S61 at Humberside, offshore engine failure!
Helicomparitor,
Accepted - in that case make the probability of the second failure 1:1,000 and the probability of one followed by the second (from independent cause) will still be 1:100,000,000.
Crab,
Clearly you are conditioned by your military experience; those of us who left the military and then flew as civilians are conditioned more by that experience.
Examine your proposition; the engine failure has been contained and the helicopter flown back to an airfield. On arrival at the airfield, the helicopter is kept at altitude until an autorotation is initiated.
Now consider the probability of an engine failure (using Helicomparitor's probability and the minute spent on finals 1: 60 x 100,000,000) against that of successfully completing an autorotation with (up to) 19 passengers on board.
Add to that the knowledge that there are far more accidents associated with training for autorotation than the real thing and that most engine failures in flight leading to autorotation do not result in outcomes without damage and the risk assessment is now in perspective.
Jim
Accepted - in that case make the probability of the second failure 1:1,000 and the probability of one followed by the second (from independent cause) will still be 1:100,000,000.
Crab,
Clearly you are conditioned by your military experience; those of us who left the military and then flew as civilians are conditioned more by that experience.
Examine your proposition; the engine failure has been contained and the helicopter flown back to an airfield. On arrival at the airfield, the helicopter is kept at altitude until an autorotation is initiated.
Now consider the probability of an engine failure (using Helicomparitor's probability and the minute spent on finals 1: 60 x 100,000,000) against that of successfully completing an autorotation with (up to) 19 passengers on board.
Add to that the knowledge that there are far more accidents associated with training for autorotation than the real thing and that most engine failures in flight leading to autorotation do not result in outcomes without damage and the risk assessment is now in perspective.
Jim
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In the early days of the Okanagan Helicopters Beaufort Sea & High Arctic ops we always ran 26 pax in the 61 with no F/A. I understand they are now down to 19.
In Edson we ran 29 (OKB?) pax with the 61L and 26 pax in the N. The destination at the mine was Hd 8500'+ in the summer.
No fuel dump on any of these a/c, but they were mostly shorter legs, so we didn't carry much center tank gas. We still used 20,500 for T/O though (or 22,000+ lbs external load), mostly.
Note 1: The Canadian East Coast was much different and more like the North Sea but with less wind and more fog.
Note 2: I was never good enough to pull off a full-on auto with this kind of load in a 61.
Generally, for an OEI approach we used a fairly flat rotor-disc-loaded (but with a little bit of power in reserve for Momma) and ran the the puppy's on.
Note 3: If you let the IAS drop below about 42 knts (at high GW) - she will fall like a stone.
Keep her above that and she's perfectly happy on one engine.
ps Been there
In Edson we ran 29 (OKB?) pax with the 61L and 26 pax in the N. The destination at the mine was Hd 8500'+ in the summer.
No fuel dump on any of these a/c, but they were mostly shorter legs, so we didn't carry much center tank gas. We still used 20,500 for T/O though (or 22,000+ lbs external load), mostly.
Note 1: The Canadian East Coast was much different and more like the North Sea but with less wind and more fog.
Note 2: I was never good enough to pull off a full-on auto with this kind of load in a 61.
Generally, for an OEI approach we used a fairly flat rotor-disc-loaded (but with a little bit of power in reserve for Momma) and ran the the puppy's on.
Note 3: If you let the IAS drop below about 42 knts (at high GW) - she will fall like a stone.
Keep her above that and she's perfectly happy on one engine.
ps Been there
Last edited by oleary; 17th Oct 2008 at 08:33.
JimL - you make it sound like an autorotation is a. dangerous and b. difficult - even at MAUM it is a straight-forward manoeuvre, especially straight in to a runway.
Consider your proposition - one engine has failed (for an undetermined reason) and you elect to fly a normal approach to running landing on your runway. During the 60 seconds on finals (I think it would probably be a bit longer), the second engine decides to let go as well and you crash into the undershoot trashing the aircraft and injuring/killing the pax. What exactly is your defence? I was following the RFM and anyway we don't practice autos because it's not good for the airframe?
I'm not saying this is the only way of doing it or that it would be possible or practical in all situations but I offer it up as an airmanship consideration to those who might not have considered this course of action because they have only been conditioned by their civilian experience.
I am clearly not alone in my thinking vis Bertie and Brian so maybe those who were so quick to condemn out of hand should maybe pause for thought.
Roundwego - in the many hours of single-engine helicopter flying I have done, the consequences of an engine fail were seldom far from my mind but as long as you kept out of the avoid curve (H-V curve) you could operate safe in the knowledge that you could enter auto and make an EoL.
A heavy twin full of pax on a single engine would have a much bigger avoid curve and so the procedure for flying a SE approach should be modified to accommodate that.
Consider your proposition - one engine has failed (for an undetermined reason) and you elect to fly a normal approach to running landing on your runway. During the 60 seconds on finals (I think it would probably be a bit longer), the second engine decides to let go as well and you crash into the undershoot trashing the aircraft and injuring/killing the pax. What exactly is your defence? I was following the RFM and anyway we don't practice autos because it's not good for the airframe?
I'm not saying this is the only way of doing it or that it would be possible or practical in all situations but I offer it up as an airmanship consideration to those who might not have considered this course of action because they have only been conditioned by their civilian experience.
I am clearly not alone in my thinking vis Bertie and Brian so maybe those who were so quick to condemn out of hand should maybe pause for thought.
Roundwego - in the many hours of single-engine helicopter flying I have done, the consequences of an engine fail were seldom far from my mind but as long as you kept out of the avoid curve (H-V curve) you could operate safe in the knowledge that you could enter auto and make an EoL.
A heavy twin full of pax on a single engine would have a much bigger avoid curve and so the procedure for flying a SE approach should be modified to accommodate that.
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Good Job Navy Torque
Crab,
Keeping it simple (No Vtoss/Vy/Vbrocs etc.)
We at Bristow (and CHC I believe) irrespective of twin type fly Commercial Air Transport (CAT) take-off and landing profiles to either Performance Class One (No exposure in the event of a power plant failure) or Performance Class Two (possible exposure for minimum period) depending on space available for take off or landing. We calculate and adhere to decision points (TDP and LDP) for each profile.
In the event of an engine failure in flight we would in almost all circumstances
Until LDP we are well outside the SINGLE ENGINE H/V curve and at LDP (for example in a Bell 412 at 100 feet rad alt and 40 kts IAS) reach the leading edge of the SINGLE ENGINE H/V curve - we maintain 40 kts to 50ft rad alt then reduce speed and altitude by flaring for a running landing staying under and clear of the curve throughout the profile.
With both engines performing impeccably or following a failure we avoid any exposure!
Hopefully you will now appreciate that we have absolutely no requirement to attempt an autorotation which may be a "piece of cake" (as Biggles and your good self would probably say!) to Chaps of your calibre but to most of us other mere mortals normally takes several attempts during Sim rides before you avoid the "red death" since we have little opportunity for practice during our day jobs.
Even in the event of a tail rotor control failure where normal options are either a full autorotation or high speed run on landing - I personally advocate a mid option which is a 1000 ft/min powered descent at 40 knots (approximately) to the left or right side of the runway (depending on rotor rotation direction) followed by a gentle flare and rapid throttle shut off (to a last minute auto landing) at approximately 30 feet to a short run on remaining at all times on the runway. Try it next time in the Sim (doesn't matter which type) - it works and has a much higher survival rate than either of the other options!
Trog
Consider your proposition - one engine has failed (for an undetermined reason) and you elect to fly a normal approach to running landing on your runway.
We at Bristow (and CHC I believe) irrespective of twin type fly Commercial Air Transport (CAT) take-off and landing profiles to either Performance Class One (No exposure in the event of a power plant failure) or Performance Class Two (possible exposure for minimum period) depending on space available for take off or landing. We calculate and adhere to decision points (TDP and LDP) for each profile.
In the event of an engine failure in flight we would in almost all circumstances
elect to fly a normal approach to running landing on your runway.
With both engines performing impeccably or following a failure we avoid any exposure!
Hopefully you will now appreciate that we have absolutely no requirement to attempt an autorotation which may be a "piece of cake" (as Biggles and your good self would probably say!) to Chaps of your calibre but to most of us other mere mortals normally takes several attempts during Sim rides before you avoid the "red death" since we have little opportunity for practice during our day jobs.
Even in the event of a tail rotor control failure where normal options are either a full autorotation or high speed run on landing - I personally advocate a mid option which is a 1000 ft/min powered descent at 40 knots (approximately) to the left or right side of the runway (depending on rotor rotation direction) followed by a gentle flare and rapid throttle shut off (to a last minute auto landing) at approximately 30 feet to a short run on remaining at all times on the runway. Try it next time in the Sim (doesn't matter which type) - it works and has a much higher survival rate than either of the other options!
Trog
And I thought we were talking about an S61 full of pax not a 412 Trog - I suspect the SE HV curve is a good deal bigger than the 412s.
Your defence is that you don't do it because you don't practice it - my answer is then go and practice it. You shouldn't be flying pax around if you can't do autos.
An ex BA 747 training captain told me that senior pilots were having to hire light twins to keep their flying skills going - their sim training was more systems failure and management thereof and they never got to fly the real aircraft because they were always full of pax. Their pure flying skills eroded in the same way you are bemoaning yours going, simply because no-one mandates you do GH every month (not profitable). Do you really think that is safe or sensible?
Many people believe that what can be done in the sim will work in real life, especially with TR failures, without understanding that the sim (any sim) isn't modelled accurately for TR malfunctions - you need the data from the real aircraft in the real configuration for that, not a best guess from interpolated data.
You carry on convincing yourself that you know better than evryone else but you'll find that 40 kts isn't sufficient to keep the nose straight with no TR and you can't expect the pitot-static system to measure it accurately anyway, especially with the high levels of sideslip involved.
Your defence is that you don't do it because you don't practice it - my answer is then go and practice it. You shouldn't be flying pax around if you can't do autos.
An ex BA 747 training captain told me that senior pilots were having to hire light twins to keep their flying skills going - their sim training was more systems failure and management thereof and they never got to fly the real aircraft because they were always full of pax. Their pure flying skills eroded in the same way you are bemoaning yours going, simply because no-one mandates you do GH every month (not profitable). Do you really think that is safe or sensible?
Many people believe that what can be done in the sim will work in real life, especially with TR failures, without understanding that the sim (any sim) isn't modelled accurately for TR malfunctions - you need the data from the real aircraft in the real configuration for that, not a best guess from interpolated data.
You carry on convincing yourself that you know better than evryone else but you'll find that 40 kts isn't sufficient to keep the nose straight with no TR and you can't expect the pitot-static system to measure it accurately anyway, especially with the high levels of sideslip involved.
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Is this boy for real?
You carry on convincing yourself that you know better than evryone else
Forgive me please for offering an opinion with my limited experience!
After leaving the RN in 1979 with only 2500 hrs of Seaking time including SAR I have obviously in the last 29 years and a further 14,000 hrs (including over 6500 on S61N North Sea and Far East) not yet amassed sufficient experience to comment or offer suggestions to an Aviator of your calibre. As a TRE/IRE/SFE I obviously believe that everything that I teach in a Simulator is absolutely accurate and I have failed over the years to notice the differences in observed simulation scenarios between simulators built by different companies.
My suggestion that we follow Well Established Approved Civilian procedures obviously offends you and what do we know anyway?
My presumption that descending at 1000 ft/min at associated low power setting will greatly reduce the need for anti torque and permit almost any helicopter to fly straight without as much bank applied up until the point that you enter autorotation as you flare is obviously bollocks and I would be much better in full auto.
I will crawl back to my cave dwelling immediately.
Trog
Trog - I guess I hit a nerve there then.
At the point where you have to start telling me how experienced you are and all the things you have been to defend your position, your argument is weakened.
By your own admission the accepted procedures for TR fail are either auto or high speed run on yet you advocate something different - how many TR failures have you had to base this technique on? And have you ever prcatised this technique with zero TR thrust in a real aircraft?
BTW do you mean single engine HV curve (ie when you are on one engine and it fails) or do you mean the Safe single engine envelope (where you are on two but will still fly if one goes)?
The military have never seen fit to produce a SE HV curve for a twin, maybe it is different in the civvy world.
At the point where you have to start telling me how experienced you are and all the things you have been to defend your position, your argument is weakened.By your own admission the accepted procedures for TR fail are either auto or high speed run on yet you advocate something different - how many TR failures have you had to base this technique on? And have you ever prcatised this technique with zero TR thrust in a real aircraft?
BTW do you mean single engine HV curve (ie when you are on one engine and it fails) or do you mean the Safe single engine envelope (where you are on two but will still fly if one goes)?
The military have never seen fit to produce a SE HV curve for a twin, maybe it is different in the civvy world.
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A very interesting thread... for my tupence if I still had an engine working on a ME type and on the balance of probability of the remaining engine also failing isn't it safer and easier to stick with a tried and tested SE profile and run the aircraft onto a runway rather than decide to go for an auto, which you may not have practiced for a while? I guess thats where the military have the advantage when it comes to not having to worry about trivia, like costs!
I guess there are numerous variables to this argument no least the aircraft & AUM, crew recency, airfield and weather... in this case the crew got home safe...
I guess there are numerous variables to this argument no least the aircraft & AUM, crew recency, airfield and weather... in this case the crew got home safe...
Trog,
I like your thinking about the event of a tail rotor control failure, but this sentences about OEI lading confuses me.
I may be not understanding your post, are you telling me that staying out of the H/V you are safe in case the last engine fails in short finals? that curve in the 412 RFM doesn't mean your are safe to do an auto, it's just the profile to achieve a safe lading with OEI onto a prepared surface, I'm sure you know that, but the issue here is the landing in OEI condition.
As crab says
I can't remember a safe single engine H/V curve in the 412 RFM.
Regards
Aser
I like your thinking about the event of a tail rotor control failure, but this sentences about OEI lading confuses me.
In the event of an engine failure in flight we would in almost all circumstances
Quote:
elect to fly a normal approach to running landing on your runway.
Until LDP we are well outside the SINGLE ENGINE H/V curve and at LDP (for example in a Bell 412 at 100 feet rad alt and 40 kts IAS) reach the leading edge of the SINGLE ENGINE H/V curve - we maintain 40 kts to 50ft rad alt then reduce speed and altitude by flaring for a running landing staying under and clear of the curve throughout the profile.
With both engines performing impeccably or following a failure we avoid any exposure!
Quote:
elect to fly a normal approach to running landing on your runway.
Until LDP we are well outside the SINGLE ENGINE H/V curve and at LDP (for example in a Bell 412 at 100 feet rad alt and 40 kts IAS) reach the leading edge of the SINGLE ENGINE H/V curve - we maintain 40 kts to 50ft rad alt then reduce speed and altitude by flaring for a running landing staying under and clear of the curve throughout the profile.
With both engines performing impeccably or following a failure we avoid any exposure!
As crab says
BTW do you mean single engine HV curve (ie when you are on one engine and it fails) or do you mean the Safe single engine envelope (where you are on two but will still (ACHIEVE A SAFE LADING) fly if one goes)?
I can't remember a safe single engine H/V curve in the 412 RFM.
Regards
Aser
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Sorry for the confusion Aser
Farmer
You are right - it's amazing how we survive.
Absolute CRAP - would you agree with: -
With both engines performing impeccably or following a failure we reduce exposure to an absolute minimum!
BHT-412-FM-4
The graph at 1.4 is titled "Height velocity diagram (OEI)"
I didn't actually say "safe single engine H/V curve" but I can see where I caused confusion.
Re the T/R failure thing - think it through - the last 30 or so guys that I have discussed this with and asked to play with the profile in 3 x different Sims agree that it is at least worth considering as an option!
Trog
Why can't you accept it? You're wrong.
You, and the manufacturers, and the operators, and the CAA, and the FAA, and the...
You, and the manufacturers, and the operators, and the CAA, and the FAA, and the...
You are right - it's amazing how we survive.
With both engines performing impeccably or following a failure we avoid any exposure!
Absolute CRAP - would you agree with: -
With both engines performing impeccably or following a failure we reduce exposure to an absolute minimum!
BHT-412-FM-4
1-10. HEIGHT-VELOCITY
The height-velocity limitations are critical in the event of single engine failure during takeoff, landing, or other operation near the surface (figure 1-4). The AVOID area of the Height-Velocity diagram defines the combinations of airspeed and height above ground from which a safe single engine landing on a smooth, level, firm surface cannot be assured.
The height-velocity limitations are critical in the event of single engine failure during takeoff, landing, or other operation near the surface (figure 1-4). The AVOID area of the Height-Velocity diagram defines the combinations of airspeed and height above ground from which a safe single engine landing on a smooth, level, firm surface cannot be assured.
The graph at 1.4 is titled "Height velocity diagram (OEI)"
I can't remember a safe single engine H/V curve in the 412 RFM.
I didn't actually say "safe single engine H/V curve" but I can see where I caused confusion.
Re the T/R failure thing - think it through - the last 30 or so guys that I have discussed this with and asked to play with the profile in 3 x different Sims agree that it is at least worth considering as an option!
Trog
Last edited by Troglodita; 20th Oct 2008 at 17:12. Reason: Remove unecessary rude comments about Crab
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Autorotative approach
Is Crab suggesting an autorative descent over an airfield and then converting to a running landing? A full blooded auto to the flare recovery does seem a little drastic old boy!!!!
Trog - you said SINGLE ENGINE H/V curve twice and the argument that accompanied it clearly tried to refute my assertion that the 'normal' or 'approved' or 'RFM' single engine approach puts you firmly in the avoid curve (I will call it that to avoid confusion).
You can call me as many names as you like but at least be man enough to admit when you are wrong.
Artificial Horizon - I believe the RN still do autos to a running landing and having flown the profile on a CFS visit to Malaysia it is a very simple and safe procedure, especially since you still have one engine to cushion the landing just like at the end of a normal SE approach. The big difference is that if the other engine quits at ANY stage during the approach, you are already perfectly setup for your endorsement-winning EOL. Not so for the 'normal/approved/RFM' profile.
You can call me as many names as you like but at least be man enough to admit when you are wrong.
Artificial Horizon - I believe the RN still do autos to a running landing and having flown the profile on a CFS visit to Malaysia it is a very simple and safe procedure, especially since you still have one engine to cushion the landing just like at the end of a normal SE approach. The big difference is that if the other engine quits at ANY stage during the approach, you are already perfectly setup for your endorsement-winning EOL. Not so for the 'normal/approved/RFM' profile.
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Crab's original post read:
'...the safest profile (in case the other one quit) would be a high level VMC transit followed by an autorotative approach to a flare recovery and running landing.'
If by safest it is meant the profile that provides the highest likelihood of a successful outcome in the event of the second engine failing, isn't Crab right?
Could those of you who disagree with him elaborate on where the stages of his profile become more dangerous than the other ones suggested.
Thanks,
HAL
'...the safest profile (in case the other one quit) would be a high level VMC transit followed by an autorotative approach to a flare recovery and running landing.'
If by safest it is meant the profile that provides the highest likelihood of a successful outcome in the event of the second engine failing, isn't Crab right?
Could those of you who disagree with him elaborate on where the stages of his profile become more dangerous than the other ones suggested.
Thanks,
HAL
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Sorry Navy Torque for stealing your post
Crab,
I did admit without reservation in my reply to Aser that I was wrong in my highlighted statement which incorrectly asserts that there is no exposure in the event of the remaining engine failing. I admitted it was
I did say single engine H/V curve twice - I will say it a third time - the H/V graph in the Bell Flight Manual is titled: -
"Height velocity diagram (OEI)"
I think that a One Engine Inoperative H/V diagram and a single engine H/V diagram are one and the same for a machine with 2 engines!
Strangely enough I don't refute your high level transit part at all (basic airmanship) and if (a HUGE IF) we were given sufficient time (and Company and Client) permission to hone our autorotative skills to the point where we could guarantee a "greaser" every single landing I would agree with that your suggestion would reduce exposure even further than our existing profile.
The latter is unfortunately never going to happen - I am painfully aware when carrying out recurrency check and training on both the Sim and the helicopter of general poor skill levels of otherwise excellent medium to large twin drivers when it comes to autorotations.
We have the facilities and requirement for our 206L4 & 407 offshore pilots in Nigeria and the GOM to carry out full engine offs to the water during annual recurrency training in Louisiana - We use a Bell 206 on fixed floats. This is excellent value and after a couple of days, a 180 degree engine off auto from 80 knots and 400 feet downwind becomes a routine event. I would love all Crews to attend this training annually but the perceived safety of the twin and the cost of providing this training precludes this in the so called "Real World" that we operate in.
Once again - our standard laid down Class One profiles are designed to keep us out of the OEI/Single Engine H/V curve at all times to minimise exposure. If we can't achieve this we are flying a Class Two profile which may place us in the H/V curve for short periods - e.g. Operating to a confined area or post commital point to an offshore platform.
Apologies for my rudeness but maybe you have been told once in a while that you can be exasperating.
Trog
I did admit without reservation in my reply to Aser that I was wrong in my highlighted statement which incorrectly asserts that there is no exposure in the event of the remaining engine failing. I admitted it was
Absolute Crap.
I did say single engine H/V curve twice - I will say it a third time - the H/V graph in the Bell Flight Manual is titled: -
"Height velocity diagram (OEI)"
I think that a One Engine Inoperative H/V diagram and a single engine H/V diagram are one and the same for a machine with 2 engines!
Strangely enough I don't refute your high level transit part at all (basic airmanship) and if (a HUGE IF) we were given sufficient time (and Company and Client) permission to hone our autorotative skills to the point where we could guarantee a "greaser" every single landing I would agree with that your suggestion would reduce exposure even further than our existing profile.
The latter is unfortunately never going to happen - I am painfully aware when carrying out recurrency check and training on both the Sim and the helicopter of general poor skill levels of otherwise excellent medium to large twin drivers when it comes to autorotations.
We have the facilities and requirement for our 206L4 & 407 offshore pilots in Nigeria and the GOM to carry out full engine offs to the water during annual recurrency training in Louisiana - We use a Bell 206 on fixed floats. This is excellent value and after a couple of days, a 180 degree engine off auto from 80 knots and 400 feet downwind becomes a routine event. I would love all Crews to attend this training annually but the perceived safety of the twin and the cost of providing this training precludes this in the so called "Real World" that we operate in.
Once again - our standard laid down Class One profiles are designed to keep us out of the OEI/Single Engine H/V curve at all times to minimise exposure. If we can't achieve this we are flying a Class Two profile which may place us in the H/V curve for short periods - e.g. Operating to a confined area or post commital point to an offshore platform.
Apologies for my rudeness but maybe you have been told once in a while that you can be exasperating.
Trog
Trog - 
I know I can get peoples backs up but that is often the problem with the written word - it is open to interpretation by the reader and often the tone and content/intent of my posts is lost on some. Back to English school for me then
I know I can get peoples backs up but that is often the problem with the written word - it is open to interpretation by the reader and often the tone and content/intent of my posts is lost on some. Back to English school for me then
Crab.
There are vast differences between military and civil flying and main one is the people in the back. A situation where you have an engine failure and fly a profile to guard against the other failing is correct under certain circumstances, but not all. I have flown close it once when I returned to Aberdeen with BOTH fuel filter lights on which is as close as I would like to be to a double engine failiure. I cannot think of another reason for doing it when you have a contained engine failure or no common source reason for the first failure.
Military crew or passengers do not worry overtly as to what is going on because they are a disiplined force and will obey and listen to instructions or explanations. Civilian passengers are not quite the same thing remembering that we are in the EU and some of their English may not be up to scratch. Any time that something does not go to plan, especially in a perceived dangerous envirionment such as an offshore helicopter, will cause serious concern or even panic.
It is hard to believe that during the time of the BV234 most of the Shell passengers believed that the British Airways Helicopters claim of ‘twin rotor safety’ meant that a Chinook could fly with just one rotor operating. Even now the vast majority of offshore passengers believe that if both engines fail on any helicopter the rotors stop and the whole lot plunges to earth. Should you have an engine failiure, especially a noisy one, those behind you will think that they have moved a big step closer to the grim reaper.
You will have little success explaining OEI performance on the way back because passengers are notorious for not understanding something they do not expect over the PA, even more in a noisy cabin. You will have even more trouble trying to explain autorotative performance. Should you approach the airfield at a perceived high level, drop the lever for your initial auto and the good engine throttles back, you will have a very good chance of at least one major cardiac arrest within your passengers.
There are tens of thousands of single engined helicopters flying around this world and a multi down to one engine is in the same league. Some twins, at a typical landing weight returning from offshore, have higher power/weight ratio on one engine than some single engined examples have total. Singles do not fly an autorotative approach profile so why should a twin on one?
Avoid curves for twins are so that they can recover on one engine. Avoid curves for singles are so that they can recover. If something happens to be in the way, that’s tough. Good singles pilots try to avoid that. The present procedures, as used by every civil operator and tested and certified by the manufacturer, has always worked so why fix it.
Taking the argument to the logical conclusion if a Boeing 737 suffered an engine failure, on your advice it would approach at 1,000 feet until within gliding range of the runway, cut the remaining thottle and stuff the nose down for a glide approach and landing.
I can see the headlines now.
There are vast differences between military and civil flying and main one is the people in the back. A situation where you have an engine failure and fly a profile to guard against the other failing is correct under certain circumstances, but not all. I have flown close it once when I returned to Aberdeen with BOTH fuel filter lights on which is as close as I would like to be to a double engine failiure. I cannot think of another reason for doing it when you have a contained engine failure or no common source reason for the first failure.
Military crew or passengers do not worry overtly as to what is going on because they are a disiplined force and will obey and listen to instructions or explanations. Civilian passengers are not quite the same thing remembering that we are in the EU and some of their English may not be up to scratch. Any time that something does not go to plan, especially in a perceived dangerous envirionment such as an offshore helicopter, will cause serious concern or even panic.
It is hard to believe that during the time of the BV234 most of the Shell passengers believed that the British Airways Helicopters claim of ‘twin rotor safety’ meant that a Chinook could fly with just one rotor operating. Even now the vast majority of offshore passengers believe that if both engines fail on any helicopter the rotors stop and the whole lot plunges to earth. Should you have an engine failiure, especially a noisy one, those behind you will think that they have moved a big step closer to the grim reaper.
You will have little success explaining OEI performance on the way back because passengers are notorious for not understanding something they do not expect over the PA, even more in a noisy cabin. You will have even more trouble trying to explain autorotative performance. Should you approach the airfield at a perceived high level, drop the lever for your initial auto and the good engine throttles back, you will have a very good chance of at least one major cardiac arrest within your passengers.
There are tens of thousands of single engined helicopters flying around this world and a multi down to one engine is in the same league. Some twins, at a typical landing weight returning from offshore, have higher power/weight ratio on one engine than some single engined examples have total. Singles do not fly an autorotative approach profile so why should a twin on one?
Avoid curves for twins are so that they can recover on one engine. Avoid curves for singles are so that they can recover. If something happens to be in the way, that’s tough. Good singles pilots try to avoid that. The present procedures, as used by every civil operator and tested and certified by the manufacturer, has always worked so why fix it.
Taking the argument to the logical conclusion if a Boeing 737 suffered an engine failure, on your advice it would approach at 1,000 feet until within gliding range of the runway, cut the remaining thottle and stuff the nose down for a glide approach and landing.
I can see the headlines now.
Join Date: May 2002
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To continue Fareastdrivers argument,with our litigous society, if one flew a profile that was outside of the recomended Flight Manual or SOP from the emergency section of the Ops Manual, you can be sure that one (at least) passenger would suffer from some sort of post-traumatic stress. Compensation about never being able to fly in a helicopter/work offshore again, from a smart lawyers angle, could amount to a huge amount. And of course, where one went, others would surely follow.
The opportunity to practice autorotative approaches, without passengers on-board, would be minimal, so the chances of a successful one in an emergency would accordingly decrease.
The opportunity to practice autorotative approaches, without passengers on-board, would be minimal, so the chances of a successful one in an emergency would accordingly decrease.