Tornado Reheat

[propersplitbrainme]

Question for you Tonka chaps.

Does the Tornado ever takeoff without using reheat? Or, to put it another way, can it takeoff without reheat or would it need an extremely long runway and have a low all up weight?

 

[Odie]

Never saw one take off without the burners lit in 21 years on the feckers. I guess if it tried it'd be relying on the curvature of the earth to get airborne or a bump in the runway. It could probably do it if it was light or had a long enough runway, but better to have the power working and use it.

 

[Jim_P_Pulfrew]

101s Definitely it needed for take off as even TTTE jets without any stores/pylons etc used a lot of runway to get off some days.

It wasn't unusual to see a reheat blow out on the take off run at or about V1 and they sometimes struggled into the air rather than cook the brakes or take the RHAG.

Ultimately I think that the old adage is if power is available use it. No use when the world is going to ratshoot on a takeoff roll, waiting for the excess power selected to kick in. If I remember rightly was there not a TBT limiter switch which was always selected to give oodles of power rather than the economy setting?

Jimps

 

[Shugster]

From Wiki..

RB199-103 - Powering Tornado IDS strike versions, with a thrust rating of 40.5 kN (dry) 71.2 kN (reheat)

That's around 75% more thrust than dry.

F=MA

Engine thrust / Aircraft mass = Acceleration

If the A/C is say 20 tons = 196.2kN ** Wrong here, should stay in kg***

So Dry gives 40.5kN / 20000kg = 2.025 m/s sq

Wet gives 71.2kN / 20000kg = 3.56 m/s sq

I'm sure Chiefy will correct my maths if I'm wrong... Which is quite likely! DT_Xtremez_30:

Edit: Actually those numbers sound low to me, I'm trying to rush in my lunch break and I'm sure I've missed something. Will post another answer later.

 

[Realist78]

From Wiki..

RB199-103 - Powering Tornado IDS strike versions, with a thrust rating of 40.5 kN (dry) 71.2 kN (reheat)

That's around 75% more thrust than dry.

F=MA

Engine thrust / Aircraft mass = Acceleration

If the A/C is say 20 tons = 196.2kN ** Wrong here, should stay in kg***

So Dry gives 40.5kN / 20000kg = 2.025 m/s sq

Wet gives 71.2kN / 20000kg = 3.56 m/s sq

I'm sure Chiefy will correct my maths if I'm wrong... Which is quite likely! DT_Xtremez_30:

Edit: Actually those numbers sound low to me, I'm trying to rush in my lunch break and I'm sure I've missed something. Will post another answer later.

Wiki is wrong with those thrust figures. A Mk 103 is thrust rated at 38.5 Kn (dry). SOT rating takes this up to anywhere (roughly) between 39.5 - 40.5 Kn. The 38.5 Kn is a given on any 103 as long as it's running below 1590K SOT, the max figure at 1590 is different for each engine, not many hit 40.5 Kn. Max thrust is approximately 66 Kn. Your figures may appear low as you have used single engine figures.

 

[rb199]

I belive that zee German Tornado with wide chord, snubber less first stage fan blades does not use reheat.

 

[Rikster]

I belive that zee German Tornado with wide chord, snubber less first stage fan blades does not use reheat.

Don't you just love the Boxheads............

 

[Shugster]

Don't you just love the Boxheads............

Yes I do love me... Well 50% of me!

But I must say after years of working for German firms, if something isn't right they don't just live with it they pull it apart and put it back together again. Even if it means tons of work.

Everything I build / repair is 100% or it doesn't leave.

 

[propersplitbrainme]

Ok, so with an uprated engine Tornado can takeoff without reheat, but otherwise its possible but not common.

 

[SecretSquirrel]

101s Definitely it needed for take off as even TTTE jets without any stores/pylons etc used a lot of runway to get off some days.

It wasn't unusual to see a reheat blow out on the take off run at or about V1 and they sometimes struggled into the air rather than cook the brakes or take the RHAG.

Ultimately I think that the old adage is if power is available use it. No use when the world is going to ratshoot on a takeoff roll, waiting for the excess power selected to kick in. If I remember rightly was there not a TBT limiter switch which was always selected to give oodles of power rather than the economy setting?

Jimps

I think the switch you're refferring to is the TBT switch which has a LOW and DATUM setting. In DATUM I think the TBT limit was 24/32 degrees higher than usual (depending on DECU/MECU state) to give extra power when running away in combat. The switch is set in the LOW position and has tell-tale wire so it's not meant to be used unless your in the sh1t.

I'm a leckie so could be wrong. DT_Xtremez_30:

 

[theladf]

I recall (back in the day) 1995 a det to Yuma in Arizona where I was on the Flight deck of a VC10 going for a trip to watch the Sqn doing some AAR prior to dropping some cluster bombs (which was permissable back then). The Boss's aircraft went into reheat (or he thought it had) and off it trundled. The problem was that the R/H burner had not lit! worse still the MECU was having a bad day along with the engine and had not detected lack of light up and was still shovelling buckets of fuel vapour into the wide open but unlit jet pipe!(rather than cancelling to ENC) this had the effect of trying to take off with one engine b@lls out and the other in taxi-nozzle!!!!!! He did make it but was close to running into downtown Yuma!!!! I asked if he noticed it was sluggish and he said that the fence at the end of the runway seemed closer than usual!!!!!!!DT_Xtremez_19:

 

[Realist78]

I recall (back in the day) 1995 a det to Yuma in Arizona where I was on the Flight deck of a VC10 going for a trip to watch the Sqn doing some AAR prior to dropping some cluster bombs (which was permissable back then). The Boss's aircraft went into reheat (or he thought it had) and off it trundled. The problem was that the R/H burner had not lit! worse still the MECU was having a bad day along with the engine and had not detected lack of light up and was still shovelling buckets of fuel vapour into the wide open but unlit jet pipe!(rather than cancelling to ENC) this had the effect of trying to take off with one engine b@lls out and the other in taxi-nozzle!!!!!! He did make it but was close to running into downtown Yuma!!!! I asked if he noticed it was sluggish and he said that the fence at the end of the runway seemed closer than usual!!!!!!!DT_Xtremez_19:

That's the working line trim that should have returned the nozzle to normal dry area at around 75% Aj. One of the reasons why periodic engine checks shouldn't be extended and extended etc. WLT drifts all over the place over time.

 

[theladf]

That's the working line trim that should have returned the nozzle to normal dry area at around 75% Aj. One of the reasons why periodic engine checks shouldn't be extended and extended etc. WLT drifts all over the place over time.

As I recall this was at a particularly bad time for the RB199 with HP Ngv's causing engine rejections after a ridiculously short time!!!!! in this case the MECU should have registered the failure of the reheat to light up, the turbine pressure ratio P2/P4 would have gone outside limits the CUE should have seen this and cancelled it automatically to dry area datum. As it was the MECU on this engine had lost the plot completely, furthermore having replaced it the MFCU decided it wasn't going to play either! I did the run and even being 'a bit brave' cancelled each start before 50% had been achieved as it was a tad warm!!!!!!!! eventually we fixed the engine only for it to fail it's next NGV Borescope 3 flights laterDT_Xtremez_09:

 

[Stevienics]

Tch..Fewer blades. Note less.

 

[Realist78]

As I recall this was at a particularly bad time for the RB199 with HP Ngv's causing engine rejections after a ridiculously short time!!!!! in this case the MECU should have registered the failure of the reheat to light up, the turbine pressure ratio P2/P4 would have gone outside limits the CUE should have seen this and cancelled it automatically to dry area datum. As it was the MECU on this engine had lost the plot completely, furthermore having replaced it the MFCU decided it wasn't going to play either! I did the run and even being 'a bit brave' cancelled each start before 50% had been achieved as it was a tad warm!!!!!!!! eventually we fixed the engine only for it to fail it's next NGV Borescope 3 flights laterDT_Xtremez_09:

Worthy of note is that for years, NGV damage was acceptable up to total loss!! This was hastily revised when NGV failure caused the stepped S17 seal to move causing HP shaft failure and the loss of at least one F3, hence the brush seal (S17 but now parallel, not stepped).

 

[foxvc10]

Way back in 1990 on 16 sqn the "Black Pig" kept on getting burner blow outs on take off. Nothing could be done about it, but because it was the "Black Pig" it tried to go everywhere, but rarely made it.

BoB Flypast - det to Honington (god I hated that place - 3rd det id done there!!) Hot day mid August ( I think) mass take off for the flypast. OC16 third of the way down the runway with no tanks/load has said a/b blow out and took a looonnnggg time to get it up and over the fence. I was watching from the top of the old 9 Sqn PBF (feeling very unwell after a night out in Bury) so never heard the alleged broadcast "The Black Pig will fly!!"

So as above - it could but only just - not recommended

 

[Stevienics]

"NGV failure caused the stepped S17 seal to move causing......"

........more S17 seal treatments than I can possibly remember. I was at EROS at the time and all I seemed to deal with is getting the seal coatings replaced on the S17 stepped seals. So, after 25 years I know why. Excellent.

 

[tonkaplonka]

"NGV failure caused the stepped S17 seal to move causing......"

........more S17 seal treatments than I can possibly remember. I was at EROS at the time and all I seemed to deal with is getting the seal coatings replaced on the S17 stepped seals. So, after 25 years I know why. Excellent.

MOD 31466 if I remember correctly.

Bloody hell, I worked in the engine bay 12 years ago.

 

[sumps]

MOD 31466 if I remember correctly.

Bloody hell, I worked in the engine bay 12 years ago.

DT_Xtremez_42:GOOD GOD MAN, YOU REALLY DO NEED TO GET OUT MORE!!!DT_Xtremez_34:

 

[Fu Fu Valve]

i'm going to have to stop reading this cos it's causing flashbacks to Leeming TPF, i had blanked that part of my life out!

DT_Xtremez_42: