Grand Van down at Eros
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Heavy Van, no flaps = Are you crazy!
She will battle!
20 Flaps climb to at least 300 ft AGL, accelerate through 90 kts, then flaps 10. Accelerate through 100 kts and minimum 500 ft AGL, flaps 0. That is how I was trained and is the way I train new Van pilots.
She will battle! 20 Flaps climb to at least 300 ft AGL, accelerate through 90 kts, then flaps 10. Accelerate through 100 kts and minimum 500 ft AGL, flaps 0. That is how I was trained and is the way I train new Van pilots.
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I tend to agree with Nyathi here, I was also trained to select flap up once stable at 100kts min, and 500ft agl. You are able to decrease some of the drag by selecting 5 degrees flap, and "step climb" I have only done this in cases where it was hot and high conditions, with a heavy load.. very sad to hear about this unfortunate incident! Condolences!
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Let's not get bogged down in the usual mudslinging, for once 
So now that we have established from the rated van-pilots that there is no procedure for taking off sans flap so as to climb out better, we may have an additional indicator of what caused this latest disaster.
So now that we have established from the rated van-pilots that there is no procedure for taking off sans flap so as to climb out better, we may have an additional indicator of what caused this latest disaster.
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Eros Van
AXE123
I'm not accusing anyone, and I just might be more informed than you think, but the fact of the matter is that a Van went down wich was obviously heavy and no engine problems were reported, this led to the death of innocent lives. You can only use flap or retain your current flap setting if you 1 or both of the following, AIRSPEED and EXCESS POWER.
If you dont climb with flap you dont have one of these, more flap will kill you and raising it increases your stall speed. There was not allot of options for the poor pilot, but how did he get in that situation, prevention is better than cure.
I'm not accusing anyone, and I just might be more informed than you think, but the fact of the matter is that a Van went down wich was obviously heavy and no engine problems were reported, this led to the death of innocent lives. You can only use flap or retain your current flap setting if you 1 or both of the following, AIRSPEED and EXCESS POWER.
If you dont climb with flap you dont have one of these, more flap will kill you and raising it increases your stall speed. There was not allot of options for the poor pilot, but how did he get in that situation, prevention is better than cure.
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@Stierado - so what is the logical conclusion if the Van is limited to 10kts tailwind ? No takeoff.
BUT - I doubt that there would have been a tailwind greater than 10 knots so 01 would have been the runway to take, especially when flying out at MTOW.
As we can read - the wind was probably just a small contributing factor to the real problem. The reason why I mentioned it, was to give the all pilots that read in this forum and that don't know FYWE a hint to keep in the back of their minds: if you ever have to fly out of Eros in conditions described above, take RWY 01 unless the tailwind component is greater than 12 knots. And if you are in doubt, ask the collegues, that have been flying there for years. If the engine was up to performance, then this is just another accident at Eros that can be attributed to human performance...and could so have been prevented.
BUT - I doubt that there would have been a tailwind greater than 10 knots so 01 would have been the runway to take, especially when flying out at MTOW.
As we can read - the wind was probably just a small contributing factor to the real problem. The reason why I mentioned it, was to give the all pilots that read in this forum and that don't know FYWE a hint to keep in the back of their minds: if you ever have to fly out of Eros in conditions described above, take RWY 01 unless the tailwind component is greater than 12 knots. And if you are in doubt, ask the collegues, that have been flying there for years. If the engine was up to performance, then this is just another accident at Eros that can be attributed to human performance...and could so have been prevented.
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Clearly with close-in obstacles the criterion is angle, not rate of climb? Isn't that where flaps come in?
As I recall 105Kts was the speed for flap retraction and initial climb, and as a colleague discovered much to his chagrin, a Caravan really does not want to get airborne at all with no flap selected, and I suspect that even if it did it; a) wouldn't want to climb and; b)certainly wouldn't accelerate. = a big mess a mile or so off the end of the runway...
ie - try a take off with no flap and your first problem is a vastly increased ground run, and then either accelerate in almost level flight to 105Kt before climbing, or try and fail to climb at high alpha and 80Kt, and mush it in.
As the photo suggests the accident aircraft seems to have had no flap deployed one might reach a logical conclusion..?
As I recall 105Kts was the speed for flap retraction and initial climb, and as a colleague discovered much to his chagrin, a Caravan really does not want to get airborne at all with no flap selected, and I suspect that even if it did it; a) wouldn't want to climb and; b)certainly wouldn't accelerate. = a big mess a mile or so off the end of the runway...
ie - try a take off with no flap and your first problem is a vastly increased ground run, and then either accelerate in almost level flight to 105Kt before climbing, or try and fail to climb at high alpha and 80Kt, and mush it in.
As the photo suggests the accident aircraft seems to have had no flap deployed one might reach a logical conclusion..?
Last edited by Agaricus bisporus; 18th Nov 2009 at 00:53.
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I am told that the aircraft didn't mush in but stalled and spun in.
Fits with the pics. There is no apparent horizonal progress made by the aircraft after initial impact, and the damage is consistent with a steep angle of arrival.
Nonetheless, very sad indeed.
Fits with the pics. There is no apparent horizonal progress made by the aircraft after initial impact, and the damage is consistent with a steep angle of arrival.
Nonetheless, very sad indeed.
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AS was said by PP, if you have not flown out of Eros it is pretty hard to imagine the scenario. Rwy 19 is a last resort as is the 27/09. The only ````runway is 01.
Sloping high ground in all directions except North. Pilots that are familier and get indoctrined into flying in FYWE will all know this. Even if there is a 5 kt wind favouring 19 the turbulance over the Komas Hochland will make your life a real misery.
This has been proven time and time again guys, and we still see this happening in Eros.
My thinkning is excactly this, the Van was performing, he was in WB, when he got airborne he turned right, this is where the mountain wave pushed him back down, combination of bank angle and loss of airspeed fighting to stay away from the ground, caused the aircraft to drop a wing and stall in.
Why I think this, it has nearly happened to me and I was lucky to learn and survive.
I have flown a single piston to a high performance turbine out of Eros and never ever tried the same trick again. 3 years there taught me a lot of respect for that airport.
It is a very charming and happy place Eros airport and a perfect GA airport, but if you fly there at least chat to the locals and get the Gen.
R.I.P to the guys and condolences to the familys in this tradgey
Sloping high ground in all directions except North. Pilots that are familier and get indoctrined into flying in FYWE will all know this. Even if there is a 5 kt wind favouring 19 the turbulance over the Komas Hochland will make your life a real misery.
This has been proven time and time again guys, and we still see this happening in Eros.
My thinkning is excactly this, the Van was performing, he was in WB, when he got airborne he turned right, this is where the mountain wave pushed him back down, combination of bank angle and loss of airspeed fighting to stay away from the ground, caused the aircraft to drop a wing and stall in.
Why I think this, it has nearly happened to me and I was lucky to learn and survive.
I have flown a single piston to a high performance turbine out of Eros and never ever tried the same trick again. 3 years there taught me a lot of respect for that airport.
It is a very charming and happy place Eros airport and a perfect GA airport, but if you fly there at least chat to the locals and get the Gen.
R.I.P to the guys and condolences to the familys in this tradgey
...the Van is limited to 10kts tailwind for takeoff
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The wing is most efficeint when it is clean, in relation to lift vs drag.
We sometimes take off with Flap 0 during high temperatures and although we accept the increased take off run (obviously done at long runways only) we gain by not needing to level off (or hardly any level acceleration) and accelerate to Venr.
It is a technicallity to avoid being limited by 2nd segment climb performance, but we have charts for every airport which gives temp vs wind on a particular runway and tells us what is the optimum flap for those conditions.
Perhaps the investigation will shed some more light on the situation rather than debating principles of flight.
We sometimes take off with Flap 0 during high temperatures and although we accept the increased take off run (obviously done at long runways only) we gain by not needing to level off (or hardly any level acceleration) and accelerate to Venr.
It is a technicallity to avoid being limited by 2nd segment climb performance, but we have charts for every airport which gives temp vs wind on a particular runway and tells us what is the optimum flap for those conditions.
Perhaps the investigation will shed some more light on the situation rather than debating principles of flight.
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Dem Ministeriumssprecher zufolge habe der Pilot kurz vor dem Absturz mitgeteilt, dass er Schwierigkeiten habe, an Höhe zu gewinnen.''
We saw that the other aircraft accidents were mainly due to technical errors.
take RWY 01 unless the tailwind component is greater than 12 knots.
Last edited by Voel; 19th Nov 2009 at 09:59.
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Helicopter down too at Okapuka
Now there is a helicopter is down at/near Okapuka
Vlieg eis nog een
Instructor survived and taken to hospital, student did not make it thou
the Namibian: One killed as chopper goes down
Flugschüler auf der Stelle tot
Vlieg eis nog een
Instructor survived and taken to hospital, student did not make it thou
the Namibian: One killed as chopper goes down
Flugschüler auf der Stelle tot
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@ suitcaseman
I'm not a professional pilot, but only have a degree in what you'd call "basic aerodynamics".
==> WRONG: his input does make sense.
Maximum ROC - flaps up will show you the maximum ROC you can get, if the flaps are retracted. It does not mean you will get the maximum ROC because your flaps are retracted.
Maximum ROC - flaps T/O will show you the maximum ROC you can get, if the flaps are in T/O position. Again, this does not mean you will get the maximum ROC because your flaps are in T/O position.
Note: you will never get as good values for your airplane in real live, simply because the POH values are flown with a new aircraft, a new engine, under nearly perfect conditions by a testpilot, who really really knows his job. Therefore, in reality, you would get climb rates which are lower than stated in the POH, because of aircraft age, engine age and your (everyone's) inability to fly perfect.
==> WRONG again.
You are right about the similarity of the Lift and Drag formulas. But drag is calculated using the coefficient of drag (CD). Therefore the right formula would look more like followed:
Drag = CD 0,5 rho v2 S
where CD is the coefficient of drag, rho is density, v is velocity and S is (wing) surface (projected).
I will keep the next one simple:
Fowler flaps would increase both S and CD, resulting in more lift. More lift means more drag, you're clearly right on that.
BUT:
==> WRONG again.
If this were the case, flaps would be pointless at all. Until a certain point, flaps increase the coefficient of lift MUCH MORE than the coefficient of drag, therefore increasing lift MORE than drag, which ultimately results in a better L/D-ratio, which reduces stall speed, take-off run etc...
You can see this if you look at a Lilienthal polar diagram, where CL versus CD is pictured.
==> WRONG again.
Sink occurs if lift is not greater or equal to the aircraft's weight. Not being at the aircraft's "best rate of climb speed" (cY) does not necessarily mean the aircraft descends. It simply means that the aircraft will not climb with the best rate of climb, but with a climb rate which is lower.
Finally:
==> TRUE, and TRUE!
==> Maybe you should have looked elsewhere or longer.
From an engineers point of view and in the interest of aviation safety, you should not be instructing or flying at all, until you increase your very "basic" knowledge of basic aerodynamics.
Cheers, Mac
Humpmedumpme – thanks for your input but unfortunately it does not make any sense.
Maximum ROC - flaps up will show you the maximum ROC you can get, if the flaps are retracted. It does not mean you will get the maximum ROC because your flaps are retracted.
Maximum ROC - flaps T/O will show you the maximum ROC you can get, if the flaps are in T/O position. Again, this does not mean you will get the maximum ROC because your flaps are in T/O position.
Note: you will never get as good values for your airplane in real live, simply because the POH values are flown with a new aircraft, a new engine, under nearly perfect conditions by a testpilot, who really really knows his job. Therefore, in reality, you would get climb rates which are lower than stated in the POH, because of aircraft age, engine age and your (everyone's) inability to fly perfect.
Drag = CL ½ Rho Vsq S
You are right about the similarity of the Lift and Drag formulas. But drag is calculated using the coefficient of drag (CD). Therefore the right formula would look more like followed:
Drag = CD 0,5 rho v2 S
where CD is the coefficient of drag, rho is density, v is velocity and S is (wing) surface (projected).
I will keep the next one simple:
Fowler flaps would increase both S and CD, resulting in more lift. More lift means more drag, you're clearly right on that.
BUT:
The increase in lift is less than the increase in drag
If this were the case, flaps would be pointless at all. Until a certain point, flaps increase the coefficient of lift MUCH MORE than the coefficient of drag, therefore increasing lift MORE than drag, which ultimately results in a better L/D-ratio, which reduces stall speed, take-off run etc...
You can see this if you look at a Lilienthal polar diagram, where CL versus CD is pictured.
Sink occurs when it is retracted due to the aircraft not being at the “best rate of climb speed”.
Sink occurs if lift is not greater or equal to the aircraft's weight. Not being at the aircraft's "best rate of climb speed" (cY) does not necessarily mean the aircraft descends. It simply means that the aircraft will not climb with the best rate of climb, but with a climb rate which is lower.
Finally:
It is rather disturbing that so many pilots and especially instructors do not understand the basic principles of flight. Look it up!
The very best instructor I could find thanks.
From an engineers point of view and in the interest of aviation safety, you should not be instructing or flying at all, until you increase your very "basic" knowledge of basic aerodynamics.
Cheers, Mac
Last edited by AHA-guy; 19th Nov 2009 at 17:41. Reason: forget the to sqare v :)
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Sorry for the spelling mistake. Life is correct. English is not my first language, it would be much easier for me to write in German.
Yes, you're right about gross and net figures in the manuals. Nevertheless, my point was to tell that the average pilot in an average (old) plane will not meet the values given in an AFM, but will more often reach values, which are slightly lower.
Flaps extended will limit the aircraft's speed (VFE - flaps extended) to a speed, which will be considerably lower than your desired cruising speed. Also, you're aircraft will fly more efficiently with flaps retracted (L/D, specific fuel, range...).
Put simply, your goal is not to reach TOC as fast as you can, but to reach your destination as fast as you can. (Yes, efficient would be the right word, efficiency as a function of speed, specific fuel flow, ... the ultimate goal is to arrive savely).
Faster desired (climb) speed will force you to retract flaps. Efficiency will also force you to retract your flaps.
Yes, you're right about gross and net figures in the manuals. Nevertheless, my point was to tell that the average pilot in an average (old) plane will not meet the values given in an AFM, but will more often reach values, which are slightly lower.
Flaps extended will limit the aircraft's speed (VFE - flaps extended) to a speed, which will be considerably lower than your desired cruising speed. Also, you're aircraft will fly more efficiently with flaps retracted (L/D, specific fuel, range...).
Put simply, your goal is not to reach TOC as fast as you can, but to reach your destination as fast as you can. (Yes, efficient would be the right word, efficiency as a function of speed, specific fuel flow, ... the ultimate goal is to arrive savely).
Faster desired (climb) speed will force you to retract flaps. Efficiency will also force you to retract your flaps.
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AHA-guy said.
'If this were the case, flaps would be pointless at all. Until a certain point, flaps increase the coefficient of lift MUCH MORE than the coefficient of drag, therefore increasing lift MORE than drag, which ultimately results in a better L/D-ratio, which reduces stall speed, take-off run etc...'
I disagree with your statement that you have the best L/D ratio with flaps down.
The reason we use flaps for take off is as you mentioned, we get an increase in lift, lower stall speed, shorter take off run - which has an effect on the ASD, otherwise we would require very long runways all over the world, also they obviously help slow planes down for the approach and landing.
(can you imagine how long the runway would need to be if a 747 took off and landed without flaps, bearing in mind the ASD and LDR)
The manufacturers accept the increase in drag for all the 'positive' gains, mentioned above, however, the best lift to drag ratio is still obtained with a clean wing, hence CLmax (best L/D ratio) is always with a clean wing and that is the best ratio of lift versus drag.
'If this were the case, flaps would be pointless at all. Until a certain point, flaps increase the coefficient of lift MUCH MORE than the coefficient of drag, therefore increasing lift MORE than drag, which ultimately results in a better L/D-ratio, which reduces stall speed, take-off run etc...'
I disagree with your statement that you have the best L/D ratio with flaps down.
The reason we use flaps for take off is as you mentioned, we get an increase in lift, lower stall speed, shorter take off run - which has an effect on the ASD, otherwise we would require very long runways all over the world, also they obviously help slow planes down for the approach and landing.
(can you imagine how long the runway would need to be if a 747 took off and landed without flaps, bearing in mind the ASD and LDR)
The manufacturers accept the increase in drag for all the 'positive' gains, mentioned above, however, the best lift to drag ratio is still obtained with a clean wing, hence CLmax (best L/D ratio) is always with a clean wing and that is the best ratio of lift versus drag.
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The 3rd segment climb is the accleration segment from climb, through flap retraction speed to final climb speed and the setting of MCP. It all seems a littel irrelevant when speaking about an accident that happened with a single engine, fixed gear aircraft.
Of some relevant interest perhaps might be the consideration of TEM/POH or Threat Error Managament.
At a recent instructor conference in Pretoria, much was made by the CAA (and by extension ICAO) of the concept of TEM and the absolute necessity to adhere with the specific POH.
Possibly and to speak with hypothesis, from the sounds of it, this accident could exemplify the possible points which the CAA were trying to illustrate in their recent seminar. An analysis of the threats posed by the conditions of the morning, such as runway, weather, take off flight path plus the errors possibly which might have been allowed to compound those threats such as loading, judgement, haste, pilot experience, ATC reports combined with a calculative thought as to what were the correct figures for take off extracted from the specific POH - or was reliance placed instead on a Mark I eyeball.
Those who have access to even a generic Caravan POH and who are familiar with the a parameters of the specific morning will be able to work out figures quite easily. Once those figures are to hand, it becomes part of Airmanship as to whether you consider your flying machine too beaten up to be able to perform according to the figures so exrtracted. A contingency is your call as the PIC and you may always imagine using wet or contaminated runway figures.
Of some relevant interest perhaps might be the consideration of TEM/POH or Threat Error Managament.
At a recent instructor conference in Pretoria, much was made by the CAA (and by extension ICAO) of the concept of TEM and the absolute necessity to adhere with the specific POH.
Possibly and to speak with hypothesis, from the sounds of it, this accident could exemplify the possible points which the CAA were trying to illustrate in their recent seminar. An analysis of the threats posed by the conditions of the morning, such as runway, weather, take off flight path plus the errors possibly which might have been allowed to compound those threats such as loading, judgement, haste, pilot experience, ATC reports combined with a calculative thought as to what were the correct figures for take off extracted from the specific POH - or was reliance placed instead on a Mark I eyeball.
Those who have access to even a generic Caravan POH and who are familiar with the a parameters of the specific morning will be able to work out figures quite easily. Once those figures are to hand, it becomes part of Airmanship as to whether you consider your flying machine too beaten up to be able to perform according to the figures so exrtracted. A contingency is your call as the PIC and you may always imagine using wet or contaminated runway figures.
Last edited by Der absolute Hammer; 20th Nov 2009 at 03:18.
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dont go on hear-say
Dear Piapito
You should know that pilots cant afford to go on hear-say and should never ever work on anything else that the hard facts.
So here are the facts:
1 The pilot worked for Aviation@work in RSA
2 The pilot had more that 1000 hours
3 The pilot weight and calculated and planned his own flight
4 The wind blowed in an western direction, which means that the pilot turned the nose of the aircraft right out of the wind - even though he had problems with lift
5 The pilot and the aircraft were chartered and not operated by Wings over Africa which is owned by Henk Burger
6 DCA recently regarded Wings over Africa as the aviation company in Namibia with the best Safety, quality and operation procedures in place.
7 Most important of all: the pilot were told by other pilots NOT to use runway 019 - and still made a consious decision to do just that.
You should know that pilots cant afford to go on hear-say and should never ever work on anything else that the hard facts.
So here are the facts:
1 The pilot worked for Aviation@work in RSA
2 The pilot had more that 1000 hours
3 The pilot weight and calculated and planned his own flight
4 The wind blowed in an western direction, which means that the pilot turned the nose of the aircraft right out of the wind - even though he had problems with lift
5 The pilot and the aircraft were chartered and not operated by Wings over Africa which is owned by Henk Burger
6 DCA recently regarded Wings over Africa as the aviation company in Namibia with the best Safety, quality and operation procedures in place.
7 Most important of all: the pilot were told by other pilots NOT to use runway 019 - and still made a consious decision to do just that.
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I have now found the full set of METARs for FYWH (alas, they don't seem to exist for Eros). I have flown from Eros, but cannot remember how the wx conditions there correlate with FYWH.
IF (and locals will be able to comment) the wind conditions are similar between the two, then in my mind there was no pressing need to take off from 19. He would have had a couple of knots tailwind taking off from 01. No big deal.
IF (and locals will be able to comment) the wind conditions are similar between the two, then in my mind there was no pressing need to take off from 19. He would have had a couple of knots tailwind taking off from 01. No big deal.