The Propless C210
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The Propless C210
Ref Thread: Prang at Livingstone
My Fellow PPruners.
Yes I would like to start an new thread away from the terrible sadness of the accident.
However I would like to appeal that this be limited to the two question I am going to pose.
The Prop and Engine are on their way to USA for Forensic Analysis. Hopefully this will yield some answers as to why the separation occurred. I don’t think we should speculate on this aspect, although I would be interested to receive reports of similar incidents. Note that the separation was the prop hub separating from the engine flange. There was no snapping of the shaft.
I was told last week of a C210 at Lanseria about 15 years ago where the prop snapped off the shaft due to an unreported prop strike 2 weeks previously. This is definitely not the case here.
Anyway the 2 questions are:
1. What happens to the C of G and thus the glide and speed ratios?
2. What happens to the engine when the prop disappears?
1.With regard to this, here are the figures for the IT pilots to put into their computers. The BEW is 2300 lbs. Front Seats 363 lbs. Middle Seats 328 lbs. Rear Seats 289 lbs. Rear Shelf 20 lbs. Rear baggage 30 lbs. Fuel 414 lbs. MAUW 3744 lbs (3800 lbs is max)
Prop weight 77 lbs and equipment list shows the prop Arm Ins of -44,5.
How radical would the shift of the C of G been? How could this be duplicated in a test flight. Could one have some ballast in the front seat that could be shifted rearwards to simulate the change in C of G?
Having stabilized the aircraft into a glide what are the new stall speeds? Can the trim cope with the new C of G or would there have to be continuous forward pressure on the Control Column? Full flap handling? It is known that the actual decent rate was 900 fpm
3) Engine. Two opinions. On separation the engine races off and goes within seconds. Or it is controlled by the Governor and only goes when the oil is gone? In this instance the engine kept going for another 2 / 3 minutes but could this be due to the throttle being pulled back? Don’t forget that you have no forward vision due to an oiled up windscreen. You have an engine still going, but no power. Do you know you have actually lost your prop?
Thank You for your help
FB
My Fellow PPruners.
Yes I would like to start an new thread away from the terrible sadness of the accident.
However I would like to appeal that this be limited to the two question I am going to pose.
The Prop and Engine are on their way to USA for Forensic Analysis. Hopefully this will yield some answers as to why the separation occurred. I don’t think we should speculate on this aspect, although I would be interested to receive reports of similar incidents. Note that the separation was the prop hub separating from the engine flange. There was no snapping of the shaft.
I was told last week of a C210 at Lanseria about 15 years ago where the prop snapped off the shaft due to an unreported prop strike 2 weeks previously. This is definitely not the case here.
Anyway the 2 questions are:
1. What happens to the C of G and thus the glide and speed ratios?
2. What happens to the engine when the prop disappears?
1.With regard to this, here are the figures for the IT pilots to put into their computers. The BEW is 2300 lbs. Front Seats 363 lbs. Middle Seats 328 lbs. Rear Seats 289 lbs. Rear Shelf 20 lbs. Rear baggage 30 lbs. Fuel 414 lbs. MAUW 3744 lbs (3800 lbs is max)
Prop weight 77 lbs and equipment list shows the prop Arm Ins of -44,5.
How radical would the shift of the C of G been? How could this be duplicated in a test flight. Could one have some ballast in the front seat that could be shifted rearwards to simulate the change in C of G?
Having stabilized the aircraft into a glide what are the new stall speeds? Can the trim cope with the new C of G or would there have to be continuous forward pressure on the Control Column? Full flap handling? It is known that the actual decent rate was 900 fpm
3) Engine. Two opinions. On separation the engine races off and goes within seconds. Or it is controlled by the Governor and only goes when the oil is gone? In this instance the engine kept going for another 2 / 3 minutes but could this be due to the throttle being pulled back? Don’t forget that you have no forward vision due to an oiled up windscreen. You have an engine still going, but no power. Do you know you have actually lost your prop?
Thank You for your help
FB
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Hi Flying Bean,
What is the c of g of the empty aircraft at 2300lbs , or the moment, index, in order to start any calculation?
I am off to Europe in 2 hours and will look again tomorrow morning at the this topic.
What is the c of g of the empty aircraft at 2300lbs , or the moment, index, in order to start any calculation?
I am off to Europe in 2 hours and will look again tomorrow morning at the this topic.
Gatvol
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As one who has not had this happen, I can only guess. Maybe this thread should go to a forum with some fixed wing types can jump in and maybe you can find someone whos Prop went south...
I am guessing, that Yes CG will change but not that much. Also that he was probably in a climb and the engine RPM may have gone through the roof until the throttle was pulled back a bit.
Im sure some here will crunch the numbers for you.
I think the aircraft could be brought down to a walk away situation. In this case it was more than likely the landing area which caused the fatalities. That has not been mentioned. Maybe someone can fill us in.
I am guessing, that Yes CG will change but not that much. Also that he was probably in a climb and the engine RPM may have gone through the roof until the throttle was pulled back a bit.
Im sure some here will crunch the numbers for you.
I think the aircraft could be brought down to a walk away situation. In this case it was more than likely the landing area which caused the fatalities. That has not been mentioned. Maybe someone can fill us in.
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Flying Bean,
I have to concur with B Sousa's analysis. I doubt the that separation of the prop would cause a really significant change of CofG and that this change could cause the aircraft to become uncontrollable.
However, having read the explaination of the sequence of events in the original post, one comment interest me in particular. It is said that at one point durung the sequence of events, the prop seperated. Does this mean that the prop seperated before the oil leak or after?
The way I see it, if a prop should separate, it should be when it is under a certain amount of stress. i.e. when power is applied. And, in such a case, it is certain that even with a high reaction time, the engine would have certainly overreved.
Thus my analysis which would be the seperation of the prop prior to the oil leak causing engine overreving and destruction, therefore causing the major oil leak which prevented the pilot from seeing where he was going and performing a proper emergency landing which would have probably avoided the crash.
I once had a major oil leak on a 150 and I can tell you that it is impossible to see in front. Luckily, this was on rotation and all I had to do was cut power and land back on the runway. I can only imagine the impossibility of performing a forced landing in bush country with no front vis.
Regards,
ZS-NDV
I have to concur with B Sousa's analysis. I doubt the that separation of the prop would cause a really significant change of CofG and that this change could cause the aircraft to become uncontrollable.
However, having read the explaination of the sequence of events in the original post, one comment interest me in particular. It is said that at one point durung the sequence of events, the prop seperated. Does this mean that the prop seperated before the oil leak or after?
The way I see it, if a prop should separate, it should be when it is under a certain amount of stress. i.e. when power is applied. And, in such a case, it is certain that even with a high reaction time, the engine would have certainly overreved.
Thus my analysis which would be the seperation of the prop prior to the oil leak causing engine overreving and destruction, therefore causing the major oil leak which prevented the pilot from seeing where he was going and performing a proper emergency landing which would have probably avoided the crash.
I once had a major oil leak on a 150 and I can tell you that it is impossible to see in front. Luckily, this was on rotation and all I had to do was cut power and land back on the runway. I can only imagine the impossibility of performing a forced landing in bush country with no front vis.
Regards,
ZS-NDV
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I would agree that the loss of the prop, although it would cause a rearward shift in C of G, is unlikely to have made the aircraft uncontrollable - simple task to calculate if the C of G is still within limits but would need to know what the C of G position was on the aircraft and what the acceptable C of G envelope is. Effect on stall speed would be negligible - stall speed increases at the square route of the weight. Effect on glide ratio would be negligible - changing weight has no noticeable effect on glide ratio although decreasing weight would decrease sink rate marginally.
I am not an expert on the engine in the C210, but I would expect that a loss of the prop with the hub assembly would lead to a rapid loss of oil pressure. If the engine uses the system usually used in CS props, the crankshaft is hollow and supplies engine oil under pressure to the piston in the prop hub, regulated by the CS unit. If the entire prop and hub came off, I guess the engine would pump oil under pressure out of the unrestricted opening. Possibly someone with more expert knowledge could comment.
I am not an expert on the engine in the C210, but I would expect that a loss of the prop with the hub assembly would lead to a rapid loss of oil pressure. If the engine uses the system usually used in CS props, the crankshaft is hollow and supplies engine oil under pressure to the piston in the prop hub, regulated by the CS unit. If the entire prop and hub came off, I guess the engine would pump oil under pressure out of the unrestricted opening. Possibly someone with more expert knowledge could comment.
Last edited by wheels up; 13th Oct 2004 at 14:19.
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Total BEW 2,299.40 Moment 94,576.12 C of G 41.13"
The first transmission was "major oil leak" followed about 45 sec later by "loss of power - turning back".
His descent was controlled as we had several transmissions including the fact he had selected a field and that his engined "failed completely" some 3,5 mins after the first transmission.
There was never a mention of the prop loss which leads me to suspect maybe he did not know?
My guess at this stage is that the oil leak was the start of the separation and the 'loss of power' was the prop separating.
The aircraft impacted in trees near his selected field, wings level at the time.
FB
The first transmission was "major oil leak" followed about 45 sec later by "loss of power - turning back".
His descent was controlled as we had several transmissions including the fact he had selected a field and that his engined "failed completely" some 3,5 mins after the first transmission.
There was never a mention of the prop loss which leads me to suspect maybe he did not know?
My guess at this stage is that the oil leak was the start of the separation and the 'loss of power' was the prop separating.
The aircraft impacted in trees near his selected field, wings level at the time.
FB
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Flying bean,
Thanks for the details. I would tend to agree with your analysis in which the major oil leak could have been the start of the separation of the prop (and CS governor?).
In my view, as previously said, an oiled up windscreen is certainly the cause of the failed emergency landing. I don't know the terrain where he attempted to land but what is sure is that it trees were present, it would have been very difficult to manage to avoid them with no vis.
Do you know whether the prop separated with the governor or by itself?
Regards
ZS-NDV
Thanks for the details. I would tend to agree with your analysis in which the major oil leak could have been the start of the separation of the prop (and CS governor?).
In my view, as previously said, an oiled up windscreen is certainly the cause of the failed emergency landing. I don't know the terrain where he attempted to land but what is sure is that it trees were present, it would have been very difficult to manage to avoid them with no vis.
Do you know whether the prop separated with the governor or by itself?
Regards
ZS-NDV
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The C of G would not change dramatically enough to cause the aircraft to be uncontrollable. Full forward stick would be enough to ensure the glide is at a proper speed.
The rpm of the engine is "controlled" by the pitch of the prop - so no prop will mean an over revving motor. At normal throttle settings with no prop (ie no resistance) the revs would run away until the motor seized ot the throttle was pulled back.
I would guess that the fatalities were the result of un unfortunate forced landing (probably with limited visability) and not due to an uncontrollable aircraft.
I am an owner of a C210 so let me know if you would like me to get the POH and do an accurate calculation of the C of G.
The rpm of the engine is "controlled" by the pitch of the prop - so no prop will mean an over revving motor. At normal throttle settings with no prop (ie no resistance) the revs would run away until the motor seized ot the throttle was pulled back.
I would guess that the fatalities were the result of un unfortunate forced landing (probably with limited visability) and not due to an uncontrollable aircraft.
I am an owner of a C210 so let me know if you would like me to get the POH and do an accurate calculation of the C of G.
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Farmpilot,
All depends on what one means by oiled-up windscreen. In the present issue, it seems a large portion of the engine oil ended up on the top cowling and windscreen. I'm not sure how many quarts of oil are in the continental/lycoming C210 engine but even 1 qt spread on the windscreen is sufficient to block all front vision.
As said previously, something similar happened to me on rotation in a C150 and I had to taxi back with my head outside as vis was close to nil.
Regards,
ZS-NDV
All depends on what one means by oiled-up windscreen. In the present issue, it seems a large portion of the engine oil ended up on the top cowling and windscreen. I'm not sure how many quarts of oil are in the continental/lycoming C210 engine but even 1 qt spread on the windscreen is sufficient to block all front vision.
As said previously, something similar happened to me on rotation in a C150 and I had to taxi back with my head outside as vis was close to nil.
Regards,
ZS-NDV
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As stated, without a load the engine would overspeed and sieze almost instantly.
With a full load of pax and baggage the aircraft would have quite a serious aft CofG and loss of the prop wouldn't help. If travelling at sufficient airspeed to excercise elevator control the pilot would have caught it and descended in the glide but with quite a lot of forward pressure on the stick. Oil on the windscreen would have complicated matters and I believe it's a combination of these things that added up to a fatal accident. any of them on their own would have been survivable.
It's always the little things that add up to a major problem......
With a full load of pax and baggage the aircraft would have quite a serious aft CofG and loss of the prop wouldn't help. If travelling at sufficient airspeed to excercise elevator control the pilot would have caught it and descended in the glide but with quite a lot of forward pressure on the stick. Oil on the windscreen would have complicated matters and I believe it's a combination of these things that added up to a fatal accident. any of them on their own would have been survivable.
It's always the little things that add up to a major problem......
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Hmmm. Sorry Gentlemen too many inconsistencies here! Especially how long the engine would run.
I am going to recheck the exact time frame between the following radio calls:
Heavy oil leak
Loss of Power
Heavy Vibration
Engine finally quit.
The total incident time is approx 5 mins and the aircraft was 5000 ft agl. The prop ended up 5,8 nm from the crash site so separation took place right at the beginning.
Standby by while I recheck time line
FB
I am going to recheck the exact time frame between the following radio calls:
Heavy oil leak
Loss of Power
Heavy Vibration
Engine finally quit.
The total incident time is approx 5 mins and the aircraft was 5000 ft agl. The prop ended up 5,8 nm from the crash site so separation took place right at the beginning.
Standby by while I recheck time line
FB
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Flying Bean there may be a few inconsistancies but I think the still believe that the loss of the prop will be the first problem which was then compounded.
Try looking at it this way:
5.8nm from prop to crash site1
C210 glide speed approx 85kts(if i remember correctly)
= approx 1.5nm/min =approx 5 mins to impact
oil leak followed closely by loss of prop
change in Cof G
massive vibration
engine fails
no forward vision due to oil leak
loss of A/H (if vacum type)
pilot struggling due to rearward Cof G possibly leading to overcontrolling
great difficulty in find open space to land
All in All it would seem that the pilot had very little chance of a successful outcome considering his experience, i very much doubt if even a much higher level of experience would have help him either.
I think you have to look at maintenance as the main area of investigation as I very much doubt the pilot had much going in his favour in this situation.
Try looking at it this way:
5.8nm from prop to crash site1
C210 glide speed approx 85kts(if i remember correctly)
= approx 1.5nm/min =approx 5 mins to impact
oil leak followed closely by loss of prop
change in Cof G
massive vibration
engine fails
no forward vision due to oil leak
loss of A/H (if vacum type)
pilot struggling due to rearward Cof G possibly leading to overcontrolling
great difficulty in find open space to land
All in All it would seem that the pilot had very little chance of a successful outcome considering his experience, i very much doubt if even a much higher level of experience would have help him either.
I think you have to look at maintenance as the main area of investigation as I very much doubt the pilot had much going in his favour in this situation.
