Talk:Ilyushin Il-62/Archive 1

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Archive 1 Archive 2

Underpowered?

AFAIK, the original Il-62 was seriously underpowered, owing to the NK-8-4 being the only available engine at launch time (it was meant to have the D-30KU or something like it from the beginning) and that the loss of a single engine during take-off meant no take-off, and possibly disaster. However, I'm not able to find a reliable source to confirm this. ProhibitOnions 10:00, 6 April 2006 (UTC)

Easy enough to check that. NK-8-4 thrust x4 divided by loaded weight. - Emt147 Burninate! 01:48, 7 April 2006 (UTC)


Yes; addressed in my last edit. The Tu-114 actually had a placard in its flight manual saying that no meaningful action could be taken in case of a single engine failing on departure, i. e., the crash was a certainty!

Who said that? It's totally wrong. Tu-114 was one of the most reliable airplanes ever built. And, of course, in the case of a failure of one engine, it could proceed with takeoff. --unpluggged 18:57, 4 May 2007 (UTC)
I think the anon who wrote this was thinking of the Il-62 and mistakenly typed Tu-114 for some reason; the same editor added quite a bit to this article, and seemed quite familiar with it. You're right, the Tu-114 was a very good design (and he's right, the original Il-62 was underpowered). Regards, ProhibitOnions (T) 20:13, 4 May 2007 (UTC)
Kirill and ProhibitOnions: I did mean the Tu-114 was underpowered. My source is the late Soviet designer Leonid Selyakov who worked at Tupolev from the early 1960s until retirement in the early 1980s, and from then on as consultant until his death. I knew Leonid. In his memoir book, Thorny Road to Nowhere ("Ternistiy put' v nikuda"), he cites the Tu-114 Flight Manual ("RLAe samoleta Tu-114"): "In the event of engine failure during the latter stages of the ground run prior to take-off, take-off cannot be completed. Selyakov had a personal reason to dislike the Tu-95 and -114, having worked on the M-4/3M competing programme. However, also see Gordon and Rigmant (Tupolev Tu-114) and other commentators both from within and outside the Tupolev camp. I am not aware of engine failures beyond V1 ["rubezh"] in Tu-114 service, and am convinced that in training no such exercises were carried out due to them being expressly proscribed in the FM.

Anonymous edits

There were some recent anonymous edits to the article that seemed to have been made to ridicule the assumption of industrial espionage, and to praise the Il-62 beyond what is appropriate to an encyclopedia. They also introduced some posibly useful aviation information, suggesting they may have been made by a pilot. I toned down the advocacy, and removed some comments about the Il-62 being a commercial success (which hardly applies in a communist economy) vs the VC-10 being a flop, but others might want to take a look.  ProhibitOnions  (T) 13:40, 10 May 2006 (UTC)


Yeah, point taken. The espionage slur really irritates me. No proof is ever offered (not that it is as regards the Tu-144). What's more, here the two aricraft are genuinely very, very different (superficial similarity notwithstanding)

Maybe. But no-one says the plane was a copy of the VC-10, just that espionage probably took place, which was quite likely, as we now know there were plenty of Soviet moles in the UK, and that there were other cases where it can be shown (the Tu-144). Unlike in the present climate, where anyone who wants to can get detailed plans of the 787 or A350 while they are being developed, the VC-10 was initially developed in secrecy, and not simply because of the Cold War, but because there were plenty of rival companies still thinking of building big jets (especially in France and the US). My guess is that some early VC-10 plans probably were transferred out of the UK, and what the Soviets learned from them was that the most advanced aircraft then being planned had a four-engined T-tail with uncanted wings. Hence, the Soviets knew that a plane in this configuration would not only be viable but probably the most up-to-date design, as it was in many respects.
That's the likely extent of the intelligence-gathering, as the layout of the two planes is obviously very similar but the technology is quite different. Unlike the VC-10 the plane was built to be low-tech and durable, and its aerodynamics were not changed during its long production run. (Meanwhile, the VC-10 was quickly killed off by BOAC's ever-changing specifications; the demands for a long-range plane that could also meet "hot and high" landing requirements made it heavier than it needed to be and correspondingly less fuel-efficient than the 707, so no-one else bought it.) OTOH, the USSR had plenty of oil and was not a market economy, so the Il-62 suited its purposes well enough. However, the engine technology wasn't quite up to the task, as you point out, and the center-of-gravity issue led to a number of design oddities in the Ilyushin, like a big water tank in the nose, and the famous fourth wheel.
There's an interesting thread here [1] discussing the Il-62, and one of the contributors describes a friend of his taking part in a minor act of aviation espionage. Hard to verify, of course, but an amusing read.
FWIW, I think I have flown on an Il-62 (as a kid flying into Bucharest), but not a VC-10, though I did see the one parked at the aviation museum near Birmingham. I was supposed to fly on an Air Koryo Il-62 a few years back but got bumped to a Tu-134 instead. Still a great plane, with its round portals, but I was disappointed... OTOH, there's an Interflug Il-62 parked near Leipzig-Halle Airport where you can have coffee on board. Regards,  ProhibitOnions  (T) 18:03, 10 May 2006 (UTC)

Yes, I agree that spying may have helped prove the concept, but hardly more than that. By the same token, Sir George (Edwards) may well have wished he knew the Il-62's secrets. And he _did_ try out a saw tooth which is still on view at Brooklands for all to see. Spying of all natures and of everything was a Soviet obsession and no doubt they tried. Hard! But as to whether they got anywhere meaningful, hard facts would seem to indicate not.

Thanks for the referral to a.net. Yes, amusing but sadly not terribly enlightening.

In fact, I am a VC10 fan in a big way and don't much like the Il-62. It just irritates me to see hearsay repeated by authors who are less than rigorous; if they had facts, I'd be the first to be delighted to read them. In a way, I almost want to provoke just such a response -- hard facts of spying on the VC10. So noblesse oblige and all that... :)

Aviation.com mentions an espionage plot regarding the VC10 and Il-62: "...reputedly leaked a carefully altered set of VC10 blueprints to the USSR..." But there is no source . http://www.aviation.com/travel/top10-notablepostwar-1.html (Click on number 5)WasAPasserBy 01:50, 1 September 2007 (UTC)

The repercussions of the espionage regarding the VC10 was one of the things that Greville Wynne was supposed to have been arrested in retaliation-for.
As for the VC10 sales versus the Boeing 707, it's as well to to point out that it was (or perhaps still is, although I think it may have been changed by bans on anti-competition laws by now) US law that an air carrier was barred from buying a non-domestic (i.e., foreign) product if a US-built alternative existed. This meant that whatever the perceived shortcomings of the VC10 were, it wasn't going to get bought by carriers in the US anyway, as the US airlines were restricted to the US-built airliners, the Boeing 707 and the Douglas DC-8 and later the Convair 880. This also applied to the Trident, as although an earlier aircraft than the Boeing 727, Boeing was able to expedite the 727s introduction by using the fuselage of the 707, and once a US-built competitor was on the horizon, it was extremely unlikely that a US carrier would be able to buy the Trident - and they didn't. This 'Buy-US' law was the reason that so much fuss was made about the first scheduled transatlantic jet crossing, viz the de Havilland Comet 4c and the Boeing 707, as if the 707 had not been available for say, another year, then US airlines would have had to choose between them buying the Comet, or not being able to use jets on the North Atlantic route at all and losing all the revenue on that route to their competitor airlines that DID buy the Comet. IIRC, the only UK airliner that DID have some success in the US was the BAC One-Eleven, as that filled a niche for which there was no US-built competition for some time, e.g., the Douglas DC-9. Once that appeared on the scene, sales for the One-Eleven were no longer possible.
This also applied to airliners produced in the former Soviet Bloc, as, apart from Certification issues, they couldn't have sold them to US carriers anyway for the reasons I outlined above.
Incidently, that's the same reason why Boeing (or another US competitor) HAS to come up with a near-equivalent aircraft to the Airbus A380, as unless it does, Airbus will take ALL the orders for large aircraft from US airlines that want to continue making money. It's that simple. Once there is a US-built competitor to the A380 available, no US carrier will be allowed to buy the A380. - — Preceding unsigned comment added by 213.40.249.228 (talk)
Then you should probably tell the US airlines that currently operate Airbius products that they are breaking the law, so they can sell them and buy Boeings instead. Quite obviously, the law is no longer in force (provided it ever was exactly as you stated, which I doubt), and airlines can purchase whatever aircraft they want now. - BilCat (talk) 16:51, 18 October 2009 (UTC)
US law that an air carrier was barred from buying a non-domestic (i.e., foreign) product if a US-built alternative existed. - actually, see the BAC One-Eleven article, c.f., Bonanza Air Lines also wanted to order One-Elevens at a later stage but was stopped by a protectionist action of the US Department of Transportation. I DID say that I wasn't sure if it was still in force, and this was in the 1960s, but it is true. The US DoT wouldn't allow US airlines to buy a 'foreign' airliner if a US-built alternative was available.
Look at it, the One-Eleven was the FIRST T-Tail rear-engined twin-jet airliner (before the DC-9) and the Trident was the FIRST T-Tail tri-jet (before the B727) and they both had better performance than the contemporary US-built 'copies'. And guess what, even the Soviets had a go at producing 'copies' of these UK originals, the Tu-134 and the Tu-154, even the VC10, as this talk pages demonstrates. The fact is that the reason few US airlines bought any of these 'foreign' aircraft (apart from the BAC One-Eleven) is because the US DoT wouldn't let them. It's called Protectionism. That's why they were 'less successful' than their US counterparts, not because they were 'inferior' - most were technically in advance of their Boeing and Douglas counterparts - the Trident was the first airliner with a FDR as-standard and was also the first airliner with a full Blind autoland facility, which most US airliners (AFAIK) still don't have today. Don't get me wrong, I'm not knocking the US airliners mentioned, or even others for that matter, but what I am saying is that the reason that they are so widespread today has little to do with any 'superiority' in their designs. In many cases it's because they now no longer have any competition, or because the airlines have little choice in the matter. I don't suppose Aeroflot would have been allowed by the Soviet Government to buy Tridents or One-Elevens even if the UK would have allowed them to be sold to the-then USSR. See, it doesn't matter how good something is, if you're not allowed to buy it, you buy something else.
Do a bit of research if you're going to edit articles. Try reading some 'proper' aviation books, preferably written by people who know what they are writing about. And also try reading some written by people in other countries, and that way you may find different angles on what you perceive as 'the truth'. As you gain more knowledge about the wider subject you will then be able to more accurately judge who is telling the truth and who is writing to some sort of an agenda. That way it may help save you from inadvertently writing misleading nationalistic crap, as so many people on Wikipedia unfortunately seem to do. —Preceding unsigned comment added by 213.40.251.216 (talk) 16:58, 31 October 2009 (UTC)
I did do some research, and found that US airlines DID use BAC 111s, and some other British and French airliners also, during the 50s, 60s and 70s, so that's whay I'm doubting the totality of your claims. - BilCat (talk) 18:07, 31 October 2009 (UTC)
OK. I'm not sure when exactly the edict was in force, nor for how long, as that sort of thing tends to change depending on the political climate at the time. To be fair I should admit that the lack of sales may also have to do with the abysmal lack of direction and indecisiveness of the primary UK airline customer of the time, BOAC/BEA (they were in effect, separate arms of the same nationalised company), as they constantly changed their mind on what type and size of aircraft they wanted, and I suspect that the UK aircraft manufacturers may have sometimes wondered if it was all worth the bother. BOAC did the same thing with the earlier Avro Tudor, which was also seriously mucked-about-with, to the point that it was almost unusable when it did finally enter service. The Trident suffered the same thing from BEA, although it was technically a fine aircraft. I suppose what I'm trying to say is that the comparative lack of 'success' of these aircraft had little if anything to do with the technical aspects of the aeroplanes themselves,
I think the only UK aircraft that had anything like decent sales in the US were the Viscount and the One-Eleven. IIRC, the only French airliner used in the US was the Caravelle. I'd be very surprised if the Viscount had any further sales after the Electra became available, and likewise the One-Eleven and Caravelle after the DC-9, although I could be wrong. It's possible that as they (the US ones) were later aircraft that they may have been better tailored by-then to the US airlines requirements, but the 'no-foreign' buys if an alternative 'domestic' product is available requirement was in force for a time. —Preceding unsigned comment added by 213.40.253.135 (talk) 12:12, 1 November 2009 (UTC)
There are many other factors involved in selecting airliners. Range (It's roughly 2500 km from London to Moscow, but nearly 4000 km from NYC to LA, so American airliners usually had better range.) Durability (high technology, esp pre-printed circuits, was less reliable) maintainability, and costs (both initial and operating costs), and so on. Large production reduces costs, thus making certain aircraft even more attractive. Protectionism would only affect US buys, but US airliners did not just sell well in the US, but world wide. The lesser US airliners did not sell well - CV-880 and 990, (but they faced two US competitors), and most US turboprop airlines - the British excelled in this area, and they sold well world-wide. The better overall product generally sells better, even if it's not "suprior" in certain areas. Lemons/turkeys usually don't, no matter who makes them, unless they're Government subsidised in some way. The free market generally makes better choices than government bureaucrats, and that gooes for protectionism too! - BilCat (talk)


Technological wonder?

This phrase is kind of amusing: "The Il-62 also uses conservative technology whereas the VC10 was a technological wonder." Now, those are strong words, possibly reflecting the opinion of the author, so some kind of citation is needed, don't you think? Or at least it should say "...the VC10 was considered by many to be a technological wonder". It's like asking "Who is the world's best author?" as a factual question... --Unsound 14:37, 19 November 2006 (UTC)

I concur. The wording isn't NPOV, and should be fixed. Itsfullofstars 23:19, 10 January 2007 (UTC)
Yep, that phrasing was added by the person with whom I had the conversation above. While there's some truth to it, it should be rephrased or removed. ProhibitOnions (T) 13:50, 28 February 2007 (UTC)

Description and Equipment section

The Description and Equipment section could use some work. First, it was a sub-section of the History section, but that didn't seem correct to me so I moved it out. Secondly, the grammar is very terse and doesn't flow. Its a difficult read (to me, at least), with a lot of unwikified aviation jargon that laymen won't understand. I added a couple of wikilinks for empennage and semi-monocoque, as a start. Itsfullofstars 23:19, 10 January 2007 (UTC)

I want to extend a Thank You to ProhibitOnions for tidying up that unwieldy section! - Itsfullofstars 17:06, 28 February 2007 (UTC)
Glad to be of help. Regards, ProhibitOnions (T) 19:18, 28 February 2007 (UTC)

Neutrality

I have seen some mention of neutrality being questioned in this article on this talk page - what does anybody think of this? I think some parts seem to be written with bias, particularly things regarding the VC10-Il62 Similarities. Could somebody confirm this to or not to be NPOV? vwozone 21:36, 17 March 2007 (UTC)

Actually, the claims of the modified version (Il-62M) being well liked by pilots are totally opposite to what was reported to be told by Polish pilots. They described flying Il-62/Il-62M as a kind of lottery and there was a lot of their positive comments published in popular press when LOT switched to Boeing. I tried to send enthusiastic statements about the 62M quality to quotes. I also added some detail about LOT reaction to the crashes to calm down the followers of the first, unofficial report version that blamed the crew and possibly maintenance for the crash (final has shown Solowiew D-30 design and manufacture flaws as the source!). Also, I found the claims of 62M better security completely wrong (far more crashes with 62M than with 62) and linked to a more accurate and up-to-date source. Hope it helps. —Preceding unsigned comment added by 212.87.26.1 (talk) 10:14, 22 July 2009 (UTC)

Safety data

A simple look at the statistics clearly shows that the Il-62M had a better record than the Il-62. There were 193 Il-62Ms compared to 83 Il-62s, but the accident rate of the Il-62M is lower. With more than 3.3 times as many Il-62Ms in operation than Il-62s (and this doesn't even include Il-62s that were upgraded to Il-62M specs), the hull loss for the Il-62M was one per 2.5 years (vs 1 loss per 1.8 years for both models combined). For comparison of western models from this era, the Boeing 707 had no fewer than 166 hull losses so the rather emotive argument that the IL-62M was a highly unsafe plane (23 losses over 42 years) doesn't make any sense. Most references I've seen suggest that the Il-62M has a good safety record. These hull loss figures for a plane designed in the 60s do not compare with modern jets, but the amount of flight data available to crews then was far less than today, and engine failure rates were much higher. As far as the LOT accidents, I would be looking at airline maintenance issues (how often were the turbines examined for example - I note that the second crashed plane had done something like 5000 hrs?) as well as a possible flaw in the engine assembly. It seems unusual that both fatal accidents happened to the same airline given the widespread and largely very safe use of the plane with other airlines. It's just unfortunate that there were so many people on board those two planes. One Polish blogger claimed that the Russians somehow hid accident statistics for IL-62s, but as the IL-62M was used on international routes to replace the TU-114 and also had a registation system which can be tracked, this is surely not the case. Incidentally, a contributor to this main article added spurious accident figures for the IL-62 to imply that the rate was three times higher than it should have been. This has now been removed. The hull loss rate of the Il-62M is actually no higher than hull loss rates of comparable planes of its era (by some measures it may be lower). Also, most hull losses occurred early on in its career (as they also did with the VC-10) with what was obviously an underpowered engine. The fact that the Il-62M is still in civilian use after more than 4 decades speaks for itself, and any reason for discontinuing its use is purely based on fuel consumption and noise restrictions. —Preceding unsigned comment added by 203.109.170.98 (talk) 18:01, 11 August 2009 (UTC)

I could only find the two LOT crashes that involved engine failure leading to a hull loss with fatalities, so it is natural to suspect airline maintenance as one possible contributing cause even if a probable manufacturing fault was identified (otherwise there would surely have been cases noted with other airlines). The other alternative is that it was coincidence (bad luck) that both losses occurred to LOT planes, but that would be highly unlikely. The accident rate overall seems not bad compared with Boeing jet losses of that era (cf. the hull loss rates of 707 and 727) but would not compare with new Boeing or Airbus models. I don't think it's correct that the 62M had a worse accident rate that the 62 because of course early 62s were converted to M early in their careers and the rest were M from new, hence the time flown by M versions is far higher (193 of the total 62s built were M versions). BTW does anyone know of any N-K 62s still in service? I read that LOT modified its engine maintenance on the 62s after the second crash (reduced inspection interval times and added extra protective material between the paired engines etc). Pilots of 62s reportedly liked the plane for its directional stability in rough weather even if it was more difficult to land in crosswinds than a plane with wind-mounted engines (will add the link if I find it again). I'd be interested to know if anyone has information on LOT maintenance of the 62s, and if any other airline had similar problems (I couldn't find any evidence of this). 23 July 2009 (UTC)

Safety data

"I'd be interested to know if [...] any other airline had similar problems (I couldn't find any evidence of this)"

OK, the links to accident descriptions just have been deleted by some Il-62M fan! They didn`t lead to fatalities, but it was rather lucky (2008: flight control lines not severed; 1998: the occuring was on the ground). Both Il-62M. Rather poor evidence to blame people for the mishap (all the text of Il-62 being first LOT`s long-range airliner does so, despite they had 8 years of experience with the type before the first accident!) They switched to Western planes shortly after the second crash and did not have a single fatality with them to this day. http://aviation-safety.net/database/record.php?id=20080420-0 http://aviation-safety.net/database/record.php?id=19980424-0

Tried to make the text more neutral, and removed all the text trying to cause people think the crews were involved. The description (btw, from WIkipedia, based on the official report) may be useful: http://en.wikipedia.org/wiki/LOT_Polish_Airlines_Flight_5055 —Preceding unsigned comment added by 212.76.37.216 (talk) 15:37, 14 August 2009 (UTC)

The IL-62 was LOTs first long-range airliner according to their official website and there was no mention of crew error in the text. Remember that this is a wiki entry for the IL-62/62M, not for LOT airlines, and that POV statements (matters of opinion be they of individuals or of people representing companies including airlines) should not be posted on wiki sites and can be reported as vandalism. I don't know who deleted the accident link data. LOTs experience with the IL-62 was unusual, but you may be interested to know that Ukraine airlines purchased the ex-LOT IL-62Ms and as far as I know are still using them. The hull loss rate of the IL-62M is not high compared to other airliners of the era - in fact it is lower than most, but it does not compare with modern jets, Ilyushin or otherwise. How do you know that if LOT operated DC-9s or early 727s, they may not have had significantly more accidents? By some measures, early versions of 727s were the most accident prone planes of their time. Again, later modifications to and versions of the 727 improved the safety rates significantly. —Preceding unsigned 05:23, 15 August 2009 (UTC)

This was the last instance where a mention of vandalism should be placed! Especially regarding these article fragments that maybe did not mention LOT crew / maintenance error in a straightforward manner, but strongly suggested such (which is in clear conflict with the official crash investigation report, and thus cannot even withstand crits as a POV). "LOT modified [...] maintenance and engine overhaul procedures"... The engine servicing that introduced faulty parts (the roller bearings that failed leading to the shaft breakage) was done in the S.U., not by LOT. Thus, removed this fragment to clarify the matters. "The hull loss rate of the IL-62M is not high compared to other airliners of the era"... If two crashes turn the stats upside down, maybe the aircraft number is not high enough to judge airline quality from its mishaps. LOT did not have a single fatality after the switch to Western aircraft (some 20 yrs ago). Is this POV? Worth considering, at least!! "Ukraine airlines purchased the ex-LOT IL-62Ms"... These planes were modified by LOT after the crashes, with double control systems, extra fire / vibration detection, reduced engine work timing... etc., making them more close to the VIP carrying examples than regular airline ones.

And once again, pls do not blame me for vandalism. It is not me who vandalises the text! I do not remove factual information or links, I do not name them POV, I do not try to blame innocent people. Maybe it is high time to protect the article from anonymous edits. —Preceding unsigned comment added by 212.87.26.1 (talk) 13:47, 29 August 2009 (UTC)


LOT safety questions

In answer to (talk) 13:47, 29 August 2009, The only conclusion that can be drawn from the data is that LOT's accident rate with the plane was significantly higher than any other operator. A similar phenomenon can be seen with Iranian Airlines which operate the Tu-154 and which has accounted for well over 10% of all hull losses in the plane's entire history (of almost 1000 planes). I can find no other airline that had similar experiences with the IL-62 that LOT had. I have gone through the IL-62 accident database and in other crashes the causes can be identified as either incorrect fire warning leading to the pilot shutting down two paired engines and then trying to land on 2 engines which is remarkably tricky in an IL-62, or fires (such as the Interflug accident which was actually caused by heat generated short circuit in the electrics bay). The Cuba crash was the plane hitting transmission lines and the other accidents are mainly takeoff/landing overruns. Because there were 11 crashes of the IL-62 in civilian use over a 42 year period (excluding the prototype testing crash), this means that LOT’s two accidents accounted for almost a fifth of all IL-62 crashes which is hugely disproportional. There is a very concise complete listing of the fates of all IL-62 that were ever put into service. http://www.sergib.agava.ru/russia/ilushin/il/62/il62l_e.htm If you look at the total hull loss rates of the plane compared to the VC 10 for example, which was only in civilian service for 16 years (1964-1980), the IL-62M still has a lower hull loss rate (even if we are generous and discount the three VC-10s destroyed by terrorists) and the IL-62M has been in service for a much longer period (35 years). Also, consider the situation that Poland was in during the 1980s. The country was in dire straits politically, financially and economically, not helped by a crippling series of strikes by the solidarity movement. LOT had for some time been looking at western aircraft to replace its IL-62 fleet, and in a 1988 article they claimed that maintenance of the IL-62 was too costly and quoted engine service intervals of 2,500-3,500 hrs which they compared to the "9000-11000 hrs" (which sounds very high according to other sources) for a Boeing 747. As a plane gets larger, so do the engines and the service intervals are hence much longer.


Well I would like to know about LOT maintenance of the IL 62 and non-one seems to have looked into that, which is strange given that their accident rate was so much higher than other airlines who used the plane (over 30 times?). The 1987 plane had 7000 flight hrs. In the investigations, did LOT state how many times the engines/turbines had been serviced and/or overhauled? The latest gas turbines used in Airbus A320 need servicing between 2000 and 9000 flight hrs depending on the number of take-offs and landings. They generally last about 5000 hrs but not much longer. The ones on the 747-400 last up to 8000 hrs. RB211 engines are completely overhauled at 3000 take-offs (or roughly 7 years of service). But with the IL 62 we are talking about 1950s/1960s turbine technology and the Il 62 is a solid heavy plane so I doubt they would last anywhere near as long as modern turbines. I would speculate that the engines would have needed overhauling long before 7000 hrs, probably even two or three times in that period. It's one thing to point to a possible manufacturing fault (which may have been) but engine servicing has more to do with reliability. If there was so much play in the bearings should this not have been picked up during routine service checks well before it got to the point of being dangerous? Also I wonder how good LOT servicing really was in the 80s - I recall one of our local importers bringing in Polish Polonez cars back then and a lot of them were blowing head gaskets after 5-10,000 mls. I asked about it at the time (because a cousin of mine bought one) and I was told that there was nothing wrong with the basic design of the engine/car but the quality of assembly and workmanship at the factory was very poor and was leading to all sorts of problems. Eventually they stopped bringing the cars in as there were so many warranty claims and it was proving too costly. The other thing in the 1987 crash was that the plane was on fire so surely the main thing would have been to land at the nearest airfield? It is possible that the crew thought that the fire was already out but how would they know that? The plane was still controllable after the engine failure, but turning around to fly back to Warsaw allowed the fire to kill the electrics so loss of control would have followed. Had they landed at a nearer airfield or even on the ground things may have been OK because you can land an IL 62 at breakneck speed even on rough land generally without major damage as it has a very strong fuselage. —Preceding unsigned comment added by Aria613 (talk • contribs) 03:20, 1 September 2009 (UTC)

Answer to Aria613 concerns from 03:20, 1 September 2009:

1. LOT`s maintenance, as it was stated in the accident report, was in no way connected to the failure. The engine logged 2793h out of allowed 3000h.

2. Comparing a consumer product (Polonez car) with an airline is somewhat too far extrapolation. I remember the problems with general consumer products, but I also remember that some parts of the Communist economy were strongly isolated from the rest. This mainly means these parts that were exposed to competition from the West, even if not directly; this resulted in a preferential access to (even Western) materials and parts. Thus, I doubt LOT experienced such basic shortages as other companies did; also airplanes produced in Poland in 1980s do not show any signs of lowered safety. BTW, the whole question appears a bit too subjective as for me.

3. The decision to land in Warsaw and not in Modlin military base was caused by lack of precise weather and runway data from Modlin (with which contact was poor and probably indirect) and better available firefighting / rescue equipment present in Warsaw. Moreover, the time required to reach Warsaw was similar to the time necessary for dumping fuel.

As it is shown by the transcripts of radio transmissions, the pilots were not aware of the fire. The lack of fire alarm was later found to have been caused by the damage done by fan blades penetrating the fuselage. The fire signal arrived shortly before crash and come not from the cargo hold (where the fire actually developed) bu from the engine nacelle. Thus, the hold detector was clearly rendered inoperative by the explosion.

Reply In answer to the unsigned comment above, regarding the poor quality of assembly of Polonez cars in the 1980s, the point is that if workmanship was so slovenly in a large state-owned car industry making vehicles for export, why would it necessarily be any better in the aviation sector? I have read several accounts of the 1987 LOT crash and they give different figures for the plane's total flight hours (varies from 5000 hrs to 7000 hrs, which seems strange as the airline should know exactly how many hours the plane had flown), as well as varying accounts of what actually happened and the sequence. It seems bizarre (and tragic) that the plane was not given permission to land either at Gdansk or Modlin, and please note that the crew would not have had to dump fuel if they landed at either of those airports because the plane wasn't rendered uncontrollable until after the cargo bay fire got out of hand. I also gather that LOT wet-leased a number of Aeroflot-owned IL-62s (actually more than the number they owned themselves) and I couldn't find that there had been problems with these, but correct me if I am wrong. As far as the maintenance issue, see this article regarding bearing failure in aircraft engines http://www.theriac.org/DeskReference/viewDocument.php?id=21 It's not as rare as some people think - it happened to one of our local commuter aircrafts last year, but luckily the plane had just landed when the engine exploded and no-one was injured. Pilot blogs mention instances of Boeing 727 engine failure after as few as 500 flight hours. The question of how many hours the plane had flown since its last overhaul is possibly even secondary to what regular maintenence it received between major overhauls. There is a standard schedule for mainenance on wide-bodied jet airliners in the US. Note especially the A and B check intervals. Vibration checks on turbines are also standard for many aircraft, but it sounds as if LOT possibly only started them after the 1987 crash. Aria613


LOT Safety questioned

I found some more information that may be relevant to why the LOT IL-62 accident rate was so much higher than anyone else's. Firstly, LOT operated a large number of Aeroflot-registered IL-62s, and as far as I can gather, had no incidents with them. These planes were maintained by Aeroflot. Both aircraft that crashed had been bought by LOT who had apparently been running them for up to 3000 hrs and then returning them to Russia for maintenance. In the book OKB Ilyushin by Gordon et al there is some releavent data on the subject. "The total number of flying hours logged per year by one IL-62 was gradually brought up to 2,300-2,500 which was comparable to the number of hours logged by the aircraft of the best foreign airlines. Making the utmost use of the operational potential inherent in the design of the IL-62, CSA (Czech Airlines) began operating the type on a 'technical condition' basis without overhauls at preset intervals. The total number of flying hours logged by this aircraft in CSA service reached 3000." (p 259) This would imply that 3000 was well beyond the service interval, yet it seems as if LOT was regularly flying its planes to this limit (the second plane that crashed had done almost 2800 hrs since the previous overhaul), and I was unable to find out what (if any) maintenance was being done between. Incidentally, this was not the only plane with which LOT had accident rates that were far higher than other airlines operating the same planes. LOT operated just two Antonov-12s (introduced in 1959, 1248 built, and still in service in numerous countries) and one of them was lost in a crash. It also lost two An-24s in crashes. The An-24 first flew in 1959 and is a remarkably robust and safe plane with over 1,000 built (excluding Chinese versions) of which 880 are still in active service. Aria613


Safety and operational data I found this information from Gordon et al. (2004), OKB Ilyushin, which states that the 62M had a good safety record, and a dispatch rate in Aeroflot service of 97%. They also say: "Unfortunately, airliners of this type [grouped rear-engined] also came to be involved - albeit very rarely - in fatal accidents. They were mainly associated with powerplant operation (uncontained engine failure, false fire warnings and the like). After the implementation of appropriate measures the IL-62M became the most reliable type in Aeroflot's fleet" (p. 264). "The experience of the first ten months of operational service with seven IL-62Ms flown by TsUMVS/210th Flight on Aeroflot's International services showed a very high dispatch reliability which amounted to 97%. On average these Il-62Ms logged 7.3 flight hours per aircraft per day. For a period of almost twenty years the IL-62M became the main Soviet long-haul airliner, for a long time it ranked first among Aeroflot machines as far as average daily utilisation was concerned. In 1997...the IL-62Ms belonging to some airlines logged as many as 17 flight hours per day." (p. 263) "The IL-62 offers an exceptionally smooth ride (it is virtually immune to turbulence) but the touchdown can be rather bumpy. (p. 377). 24 July 2009 (UTC)

LOT Safety

Just a small addition to the question of LOT safety record:

1. Il-62 and -62Ms did have similar, uncontained engine failures in other airlines, just search top safety sites for photos of their burst casings with clearly visible damage to adjacent structures. It was apparently just a matter of luck they did not kill anybody (one case on the ground and another with the debris just missing control lines!)

2. Compare LOT`s (and other airlines`) workhorse, the Tu-154. LOT had a number of Tu-154s, in the version which was engined with the same powerplant as Il-62M. None of them ever had a known accident, which would have to happen if LOT maintenance was involved. Actually, all cases I know involved no. 2 engine of Il-62 / -62M... I do not know if it was an accident or it really was connected to the powerplant fitting / usage on the 62, but it is worthy considering that the thrust / weight ratio was significantly more favorable in the case of Tu-154. If you doubt engine mount could make so big difference, just compare the case of Napier Sabre fitted to Avro Manchester and Hawker Tornado.

And the final argument: the OFFICIAL ACCIDENT REPORT found the Soviet engine manufacturer and maintenance faults were responsible for LOT crashes, despite reported strong pression to state otherwise. Knowing Soviet-style reality, I would really pay attention to a document that went so far against then-dominating tendencies. —Preceding unsigned comment added by 133.30.183.147 (talk) 06:13, 23 March 2010 (UTC)


In reply to talk:133.30.183.147, interesting points that you make, some of which I agree with although there are a couple of issues:

1) I think it extremely unlikely that an assembly/manufacturing issue was the cause of IL-62 engine failure because if that was the case you would expect to get random failure. In three of four cases (SP-LAA, SP-LBG, CU-T1283) the unit affected was # 2 innermost engine (as you note), and I suspect that it was also #2 in the 4th case (YR-IRD) which surely implies an installation/access or maintenance issue. I've never heard of engine # 1, 3 or 4 failing yet these would have the same odds of doing so if it was an assembly/manufacturing issue. Perhaps engine # 2 is the most difficult to access due to the proximity of control linkages or there may be a reason that the turbine shaft can flex during installation if performed incorrectly.

2) I'm not sure that anyone has claimed that there were no other instances of IL-62 engine failure, it's just that they didn't lead to the catastrophic crashes that LOT had. I also heard that LOT did indeed experience failures of their Tu-154 engines (including one at takeoff, although none was fatal, hence they are nor recorded). The Tu-154 mostly had NK-8 engines whilst the Tu-154M had the D-30. The Tu-154 is far more suited to rugged, basic servicing facilities compared to the 62, so servicing of the two can't really be compared.

3) I very much doubt that there is any inherent fault with either the NK-8 or the D-30 powerplants because both are known to be very rugged units with many thousands having been installed on various types of plane. They can even operate submerged as evidenced when a Tarom Tu-154 landed short of the Mauritania runway in 1980 due to control tower error (the engines ran under water for several hours allowing passengers to get to shore as the noise kept sharks away). Perhaps airlines that routinely removed 62 engines were aware of the engine installation issue, which would explain why countries that operated fleets over several decades (eg. Ukraine, Cuba, Germany, Czechoslovakia) never experienced fatal engine failures. The aborted CU-T1283 takeoff came near the end of Cubana's 31-year service period with 62s (1979-2010) and in 2000 they said that they had trouble getting spare parts and had only kept them in service whilst awaiting new models.

Some Polish commentators claim that Ilyushin would not allow LOT or other airlines to remove engines but I find this very hard to accept because other airlines clearly did remove and service engines on a regular basis. It is far more likely that LOT simply did not have the necessary equipment/workshops to remove/service engines, so any invasive maintenance was left to be done at overhaul. Others have also suggested or implied that the reason that the IL-62 accident rate appears low is because some airlines have 'hidden' accident statistics. The obvious problem with this argument is that the 62 is a long-haul jet mostly used for international routes, many of which were western destinations. It was also used (on long haul) by some western airlines so any conspiracy to hide accidents would involve countries as well as airlines (which begs the question of why they would even do so). If the plane was unsafe, why did Aeroflot quickly retire its Tu-114 fleet and replace it with the 62 even when the 114 still had service life left and actually used far less fuel than the 62. Finally, there are very comprehensive registries for the 62 with histories and fates of every plane built so if there was a whole batch of missing registration/hull numbers I'm sure aviation authorities would know of them.

The accident rate of the 62 in its early days was higher than later when far more planes were in service, which could be due to several reasons including airlines becoming more accustomed to its operation as well as its idiosycracies (using reverse thrust after landing etc). There are also various updated powerplants available for the more recently built 62s, which might explain why the fatality rate dropped to 0 for the last two decades. Maxzden March 26 2010 —Preceding unsigned comment added by Maxzden (talk • contribs) 18:23, 26 March 2010 (UTC)

In response to the remarks by Maxzden:

Safety

In reply to talk:Maxzden, I would like to point out in response to your remarks:

Ad. 1, 3. The bearing manufacture / assembly fault was cited straightforward in the official accident report as the root cause, this is why I insist on this. I think it is crucial to get access at least to an extract of this document before proceeding with our discussion. According to it, the fault was in a roller bearing that was manufactured against the original project and caused premature failure to the shaft.

Ad. 2. As far as my data is correct, LOT had only Tu-154M, not the earlier versions. Tu-154 is indeed meant to serve in rough conditions, but the comparison is unavoidable provided the same engine type the two planes use.

Ad. 3. LOT used Il-62 and -62M for ~15 years before the accident.

Others: Neither do I believe it was possible to hide Li-62 crashes; the worst things I read in ~credible sources was that the Soviets tried to press towards changed investigation outcomes. Regarding Aeroflot retiring Tu-114 we should remember it was a turboprop, already close to obsolescence when introduced. The work on Il-62 started even before 114`s introduction. This was the reason for the hastiness, and I do not think it was possible to estimate 62`s safety level then.

In reply to Maxzden:

Ad. 1. It looks like uncontained failure of engine #2 or #3 would result in severe fuselage damage and a plane would either crash (SP-LAA, SP-LBG) or would have to be written off (CU-T1283 and possibly YR-IRD). I believe that similar damage to engines #1 or #4 would normally lead to minor damage or no damage to fuselage at all. It is quite easy to find information about hull-loss accidents of planes used in Soviet Union but it's more difficult to obtain any data on other types of occurrences apart from hijackings. This is an exception: http://www.il-62.ru/library/incidents/86464. In this particular case Il-62M took off from Domodedovo Airport in Moscow with 195 people and 2000kg of luggage on-board. A flight to Yuzhno-Sakhalinsk was interrupted by failure of engine #4 immediately after take-off. Tower controller informed crew their right engine was on fire and fire alarms for engines #3 and #4 were activated. A plane was fully loaded and crew didn't want to switch both engines off, beacuse CCCP-86513 had been lost in similar circumstances in 1982. Crew also rememberd that fire alarms could be faulty, so they assumed only engine #4 was damaged as its fire alarm was activated first- photos of a faulty engine prove them right. Plane landed safely with 3 engines running, 7 minutes after take-off. Crew didn't have time to dump fuel so they landed with extra 50 tons above limit set by manufacturer, but landing gear didn't collapse. Two photos show the damaged engine and damage to fuselage caused by fragments of turbine and compressor which separated from engine. Two other pictures show copy of accident report. This document states that engine damage was caused by disintegration of second stage low pressure compressor disk, this in turn was a result of pre-exixsting crack on disk which was used during last overhaul. So the cause of accident was, according to Soviet experts, design and manufacturing flaw. The document also reveals that contributing factor was lack of reliable means and methods of diagnostics of technical condition of disks and it didn't allow to find cracks during maintenace and overhaul. Nevertheless factory, which carried out an overhaul, was able to find similar cracks on disks of second and third stages of low pressure compressor in 5 other engines. Inspections carried out by maintenance never gave such results. —Preceding unsigned comment added by 86.145.118.221 (talk) 20:52, 17 November 2010 (UTC)


In response to unsigned comment of Nov 17

I've never heard of an engine #3 failure and am not sure that it would necessarily result in contagion as it is on the opposite side of the fuselage to known instances involving #2. CU-T1283 would have been returned to service following repair but it was decided to write it off because of its age and number of flight hours. The ultimate cause of the SP-LBG crash was loss of control due to the on-board fire (the distinction being made was that if the plane had been landed it would not have crashed, but I'm not going to re-open that argument given the hugely disproportinate air time it has already received). I'm not sure that cracks in turbine discs necessarily mean that the turbine is faulty. 747 engines have been found with cracked turbines but it depends where the cracks are and when they formed (are they superficial cracks from casting or are they fatigue cracks that are spreading and so on. I doubt that there was X-ray technology to distinguish this in the era of the 62, so turbines may have been re-used in instances when they should not have been. Today, I'm pretty sure that such diagnostics are standard. I've found that 62 operations and history appear to be well documented on Russian websites allied to registries (which often include data from planes operated in countries apart from Russia), moreso than for the VC10 for which it is somewhat harder to obtain. Part of the reason may be that the 62 is still in civilian service. Maxzden Nov 2010

The thing is that СССР-86464 was lucky because fragments of engine that had exploded narrowly missed engine #3, with only 2 engines running there was little chance they would survive. SP-LAA on the other hand was particularly unlucky because fragment of turbine which separated from the engine #2 penetrated fuselage and damaged engine #3. The same situation would be possible after an explosion of engine #3. If there ever was such failure it didn't have such tragic consequences. As for SP-LBG- pilots lost elevator control because fragment of turbine disk severed any connection between control column and elevator. Trim tab still worked but it didn't offer sufficiently precise steering during an approach in turbulent air at very low altitudes- three weeks after the crash Polish and Soviet pilots carried out some test flights using only trim tab to change altitude. You also need to remember that as a result of engine explosion SP-LBG lost 3 out of 4 electric generators, they couldn't use flaps and landing gear so an approach would be very fast, plane had still lot of fuel left- it would be very difficult lo land safely in such circumstances. It isn't clear what exactly happened in last seconds of that flight i.e why pilots were unable to recover from dive, there are several possible explanations, but they couldn't be verified by data from FDR or CVR- power supply to black boxes was cut off several minutes before crash, last words from crew were recorded on ATC tapes. Rynek (talk) 00:11, 22 November 2010 (UTC)

If you read an article about CCCP-86464 you'll know that there was nothing wrong with turbine disks and cracks were found on compressor disks (low pressure compressor or fan in case of D-30KU). Those were fatigue cracks which would spread as a result of friction between disk flange and brass bushing. If a crack was detected during overhaul entire disk was considered faulty and had to be replaced with new one because there was no way of checking the condition of disk during routine maintenance.I think the biggest issue for CU-T1283 was that it couldn't be temporarily repaired and therefore it couldn't be brought back to Cuba for permanent repairs. It was one of the latest Il-62's delivered to Cubana and at 18 years old it wasn't among the oldest Il-62's in use.Rynek (talk) 00:13, 22 November 2010 (UTC)

Reply to 'Rynek'.

You say that CUT1283 "couldn't be brought back to Cuba for permenant repairs" but if you look at aviation forums on this topic they mention that the plane was flown back to Havana, presumably on the three remaining engines (the flight was apparently kept at low altitude because of the lowered cabin pressure). You can also find photos of CUT1283 at Havana airport from 2009 and 2010 (the incident at Santo Domingo happened in 2008). It wasn't considered economic to repair this plane back to service level however and presumably it was used for spare parts which would fit with Cubana returning two planes into service recently in spite of announcing that they would all be retired many years ago due to a lack of spare parts. Aria613 31-12-2010 — Preceding unsigned comment added by Aria613 (talk • contribs) 19:04, 30 December 2010 (UTC)

Discussion of T-tail dynamics

The discussion of T-tail dynamics tries to pack too many thoughts into too few sentences, resulting in a bit of confusion for the uninitiated reader.

For one thing, if the centre of gravity really is "aft of the main gear", as the article states, then there would be no need for hydraulic assisted nose wheel steering, because the nose wheel would carry no weight. (Indeed, the nose wheel would hardly ever be on the ground.) What the article should say, is that the centre of gravity is "less far forward" of the main gear than in most other designs, making the IL-62 design more "aft-tippy".

Secondly, for a smaller (and lighter) tail-plane to suffice for rotation, the aircraft needs to be more aft-tippy not only about its static pitch fulcrum (i.e., its main gear), but also about its dynamic pitch fulcrum (i.e. its centre of lift), which means its wing. However, this has implications for the design's aerodynamic stability at higher speeds, which should be discussed. The article speculates about shifting water ballast fore and aft, but it should talk more explicitly about how this relates to T-tail dynamics.

The article should not try to be so economical with sentences. One or two more sentences would help a lot.

Grandmotherfrompeoria (talk) 01:56, 2 April 2009 (UTC)

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