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
Hovering AND talking
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Bug, does that mean you have developed an engine which coughs and splutters noisily first before it quits? 
I have suffered an SEP engine failure (albeit a 1985 Ford Escort on the outside lane of the M25 of a Friday evening!) and can confirm that there were enough warning signs in order for me to get the indicators on and move over (relatively safely) to the hard shoulder!
It seems from previous posts that ~ 2 seconds is about right.
Cheers
Whirls
I have suffered an SEP engine failure (albeit a 1985 Ford Escort on the outside lane of the M25 of a Friday evening!) and can confirm that there were enough warning signs in order for me to get the indicators on and move over (relatively safely) to the hard shoulder!
It seems from previous posts that ~ 2 seconds is about right.
Cheers
Whirls
Me too, however mine was an instantaneous failure! Overtaking at 85 mph on the M3, in a 1979 Golf diesel, when the cam belt 'slipped'. 22:1 compression ration and out of timing cam shaft made for an interesting few seconds. Of course, having managed to cross 3 lanes without power (but a large smoke screen to confuse followers) onto the hard shoulder, I was then reminded that the brake servo uses engine produced suction!
SAS, I would have replied with the bit about bunting causes Nr decay, but assumed a man of your Kaliber would have known
SAS, I would have replied with the bit about bunting causes Nr decay, but assumed a man of your Kaliber would have known
Hovering AND talking
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Originally Posted by 212man
Kaliber
Cheers
Whirls
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Bang or no bang
If I was going to have an engine failure in a helicopter I think I would be far more likely to know what was going on with an engine failure that happened quickly and preferably with a loud bang rather than one 'giving hints' as to its future demise. WHY - because its amazing how massive hints can get ignored.
True Story: I am in command of a high performance fixed wing aircraft at the threshold ready to take off on a 800m strip. Been flying these toys for 20 years or more. Power checks fine. Start roll at full power. 2 seconds later engine note changes and then recovers. Cant read any instruments due to severe vibrations. I somehow convince myself its OK and continue the take off. Result: clearing the trees by 100 feet instead of 800 feet.
My mind played tricks on me. It took me over 30 seconds to realise that something was definately wrong.
Landed without incident. Problem would not appear for engineer. Engine cleared for flight. Problem found 5 flying hours later. Fleck/flake of metal inside injector occasionally blanking off fuel flow to one cylinder = one draggy cylinder.Engine note recovery was the constant speed propellor reducing pitch to maintain revs. Realized if it had not been a severley overpowered little aeroplane in the first place [and capable of decent performance with one cylinder out] I might have hit the trees.
I wonder whether a partial engine failure like this happening in a helicopter could have similar effects on the pilot. I guess it would translate so... engine power reduces, vibrations, pilot or correlator reduces pitch to maintain revs - helicopter no doubt starts decending and wont thave enough power to hover - but are you going to realize that with the likely confusion.
Hence I just rather it go bang and I can get on with the auto.
True Story: I am in command of a high performance fixed wing aircraft at the threshold ready to take off on a 800m strip. Been flying these toys for 20 years or more. Power checks fine. Start roll at full power. 2 seconds later engine note changes and then recovers. Cant read any instruments due to severe vibrations. I somehow convince myself its OK and continue the take off. Result: clearing the trees by 100 feet instead of 800 feet.
My mind played tricks on me. It took me over 30 seconds to realise that something was definately wrong.
Landed without incident. Problem would not appear for engineer. Engine cleared for flight. Problem found 5 flying hours later. Fleck/flake of metal inside injector occasionally blanking off fuel flow to one cylinder = one draggy cylinder.Engine note recovery was the constant speed propellor reducing pitch to maintain revs. Realized if it had not been a severley overpowered little aeroplane in the first place [and capable of decent performance with one cylinder out] I might have hit the trees.
I wonder whether a partial engine failure like this happening in a helicopter could have similar effects on the pilot. I guess it would translate so... engine power reduces, vibrations, pilot or correlator reduces pitch to maintain revs - helicopter no doubt starts decending and wont thave enough power to hover - but are you going to realize that with the likely confusion.
Hence I just rather it go bang and I can get on with the auto.
Reaction Time.
Maybe Nick Lappos can clarify but I always understood that it was a certification requirement that any civilian aeroplane had to be able to cope with a two second reaction time by the pilot.
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How long have you got
Whirlygig. No not an engine that gives prior warning of failure. A rotor design for a VLH that will give you time to scratch your ear before lowering the lever. Bug
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Firstly,
a helo pilot that doesn't drink coffee? I don't understand? 
Secondly,
Were this true, you will become a very rich man and save lots of lives, I am sure...
I have to concur with the 2 second average... but in other words:
long enough for your heart to skips three beats, your knickers to become very damp, and your cyclic hand to get the shakes. Oh, and possibly, if you're good enough, to blurt out F
K.
and never touch coffee
Secondly,
A rotor design for a VLH that will give you time to scratch your ear before lowering the lever. Bug
I have to concur with the 2 second average... but in other words:
long enough for your heart to skips three beats, your knickers to become very damp, and your cyclic hand to get the shakes. Oh, and possibly, if you're good enough, to blurt out F
K.
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Kiwi Chick -
What thoughts to start my day - at least its the start of the day here in the UK.
Firstly you talked about taking your flight tests naked on another thread (3 most important qualities.....) and now your references in the last para of your posting, above.......
Phew.... I'm off for a cold shower.......................
Firstly you talked about taking your flight tests naked on another thread (3 most important qualities.....) and now your references in the last para of your posting, above.......
Phew.... I'm off for a cold shower.......................
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Fareastdriver,
The time delays after failure are varied depending on the flight regime. For the region where the sticks are continuously moving to pilot command (the hover, and the area of the HV curve below the "knee") the time delays are nil, and the only time interval after the engine cut is a 0.3 second pilot reaction time (before the collective can be lowered.)
For level flight, the delay is presumed to be 1.0 second, and the reaction time is imposed on top of that, giving 1.3 sec total from cut to collective down.
The calculation I gave below was in theoretical "seconds of total rotor stored energy" and does not precisely correlate with the figures above, except in a general way.
The time delays after failure are varied depending on the flight regime. For the region where the sticks are continuously moving to pilot command (the hover, and the area of the HV curve below the "knee") the time delays are nil, and the only time interval after the engine cut is a 0.3 second pilot reaction time (before the collective can be lowered.)
For level flight, the delay is presumed to be 1.0 second, and the reaction time is imposed on top of that, giving 1.3 sec total from cut to collective down.
The calculation I gave below was in theoretical "seconds of total rotor stored energy" and does not precisely correlate with the figures above, except in a general way.
Purveyor of Egg Liqueur to Lucifer
Whirlygig,
WG, you have no need for concern.
Simply start eating Mars Bars or in fact any chocolate bar beginning with the letter 'M'. Failing that, the formula is flexible enough to allow the 'm' to stand for mocca (coffee) and the 'c' to be Cadburys chocolate (my fave!)
Tea cannot come into the equation in itself (because it doesn't start with c or m), however because tea has generally the same caffeine content as coffee dependant on brew time, tea can replace the coffee.
As for the Jordans crunchy bars, you'll like this...
Jordans crunchy bar --- 464 Kcal/100g source
Mars Bar --------------- 452 Kcal/100g source
So...if you drink strong tea and eat Jordans crunchy bars, you would in fact better off health wise with the mars bar and coffee as stated in the formula.
In conclusion, in your individual case, because of your extra caffeine and calorie intake, you are better off than most in the reaction time stakes.
SS
'Ang on Sid, I don't eat Mars bars and never touch coffee which gives me a numerator of zero i.e. no reaction time at all. This concerns me somewhat!
Please can you let me know the additional constant factors to be applied to your formula for a consumption of Jordan's Crunchy Bars (fewer calories and no cocoa) and Tetley Tea (less caffeine).
Please can you let me know the additional constant factors to be applied to your formula for a consumption of Jordan's Crunchy Bars (fewer calories and no cocoa) and Tetley Tea (less caffeine).
Simply start eating Mars Bars or in fact any chocolate bar beginning with the letter 'M'. Failing that, the formula is flexible enough to allow the 'm' to stand for mocca (coffee) and the 'c' to be Cadburys chocolate (my fave!)
Tea cannot come into the equation in itself (because it doesn't start with c or m), however because tea has generally the same caffeine content as coffee dependant on brew time, tea can replace the coffee.
As for the Jordans crunchy bars, you'll like this...
Jordans crunchy bar --- 464 Kcal/100g source
Mars Bar --------------- 452 Kcal/100g source
So...if you drink strong tea and eat Jordans crunchy bars, you would in fact better off health wise with the mars bar and coffee as stated in the formula.
In conclusion, in your individual case, because of your extra caffeine and calorie intake, you are better off than most in the reaction time stakes.
SS
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I was always taught to dump the lever PDQ or quicker, but then was shown by a very experienced and top flight instructor just how long you could take before things went to Rat Sh*t, to say the least the latter was very scary
Vfr
PR-B
Vfr
PR-B
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Originally Posted by Bug
No not an engine that gives prior warning of failure. A rotor design for a VLH that will give you time to scratch your ear before lowering the lever.
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Bug,
The drunk was searching for his keys around a light pole and a fellow stopped to help him. They crawled around for 15 minutes and then the Samaritan asked, "Precisely where did you lose the keys?" The drunk said, "about 100 yards over there." The Samaritan said, "Why are we looking over here?" The drunk said, "This is where the light is."
To build a rotor that has the inertia to allow you to sleep during the failure, you will leave one or two passengers home, and spend that payload on the rotor and rotor head. If protection from engine failure is what you seek, why specify a rotor solution? If you want engine safety, ask for safe engines!
The drunk was searching for his keys around a light pole and a fellow stopped to help him. They crawled around for 15 minutes and then the Samaritan asked, "Precisely where did you lose the keys?" The drunk said, "about 100 yards over there." The Samaritan said, "Why are we looking over here?" The drunk said, "This is where the light is."
To build a rotor that has the inertia to allow you to sleep during the failure, you will leave one or two passengers home, and spend that payload on the rotor and rotor head. If protection from engine failure is what you seek, why specify a rotor solution? If you want engine safety, ask for safe engines!
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Sid,
I have just done a 10 hour duty and experimented by eating as much cereal and crunchy bars as possible; interspersed with about 18 gallons of tea and coffee and a load of dodgy looking things stolen from the fridge;
The deduction is that from the bog it is physically impossible to start up and thus negating the potential to require to enter auto by lowering the lever after a DEF.
Faeces sculpting aside......2 secs is a decent figure to dangle ones trilby on I recon.
I have just done a 10 hour duty and experimented by eating as much cereal and crunchy bars as possible; interspersed with about 18 gallons of tea and coffee and a load of dodgy looking things stolen from the fridge;
The deduction is that from the bog it is physically impossible to start up and thus negating the potential to require to enter auto by lowering the lever after a DEF.
Faeces sculpting aside......2 secs is a decent figure to dangle ones trilby on I recon.
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but then was shown by a very experienced and top flight instructor just how long you could take before things went to Rat Sh*t, to say the least the latter was very scary
This alarms me just a little?? How did the instructor know "just how long you can take" before things got bad?
It's not like you can push the limits until you go past the point of no return, then go "right, just a LITTLE bit quicker than THAT" - is it?
Or am i missing something? Granted I am very inexperienced so "NICE" feedback wud be welcomed!!
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K chick,
The reason for the demo was in answer to my question " how long do you actually have to dump the lever, is it really only milliseconds" as I was on a yearly check ride the FTi showed me just what was the problem at lower perscentages of rotorspeed, as already stated it was not a nice feeling.
Peter R-B
The reason for the demo was in answer to my question " how long do you actually have to dump the lever, is it really only milliseconds" as I was on a yearly check ride the FTi showed me just what was the problem at lower perscentages of rotorspeed, as already stated it was not a nice feeling.
Peter R-B
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There's no strict answer to that question, depends on lots of factors. The often-quoted 1.3 seconds for the R22 isn't strictly true, depends on airspeed/alt/power in use/weight/temp/rpm, it also depends on what else you do when you lower the lever, ie hauling the cyclic back and standing the R22 on it's tail (as long as you have at least 60kts) will restore the RPM in the green pretty sharpish.
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Originally Posted by NickLappos
To build a rotor that has the inertia to allow you to sleep during the failure, you will leave one or two passengers home, and spend that payload on the rotor and rotor head. If protection from engine failure is what you seek, why specify a rotor solution? If you want engine safety, ask for safe engines!
Bug, this post will self-delete if you PM me...
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How long have you got
OK NIck Lappos hitthe nail on the head ie massive inertia requires big hub lots of weight. which requires more power etc,etc, I have a one fifth scale working model of a rotor system that overcomes all of these problems. The question is where do i find the man that is going to make me rich and be sure he is not going to rip me off Bug