Why civil airliners crash less often than fighter aircraft

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shiv
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Why civil airliners crash less often than fighter aircraft

Postby shiv » 20 May 2015 06:31

Nobody wants aircraft to crash and in India we hear about 6 to 10 military aircraft crashes a year and we almost never hear about a civilian air crash.

In addition, the media in India consist of reporters whose narrow interest (when it exists) is in their job and most defence or aviation reporters are neither dedicated nor knowledgeable. For every Saurav Jha, Tarmak or Sandeep Unnithan there are ten thousand twits who cannot tell the difference between an aircraft and a car - and "press freedom" allows even the most ignorant press nincompoops to impose their ignorant views on an already ignorant Indian population.

The result of this situation is that the average educated Indian who is genuinely concerned about military issues comes on to BRF and other fora thinking that The Indian Air Force specialises in crashing planes while everyone else on earth is merrily flying around with no trouble whosoever. This generalization that I have made has been true on BRF from the year 2000 right up to 2015. Millions of posts, hundreds of discussions and dozens of experts and valuable BRF contributors have come and gone but neither the media or the general public in India seem to have any idea that there may be something different in military aircraft flying compared with civilian flights. Astoundingly a whole lot of educated Indians (led by the media and half-wit reporters) go around talking like the stereotype village simpleton of Bollywood who may look at an Airbus A 320 and a Su-30 and say "Woh bhi hawaii jahaz yeh, aur yeh bhi hawaii jahaaz. Ek bada aur ek chhota. Us mein 150 log baith sakte hain. Is mein sirf do pilot" (That is a plane and this one is also a plane. That one can seat 150 people and this one only two pilots) Technically this is 100% correct but it reality the accuracy is the same as calling a gale and fart as being exactly the same. "Woh bhi hawa, aur yeh bhi hawa" (That is also wind and this is also wind)

In this sense, over the years BRF has fallen behind certain other forums - and in this case I am referring to DFI. DFI has a thread dedicated to all military accidents:
http://defenceforumindia.com/forum/thre ... tion.1546/

Any innocent person who asks if only IAF planes crashes can be pointed to that thread to check for himself - because the non Indian members of DFI and others take pains to post reports of air force accidents from all over the world.

Let me first point out that if I say "Lots of people have AIDS in the world", it does not mean that I believe that it is fine and dandy to have AIDS. When I say military aircraft crash more than civilian aircraft, I am not saying that it is fine and dandy to have them crashing. I am trying to point out a fact. It so happens that military aircraft have more accidents than civilian aircraft.

Why? Air forces are neither stupid nor suicidal. Flying fighters is inherently more risky that piloting a civilian airliner. There are many reasons for this and over the course of time I will fill in what I know to try and educate Indians who visit BRF to make them understand that there are significant differences between air force fighter and helo flying and what pilots of Jet Airways and Indigo are expected to do. We are discussing some of this stuff all the time - but somehow the information about difference in fighter flying and civili airliner flying does not sink into the Indian public and into the heads of reporters for the media.. I cannot put it all in one post, so I will start with this and come back later

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Re: Why civil airliners crash less often than fighter aircra

Postby johneeG » 20 May 2015 08:18

deleted by ramana
Last edited by ramana on 20 May 2015 09:01, edited 1 time in total.
Reason: ramana

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Re: Why civil airliners crash less often than fighter aircra

Postby shiv » 20 May 2015 08:20

johneeG could you please delete your posts. They are connected with crashes but are not connected with the purpose of this thread.

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Re: Why civil airliners crash less often than fighter aircra

Postby johneeG » 20 May 2015 08:21

shiv wrote:johneeG could you please delete your posts. They are connected with crashes but are not connected with the purpose of this thread.


What is the purpose of this thread? Is this thread not related to crashes of fighter aircrafts?

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Re: Why civil airliners crash less often than fighter aircra

Postby shiv » 20 May 2015 08:25

johneeG wrote:
shiv wrote:johneeG could you please delete your posts. They are connected with crashes but are not connected with the purpose of this thread.


What is the purpose of this thread? Is this thread not related to crashes of fighter aircrafts?

The purpose of this thread is not simply "connected with crashes". There is a thread dedicated for that purpose (Military Flight safety) .

This thread is about WHY fighters crash more than civilian aircraft. I am making a request to you to delete the post. I requested admins as well. I am hoping to make the thread informative in a different sense and not fill it with news reports

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Re: Why civil airliners crash less often than fighter aircra

Postby johneeG » 20 May 2015 08:39

shiv wrote:The purpose of this thread is not simply "connected with crashes". There is a thread dedicated for that purpose (Military Flight safety) .

This thread is about WHY fighters crash more than civilian aircraft. I am making a request to you to delete the post. I requested admins as well. I am hoping to make the thread informative in a different sense and not fill it with news reports


I thought you were trying to highlight the issue of crashes in IAF. So, I posted the articles because they seemed to be informative rather than just opinionated rants.

Even for your intended purpose, you would still need stats(provided by those articles) to compare military aircraft crashes to civilian airline crashes. But, such a comparison seems like a useless exercise because most people already know that military aircrafts are more sophisticated than civilian airlines.

A more relevant comparison would be to compare number/percentage of IAF crashes with crashes by other air forces. That would determine whether IAF is having more crashes than other air forces or not.

If admins/mods decide to delete the posts, its their call. I request them to move the posts wherever they are relevant. I hope there is a dedicated thread for IAF crashes where this issue can be discussed because many young pilots seem to be dying due to this issue.

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Re: Why civil airliners crash less often than fighter aircra

Postby Abhay_S » 20 May 2015 08:43

Shiv Ji,

Thanks for taking time to Explain This issue. i was one of those people you describe below and found BRF when digging for Answers. What interested me was a Talk By Stephen Cohen where he goes on to say that IAF flys 'Dangerous Planes' and should buy American Planes. According to him corruption in Russian and Indian defense industry has led to this. I initially did my research thru newspapers and found quite a few Mig 21 crashes and his argument sounded plausible. but then i read about a F-15 crash in US, now how does this happen hain ji?

After reading BRF for abt a year i find that this issue is very complex for Aam Abduls like me whose Aeronautical knowledge starts and ends at the price of the ticket to understand. Things are made worse by dumb reporters and salesmen with an Agenda. I think a detailed analysis with the type of aircraft and their role will help us a lot.


PS: Stephen Cohen want to sell us the A-10 for CAS.

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Re: Why civil airliners crash less often than fighter aircra

Postby shiv » 20 May 2015 08:50

johneeG wrote:
shiv wrote:The purpose of this thread is not simply "connected with crashes". There is a thread dedicated for that purpose (Military Flight safety) .

This thread is about WHY fighters crash more than civilian aircraft. I am making a request to you to delete the post. I requested admins as well. I am hoping to make the thread informative in a different sense and not fill it with news reports


I thought you were trying to highlight the issue of crashes in IAF. So, I posted the articles because they seemed to be informative rather than just opinionated rants.

No I was not trying to highlight the issue. That issue is well known and I recall seeing no posts from you in the thread dedicated to that issue on this forum in the last 5 years. The words "opinionated rants" have been used by you and if that is how you feel about your posts - that is your prerogative and I have no reason to disagree. The idea of this thread is to explain why civilian airliners do not crash so often as fighters leading to the impression that fighters are crashing a lot.

Anyhow - it is too late now. This is a free forum. Please use whatever space you need to make any posts that you want. If they are useful to someone so be it. I will attempt to continue with the purpose I had in mind for this thread.

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Re: Why civil airliners crash less often than fighter aircra

Postby johneeG » 20 May 2015 09:07

shiv wrote:No I was not trying to highlight the issue. That issue is well known and I recall seeing no posts from you in the thread dedicated to that issue on this forum in the last 5 years. The words "opinionated rants" have been used by you and if that is how you feel about your posts - that is your prerogative and I have no reason to disagree. The idea of this thread is to explain why civilian airliners do not crash so often as fighters leading to the impression that fighters are crashing a lot.

Anyhow - it is too late now. This is a free forum. Please use whatever space you need to make any posts that you want. If they are useful to someone so be it. I will attempt to continue with the purpose I had in mind for this thread.


Actually, I haven't seen any dedicated thread for IAF crashes on the forum going by thread titles. There seem to be one general thread about military crashes. I didn't visit that one till now. Does that generic thread compare IAF crashes with crashes of other air forces? Anyway, if I didn't visit a thread, that does not mean I can't post about that issue now, right?

I used the words 'opnionated rants' to refer to general posts of any members in any forum or journo articles in any paper/magazine. I was trying to say that those articles were based on stats released by then Minister of Defence in parliament and not just opinionated rants. You seem to have assumed that those words were directed at you and tried to hit back at me.

Even if you want to explain why civilian airlines crash less than fighter aircrafts, those stats would still be necessary. Since, I already provided the military crashes stats of IAF from minister of defence, now, someone needs to provide the number of civilian airline crashes in Bhaarath and then you can explain why such high/low percentage of difference exists between civilian and military airlines.

Then, someone can compare between military and civilian aircraft crashes for different countries to see if they show any deviation/peculiarity.

Otherwise, the whole exercise would just be opinionated rants without any substance/stats to back up the case.

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Re: Why civil airliners crash less often than fighter aircra

Postby shiv » 20 May 2015 09:10

One thing that is worth looking at is how and why civil airline travel has become so safe.

Without going into what i know of the history of civil airliners, I will just summarize one fact - that is over the decades since civil airliners came into widespread use, most of the usual causes of crashes have been discovered and measures taken to avoid them

Things like structural failure (aircraft structure not strong enough) or failure due to fatigue have been remedied or are kept under surveillance so that does not occur with any frequency nowadays in civilian airliners.

Engine failures are bypassed by having very good, very reliable engines that can function for thousand of hours without failure and by avoiding mechanical causes like bird hits or flying through a volcanic cloud.

That still leaves some more causes of crashes. One is the weather - severe atmospheric storms and turbulence can cause crashes. This is prevented by modern weather monitoring systems that warn of weather up ahead and by aircraft that ca simply fly above the weather in some cases.

Passenger aircraft are designed to be stable in flight. They are not required to perform violent manoeuvres for dogfighting or avoiding incoming missiles. Once a passenger plane climbs to its cruising altitude the flight is remarkably safe. It is very very rare for a flight to crash at any time after 20 minutes after takeoff right up to landing. Causes of such catastrophic mid-flight accidents in recent years have been bombs (Air India, Pan Am); missiles (Korean Air, Iran Air, Malaysian Air lines), collisions or pilot suicide. Some mystery crashes have occurred - but they are rare - like MH 570 and the Air France Airbus whose mystery crash was pinpointed to be icing up of sensors and pilot error following that

Crashes of passenger airliners do occur during takeoff and landing. These have been reduced to a very great extent. Planes with more than one engine all have the capability to continue to take off even is one engine shuts down (eg by a bird hit). Landing has been made much safer by instrumentation and good training. Still poor visibility and bad weather do lead to some crashes. There can also be unexpected events like wake turbulence from an aircraft that has just taken off, or a sudden downdraft. But these are uncommon - and that makes civilian flights very safe. I am a bit short of time now but will make a separate post to say why military flying ends up with so many more incidents/accidents

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Re: Why civil airliners crash less often than fighter aircra

Postby TSJones » 20 May 2015 09:20

Every civilian airliner part is built to a calculated mean time between failures and tested rigorously for it. And then it is never operated or used, close to its MTBF ratio. Everything is overbuilt in other words. Every bolt, nut, and piece of hardware. And then, it NEVER approaches its MTBF ratio, ever. Military jets do not have that luxury.

Sometimes its engines and sub systems must strain to operating capacity in order to survive in a hostile environment. sometimes you've got to have that military jet in the air regardless. you can't let it be a hanger queen. MTBF ratios are sometimes closely approached. Flight manuevers can be excruciating to the equipment and systems. The equipment are maintained by very young men sometimes in daunting environments. there may be very little careerism in the mechanics personnel like there are in the civilian arena which requires licenses. No license required to work on planes in the military. sometimes just OJT is deemed sufficient.

there are other reasons but i am not an engineer. I just worked on military jets for three years after going to tech class for year.

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Re: Why civil airliners crash less often than fighter aircra

Postby deejay » 20 May 2015 10:37

Before we look at why civil airliners crash less often than fighter military aircraft, I think an understanding as to why aircraft crash at all is necessary. I will again qualify this assessment of mine as that of some one with short exposures to both military flying and civilian commercial flight ops. I am also doing this to explain the issues and I may be incorrect in description to the 'T' if one would look at say NTSB (USA) or IAF's own assessment.

Aircraft crashes or accident / incidents are often looked at though the prism of 'Cause'. These are (in the military at least) split in to:

Human Error (Air Crew) or simply Pilot Error. There are further break downs of this.
Human Error (Technical / Engineering) or simply some wrong maintenance practices (Spanner left in the engine Nacelle)
Technical Failure - Breakdown in equipment, incorrect equipment operation, fatigue, now even Software malfunction, etc.etc.
Design / Manufacturing errors (rare, happens mostly in testing phase)
Weather (of course) and will put things like Bird Ingestion here along with FOD here as these are all part of Operating Environment.

Most military aircraft accident/incident would be categorised under Human Error (Aircrew) and the next in line is Human Error (Technical). I have heard people say that 'Man' is the weakest link in the chain. But I disagree.

Another important way to understand is in what / which phase of flight ops did the accident / incident occur:

- Ground Operations (Prior to take off or after landing run)
- Take Off
- Climb
- Cruise (Operational activity for military aircraft)
- Descent
- Landing

I do not have comprehensive data but it will be safe to say that ~90% of accidents / incidents happen in Take Off / landing phases or while operating close to ground. Accidents / Incidents in 'Ground Operations' phase are the most under reported.

As and when time permits and if it is OK to post on these lines here I shall try and elaborate these points to explain each point of view to a general reader. The idea is to finally get down to explaining why a military aircraft is more likely to be in a crash than a civilian airliner. In case there is a disagreement, please do post it and I will be happy to correct myself.

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Postby ArmenT » 20 May 2015 12:44

I remember reading something concerning this, written by some Lockheed big-wig (Ben Rich perhaps?) and he thought it had mainly to do with ground crew and maintenance issues.

He pointed out that USAF was much more inefficient than civilian contractors, when it came to maintaining the aircraft. As an example, he pointed out two airbases that had to service the same number and type of aircraft, one was staffed by an USAF crew, another with a bunch of workers from Lockheed under contract to the USAF. Apparently, just 8 Lockheed guys did much more than something like 50-60 USAF personnel and they had less mishaps. Mind you, we aren't talking two different types of aircraft, they were the same model and flown under the same conditions.

He thought the main reason was because when there were less personnel to go around (fewer cooks in the broth), communication was much smoother and errors were caught faster. Also, one more major factor he pointed out was that the Lockheed guys were all lifers (i.e.) they'd worked before on the shop floor for a while and had learned from all the most experienced technicians and engineers and were passing their knowledge on to the others, so they were all much more experienced. By contrast, most of the USAF ground crew were fresh faces out of high school, and most were going to leave after their enlistment period was done, thereby the next batch lost the institutional knowledge that they'd learned.

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Re: Why civil airliners crash less often than fighter aircra

Postby Gagan » 20 May 2015 16:16

I think we have an overwhelmingly russian fleet, which are still built the way things were built back in the 60s-70s. With poor build quality.
On top of that we have problems with spares supply, these old gen aircraft are not very servicable.
I think that the IAF engineers do a splendid job.

I think we can differentiate between crashes of the older gen aircraft vs the newer gen ones - say Mirage 2000 onwards in IAF service.

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Re: Why civil airliners crash less often than fighter aircra

Postby shiv » 20 May 2015 16:38

Thanks deejay - your inputs would be invaluable here. I think no one in India has bothered to point out to the public that military flying is not the same as civilian flying and that the former has some inherent risks - so the first thing for the public, and particularly the media is to understand that there is no special stupidity or incompetence in the Air Force leading to accidents - it is in the nature of the job.

While I await further inputs from you I will carry on with what I have been meaning to say

Technically all flight can be divided up into three phases - and each of these phases has some special causes of accidents
1.Take off
2 Cruise (LOL - only civil airliners and military transports have the luxury of a middle "cruise" phase)
3.Landing

1. Take off: Military aircraft are often single engined and if there is a bird strike during takeoff the plane will have no power to climb and will likely crash unless the pilot has not left the ground and is able to abort takeoff. With over 70% of our air force fighter fleet having been composed of single engines at one time - quite a few crashes have occurred due to this. There was also a famous MiG 29 crash at an airshow because of bird ingestion.

2. Only civil airliners are required to climb to a comfortable altitude and cruise up there until very near the destination. Military aircraft are flown by people who are practising for war. they may take off and land in darkness or in poor weather/poor visibility. they may have to fly at treetop level. they have to put the aircraft through manoeuvres (like High G turns) that can lead to disorientation and even brief loss of consciousness. Passenger planes on commercial flights probably do not even exceed 1.5G. Unless the pilots get drunk or faint, nothing about the flight should make them lose consciousness or even grey out for a short while. The airframes are put through far greater stresses so fatigue life of the airframes can be affected by unusual stresses. Military engines are constantly made to change power settings - they are revved up to max power, flown at very high power levels and rapid changes of power are done leading to greater wear and tear. civilian airliner engines are taken through their paces at a a controlled rate - and the power setting is not changed much during many hours of cruise flying. So in the case of military flying both man and machine have a greater chance of failure because of the circumstances of military flying.

Finally landing again is different for military jets. Landing speeds are higher and pilots have to hurtle down towards the ground. they have to practise landings under adverse circumstances. A peacetime airports radiates light and other EM waves that make it easy to be recognized and for planes to home in. Air bases preparing for war like scenarios will not offer such luxuries to the landing pilot.

Even a 1 hour sortie that goes through high Gs can leave a pilot physically stressed - especially in older aircraft where the pilot has to do flying, navigation. manoeuvring and weapon delivery. Helicopter operations have their own risks and I think deejay will be able to say the sorts of things that helo pilots have to do that no one else on earth is required to do.

The long and short of it is that military flying is inherently more stressful and risky for man and machine. If you air force flies rather than practicing on the ground - then there will be more crashes than in civilian flying. That does not mean that the vayusena accepts this philosophically. Every accident is carefully analysed to try and see if they can come up with a cause. Unfortunately when no cause can be found and the pilot is dead the conclusion is put as "pilot error". When lay media read such reports they think bums are being sent up to fly. But its the media and public who are bums because they don't have a clue. How do you take a million pieces of burnt and broken aircraft and piece together the exact circumstances of the crash. yet this is done and many stories have been posted right here in BRF - but there are very few dedicated aviation enthusiasts who have spent time trying to read and understand. i will post the stories I can link and relate stories I know. Long ago I had tried to get these same points across when I started the thread called "military flight safety. Today,on this thread, I am informed that no thread exists for discussing flight accidents :shock: In general we are all too clever here. Some of the most knowledgeable contributors have been driven off by our cleverness. One such person with decades of experience under his belt was Abhibhushan or Air Cmde (retd) Tikoo Sen His blog has some interesting stories. Will link that and others by and by.
Last edited by shiv on 20 May 2015 16:47, edited 1 time in total.

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Re: Why civil airliners crash less often than fighter aircra

Postby shiv » 20 May 2015 16:45

[quote="deejayI do not have comprehensive data but it will be safe to say that ~90% of accidents / incidents happen in Take Off / landing phases or while operating close to ground. Accidents / Incidents in 'Ground Operations' phase are the most under reported.

As and when time permits and if it is OK to post on these lines here I shall try and elaborate these points to explain each point of view to a general reader. The idea is to finally get down to explaining why a military aircraft is more likely to be in a crash than a civilian airliner. In case there is a disagreement, please do post it and I will be happy to correct myself.[/quote]
deejay all inputs from you will be greatly appreciated

meanwhile let me post a brilliant story..

http://www.bharat-rakshak.com/IAF/histo ... -nose.html

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Re: Why civil airliners crash less often than fighter aircra

Postby shiv » 20 May 2015 16:49

Gagan wrote:I think we have an overwhelmingly russian fleet, which are still built the way things were built back in the 60s-70s. With poor build quality.

Gagan have you looked at the accident rate of Il 76 and An 32. Also Russian. Rusian per se is not the problem although that conclusion is sure to please some groups of people

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Re: Why civil airliners crash less often than fighter aircra

Postby NRao » 20 May 2015 17:00

More safety is built into a civilian air craft - such as they can glide (for some distance) and do not fall like a brick out of the sky. Engines and pretty much all systems are designed and tested with safety in mind.

Military air crafts are designed with more risks, with far more dependency on things like maintenance.

It is relative. Have the military guys design, build, test, etc with more safety, things should be different. But a military craft with the safety of a civilian will cease to be a military craft.

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Re: Why civil airliners crash less often than fighter aircra

Postby Gagan » 20 May 2015 17:07

shiv wrote:
Gagan wrote:I think we have an overwhelmingly russian fleet, which are still built the way things were built back in the 60s-70s. With poor build quality.

Gagan have you looked at the accident rate of Il 76 and An 32. Also Russian. Rusian per se is not the problem although that conclusion is sure to please some groups of people

IL 76 has 4 engines
AN32 is a turboprop - they traditionally have simpler engines, much much less prone to mechanical failure.

I discount the weather and difficult terrain they work with.
AN 32s, helos that operate in high mountains with unpredictable wind gusts, bad weather crash more frequently than other aircraft.

Civilian aircraft don't fly when there is inclement weather.
Military aircraft fly 24x7, weather be damned sometimes.

Civilian aircrat never fly fast and low, fighters and transporters do that all the time. And on top of it if there is a mechanical failure, there is a very miniscule window for recovery.

With the older gen russian aircraft, upto the Mig - 27, these were designed back in the 60s. Older tech, older metullrugy, more prone to failure. These are illfitting into the demands of 21st century military aviation. The IAF is still flying them, but ideally they should not be.

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Re: Why civil airliners crash less often than fighter aircra

Postby NRao » 20 May 2015 17:17

^^^^^

You have a point about normalization.

However, even if one were to stick to one manufacturer (say Boeing), very same era (say 1990-2000), etc, etc, etc, the military air craft is not designed with the same mind set as the civilian. So, gliding is one, how about hard landings, short landings, etc. It is in the design phase itself that the risks are higher with a military craft - since it is expected to do things that a civilian is not.

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Re: Why civil airliners crash less often than fighter aircra

Postby Philip » 20 May 2015 17:17

I've just posted the link to global aircraft accidents.Looking at the stats,most are civilian types,but predominantly more light aircraft than airliners. WE should have similar stats/database for all Indian air accidents,along with the official reasons.

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Re: Why civil airliners crash less often than fighter aircra

Postby NRao » 20 May 2015 17:23

Philip wrote:I've just posted the link to global aircraft accidents.Looking at the stats,most are civilian types,but predominantly more light aircraft than airliners. WE should have similar stats/database for all Indian air accidents,along with the official reasons.


where did you post it?

And, I bet this "stat" ("most are civilian") you talk of is skewed. "predominantly more light aircraft" gives the "stat" away (light air crafts, perhaps, are not maintained as well as airliners are).

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Re: Why civil airliners crash less often than fighter aircra

Postby Philip » 20 May 2015 17:32

Oh please! Do you have anything worthwhile to contribute? Hunt the stats out for yourself from the link in the Su-30 td.

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Re: Why civil airliners crash less often than fighter aircra

Postby NRao » 20 May 2015 17:56

Not a good site (as I had expected) (it is a wiki and self administrated), however:

http://aviation-safety.net/graphics/inf ... c_2014.jpg

The web site (posted in the Su-30 thread!!!!) states:

The number of fatal airliner (14+ passengers) hull-loss accidents and fatalities per year is given. The figures do not include corporate jet and military transport accidents/hijackings.


So, it is skewed.

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Re: Why civil airliners crash less often than fighter aircra

Postby shiv » 20 May 2015 19:46

I once read an article written by an IAF transport pilot - and I think his statement was in humour and partly tongue-in-cheek. he claimed "We transport pilots are not under the sort of pressure to keep flying like pilots of civil airliners. If something is not 100% right we just postpone the flight"

But the IL 76 has a good safety record.

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Re: Why civil airliners crash less often than fighter aircra

Postby deejay » 20 May 2015 20:57

shiv wrote:...

meanwhile let me post a brilliant story..

http://www.bharat-rakshak.com/IAF/histo ... -nose.html


Shiv Sir! It is a brilliant story. Dettachment for 03 months at Chakbama. Oh My God!.

Thank You, for sharing it. It sounded very familiar, separated by time. The rum cost around Rs. 2.50 a large in my time.

NRao
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Re: Why civil airliners crash less often than fighter aircra

Postby NRao » 20 May 2015 21:11

Data point:

Jun, 2013 :: 'Least safe' aircraft models revealed


And make sure to read the comments.

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Re: Why civil airliners crash less often than fighter aircra

Postby Jagan » 21 May 2015 04:26

Philip wrote:I've just posted the link to global aircraft accidents.Looking at the stats,most are civilian types,but predominantly more light aircraft than airliners. WE should have similar stats/database for all Indian air accidents,along with the official reasons.


Guys (And not just philip) where have you all been? ;)

http://www.bharat-rakshak.com/IAF/datab ... dents.html

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Re: Why civil airliners crash less often than fighter aircra

Postby UlanBatori » 21 May 2015 06:47

To quote Alistair MacLean:
A DC-9 without engines has the gliding characteristics of a block of concrete

Military planes have higher risk for several reasons.
a. Fighter planes (of most interest here) are jet planes, designed for high "wing loading" (W/S, weight divided by wing planform area). High W/S is essential, because you don't want large, long wings, which make roll and other maneuver performance poor and sluggish. Since W/S = Lift/S = 0.5(density)(speed^2)(Lift Coefficient), if speed is low, you have to have a high lift coefficient - danger of stall. Also, high lift coefficient means high drag coefficient, so you lose speed rapidly. IOW, you can't glide very far. Drag coefficient induced by lift ~ (lift coefft^2)/(Pi*AR) where AR is aspect ratio, (wing-span^2/AreaS), which is also quite small for fighters (say 4 vs. 8 or 10 for civil airliners). So as lift coefficient rises, drag rises very fast.

Unlike today's civil airliners which have at least 2 engines, many fighter planes have only one engine.

If an engine fails, these planes are in big trouble. You have to try to glide to a landing. The lowest speed at which you can obtain any decent amount of lift, is still quite high because your wings are pretty small. So chances of a soft landing are remote, and the distance that you can glide is small.

Stability margin: Civil airliners are made to be stable. Center of gravity is far forward, well ahead of the center of pressure. This also makes them hard to maneuver. Fighter planes are close to being neutrally stable, in order to make them uber-'controllable', and modern ones like LCA are statically unstable, (I think, unless it has a canard) and computer-augmented.

So if things get bad, they are pigs to try to control. Rapidly go into wild yaw/roll/pitch aka stall and spin.

b) Military Transports: Military planes have to go in and out of dangerous places, on short notice. Pilots may lose their way (remember all the airline pilots landing at Juhu Beach instead of MUM?)

c) Military Helicopters: Tail rotor may touch something (finis) or engine might fail due to all sorts of reasons, maybe dust and leaves entrained, whatever.

BTW, check out the accident rates for "General Aviation" meaning small non-airline planes which are used by private parties for trips to all sorts of places, often at short notice. Bizjets, prop planes etc. That is the more apt comparison.

BTW, if there are 2 engines, the general rule is that the plane can take off if one engine fails. Which is why I find the story of the HF-24 crash as written on the BR site to be a bit less than credible. The Group Captain claims that his best test pilot Suranjan Das did not observe check-lists (he forgot to close the canopy!!!!!) AND that one engine failed during the takeoff. Which should still have allowed the pilot to get the plane into the air. So why did it crash? The story doesn't compute. I claim that there is some reason to believe that the Group Captain participated in a slight altering of reality to cover the backsides of others, putting the blame on the dead pilot.

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Re: Why civil airliners crash less often than fighter aircra

Postby Kannan » 21 May 2015 08:35

UlanBatori wrote:To quote Alistair MacLean:
A DC-9 without engines has the gliding characteristics of a block of concrete

Military planes have higher risk for several reasons.
a. Fighter planes (of most interest here) are jet planes, designed for high "wing loading" (W/S, weight divided by wing planform area). High W/S is essential, because you don't want large, long wings, which make roll and other maneuver performance poor and sluggish. Since W/S = Lift/S = 0.5(density)(speed^2)(Lift Coefficient), if speed is low, you have to have a high lift coefficient - danger of stall. Also, high lift coefficient means high drag coefficient, so you lose speed rapidly. IOW, you can't glide very far. Drag coefficient induced by lift ~ (lift coefft^2)/(Pi*AR) where AR is aspect ratio, (wing-span^2/AreaS), which is also quite small for fighters (say 4 vs. 8 or 10 for civil airliners). So as lift coefficient rises, drag rises very fast.


I think you're over thinking things here. A 747 is more highly loaded than a fighter jet... I don't think there's a correlation between loading and flight risk. Fighter jets have ejection seats, so the certification process doesn't impose the same glide characteristics. This is why the hotshots flying L-39s and MiG-15s in the States are doing some risky business flying a brick attached to an engine with an unserviced ejection seat.

Unlike today's civil airliners which have at least 2 engines, many fighter planes have only one engine.

If an engine fails, these planes are in big trouble. You have to try to glide to a landing. The lowest speed at which you can obtain any decent amount of lift, is still quite high because your wings are pretty small. So chances of a soft landing are remote, and the distance that you can glide is small.

Stability margin: Civil airliners are made to be stable. Center of gravity is far forward, well ahead of the center of pressure. This also makes them hard to maneuver. Fighter planes are close to being neutrally stable, in order to make them uber-'controllable', and modern ones like LCA are statically unstable, (I think, unless it has a canard) and computer-augmented.

So if things get bad, they are pigs to try to control. Rapidly go into wild yaw/roll/pitch aka stall and spin.

b) Military Transports: Military planes have to go in and out of dangerous places, on short notice. Pilots may lose their way (remember all the airline pilots landing at Juhu Beach instead of MUM?)

c) Military Helicopters: Tail rotor may touch something (finis) or engine might fail due to all sorts of reasons, maybe dust and leaves entrained, whatever.

BTW, check out the accident rates for "General Aviation" meaning small non-airline planes which are used by private parties for trips to all sorts of places, often at short notice. Bizjets, prop planes etc. That is the more apt comparison.

BTW, if there are 2 engines, the general rule is that the plane can take off if one engine fails. Which is why I find the story of the HF-24 crash as written on the BR site to be a bit less than credible. The Group Captain claims that his best test pilot Suranjan Das did not observe check-lists (he forgot to close the canopy!!!!!) AND that one engine failed during the takeoff. Which should still have allowed the pilot to get the plane into the air. So why did it crash? The story doesn't compute. I claim that there is some reason to believe that the Group Captain participated in a slight altering of reality to cover the backsides of others, putting the blame on the dead pilot.


It's really as simple as people before mentioned it - military aviation explores parts of the envelope civil aviation doesn't reach, and is insured by the government whereas typical civilian operators are governed by insurance. Most countries split their aviation into general aviation, scheduled transport, and chartered transport. Even that isn't a totally fair way to compare because medevacs, firefighting aircraft etc. are lumped in under general aviation, along with private aviation departments of major companies, i.e if John Deere owns its own planes, and private aviation.

Charters typically face a lot of get-there-itis whereas a similar operation done by a private aviation department for its own employees (i.e not public carriage) have dramatically different accident rates - employee pilots are less prone to being pressured into making stupid/risky decisions.

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Re: Why civil airliners crash less often than fighter aircra

Postby shiv » 21 May 2015 08:49

Here is a classic example of how the media jump the gun to create a false image of what happens after aircraft accidents. Naturally the public swallows such stuff whole and imagines that the IAF is crashing all the time - even when they land on a highway as a test.

As soon as an Su 30 crashed someone assumed that the Astra missile test would be postponed as Sukhois will all be grounded
http://idrw.org/sukhoi-snag-hits-astra-testing/

It turns out that there were not grounded this time
http://idrw.org/astra-test-fired-while- ... -maneuver/

Are all fighters grounded as soon as one carshes?

No.

If it is a mystery crash, an unexplained one - they will be grounded for checks. In rare instances pilots who have bailed out may be able to say exactly why the plane went down (eg he may have radioed "bird hit"). In such instances a court of enquiry is set up as usual - but the entire fleet need not be grounded.

If you keep on reading the reasons for accidents - you soon learn which ones may have been related to the pilot, which one to weather and which one to other causes.

For example - just before Vayushakti (2010 I think) a bomb exploded on the bomb rack of an Su 30. Sukhois were not grounded. They flew in the show but did not drop those bombs

In another case there was a fire in the engine of the Su 30. All were grounded and I am not sure what the findings were - may have been "fuel hose clip had not been replaced" or some such thing. I am guessing here.

One early Su 30 crash was when the Flight Control software shut down (or was accidentally shut down because of its proximity to another switch)

At least one (maybe two) accidents occurred from unexplained firing of the ejection seat. Actually I think there were 3 accidents. One was a flying Su 30 and two on the ground.

So the actual causes of accidents can be many and reaching premature conclusions is wrong. Now tell me how many civilian airliners have to have malfunctions in their bombs or ejection seats as a cause of crash.

We all probably recall a MiG 29 that went down in the Himalayas a few years ago. The wreckage was not located for a long time. That was put down to a combination of bad weather and pilot disorientation.

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Re: Why civil airliners crash less often than fighter aircra

Postby shiv » 21 May 2015 08:51

Kannan wrote:
UlanBatori wrote:T
a. Fighter planes (of most interest here) are jet planes, designed for high "wing loading" (W/S, weight divided by wing planform area).


I think you're over thinking things here. A 747 is more highly loaded than a fighter jet... I don't think there's a correlation between loading and flight risk.

er - "wing loading", not loading.

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Re: Why civil airliners crash less often than fighter aircra

Postby shiv » 21 May 2015 08:59

If one is really interested in military aviation rather than for timepass shoot and scoot - an idea of the complexity of a military aircraft and how problems can occur is described in this story.

I know that there will be people who will not read this fully and say "How come this never happened to anyone else?" My advice to such a person would be "Become a defence reporter. You will have a great future ahead of you if you can reach conclusions without knowledge and keep the public in an embrace of mutual dumbness"
https://tkstales.wordpress.com/2011/06/ ... -aircraft/

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Re: Why civil airliners crash less often than fighter aircra

Postby TSJones » 21 May 2015 10:06

So why did it crash? The story doesn't compute. I claim that there is some reason to believe that the Group Captain participated in a slight altering of reality to cover the backsides of others, putting the blame on the dead pilot.


In a non-combat fatality, they will step on the pilot's ashes every time.

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Re: Why civil airliners crash less often than fighter aircra

Postby Philip » 21 May 2015 11:00

Just for the record of MKI production and signal achievement of greater indienous production right from the raw material stage,local overhauls,and BMos upgrade.

http://defense-update.com/20150216_su30 ... V144suJhjp

Su-30MKI are made in India
Feb 16, 2015
IRKUT Corporation of Russia will complete deliveries of Su-30MKI aircraft kits to Hindustan Aeronautics Limited (HAL) this year. By that time, IRKUT Corporation will have successfully delivered 222 aircraft kits for assembly at (HAL) Nashik plant, Irkut announced today.

Currently HAL is manufacturing parts from the raw material stage with complete transfer of technology from IRKUT Corporation under Phase IV of the assembly. HAL has also mastered the overhaul of Su-30MKI program and delivered the first overhauled aircraft to the Indian Air Force (IAF) at the end of 2014.

IRKUT supplied the overhaul equipment and assisted in their installation at HAL. The Russians also shared their experience in such work. IRKUT Corporation is happy to state that HAL and several Indian companies involved in the Su-30MKI program have mastered the technology of manufacturing many complex parts and assemblies of this front-line fighter aircraft.

Going forward, Irkut and HAL are planning to embark on an upgrading program of India’s Su-30MKI aircraft, with the integration of the Brahmos supersonic cruise missile. This upgrade will be undertaken by HAL in India. Forecast International analysts estimate the cost to integrate the BrahMos on India’s Su-30MKIs at around $50 million, which includes reducing the munition’s weight and performing some additional structural modifications to the aircraft itself.

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Re: Why civil airliners crash less often than fighter aircra

Postby tsarkar » 21 May 2015 13:45

Last weekend, my friend who is a British Airways Boeing 777 commander lamented that airline flight is on well define fight paths with numerous air traffic controls tracking progress, and transponders monitoring the slightest deviations, with controlled and highly instrumented take off and landings and rigorous planning by operations on routes, backed by weather & other data. The pilot & co-pilot is mostly there for contingencies. Infact, for cost control reasons, most pilots these days are cabin & ground crew given pilot training by the airline to save costs. Pilot salaries have fallen significantly.

Fatality statistics will confirm that air travel is safer than cars/roads that lack such high levels of automation.

Very different than military flying when one flies into the danger zone.

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Re: Why civil airliners crash less often than fighter aircra

Postby Atri » 21 May 2015 14:57

I do not know much - but aren't fighter aircrafts designed to be unstable?

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Re: Why civil airliners crash less often than fighter aircra

Postby UlanBatori » 21 May 2015 16:20

military aviation explores parts of the envelope civil aviation doesn't reach,

Most crashes occur during takeoff. A few during landings (OK, ALL occur during landings, sorry! :( )
To quote the mantra of the aerospace profession:
The Optimist fell ten storeys
At each window bar
He called out to his friends:
ALL RIGHT SO FAAAAAR!


Most frequent cause is that the engine failed. I know of one case where both engines of an SU-27 failed when they ingested the exhaust from missiles being launched (or maybe guns being fired, or going through the debris cloud of a bombing exercise). 2-engins may be safer, but if one engine explodes or catches fire and it is an internal engine like on fighters, it is going to take out the other one too. So I guess one engine failure is fatal to even 2-engined fighters, and since there are 2 engines instead of just one to fail, perhaps the crash probability is doubled.

Regarding wing loading, yes it is different from 'loading'. :mrgreen: As I explained above with equations and all.

It is in fact true that a 747 in cruise configuration has a wing loading not far from that of a fighter plane (something like 120 psf - these are optimized for the expected flight speed and altitude), but at landing with flaps extended, the wing loading is far lower, so landing speed is brought down to near 160mph or so.

Naval aviation is always dangerous - every takeoff and landing is a high-G, high-adrenalin 'event' and many times goes wrong. I tried that on a simulator - no hope of even finding the proper height of the deck unless I had some 'guiding beam'. I have no idea how they do that. I guess it beats having the ship sunk by enemy bombs.

The real story on 'safety' becomes clearer, like I said, when you compare General Aviation with Military Aviation. I think military is safer by a wide margin there. Practically every day one reads of General Aviation fatal crashes. A week ago one crashed on the highway around a big US city, circa 9:30 AM on a weekday, after losing power following takeoff from the nearby. No one on the highway was hurt, but the 4 occupants were gone in a flash - all that was left was a small pile of burnt wreckage. Highway hosed down inside 3 hours, everything back to normal except for the victims' families - and insurance companies, I suppose. They were headed for their grandson's graduation from a university, all family members.

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Re: Why civil airliners crash less often than fighter aircra

Postby UlanBatori » 21 May 2015 16:27

tsarkar wrote:Fatality statistics will confirm that air travel is safer than cars/roads that lack such high levels of automation. Very different than military flying when one flies into the danger zone.


True, but also consider the statistics for fatal bus crashes vs. fatal automobile or motorcycle crashes - buses are much safer. Not to people outside the bus if we are talking about KSRTC, :eek: but to people inside - even though I don't know of any buses that insist on everyone wearing seat belts.

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Re: Why civil airliners crash less often than fighter aircra

Postby NRao » 21 May 2015 16:37

IF the discussion is about "Why civil airliners crash less often than fighter aircraft", then one does not need to read much: it is a matter of "risk" (or as another poster called it "insurance") - thus the "designs" of the two differ.

For "how" it is achieved, one needs to read up. "Why" really does not need reading.

(All that IMHO of course.)




OK, for filing under "stats", the recent A-400 crash in spain:

Airbus warns of engine bug after A400 crash

Add software bugs to the list of why they can crash.


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