How long have you got if the engine(s) go quiet
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How long have you got
Untill a rotor system is developed that gives your novice pilot about five seconds to recognise he is in deep trouble, then these light helicopters just aint safe. I do however have such a system. Bug
Join Date: Nov 2004
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Hehehe, FGF. Good story. I wear a seat belt when i drive, but not because i am intending to crash. It only takes one saved life to justify AAED...
TET, failure modes are a good point. By using the Rotor Nr, once engine N1 has drooped, the collective will gently trim as required to maintain ~100% Nr. I suggest an "orange warning" for N1 dropping to say 95%, and a "red warning" for N1 dropping to 90%. Near ground at speed pilot should be on collective to quickly overide system. Cyclic can be pulled back as normal and collective will trim to maintain 100% Nr, so some height gain may be possible. It can always be turned off as a final measure.
thekite, it is also possible pilot attempts to restart piston engine after lining up. No need to force landing for a bubble in the fuel line.
Some thought needs to go into "orange" and "red" warnings. Orange could be an intermittent alarm, with red continous. This also quickly informs pilot whether there is anything left in the tap. Also a Failure Mode Effect Analysis will reveal whether system malfunction can cause unrequested autorotation entry. The trick is to keep the design simple, using two circuits which must agree before any action is taken. Ultimately servo is weak enough to be overpowered for flare, or system can be turned off.
TET, failure modes are a good point. By using the Rotor Nr, once engine N1 has drooped, the collective will gently trim as required to maintain ~100% Nr. I suggest an "orange warning" for N1 dropping to say 95%, and a "red warning" for N1 dropping to 90%. Near ground at speed pilot should be on collective to quickly overide system. Cyclic can be pulled back as normal and collective will trim to maintain 100% Nr, so some height gain may be possible. It can always be turned off as a final measure.
thekite, it is also possible pilot attempts to restart piston engine after lining up. No need to force landing for a bubble in the fuel line.
Some thought needs to go into "orange" and "red" warnings. Orange could be an intermittent alarm, with red continous. This also quickly informs pilot whether there is anything left in the tap. Also a Failure Mode Effect Analysis will reveal whether system malfunction can cause unrequested autorotation entry. The trick is to keep the design simple, using two circuits which must agree before any action is taken. Ultimately servo is weak enough to be overpowered for flare, or system can be turned off.
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I guess its time to wheel out my favorite rant:
We practice what we can, often, then we have accidents caused by entirely different things.
We perseverate about autorotations and engine failures, until we are blue in the face (I once saw a US Navy crew do 8 power recovery autos in a row in a 3 engined CH-53E!!), we chomp at the bit for a system to dump the collective, we ask for rotors so heavy they yawn once or twice after the engine quits before that start to lose rpm. We demand hard Cat A machines where one engine is a spare for the other, so that every normal maneuver can be done with either. We beg for helos that carry half the passenger load, and go half the distance, but that can survive our imagined worst nightmare.
We imagine that nightmare because we are so much like Pavlov's dogs that we actually salivate when someone mentions the several accident scenarios that we have been practicing since we were wet behind the ears. WE KNOW thats what causes accidents, because THAT's what we have been practicing all those years!! Would our trusty instructor lie to us? No! Could the flying handbooks be wrong? NO! Quick, get a bigger set of engines, get a heavier rotor, buy a collective with a big spring so it can drop itself when the engine quits.
Of course, if we invest in EVERY wet dream mentioned in this thread, our accident rate would not go down more than a few percent, perhaps not at all! Why?
Because, quietly, the REAL accident causes sit and laugh at the trained pilots who jump up and down for more autos and auto protection systems. The real accidents wait...
Answer THESE questions and THEN ask for improvements where they are needed:
1) When was the last time you and your instructor practiced preventing CFIT?
2) When was the last time you and your instructor practiced skud running and then inadvertent IFR recovery (to a full instrument landing?)
3) When was the last time you purposely flew into a pilot error situation to practice the recognition/recovery techniques?
4) When did your instructor last tell you, "Oops! You have 10 minutes of fuel left, what do you do?" and then watched as you solved the situation?
5) Can you list the exact accident causes for helicopters, from most prevalent to least, and tell how you KNOW you won't have each, because.....?
We practice what we can, often, then we have accidents caused by entirely different things.
We perseverate about autorotations and engine failures, until we are blue in the face (I once saw a US Navy crew do 8 power recovery autos in a row in a 3 engined CH-53E!!), we chomp at the bit for a system to dump the collective, we ask for rotors so heavy they yawn once or twice after the engine quits before that start to lose rpm. We demand hard Cat A machines where one engine is a spare for the other, so that every normal maneuver can be done with either. We beg for helos that carry half the passenger load, and go half the distance, but that can survive our imagined worst nightmare.
We imagine that nightmare because we are so much like Pavlov's dogs that we actually salivate when someone mentions the several accident scenarios that we have been practicing since we were wet behind the ears. WE KNOW thats what causes accidents, because THAT's what we have been practicing all those years!! Would our trusty instructor lie to us? No! Could the flying handbooks be wrong? NO! Quick, get a bigger set of engines, get a heavier rotor, buy a collective with a big spring so it can drop itself when the engine quits.
Of course, if we invest in EVERY wet dream mentioned in this thread, our accident rate would not go down more than a few percent, perhaps not at all! Why?
Because, quietly, the REAL accident causes sit and laugh at the trained pilots who jump up and down for more autos and auto protection systems. The real accidents wait...
Answer THESE questions and THEN ask for improvements where they are needed:
1) When was the last time you and your instructor practiced preventing CFIT?
2) When was the last time you and your instructor practiced skud running and then inadvertent IFR recovery (to a full instrument landing?)
3) When was the last time you purposely flew into a pilot error situation to practice the recognition/recovery techniques?
4) When did your instructor last tell you, "Oops! You have 10 minutes of fuel left, what do you do?" and then watched as you solved the situation?
5) Can you list the exact accident causes for helicopters, from most prevalent to least, and tell how you KNOW you won't have each, because.....?
To add to that Nick - once all the sooper-dooper safety systems were installed in your pilot-proof helicopter, how many accidents would be caused by system failure (lever lowered at inappropriate moment due to slight Nr decrease following mild overpitching approaching a high hover for example).
In many accidents where failure to enter auto properly was the main factor, it is often a pilot's procedural error (running out of fuel/no carbheat etc) or pilot's lack of current practise. If you want to be a pilot get your chequebook out - if you want to be a good pilot stay current. Continuity of flying skills is vital, especially in the less experienced.
In many accidents where failure to enter auto properly was the main factor, it is often a pilot's procedural error (running out of fuel/no carbheat etc) or pilot's lack of current practise. If you want to be a pilot get your chequebook out - if you want to be a good pilot stay current. Continuity of flying skills is vital, especially in the less experienced.
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Absolutely i would not pretend to be a real pilot, nor have i reviewed accident statistic data, but this system might just give a couple of extra seconds. There may only ever be one pilot in the future who benefits, but isn't that enough?
I'm not proposing a system which spring drives collective to the floor, forcing helicopter into a death dive. The system i am proposing does absolutely no more than the pilot would, by maintaining ~100% Nr while pilot takes stock. At the worst it would do absolutely nothing, which is where the state of the art is now.
Agreed that the ideal is a radioaltimeter input, with auto flaring, but that adds additional complexity. This is not Comanche style FBW.
I'm not proposing a system which spring drives collective to the floor, forcing helicopter into a death dive. The system i am proposing does absolutely no more than the pilot would, by maintaining ~100% Nr while pilot takes stock. At the worst it would do absolutely nothing, which is where the state of the art is now.
Agreed that the ideal is a radioaltimeter input, with auto flaring, but that adds additional complexity. This is not Comanche style FBW.
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Folks, reading through this thread as a mere 747 pilot scares me sh*tless and reminds me why I chose the route I did!
You are heroes for risking flying these lethal machines that patently should never have been certified in the first place .... maybe I'll change that to say it is you that should be certified.
No wonder they don't make a long haul helicopter, you'd be lucky to find a sub 10 second reaction time in the cruise after 6 hours
You are heroes for risking flying these lethal machines that patently should never have been certified in the first place .... maybe I'll change that to say it is you that should be certified.
No wonder they don't make a long haul helicopter, you'd be lucky to find a sub 10 second reaction time in the cruise after 6 hours
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I sense and share your esaperation Nick and note that you have often exasperated about those who CFIT.
With respect, there is also a problem as highlighted by your comment (3) , where Uncontrolled Flight into Terrain (or something solid) is also quite a problem.
That at least should be rectified in part with adherence to some decent preventative training.
Re your quote below;
Small percentage rates, is what drives amongst other things, successful bank balances, good copy in accident reports and jet engines.
Attention to detail is what drives the difference in the percentages in the right direction.
Never give up on presenting the detail if we wish to strive for better equipped pilots in the community.
cheers tet
With respect, there is also a problem as highlighted by your comment (3) , where Uncontrolled Flight into Terrain (or something solid) is also quite a problem.
That at least should be rectified in part with adherence to some decent preventative training.
Re your quote below;
our accident rate would not go down more than a few percent
Attention to detail is what drives the difference in the percentages in the right direction.
Never give up on presenting the detail if we wish to strive for better equipped pilots in the community.
cheers tet
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The main cause of accidents is failure of the apparatus between the ears and if you want real improvement in statistics, improve the decision making process of that device.
