Helicopter ejection seats [Archive]

Lu Zuckerman

28th Jan 2002, 19:31

To: Vfrpilotpb

The problem with the use of explosive bolts to sever a rotorblade from the rotorhead is that the reliability of the explosive bolt would have to be 1. This would require multiple squibs, multiple firing paths and multiple explosive charges. Also required is the correct material in the bolt to make it 100% frangible 100% of the time. If there were a slight delay in the firing of the squibs in the bolts attaching one blade the ensuing vibration / out-of-balance would tear the helicopter apart.

Regarding ejection seats in helicopters the first Cheyenne flight vehicle had an ejection seat. It was downward firing and saw service in a Boeing B-47. On the one flight where it could have been used the helicopter was too close to the surface of the Pacific Ocean to be of any use. The helicopter suffered rotor incursion killing the pilot.

The Robinson does not need a system of explosive separation of the rotor system from the helicopter. If the helicopter is mishandled the separation will occur automatically.

MightyGem

28th Jan 2002, 21:24

The one in the programme was Russian, Peter.. . <img src="wink.gif" border="0">

NigD

29th Jan 2002, 02:17

Excellent programme,some toe curling after effects of ejection and some ingenious engineering.

The g-testing bloke with the bloodshot eyes looked like he'd been out with PLH the night before!!

RW-1

29th Jan 2002, 02:24

"Yes, it's true, the ejection seats work well. Those blade synchronizer issues are merly rumours ...". . - Cdr. "Stump" Johnson. . Heli Test Pilot

Dave Jackson

29th Jan 2002, 02:41

Sorry RW-1

When the pilot ejected, he took the posting before yours with him.

The following is an attempt at piecing together this shredded document. <img src="smile.gif" border="0">

[quote]What about ejecting the pilot through the rotor disk, just like some of the WWII fighter plane fired their machine guns through the propeller?<hr></blockquote>

widgeon

29th Jan 2002, 05:21

I guess its ok for Mil types to have bits come off but for civil aircraft is there some FAR that says you should not have parts detatch even in emergency ?.. .What ever happened with the emergency chute for light aircraft I once saw advertised ?.

Lu Zuckerman

29th Jan 2002, 05:45

To: widgeon

The FAA requirements for a single point failure that would cause death or the loss of the aircraft and its' crew / passengers is 1 10-9 or one time in a billion hours of fleet operation.

That would lead you to believe that the aircraft is very safe. However on complex designs there may be 20-30 or more items that if they failed it would result in catastrophic loss of personnel or the entire aircraft. Let's take those 30 items and divide them into the 1 10-9 requirement and you get 33,333,333 hours of fleet operation. Now you add in failures caused by manufacturing defects or maintenance errors or overstress by the pilot in maneuvering and the time between failure drops even further. The FAA requirement is meaningless and the engineers are yet to meet that requirement. The product assurance group cooks the numbers in order to meet the requirements. The loss of the rudder on the AA A-300-600 had the 1 10-9 requirement and it failed long before the meeting of the 1 10-9 allowable failure rate. S-76s lost rotor blades and a BV 234 was lost due to a defect in the transmission design long before the respective helicopters accumulated 1,000,000,000 hours. It gets worse on commercial aircraft because of fleet size and the rate of accumulation of hours. I could go on and on but I think you get the Idea. This is the reason I don’t like to fly any more.

Ed Winchester

29th Jan 2002, 07:02

Lu,

If flying worries you that much, I presume that you also don't drive; a much more hazardous sport (especially in Quebec!).

I would imagine that the reliability of the components of any ejection system (not just rotor seperation charges) would need to be 1. It is, after all, the last resort, and failure of the system is likely to lead to a Pk of 1. <img src="eek.gif" border="0">

Lu Zuckerman

29th Jan 2002, 19:50

To: Ed Winchester

Here is an example why I don’t like to fly although if I have to I will. Shortly after submitting a design deficiency report to my boss, relative to the wing of the A-310 and A-300-600, explaining that under certain conditions the wing would either explode of struck by lightning or if there was an internal failure of the flap PCU it would result in the flaps ripping off of a supercritical wing causing loss of the aircraft I had to fly to England for a meeting at BAe. I drove to Zurich (Cloten) and got on a Swiss Air airplane. To my good luck it was an A-310. The whole flight was of the white-knuckle variety. I got a chance to sit up front with the flight crew and I told them about the problems. When I left the flight deck the pilots were blankly staring out the windows.

On my present assignment I had to fly on an A-330 shortly before the Air Transat dead sticked into an island airport.

Regarding driving I do a lot of that to include trips of several thousand miles each way when going on a work assignment. Quebec is another story. In a conversation with an acquaintance I told him that in the United States they teach defensive driving. He asked what that was and I gave him the following example. In the USA they teach you to drive defensively by imagining that behind every corner there would be a big green truck and it would be partially in my lane. I was taught to consider that eventuality under all circumstances. The Quebecer asked the significance of the green truck and I told him that in Quebec everybody drives green trucks.

Agaricus bisporus

29th Jan 2002, 23:56

Lu, if your remark re the BV234 refers to G-BWFC then I wish to take issue in the strongest possible terms.

Fox Charlie was lost as a direct result of a modification involving engineering procedures ordered by the CAA in an attempt to rectify a percieved yet non existant problem that had already been pre-empted by local engineers, with, if memory serves, the approval of the manufacturer, Boeing Vertol. The engineering defect was not Boeing's. It was that "fix" that killed 46 people.

Not really the fault of the aircraft in this case!

[ 29 January 2002: Message edited by: Agaricus bisporus ]

Lu Zuckerman

30th Jan 2002, 00:22

To: Agaricus bisporus

Hopefully we are addressing the same accident. In the accident I referred to there was a failure of a retaining device in one of the transmissions and the part entered into the gear mesh. This caused a catastrophic failure in the synchronizing (shaft running between the combining box and one of the transmissions).

I am not sure but I believe it was the failure of a part of the planetary gear reduction. This part was a retaining device (similar to a nut) that applied a clamping load to the axis of one of the planetary gears. The design of the part had been modified but was not fully tested. It should be noted that the original design of the transmission system was on the CH-47, which required a plethora of tests to include accelerated exposure to a salt-water environment. The new design was not tested in accordance with the original design specification to include operation in a salt environment.

In the operation of the gearbox heat is generated and when the helicopter shuts down the heat dissipates and cool air will enter the transmission. If operating in a salt-water environment the air entering the gearbox will have salt entrained along with moisture from the surrounding environment.

The old part was designed so that the moist salt entrained air could not penetrate into the clamping surface. With the new design the moist salt laden air could enter this area and it eventually caused salt induced corrosion. This lead to the eventual failure which resulted in the crash.

Lawsuits were filed in England but the English lawyers hired an American firm to try the case. Boeing was sued along with the chief engineer and the design manager of the transmission design group who approved of the design.

At least that is what I heard from Boeing employees and from an organization that I belong to.

[ 30 January 2002: Message edited by: Lu Zuckerman ]

turboshaft

30th Jan 2002, 17:19

The five-blade rotor desciption doesn't fit, but the Russian 'bang out' helicopter is the Kamov Ka-50 (3-blade co-axial rotor). The following comes from Jane's:

"Specially designed Zvezda K-37-800 ejection system for safe ejection at any altitude; following explosive separation of rotor blades and cockpit roof, pilot is extracted from cockpit by large rocket; alternatively, he can jettison doors and stores before rolling out of cockpit sideways."

T/shaft

Jed A1

30th Jan 2002, 17:35

The system would have to have a reliability of one! Get real. Tell me a system that is that reliable.

Ordinary ejection seats aren't. That is why they have canopy breakers on the top in case the MDC fails to shatter the canopy or the canopy fails to jettison.

A helicopter system could have that kind of redundancy i.e. a way of going through the blades if they fail to come off!

The top and bottom of it is, that anything is worth a try once you get into a situation which is that terminal.

Ask yourselves how many people have failed to survive a normal ejection! That doesn't put me off sitting on a bang seat.. . <img src="smile.gif" border="0"> <img src="eek.gif" border="0">

Lu Zuckerman

31st Jan 2002, 01:29

To: Jed A1

“The system would have to have a reliability of one! Get real. Tell me a system that is that reliable”.

Response:

You have made my point. Engineers have yet to design anything that has a reliability of 1 with the exception of an un used anvil but even that would eventually fail long before reaching one billion hours. In the case of the explosive bolts there would have to be multiple redundancy within the firing circuits and a means of testing the circuit prior to flight. The conventional thinking in the field of reliability and safety is if something has not failed in the first hour of operation then it should not fail in the second hour or the third and every hour after that until it reaches the limitation of 1 10-9 and at that time it is predicted to fail. If one of the elements fails prior to 1 10-9 then the next failure can not occur prior to the expiration of one billion hours of operation.

Take the Ballistic Missile Defense System proposed by Dubyah. This system has to have a reliability of 1 otherwise a ballistic missile could impact Los Angeles or New York. It must also hit the target with its’ high powered LASER because if it is off by a 10th of a degree it could turn a lot of people on earth to toast. The system is made up of millions of parts and must have multiple redundancy in order to reach the reliability goals but this design concept is yet to turn out a device that has a reliability of 1. When the blades are commanded to blow off then they must blow off otherwise all is lost. The same goes for the interception of a ballistic missile or a reentry vehicle.

“Ordinary ejection seats aren't. That is why they have canopy breakers on the top in case the MDC fails to shatter the canopy or the canopy fails to jettison. . .A helicopter system could have that kind of redundancy i.e. a way of going through the blades if they fail to come off”!

Response:

The canopy breakers are worthless if the seat does not fire. The canopy breakers are there because the designers can’t guarantee that the explosive charges will work or the canopy does not jettison because of a reliability and safety related failure.

Here is an example. The Saturn IVB (the upper stage on the Saturn Apollo boost vehicle) was predicted to have a reliability of 5 Sigma or .99999 where perfect is .999999999999. Even with this high reliability Douglas only predicted a confidence factor of 70% that it would achieve the goal of 5 Sigma. That was the highest. Just think about the two stages below the S IVB. The only people not in attendance when these figures were being discussed were the Astronauts.

A point to ponder: 1 10 9=114,155.25 years.

helmet fire

31st Jan 2002, 02:55

Lu,

I will try and find the reference in a week or two, but I am pretty sure that it says something like this:

You would have to catch a commercial airliner every day for 26,000 years to gaurantee being involved in a fatal accident.

Flying a commercial airliner is 9 times safer than driving a car.

It seems you believe the media beat ups too.

BTW, if it was such a life threatning fault with the Airbus, why on earth would you have gotten on board? <img src="eek.gif" border="0">

Lu Zuckerman

31st Jan 2002, 07:58

To: helmet fire

“You would have to catch a commercial airliner every day for 26,000 years to guarantee being involved in a fatal accident. Flying a commercial airliner is 9 times safer than driving a car”.

These types of statements are based on the party line put out by all of the airlines and are based on seat miles traveled. Here is an example. Airline A has thirty aircraft that are capable of carrying 200 people. Each of these aircraft flies full from LAX to JFK and return a distance of 6000 miles.. .Each aircraft makes one round trip a day. Each trip takes a total of 9 hours round trip. In one day they accumulate 72,000,000 million passenger seat miles. In one month they accumulate 2,160,000,000 passenger seat miles. In one year they accumulate 788,400,000,000 passenger seat miles. On the last day of the year they lose one aircraft and 200 passengers plus crew due to the failure of a single part. In their advertisement they state proudly that they have had only one major accident and having flown 788,400,000,000 passenger seat miles. However they have accumulated only 98,550 flight hours on the 30 aircraft. The FAA states that the loss of an aircraft or death to a single passenger caused by a single point failure can occur no more frequently than 1 10 9 flight hours for the fleet or one time in a billion hours.

As I indicated in my post above there are many single point failures that have downed aircraft and they occurred long before the respective fleets had accumulated 1,000,000,000 hours of operation.

Here is another way the FAA obfuscates the truth about the calculated safety of an airliner. Hopefully you have some knowledge of a Fault Tree Hazard Analysis. It consists of and gates and or gates that represent different elements of a given system. The place these various gates in a logical order so that it can be shown how the elements of the system are related to each other when the system / systems are operational. In every case the top gate in every system is a “and” gate which means that several things have to occur at the same time for the system to fail. Using Boolean Algebra it can be “Proven” that the system has a predicted rate of failure of 1 10 12th or up to 1 10 17th. The problem is that if any one of these systems fails you lose the aircraft so, to truly represent the operational safety of the aircraft as a total entity each system must migrate upward to an “or” gate. Using the same Boolean Algebra it can be shown that the aircraft as a total entity has a failure probability of less than 1 10 9th. The FAA regs. do not require the last step as to do so would indicate that the aircraft is not as safe as they state in the regs.

Nick Lappos

31st Jan 2002, 22:42

Vfrpilotpb,. .That film is of the Sikorsky/NASA Rotor System Research Aircraft (RSRA) an experimental flying wind tunnel that was built in the 1970's. It had an S-61 rotor system (5 blades) and the fuselage derived from the S-67 Blackhawk. The extraction seats used a nylon tethered rocket to pull the pilot from the seat and out the upper window, after the blades were severed with explosive (!!) charges. The film was made during a NASA rocket sled test.. .I saw the film in a safety meeting about 1975, and when we test pilots saw it, we sat there, stunned!

The KA-50 Werewolf counter-rotating gunship uses a blade separation system with ejection seats that seem to work very well. At a symposium once, I spoke right after Dr. Sergei Mekeyev described the system to the group. When I was asked if Comanche had such an ejection system, I told the group, "We did not chose to spend the 250KG of weight on an ejection system, we instead spent it on weapons and sensors to make sure the other guy used his." :)

Regarding the long tirade on "another way the FAA obfuscates the truth", Lu can speak his opinion, but I have always found the authorities quite open about all this. First, it is the NTSB who publish the data that Lu doesn't trust, so no wonder he finds the FAA a problem, he's looking in the wrong place! Here it is for all those who might want to see it:

<a href="http://www.ntsb.gov/aviation/Stats.htm" target="_blank">http://www.ntsb.gov/aviation/Stats.htm</a>

As you can see, there is no obfuscation at all!

Simply said, the airline carriers have a 20 year safety record of 2303 passengers dead in 9.4 billion passenger emplanements. That is a rate of 244 deaths per billion emplanements, or about 1 fatal airline accident per billion flights, if the average aircraft holds 244 people.

Not too shabby.

For 270 million Americans, with about 40000 dead each year in cars, it works out to 1 car death per 6750 citizens. That works out to 1.57 deaths per 100 million miles driven, or 15.7 per billion miles driven (see <a href="http://seattletimes.nwsource.com/news/local/html98/s1cars23m_20000723.html)" target="_blank">http://seattletimes.nwsource.com/news/local/html98/s1cars23m_20000723.html)</a>

For the Airlines, at 2303 deaths for 9.4 billion emplanements, it is 4 million emplanements per death. If we assume 500 mile average flight, it is 1 death per 2 billion miles of airline flight.

So the Airliner in the US is about 30 times safer than a car in the US.

[ 31 January 2002: Message edited by: Nick Lappos ]

spekesoftly

1st Feb 2002, 05:35

I mean no disrespect, but as the majority of airline passengers also travel to/from airports by road, aren't all these comparative statistics a tad academic! Door to door safety is what really counts ..... mind you, your own kitchen can be dangerous!

Dave Jackson

1st Feb 2002, 09:08

If the purpose of traveling is to get from 'A' to 'B', and 'A' to 'B' is a measurement of distance, then jogging may result in the most deaths per miles traveled.

When the ticky-tick-ticker translates into the past tense. <img src="smile.gif" border="0">

Lu Zuckerman

1st Feb 2002, 10:12

I would strongly suggest that Nick redo the math. The FAA design guidelines stipulate that you can not have a failure of a mechanical or electronic component as well as structural elements that can bring down an aircraft no more frequently than one time in a billion hours of operation. They do not reference emplanements or seat miles they reference hours of operation for the fleet. That includes all aircraft of the same type operated by any number of operators.

How many emplanements were there on the 737 models several of which crashed due to a faulty tail power control unit or a damper? How many hours did these aircraft accumulate? I can guarantee that it was well below the 1 billion mark no matter how many people boarded the aircraft type.

How many emplanements were there on the 767 series at the time of the Lauda Air crash? How many hours had been accumulated at the time of the crash? Again well below 1 billion hours.

How many emplanements were there on the 737 series when an engine exploded at the Manchester Airport in the UK? How many hours had accumulated on the 737 series? Again the answer is the same.

I could go on and on but it would always be the same. The commercial aircraft have never met the design goals set up by the FAA and they never will. If there is a crash and the NTSB finds the reason the FAA will perform a cost benefit analysis. They apply a cost of human life of approximately 2.5 million dollars. In the analysis if it is proven that the cost of making the repair fleetwide is in excess of the number of persons killed times 2.5 million dollars in another crash of that aircraft type they will not require the change. This is definitely in favor of the airlines.

Another point, any reference I have made in my post above relative to safety or failure came from the FARs and Advisory Circular 1309 and Advisory Circular 23.1309-1C, which are published by the FAA and not the NTSB.

I think we have deviated from the reason for this thread.

Lu Zuckerman

3rd Feb 2002, 09:07

While working as a techrep on the Atlas missile I had the pleasure of working with an Air Force Captain by the name of Jim Ure. After a while I thought there was enough of a relationship and I asked him about a limp and the fact that his right arm was always in the same position. He told me the following story. He was flying an F-80 over Korea when he had his flight controls seriously damaged making his aircraft roll quite rapidly. He was close to the ground so he elected not to eject because if he were upside down he might be shot into the ground. He popped his canopy and released his restraints. He held onto the inside structure and when he was right side up he let go and the “CENTRIFUGAL FORCE “ * ejected him but not fast enough to clear the vertical fin. On the way down he tried pulling the D ring but nothing happened. His hand was on it but his arm was no longer mechanically connected to his hand. He eventually pulled the D ring with his left hand. He looked down and saw blood running out of his flight suit. He was losing a lot of blood from a seriously damaged leg, which he eventually lost. His comment to himself was ‘Ure you really F****d up this time. He was rescued by friendlies and eventually married his nurse. He is now living in Southern California.. .*You may have noticed CENTRIFUGAL FORCE in caps. Those of you that participated or read the thread on centrifugal Vs centripetal force will understand.

Weight and Balance

4th Feb 2002, 04:07

Nick's post describing the Sikorsky ejection program reminded me...

When I first saw that program on TV, I was working on chasing down an EMI/EMC problem on a certain European helicopter. Seemed every time you switched the defrost onto HIGH, the helicopter entered a slow right turn. The helicopter had been in production for several years before the problem was recognized.

The project pilot and I discussed the show the next day at work, and we both had the same though while watching it. What about EMI/EMC with the blade charges? You would have to be VERY certain everything was worked out before you went flying.

Lu Zuckerman

4th Feb 2002, 07:47

If a squib firing circuit is properly designed and there are specific guidelines the system is immune to EMI and EMR. One of the biggest contributors to EMI/EMR are solenoids. If a solenoid circuit is properly designed it will incorporate a back EMF suppression diode either on the solenoid or in the circuit.

If the solenoid does not have this installed on itself or in the circuit it can generate up to 1400 volts which will pass through the circuit and arc across the control switch. This arcing can be picked up in the electronics system. Also this high voltage can impress itself onto an adjacent circuit. Critical circuits such as squib firing or autopilot discreet command circuits will be twisted pairs and shielded to ground. When this high voltage reaches ground it can induce a high spike on the ground circuit and effect a completely separate system or black box.

If two solenoids are close to each other this back EMF can impress itself on the adjacent solenoid and cause it to operate. Shielding is all-important in the design of electrical systems.

[ 04 February 2002: Message edited by: Lu Zuckerman ]

[ 06 February 2002: Message edited by: Lu Zuckerman ]

RW-1

6th Feb 2002, 18:32

Gee, I had to weigh in on the odd thing.

Airlines want you to sit and feel cozy in the tube at altitude and not think about the obvious: if something happens, gravity works.

I look at it this way, there is inherant risk in flying, all pilots accept it, passengers must either accept it, or find another mode of transportation that they will accept for their own risk management. For the airlines to paint a risk free picture is just insane.

We can calculate the odds, (which are high BTW) but that doesn't assist you if you happen to be on THAT flight that has the mishap <img src="smile.gif" border="0"> Which is why I refer back to the above paragraph.

[ 07 February 2002: Message edited by: RW-1 ]

Geronimo 33

10th Feb 2002, 21:46

Lu,

If the electrical portion of the ejection seat/blade disposal system is made by Smiths or Lucas....then we know it will have a "failure" rate of 1......not a reliability rate of 1. I have been flying helicopters since 1967 and I snicker when this topic comes up. I am as a result of that helicopter experience a devout pessimist when it comes to things mechanical/electrical/hydraulic/electronic....they will all fail on you at the worst possible moment it seems. The image of hitting the "let's get the heck out of Dodge button". .....and only a partial success occurring just fills me with dread.

Lu Zuckerman

10th Feb 2002, 23:33

To: Geronimo 33

I have worked on a consulting basis with two divisions of Lucas and I thought they were pretty good. However there were minimal electrics involved in the two programs. I am not familiar with Smiths equipment so I can’t comment. Now if you want to add Marconi to the mix I can tell you some horror stories regarding the fact they never conform to the design specified by their customers and they do not take constructive criticism. I worked with them on the Tornado Program and the Airbus program and all I can say is that they suck. IMHO.

[ 10 February 2002: Message edited by: Lu Zuckerman ]

helmet fire

21st Feb 2002, 10:02

Lu:

The references I mentioned to you earlier in the thread:

"if you were to board a jet aircraft at random every single day, it would be 26,000 years before you were involved in a major crash (this is less than one fatal accident every millioin flights)"

Faith, N. 1998. Black Box: the final investigations. Boxtree, UK.

and, I was wrong about the nine times safer stat,it appears that it is actually 90 times safer!!:

in comparing air travel by fatalities per billion passenger kms,

"It should be noted that ALL FORMS of paid air travel are safer than travelling by car - varying from about twice as safe if the travelor charters a small plane, to five times as safe in a commuter aircraft, to 90 times safer with the airlines"

Smith, D. 1991. Facts not phobia,: Informing the public on aviation safety levels. The Royal Aeronautical Society's 1991 Sir Charles Kingsford Smith Memorial Lecture delivered in Sydney, Australia, 25 September, 1991.

But then when have you not had a theory that differs from the presented facts?

:) :)

Lu Zuckerman

21st Feb 2002, 18:49

To: helmet fire

You have to understand that there are lies, damned lies and statistics.

Here is another point that must be understood. The certification authorities do not use passenger seat KMs or miles. They use hours of accumulated fleet operations. If you will please refer to my post above you will see an example of passenger seat miles being used in the statistics presented by an airline which advertised that they had only one fatal crash while having accumulated 728,400,000,000 passenger seat miles. According to your statistics this is pretty good. However what the airline neglected to inform the traveling public they had only accumulated 98,550 flight hours on their fleet of aircraft in the accumulation of the stated safety figure.

Using your argument above if a person spent his entire life and then some flying in 737s he should never experience a single point failure that resulted in the loss of the aircraft. The FAA dictates that a single point failure in any system that can cause the loss of an aircraft should not occur more frequently in 1,000,000,000 hours of accumulated fleet operations. Or, one time in 114,155 years of fleet operations. Yet, there have been at least two fatal accidents on 737s involving the rudder actuator or the yaw damper in just the last five or six years.

In the first paragraph of you post you stated, "if you were to board a jet aircraft at random every single day, it would be 26,000 years before you were involved in a major crash (this is less than one fatal accident every million flights)"

Using an average flight time of 4 hours you would have accumulated 4,000,000 flight hours collectively on those million flights and the FAA states that no single point failure can occur no more frequently that 1 10 9 flight hours.

Here is a story that describes the thinking and mindset of individuals that quote statistics as if they were the truth.

During the Saturn Apollo Program there was a statistician that worked for North American Rockwell the builders of the Apollo capsule. This man was deathly afraid to fly because he calculated that the probability of their being a bomb on the aircraft was 1 in a million and a half. One day his boss told him that he would have to fly to the Cape and if he refused he would be fired. His colleagues were at the airport when he appeared. They asked him what had changed his mind about flying. He replied that he had calculated to probability of their being two bombs on board the aircraft were 1 in 10 billion so, he was carrying his own bomb.

To put it in understandable terms Jesus Christ roamed this planet approximately 2001 years ago. In hours it comes to 17,528,760. A billion hours equates to 114,155.25 years.

The FAA requires A billion hours and yet no single aircraft model has ever complied with that safety requirement. And, it never will. Even though the requirement is in hours the FAA and other certification authorities will use passenger seat miles or passenger seat kilometers as their justification for airline safety.

The key word here is OBFUSCATION.

helmet fire

22nd Feb 2002, 03:45

Lu:

As before, no arguement with your point about time between failures, however, the point I was trying to make is that despite all your concerns, AIRLINE TRAVEL IS STILL 90 TIMES SAFER THAN DRIVING!!! Facts, son, just the facts.

And you still didn't address my original question: if it was such a life threatning fault with the Airbus, why on earth would you have gotten on board? <img src="eek.gif" border="0">

Lu Zuckerman

22nd Feb 2002, 04:28

To: helmet fire

“And you still didn't address my original question: if it was such a life threatening fault with the Airbus, why on earth would you have gotten on board”?

There were two problems that could have caused the loss of the A-310 on which I was riding. One was if a partially extended slat had been struck by lightening and the other was if an internal crack in the flap power control unit developed and migrated inward instead of outward. If it migrated outward we would have lost one hydraulic system and if it migrated inward we would have an uncommanded extension of the flap system. Granted either of these occurrences (lightning strike and internal leak) could have caused the loss of the aircraft but the probability of either occurring was very low. Besides I had the opportunity to go up front and talk to the pilots and telling them how to counter the uncommanded extension of the flaps. So if Mr. Murphy decided that on that flight the flaps would extend without being directed to extend the pilots would save the day. The rest of the flight was mainly my hoping that there was no thunderstorm over London. I have flown on many Airbus Aircraft since that flight and even if it is not on an A-310 I still go up front and talk to the pilots. I do this mainly because of similar system architecture on all Airbus aircraft and the fact that the same companies that supplied the flap and slat system drive on the A-310 are involved in all Airbus Aircraft.

Nick Lappos

22nd Feb 2002, 05:41

helmet fire-

Haven't you figured it out by now? Why are you troubled by some need to actually have to stay on the subject? Lu has no such problem.

BTW he never has answered your reasonable question, nor will he, I'll bet! <img src="wink.gif" border="0"> <img src="wink.gif" border="0"> <img src="wink.gif" border="0">

helmet fire

22nd Feb 2002, 07:38

Nick:. .Not so much troubled, as highly amused. I also get to learn lots of cool stuff like how to save the day from uncommanded flap extensions. Tips such as using the glow self generated by my rotors to save me turning on the nitesun, and how to throw out my high school physics book using only centrifugal force. Oh...and I also get to learn about conspiracies such as the FAA continuing to allow the worlds most popular helicopter to fly despite its tendency to have sudden, unexplained mast seperations, and then there is the EH101 coverup that may have averted two fatal accidents. If I didnt ask "Lu, why did you get on the plane?" we may never have encouraged Lu to share these pearls with us, and I would be all the more ignorant of such things as uncommanded flap extension.

Mind you, the actual answer would be fascinating wouldn't it?

So, Lu, if the problem on the Airbus was as life threatening as you claim, why would you even get on board?

And here is a prompt for you Lu:

"Despite the life threatening danger of the Airbus, I flew on it because......(insert answer here).....................

<img src="cool.gif" border="0"> <img src="cool.gif" border="0">

Lu Zuckerman

22nd Feb 2002, 08:40

To: helmet fire

"Despite the life threatening danger of the Airbus, I flew on it because......(insert answer here)..................... I got on the A-310 for the same reason you get into your helicopter every day. It is a part of our work to do so. I like you realize that there are a lot of things that can go wrong both on your helicopter and on a commercial jetliner but I had to get from Zurich to London. I would mention two city pairs in OZ that you fly from and to but I’m not familiar with the layout of the land. Like you getting into your helicopter and me getting on the A-310 I / you realize that the probability of something bad occurring is very low although it is possible. If I refused to fly I would lose my job and if you refused to fly because you knew that there was a possibility of something going wrong then you would lose your job.

When I flew in the military our planes were for the most part very old and well worn from service in WW2 however I figured that if the pilots had the balls to get in and fly then I could also do the same. What I didn’t know at the time was that the pilots carried a bottle of engine smoothener in their nav cases.

Nick Lappos knows very well what can go wrong on a helicopter but he still gets into them every day. If he dwelled on the potential problems and their ramifications he too would have to carry a bottle of “engine smoothener” in his kit bag that is if he doesn’t do that already.

You make light of my comments about what could possibly go wrong and that’s OK but it would surprise you how many times I told my clients what could go wrong and for whatever reason they ignored it. That too is OK but you and the other guys on this forum are flying in those aircraft where problems were ignored for whatever reason.

helmet fire

23rd Feb 2002, 03:57

Lu,. . thanks for the answer. Lets see, here it is: To: helmet fire. ."Despite the life threatening danger of the Airbus, I flew on it because I got on the A-310 for the same reason you get into your helicopter every day. It is a part of our work to do so.". . <img src="eek.gif" border="0"> . .Actually Lu, you are wrong. I am NEVER paid to fly non airworthy or life threatening aircraft, in fact I am paid NOT to risk my client, myself, nor the machine by doing so.

Your reason that you "had to get from Zurich to London" is hardly a reason I would risk my life for, but there you go, the world takes all types. Or, are your claims of life threatening failures a bit overstated after all?

I only make light of your huge calls Lu, not the intent and aim of your discussions.

BTW an equivalent of Zurich to London might be Tamworth to Bendigo in Oz!

<img src="cool.gif" border="0"> <img src="cool.gif" border="0">

Lu Zuckerman

23rd Feb 2002, 05:16

To: helmet fire

“Actually Lu, you are wrong. I am NEVER paid to fly non airworthy or life threatening aircraft, in fact I am paid NOT to risk my client, myself, nor the machine by doing so”.

The potential for failure is always there and under those conditions the helicopter becomes un-airworthy when a rotor blade comes off or you have a transmission failure that locks up the gear train. The other way you have to know your aircraft is un-airworthy is when your mechanic discovers a defect or you note a problem during a flight and the mechanic investigates the problem and grounds the helicopter. Then there is another way of finding out that your aircraft is un-airworthy and that is when an AD is issued grounding your helicopter and all other models of the same helicopter. In order for that AD to be issued a pilot and his passengers had to die.

Every time you fly you have the potential of discovering that your helicopter is un-airworthy yet you get in and start it up and flyaway. The reasons you do this on a daily basis are because of faith in yourself as a pilot. The faith you have in your machine and hopefully the faith that you have in the people that maintain you machine the faith in the design of the helicopter and the faith in the engineers having gotten it right. You should also have faith that the manufacturer had someone like myself to identify potential problems and most of all you have the faith that the manufacturer listened to the criticism.

Regarding my flying on the A-310 what would you have me do? I brought the problems to the attention of the top management of the company I worked for and they refused to do anything because they would have to pay for any redesign. Their theory was that if someone above our company or even Airbus discovered the problems they would issue a change in scope and our company would get paid for the change. I took the problem to the wing integration contractor in Northern Germany and they told me the same thing and for the same reasons. I then took it to the wing designer in the UK and they told me they were sympathetic to my problem but they could offer no help. Now consider the following. The contract required that Airbus and the certification authorities be notified in the event of the discovery of Reliability, Maintainability or Safety problem and none of the three levels of contractors told them. Here is another point. Airbus prepared a specification that outlined a series of tests to be performed on every plane prior to roll out. These tests were to prove the bonding integrity and ability to resist damage due to lightning strike. Well since it was proven that the flaps and slats were not grounded it only indicates that Airbus never performed the tests outlined in their own specification.

With all of that, what excuse would you suggest I have used to take another flight on a Boeing or Lockheed or McDouglas aircraft?

helmet fire

23rd Feb 2002, 08:27

Nick: Do you see my point now? <img src="wink.gif" border="0">

Lu: . .You said: >>"the helicopter becomes un-airworthy when a rotor blade comes off or you have a transmission failure that locks up the gear train".<< I strongly agree with this astute oberservation, Professor. Lets hope I never attempt to fly without first checking the aircraft has all of its rotor blades on and its' drive train working (though I suspect I might notice shortly after start).

But, methinks, here is the crux of our differences: . .You said: >>"Every time you fly you have the potential of discovering that your helicopter is un-airworthy yet you get in and start it up and flyaway"<

This is true Lu, but unfortunatley irrelevant to my question to you. Irrelevant because you are going on about "potential" of losing airworthiness aonce airborne, whilst I am posing the question about an aircraft that, according to your previous statements, is not airworthy to begin with. I say again, I do not fly in aircraft that I believe to be unairworthy, yet you claim the Airbus is such an aircraft and then you jump on board "hoping" that your brief to the pilots and the total absence of thunderstorms will allow you to arrive safely. Thus your answer to my question (that you would fly for the same reasons I would fly) is not correct, because I WOULD NOT and yet YOU WOULD.

Lu, you went on to ask: >>Regarding my flying on the A-310 what would you have me do?<<

Answer: I dont care what you do Lu. If you want to get on an aircraft you believe is unsafe, then do it. I dont.

In regard to you statements about the A-310, I hope you collected all of your supporting evidence to clear you as you state: >>The contract required that Airbus and the certification authorities be notified in the event of the discovery of Reliability, Maintainability or Safety problem and NONE of the three levels of contractors told them.<<

Some questions immediately spring to mind.... .1. Were you not a contractor? . .2. Did you inform the Certification Authorities AND Airbus? . .3. Just like the EH-101 and R22, do you do the right thing by families of the victims, and contact them to offer expert witness support in their time of need?

I suspect the first line of questions from any examining lawyer might be:

Lawyer: "Mr Zuckerman, do you wish to commit suicide?". .Lu: (insert answer here - I'll assume the answer is negative). .Lawyer: "If you REALLY believe that the aircraft was bound to crash due to these design faults you discovered, and claim to have been ignored/covered up by the manufacturer, why on earth would you risk YOUR life by regularly flying on them?"

Fairly close to my original question, n'est pas? . . <img src="rolleyes.gif" border="0">

:) :)

Lu Zuckerman

23rd Feb 2002, 20:18

To: helmet fire

“Some questions immediately spring to mind”.... .“1. Were you not a contractor? . . 2. Did you inform the Certification Authorities AND Airbus? . . 3. Just like the EH-101 and R22, do you do the right thing by families of the victims, and contact them to offer expert witness support in their time of need”?

. .Response:. .1) Yes. .2) While I was still actively involved in the program and when I went to work for Agusta I decided that I had done every thing within my power to present the problem to the major contractors for the A-310 wing but to no avail. I decided that I would not take it any further unless and until the A-310 was certificated in the United States. While at Agusta I found that this certification was granted and at that time I contacted the FAA. It took two very detailed letters to convince them to take action. However the kicker in my second letter was that I was absolving myself of any responsibility and if an aircraft were lost due to the described defects it would be their fault. They finally took action and the Vice President and chief program manager were fired. Both of these gentlemen went on to better jobs in the German aircraft industry and even though the FAA took action the design was never changed so the same problems exist. Upon my return to the States I contacted every American operator of the A-310 and spoke to the respective safety pilots advising them of the problems and how to counter a runaway flap system. I don’t believe I could have done any more than I had done.. .3) Two lawyers to support their investigations into two R-22 crashes have placed me on retainer and as I had previously stated in another post the Royal Navy regarding the EH-101 crash contacted me. I also belong to an organization made up of mainly Aviation Accident Lawyers and they all know my technical background so if any lawsuits are brought forward relative to the three EH-101 crashes I will most likely be contacted.

. .I suspect the first line of questions from any examining lawyer might be:

Lawyer: "Mr. Zuckerman, do you wish to commit suicide?". .Lu: (insert answer here - I'll assume the answer is negative) . .Lawyer: "If you REALLY believe that the aircraft was bound to crash due to these design faults you discovered, and claim to have been ignored/covered up by the manufacturer, why on earth would you risk YOUR life by regularly flying on them?" . . . .Response to first question:

No sir I do wish to commit suicide.

Response to the second question:

But sir, I did not believe that the aircraft was bound to crash but that the potential for the aircraft to crash was there but the probability of occurrence was minimal and dependent upon two very different circumstances. The first was the aircraft being struck by lightning during let down with the slats partially extended. Then there were two other subsets to this which were the probability of the lightning hitting the nose which is the primary attach point and second being struck on the edge of the partially extended slat. The presence of an electrical storm in the vicinity of LHR was minimal and the possibility of being struck on the slat was a 50-50 possibility. The use of the term regularly is an over statement as I only flew on an A-310 only one time. Regarding the potential for an uncommanded flap extension the probability was minimal and in this case if a crack were generated the possibility of the crack migrating inward or outward was also 50-50.

Now,let's explore what I would do as opposed to what you would do:

Would you fly on a 747-200 with TWA 800 in mind? Would you fly in a MD-10 with the vision of the crash in Sioux City? Would you fly in a MD-11 with the thought of the crash in Peggys’ Cove? Would you fly in a 737 with the vision of the possibility of extreme rudder excursions? Would you fly in a 737 with the vision of the roof blowing off or the vision of an uncontained engine explosion resulting in the deaths of many passengers in Manchester, England? How about flying in a 767 with the vision of an uncommanded thrust reverser causing the loss of the aircraft. I could go on for a long time but I hope by now you can understand where I am coming from. Each of these aircraft were deemed airworthy when they left the ground but each had a potential flaw that was either overlooked, disregarded or totally unknown and in each case this flaw manifested itself much to the detriment of the passengers and crew.

Even though you were fully knowledgeable of these crashes and the reasons for them you would still get on any one of them and fly from point A to point B and possibly on to point C. Why, because the certification authorities told you the aircraft were safe to fly on and the airlines offered statistics showing how safe they were based on passenger seat miles or, passenger seat kilometers flown.

Now if you would not fly on these aircraft within Australia you could take a train assuming it was going in the right direction or you could ride on a sheep truck or if you were going long distances you could take a ship.

Now, let’s address accident rates on trains, sheep trucks and ships…

Nick Lappos

23rd Feb 2002, 21:18

Lu Zuckerman slams so many fine aircraft in so many ways. It is fortunate that so few actually read his posts, and so many fewer actually believe them. :)

Lu Zuckerman

23rd Feb 2002, 23:49

To: Nick Lappos

I am very sorry that you feel the way you do but let me ask you a question.

Were you involved in the certification testing of the S-76? Were you in constant contact with the various design groups? Did you and the designers investigate every possible safety feature of the design? Did you get involved in the verification testing of all of the major dynamic systems or, did Sikorsky elect to demonstrate the relative safety of the design by computer analysis just like Boeing did on the 767 thrust reversers. If you were not directly involved in the certification process then did the certification test pilot that was involved perform all of the above activities?

Now, assuming that you or another colleague did all of the above then please explain to the readers of this post how the blades failed on I believe two S-76s with the loss of crew and passengers. From what I understand the blades had redundant load paths and the secondary load path failed placing the entire load on the primary load path with the end result, for whatever reason, the primary load path failed and the blades came off due to Centrifugal force.

I have been in the aerospace industry since 1955 and have been exposed to the genius and arrogance of the various design departments in the companies I worked in. I have been involved in RMS since 1968 and I have been exposed to those firms that really promoted the concepts of RMS. And I have also been in companies where the engineers had a not invented here attitude and ignored the RMS personnel or, they swept the problems under the carpet hoping that the systems would not fail during the guarantee period.

Where do you feel that Sikorsky fits into these extremes relative to the promotion and acceptance of RMS? If you rate them very high then again I ask you to explain the problems of the S-76 and other Sikorsky products.

Let’s face the truth. The engineering and test departments at all of the aerospace companies never get it 100% right and the operational pilots are really test pilots until all of the bugs are removed and or corrected and in the process some of them get killed along with their passengers.

The same for the automobile companies.

John Eacott

24th Feb 2002, 02:29

Nick,

Are you getting a sense of deja vu? Give it up, no one in their right mind reads this interminable drivel, you're only fanning the flames.

Lu Zuckerman

24th Feb 2002, 02:42

To: John Eacott

You obviously read it. If you think that what I post is drivel then if you never read anything else that I post please read and remember this:

“Let’s face the truth. The engineering and test departments at all of the aerospace companies never get it 100% right and the operational pilots are really test pilots until all of the bugs are removed and or corrected and in the process some of them get killed along with their passengers”.

John Eacott

24th Feb 2002, 12:01

LZ,

Nothing "obvious" about it. I can tell from the first two lines of your postings whether to scan on to the next, and that's generally what I find myself doing.

Your interminable bickering and meandering from the thread gives me the irrits. I'm sure that you could contribute much from your years in the industry, if only it could be put in a less agressive and, quite frankly, boring manner.

XV666

24th Feb 2002, 12:16

Heartily agree. How did we get here from a thread about ejection seats, anyway? . . <img src="confused.gif" border="0"> <img src="confused.gif" border="0">

[ 24 February 2002: Message edited by: heli ]

Matelot B'stard

6th Nov 2003, 22:40

Can anyone point me at the old video showing an ejection seat trial, where the blades get blown off at their roots, and then the seat departs the aircraft?? Might have been Sikorsky, but not sure.

Thanks:ok:

heedm

7th Nov 2003, 00:03

I think it was a James Bond movie about 15 years ago.

DynamicallyUnstable

7th Nov 2003, 01:09

Man, I'm not flying any helicopter that has something on board that can "blow the blades off at their roots".

ShyTorque

7th Nov 2003, 01:19

Yeh, it upsets the passengers.

I think it was actually a Russian trial, not a U.S. Sikorsky one. They also had the idea of a sideways firing bang seat.

Lu Zuckerman

7th Nov 2003, 01:40

One of the first Cheyenne (AH-46) test birds had a downward firing ejection seat. it was located in the gunners position. The pilot would fly in the gunners position on certain flights in the event of a major failure. I believe the mechanism was taken from a B-47.

:E :E

Hughesy

7th Nov 2003, 08:08

I saw that trial on the Discovery Channel a while back, the programme was called Ultimate Machines, which was all bout choppers. I don't think it got past testing stage as it was too unreliable. :ooh:
DynamicallyUnstable is right, I wouldn't want to fly anything with those bolts either. I prefer my blades firmly attached to my rotor head!:ok: :ok:

Barannfin

7th Nov 2003, 11:40

Re: downward firing seats. Don't you have to be fairly high (helicopter terms) like 2k in order to succesfully use those? seems like the downwards one would be pretty useless. Not sure i would trust the side fire either. Guess thats why we dont see em in use then eh?

Matelot B'stard

7th Nov 2003, 15:58

Thanks fellas, I realise that its a topic which is the source of much amusement, but I just recall seeing a video from on board the aircraft as it blew the blades and fired the seat, back in the 80's at the Royal Navy's Air Engineering School. It was just for interest value, you wouldn't get me in a contraption with exploding blade roots either.. I do have a few brain cells left;)

Ascend Charlie

7th Nov 2003, 16:19

It has been on Discovery channel, and also I think it was on a 1-hour special called The Chopper. I used to show it to my students at night school to put them off helos.

The blades were fired off in sequence, then little rockets that spun like pinwheels pulled each crewmember out of the seat on a long cord and opened the parachute. Only demo'd with dummies borrowed from a Volvo commercial.

southcoast

7th Nov 2003, 18:05

The Russians are still flying one. I first saw it at the Paris Airshow in 93 where they managed to initiate the first part of the ejection sequence during the pre-flight. All the blades came off but after some "words" with the aircrew and a durry, the mechs had them back on in about half an hour in time for the flying display.:ooh:

_________________________________--

The Ka-50 is the world's first operational helicopter with a rescue ejection system, which allows pilot to escape at all altitudes and speeds. The K-37-800 Rocket Assisted Ejection System is manufactured by the Zvezda Research and Production Enterprise Joint Stock Company in the Moscow Region. The seat operates by pulling the pilot from the helicopter cabin using a solid-propellant rocket motor. The system comprises the seat, a control unit and a pullout rocket motor. The seat is fitted with a survival pack containing an NAZ-7M survival kit, a life raft and a PS-37A parachute system. The seat provides safe forced emergency escape from helicopters in the speed range 0 to 350 km/hour and at altitude 0 to 6,000 metres. The seat also provides safe ejection during inverted flight (at speeds 0 to 330 km/h with zero vertical velocity) at a minimum altitude of 90 metres.

Spaced

6th Jan 2004, 12:17

This is actually a serious question, so no jokes:D .
I was watching discovery last night, it was a doco on ejector seats. THey were covering different systems, when all of a sudden they start talking about helicopter systems.
I know the russian Ka-50 has a zero-zero style seat, which as far as I know is the only operational one in a helo.
But hte one they were showing on this program looked like a S-62 fuse, on a track complete with rotating blades. The blades were all fired off, one at a time, the the crew were ejected out.
Heres the strangest bit though, instead of rockets under the seats, they were pulled out of the cabin via 4 or 5 rockets spinning, connected to the crew by a cable.
Maybe they though helo pilots would only accept rotating propulsion?
If any one knows about this program, I would appreciate any info.

Gomer Pylot

6th Jan 2004, 12:49

I didn't see the program, so I can't say what was shown, but the part about ejecting the blades one at a time sounds fishy. As soon as one blade is gone, the imbalance is so bad that the entire transmission generally exits, within a fraction of a second. To work, all the blades need to exit at the same time.

There has been some sporadic work on helicopter ejection seats over the years, but AFAIK no functional system has been fielded. The problem of the blades is not trivial, and the only alternative is to fire the seats out the bottom, which is also not optimal.

Personally, I would prefer to ride down inside the helicopter than an exploding seat and parachute that might or might not work, and I say that as a former paratrooper and current helicopter pilot.

Flytest

6th Jan 2004, 15:01

I asked the same question a few weeks back, glad I'm not actually losing my marbles!!

When I was at the Navy's Air Engineering school I saw probably the same clip you refer to. The blades were all blown off (Don't remember them going sequentially, but wouldn't argue) and the crew exited vertically, and successfully. The other one I saw was a sideways firing seat.. now that looked iffy!!!

As far as I am aware, no assisted escape system actually exists in service in the west. I don't subscribe to the the "autorotation or doom" philosophy. I think any poler in a situation of extreme peril (Deep sh!t as we commoners say!!) would welcome a last ditch method of potential escape, if he was being honest.;)

Ascend Charlie

6th Jan 2004, 16:37

That footage dates back to pre-87, and the blades were fired off two at a time, from opposite sides of the mast, but in a fraction of a second.

The pilots were pulled out through the overhead window (also blown out) by their harness using a rotating rocket system.

never put into production.

Can you imagine some dopey passenger saying "What does this button BOOM! BOOM! Phhhhiizzzzzz!......... ooops.."

Helo seats have to be different from aeroplane seats as they need to absorb vertical accelerations - plank seats take mostly forward forces. So there is no room under a helo seat for an ejection system, and they are heavy and require huge amounts of maintenance. Specialist cracker people. Parachute people, plus pulling the rotten things out at regular intervals and testing and repacking them. Big costs.

And as far as i know, civil aircraft aren't permitted to have active ejection seats. When the old warbirds fly, the pilot knows he has to ride it in. Many have done so.

And anyway, how do you also eject 12 or 14 pax down the back? And an S76 doesn't even have an overhead window!