When I flew Tornados at very high speeds, it was during development trials from Boscombe Down. At that time, there was no RTS so we had to test the aircraft so that MOD(PE) could make Service Release Recommendations to the RAF. We flew under Airworthiness Flight Limitations (AWFLS) promulgated by BAe/Panavia.

Thank you Kitwe, I understand that, and the enthusiasm of the "I wonder what she'll do" people who have always existed and long may they and their enthusiasm be around, but given all the reasons on this thread, there seem to be none which would include supersonic speed as a best option.

If I carry a pack and with the knowledge that I know where I'm going and what it's going to take to get there, when I come to a hill I don't increase speed and run up it, because then I might not get where I'm going!

Is supersonic necessary
 

Trust me Samuel, I think you'll find supersonic very practical when there's an enemy fighter at 4000m in your 6!

I do Max[trust you], and I guess you can never have too much power, but that wasn't the question, and I gather from the answers that, while it is possible, it doesn't happen too often for a variety of reasons. Given the circumstance you describe, and adding the factor that you have everything hanging that can hang, would you be able to accelerate fast enough?

Samuel

Max has hit the nail on the head. Although there can be few excuses for deliberately exceeeding Vne in peacetime, there will be occasions (such as the baddie with hostile intent in your 6) in times of tension/war when the only way to save your aircraft and your life is to park the throttles in the top left corner and run. If required, you can always jettison those stores that are limiting your speed/acceleration. In your example, if a 7ft tall baddie with murderous intent and armed with an axe was closing on you as you climbed your hill, would you not consider jettisoning your pack and running away?

Very much so! And downhill, albeit subxonic with my legs!

Thank you both for your explanations.