A few questions on bae lightning

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11 years 2 months

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Who can tell me why its engine was installed vertically? I thought there must be reason, but I didn't get it. Are there any other's engine set just like it? The station upon its wing were capable to carry fuel tanks, is it possible to weapons?
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It can't have been that great an great idea as no-one else has done it. I think the Short Sperrin had engines that were top of each other mouned on the wings.
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a side by side configuration provide more body lift, lift is also drag tho, so possibly for a straight line interceptor, you'll want as little area as possible at behind, but for a turning fighter, the added lift is valuable even at expense of drag. Lightning wasnt ideal for either, drag wise, it had been better off single engined, but engines those days was abysmal and unreliable.

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a side by side configuration provide more body lift
True... but (and I haven't read up on the lightening much) but its possible that given this was a design from the 1950/60s that engines were still not that reliable. Mounting them on top of each other would mean no asymmetric thrust issues during engine failures, also spooling up time would vary possibly between engines. so that during take off it would be hard to keep it straight down the runway ....
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Yes, guessing spool time was quite an headache those days, along with a range of other issues with engines of that era, those days are luckily gone, not least pilots shall rejoice that rabble is scrapped
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I don't know why anyone would rejoice over that. Stacked engines provided consistency for airflow between the two engines with a single, less problematic shock cone than what was possible by using side by side engines. Jet fighter designs were in their infancy and the engineering limitations were quickly evolving by the next decade. Too bad they never figured out how to squeeze rb199's into them while stringing out their useful lives.

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As well as the Short Sperrin, the French Sud-Est Grognard also had stacked engines. I can't think of any other designs - although the Soviet Sukhoi Su-10 project had staggered stacked engines. Quite a few early Soviet jet fighters also employed twin stacked engines - although they were well staggered. The original Sukhoi Su-15 ("P"), and the MiG I-320 and Lavochkin La-200 all had twin verticall staggered engines - although one was mounted forward and exhausted under the fuselage, the other via a 'normal' jetpipe in the rear. Ken

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Who can tell me why its engine was installed vertically? I thought there must be reason, but I didn't get it. Are there any other's engine set just like it? The station upon its wing were capable to carry fuel tanks, is it possible to weapons?
As for weapons on top of the the wings, the export Lightnings to Kuwait and Saudi Arabia seem to have been cleared for unguided rocket pods on the above wing station. Believe these were the only Lightnings (other than perhaps some test version in the UK) to be fitted with any weapons on this above wing station. Picture here (scroll down a few pictures): http://www.f-16.net/forum/viewtopic.php?t=16135 With an additional requirement and some testing, I see no reason why other weapons could not be fitted there, but IIRC none were so fitted in UK service. Beside the ones already mentioned, there were a few rocket or mixed power aircraft with stacked engines, including the Thunderceptor, X-15 (early)
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Dark Duke, To amplify some of the answers/comments here: Stacked layout: this was done to reduce frontal cross-section and therefore drag. The result was a a genuine Mach2 fighter with a staggering initial rate of climb (50000'/min) and the ability to maintain supersonic speed without reheat. The downside was that there was nowhere in the fuselage to put fuel. Spool time: by now the Avon was a proven, reliable engine and, being axial flow spooled up very quickly. Certainly a lot quicker than the Spey in the F4 and the RB199 in Tornado and I have flown all three. I would therefore totally disagree with the posts re slow spool time and unreliability. I have over 2000 hrs on Avon powered fighters and in all that time never had a single engine failure. On the Lightning the stagger did not always provide 'consistency for airflow'. When taxiing, the No 2 engine (top) was kept at 65% to keep the electrics on line with the No 1 at idle. On take off you had to bring the No 1 up to match No 2 before selecting full power otherwise the No 2 would 'steal' all the intake air which would lead to a very slow spool up of no 1. It was quite common to see inexperienced pilots launching off down the runway with the top engine in reheat and the bottom still trying to accelerate to 100% Weapons were never carried overwing although BAC (as they were then) did propose overwing SNEB pods: [ATTACH=CONFIG]225625[/ATTACH] Only fuel was carried overwing and only by the F6. Although jettisonable they had to be empty first so there an emergency dump facility which blew the back flap of the tank off. I hope that this helps.
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I imagine that RB199's spool up time couldn't be that awful in comparison. The Lightning wasn't designed with a very long fuselage and I am surprised how compact it is in comparison to other twin engine fighters. It basically has 50% more engine in the same volume as a MiG-19. Its no wonder why it was considered such a short legged fighter. That picture really displays the madness of using rocket packs. I am too lazy to count or to look up how many are in such a configuration, but my wild guess is 170-ish. That's a lot for throwing up in front of a bomber pack, but cannot imagine real effective in pursuit roles. There probably was a way to sling ten missiles in the same way, but the old saying goes not to put all your eggs into one basket. They most likely didn't have enough missiles in the inventory to equip more than a pair at a time. http://crimso.msk.ru/Images6/AI/AI77-2/9-3.jpg http://farm8.staticflickr.com/7343/11177634876_702a1b5b40_o.jpg http://home.eblcom.ch/f5enthusiast/Pictures/Saudi%20Arabia/F-15F-5Lightning.JPG http://i841.photobucket.com/albums/zz338/lightningmate/Aircraft/LightningEaglesPrune.jpg
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The RB199 is a triple spool turbofan and thus suffers from the same sort of lag as a turbo charged car. I did not say that the spool up time was awful but, trust me, it is significantly slower than the simple Avon. I agree that the BAC 'concept' demonstrator was a bit OTT but the overwing and underwing pods are SNEB for use in a ground attack role, not for discouraging bomber streams. The retractable fuselage pack was, however, an air-air rocket system and was originally envisaged for the F1 Lightning.

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Hello. I think that the rocket pack was for the in front interception (or a lateral interception, under computer control of the launch). In most cases, the bombers have to come forward and a chase may already be a failure of the mission of interception. So the rockets completed the absence of all aspect missiles, because the Firestreak missiles (a.f.a.i.k.) were only "rear-aspect".

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Yes, Lothar, it is helps indeed. According to the photo you contributed, it seems that rocket bay could not be fitted with missile launch station simultaneously, am I right?
On the Lightning the stagger did not always provide 'consistency for airflow'. When taxiing, the No 2 engine (top) was kept at 65% to keep the electrics on line with the No 1 at idle. On take off you had to bring the No 1 up to match No 2 before selecting full power otherwise the No 2 would 'steal' all the intake air which would lead to a very slow spool up of no 1. It was quite common to see inexperienced pilots launching off down the runway with the top engine in reheat and the bottom still trying to accelerate to 100%
This description gives me vivid image how the powerplant works on Lightning. Now I am wondering if the upper engine (its 1# engine I guess) failed or needs restart in any case, would it be waiting untill the 2# engine down its air flow or you could tell me even 2# engine was staying at maximum speed, the 1# engine were able to restart still?
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Hello Dark Duke, Glad that I was able to shed some light for you. The fuselage rocket pack was substituted for the missile pack so, no, you could not have both rockets and missiles. The concept of interchangeable weapons packs was quite advanced for its time; there was the rocket pack (never entered service), Firestreak and Red Top missile packs and even a reconnaissance pack which, I believe, may have been used by the Saudi variant - can anyone verify? As to engine relights, there was no limitation on engine RPM on the live engine for relighting either engine but common sense dictated that it would have been unwise to be at 100%. Anyhow the Lightning flew very happily on one so rarely the need to be at 100%, indeed whole sorties after take-off have been flown single engine. The top engine, by the way, was designated No 2 but no difference except that the hydraulics for the brake chute doors only operated off the no 1.
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I would imagine running single engined should have given a significant boost to its running time.

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Hi, Lothar: You confused me by following words
As to engine relights, there was no limitation on engine RPM on the live engine for relighting either engine but common sense dictated that it would have been unwise to be at 100%. Anyhow the Lightning flew very happily on one so rarely the need to be at 100%, indeed whole sorties after take-off have been flown single engine. The top engine, by the way, was designated No 2 but no difference except that the hydraulics for the brake chute doors only operated off the no 1.
I did some research, and I found the air flow passed inlet of Lightning certainly would reach the down engine first. Additionally, the top engine which gets much more curved air pipeline to transfer the airflow to has almost illogical to steal air flow from buttom engine, especially while the No1 engine during max. power. Would you mind enlighten me with more visual explaination?
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When we consider the design of the Lightning context is important. Remember the thinking around the specifications was derived from a realisation that no RAF fighter could intercept a large bomber flying at over 50'000ft at Mach 0.85. The major perceived threat to the UK ADIZ was that of a Soviet bomber coming in at high altitude to drop bombs on our major cities and industrial centres. The EE Lightning was intended to be able to intercept that bomber and shoot it down. Time to altitude was the critical decider in its design, the EE Lightning was never intended to get into dog fights so the design was optimised to get the jet up to altitude quickly initially with a rocket pod then with the new generation of air to air missiles. The air to air missiles carried on the Lightning are optimised for taking out bombers and a payload of two missiles was regarded as more then adequate considering the RAF fielded far more fighters at the time. At the time there was no benchmark of how to meet those design requirements so it naturally led to some rather unique solutions in the UK and abroad. The RAF was also more keen on the idea of a hybrid rocket/jet powered fighter which would of been optimal for that kind of mission profile.
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Relighting DD, Sorry if I may have confused you so here I go again: you could relight a 'dead' engine regardless of the RPM on the live engine. Is that clearer? Although the no 1 engine (bottom) was indeed further forward than the top (No 2) engine, I am not personally aware that there was any difference in airflow to the two engines apart from the example that I gave but I am happy to be corrected. The 'throat' to the upper engine was narrower than that to the lower engine because of where the main spar bisected the duct. If you accelerated the engines with parallel throttles, they spooled up at the same rapid rate.

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Here is a simplified internal layout:
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Lothar: According to the video from youtube, what you told me was right. However, that bottum engine distance the inlet lip more closer than the top engine, so clearly, the buttom one get airflow first, how could the top one steal the airflow in sharing air pipeline even while the buttom one during maximum power.