Touchdown point
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We have two main runways, one sealed, 1100m long and a parallel grass one about 400m long. Circuits start on the seal, and eventually when teaching max perf. t/o and ldg, we move them onto the grass. It's a conversion like John Farley said, but I didn't even realise that's what we were (are) doing.
We give them the touchdown markers on the seal as their initial aim point, then they float to about the 1000' markers (C152). PAPIs on one runway and T-VASIS on the other normally show two dots high for the appropriate C152 approach. This keeps their options open, but we demand all three of John Farley's parts before sending them solo. They have to know what to do (even if it means they talk me round a circuit, how does this look? what do I have to do?), they have to be able to do it themselves and then we work on the accuracy and I mean work.
Vigilant Driver
Are the PAPIs or VASIS that you use set for your aircraft type or for a commercial length aeroplane? If the aeroplane they are set for is longer in the fuselage then a standard light trainer (C152 / PA28/38) will be landing much too far in. I agree with the "hold off" part of landing though, "Level off, power off, hold off" seems to work quite well.
grade_3
If we didn't fly single-engine over water, there would be hardly any North Island aeroplanes at Warbirds over Wanaka. We just fly from North Island shore to boat to ferry to boat to boat to South Island shore!
Oh Captain Crash, you've done it now...
I fully agree with you. Except for "When trying to teach landing ..." surely this is meant to be "When teaching landing..."?
editted for speelingg
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Confident, cocky, lazy, dead.
[This message has been edited by chicken6 (edited 23 January 2001).]
We give them the touchdown markers on the seal as their initial aim point, then they float to about the 1000' markers (C152). PAPIs on one runway and T-VASIS on the other normally show two dots high for the appropriate C152 approach. This keeps their options open, but we demand all three of John Farley's parts before sending them solo. They have to know what to do (even if it means they talk me round a circuit, how does this look? what do I have to do?), they have to be able to do it themselves and then we work on the accuracy and I mean work.
Vigilant Driver
Are the PAPIs or VASIS that you use set for your aircraft type or for a commercial length aeroplane? If the aeroplane they are set for is longer in the fuselage then a standard light trainer (C152 / PA28/38) will be landing much too far in. I agree with the "hold off" part of landing though, "Level off, power off, hold off" seems to work quite well.
grade_3
If we didn't fly single-engine over water, there would be hardly any North Island aeroplanes at Warbirds over Wanaka. We just fly from North Island shore to boat to ferry to boat to boat to South Island shore!
Oh Captain Crash, you've done it now...
I fully agree with you. Except for "When trying to teach landing ..." surely this is meant to be "When teaching landing..."?
editted for speelingg
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Confident, cocky, lazy, dead.
[This message has been edited by chicken6 (edited 23 January 2001).]
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I just read an interesting thread covering much the same points as you have here... http://www.pprune.org/ubb/NonCGI/For...ML/000501.html in reference to carby heat, go-arounds and different approaches.
I am not totally sure about the rest of the world but the Aussie Flight Manual broadly states that for "Light Aircraft" the aircraft will fly over the threshold at a height of 50' with full flap, idle power and at the Vref (based on 1.3Vs). That part of the equation on our end of the planet is not open to interpretation...
...what is quite unclear is what happens in the "period of indecision" between 50 feet and touchdown! This is left to the individual operator. Most would argue that you would hold Vref to the flare and ideally touch down at the nominated touchdown speed. This becomes awkward when it's the same speed that you have maintained til 50'agl. Regardless, it should theoretically be done. TKOF and landing distances are calculated using this method so you're not going to run out of runway if you did your math right.
Having said that, I think it's in every instructors best interest to "share" the aircraft's operating envelope with a student. Even though the published performance charts are based on achieving 50 feet above the threshold under the above discussed conditions - it still makes sense to teach real short field performance. Aim for the grass to touch down on the first inch of runway kinda thing...and find a local grass runway if you can - makes it more fun and helps make it "real".
Each company should have it's own approach procedures for both the instructional training syllabus and 'real life' commercial operations. Read your Operations Manual as your bible. If you have ideas, comments or suggestions tell your Chief Pilot who can possibly action the change if it's in the companies best interest. dragchuteillustrated this. I don't think that a 1.1 Vs is in the POH but in the light of operational experience if you can prove that it works you can write it into your SOPs or Ops Manual and then it does become legally binding. Your company then accepts responsibility or becomes 'liable' for your operating procedures...very different to becoming responsible for your flying mind you.
Capt Crash. If leaving carby heat ON until after landing is what your company does - good luck to you! We couldn't get away with that in the heat at Sydney (or anywhere else in OZ) when you REQUIRE full power out of the engine at times. Full power is NOT possible with carby heat on. I would suggest you re-think your company’s approach here. I do think this is a terrible idea for all the reasons discussed in other posts.
I am not totally sure about the rest of the world but the Aussie Flight Manual broadly states that for "Light Aircraft" the aircraft will fly over the threshold at a height of 50' with full flap, idle power and at the Vref (based on 1.3Vs). That part of the equation on our end of the planet is not open to interpretation...
...what is quite unclear is what happens in the "period of indecision" between 50 feet and touchdown! This is left to the individual operator. Most would argue that you would hold Vref to the flare and ideally touch down at the nominated touchdown speed. This becomes awkward when it's the same speed that you have maintained til 50'agl. Regardless, it should theoretically be done. TKOF and landing distances are calculated using this method so you're not going to run out of runway if you did your math right.
Having said that, I think it's in every instructors best interest to "share" the aircraft's operating envelope with a student. Even though the published performance charts are based on achieving 50 feet above the threshold under the above discussed conditions - it still makes sense to teach real short field performance. Aim for the grass to touch down on the first inch of runway kinda thing...and find a local grass runway if you can - makes it more fun and helps make it "real".
Each company should have it's own approach procedures for both the instructional training syllabus and 'real life' commercial operations. Read your Operations Manual as your bible. If you have ideas, comments or suggestions tell your Chief Pilot who can possibly action the change if it's in the companies best interest. dragchuteillustrated this. I don't think that a 1.1 Vs is in the POH but in the light of operational experience if you can prove that it works you can write it into your SOPs or Ops Manual and then it does become legally binding. Your company then accepts responsibility or becomes 'liable' for your operating procedures...very different to becoming responsible for your flying mind you.
Capt Crash. If leaving carby heat ON until after landing is what your company does - good luck to you! We couldn't get away with that in the heat at Sydney (or anywhere else in OZ) when you REQUIRE full power out of the engine at times. Full power is NOT possible with carby heat on. I would suggest you re-think your company’s approach here. I do think this is a terrible idea for all the reasons discussed in other posts.
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Y, I think Crash meant carb heat on until touchdown, which is SOP at all the schools I know in Canada. During the rollout we take carb heat off then raise the flaps. In a Go-around, our procedure is nose up, then full throttle, then carb heat off, then flaps 20.
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Squawk:
I fly around NF and Lab, most of the time with carb heat on and a little extra leaning to compensate. Of late with temps below -15 regularly I find carb heat produces very little effect one way or the other, I suppose because the humidity is so low. I use it only on descents and touchdown & push it in on roll out. I obsess about it in summer
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[This message has been edited by Code Blue (edited 24 January 2001).]
I fly around NF and Lab, most of the time with carb heat on and a little extra leaning to compensate. Of late with temps below -15 regularly I find carb heat produces very little effect one way or the other, I suppose because the humidity is so low. I use it only on descents and touchdown & push it in on roll out. I obsess about it in summer
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[This message has been edited by Code Blue (edited 24 January 2001).]
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Y
…”period of indecision” between 50 feet and touchdown… Check our Part 4 of the POH specific to aircraft type.
For instance the Cessna 152 manual suggests “…make an approach at 54 KIAS with 30 deg. flaps using enough power to control the glide path. After all approach obstacles are cleared, progressively reduce power and maintain 54 KIAS by lowering the nose of the airplane. Touchdown should be made with power-off and on the main wheels first…slightly higher approach speeds should be used under turbulent air conditions…” CASA Flight Manual nominates 54 KIAS (1.3 Vs) as approach speed.
I find that once power is reduced to idle at fifty feet and speed pinned at the prescribed figure, continued monitoring of the ASI is unnecessary. Your student should scan the touch-down zone and the upwind end of the runway. During the flare, speed will reduce as induced drag increases. Ground effect will compensate.
My comments pertaining to 1.1 Vs were included to simply demonstrate the margin of safety built-in with 1.3 Vs. Our operational reasons for using such figures revolved around SAR and similar issues and I would NOT advocate such techniques unless circumstances left little or no alternative. We trained regularly to fly accurately at such reduced speed – and the tail-wheel configuration and spring-steel legs ensured adequate propeller clearance and shock absorption resulting from such a steep approach.
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dragchute
email: [email protected]
…”period of indecision” between 50 feet and touchdown… Check our Part 4 of the POH specific to aircraft type.
For instance the Cessna 152 manual suggests “…make an approach at 54 KIAS with 30 deg. flaps using enough power to control the glide path. After all approach obstacles are cleared, progressively reduce power and maintain 54 KIAS by lowering the nose of the airplane. Touchdown should be made with power-off and on the main wheels first…slightly higher approach speeds should be used under turbulent air conditions…” CASA Flight Manual nominates 54 KIAS (1.3 Vs) as approach speed.
I find that once power is reduced to idle at fifty feet and speed pinned at the prescribed figure, continued monitoring of the ASI is unnecessary. Your student should scan the touch-down zone and the upwind end of the runway. During the flare, speed will reduce as induced drag increases. Ground effect will compensate.
My comments pertaining to 1.1 Vs were included to simply demonstrate the margin of safety built-in with 1.3 Vs. Our operational reasons for using such figures revolved around SAR and similar issues and I would NOT advocate such techniques unless circumstances left little or no alternative. We trained regularly to fly accurately at such reduced speed – and the tail-wheel configuration and spring-steel legs ensured adequate propeller clearance and shock absorption resulting from such a steep approach.
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dragchute
email: [email protected]
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Squawk 8888, if that's your SOP then great, however I do have to disagree with the way your copmany operates.
Most would argue that touching anything at all on the runway is a bad idea. Our company policy prohibits the retraction of flap until clear of the runway. Even after exiting the runway a visual identification is made by the Captain - followed by identification and verification by the FO. Rolling down the runway is not the time to be doing this. If single pilot and in the heat of the moment you can quite easily inadvertantly retract the gear. What you are doing by adhering to your company SOPs is maybe doubling your chances of retracting the gear by retacting flap and turning carby heat off.
Retracting flap on the roll has it's time and place but certainly not under normal operating conditions.
First, applying the nose up to the climb attitude in most training aircraft (especially if at low or idle power) can possibly result in a stall. I assume you got your procedure a bit "backwards" and power is applied before pitching the nose up into your positive climb attitude?
Second, you should really apply carby heat to the off position prior to applying full power. Full power (when carby heat is on) may possibly result in detonation (i.e. very high CHTs and low approach speeds).
Correct use of carby heat
The correct use of carby heat is defined differently in different climates, condtions and countries. Where you may not use carby heat ever in Central Australia, for example, you may find yourself using it often on the South Coast of OZ.
Use Carby heat when either:
a)The Aircraft's Flight Manual Dictates its use at a particular power setting or particular climatic conditions;
b)The Conditions are conducive and you suspect that Carby Ice will form - this is open to interpretation from pilot to pilot. Most people generally use RH 50% or greater and a temp range of -10 degrees to +25 degrees celcius. There is an excellent chart produced from CASA that, based on current conditions, assess your carby ice risk. I'll try and locate it soon...
c)You have ice and want to remove it.
Our own Operations Manual requires carby heat to the OFF position by 300'agl if it was applied so maximum power is available in a go-around. Keep in mind though that although you want maximum power available to you in the missed approach - that does not mean that carby ice will not form with full power set. You must stil keep a good lookout out for the symptoms of the formation of ice.
Minimising the use of Carby heat will undoubtedly increase the life of your engine. Remember that's it's hot unfiltered air that's making its way into the cylinders - not a good thing!
Bottom line. Read your Copmany SOPs, Flight Manual or Pilot's Operating Handbook. If it has been written up correctly then there is a relevant section explaining your company procedure on the above matter.
Touchdown Point
As -Y- correctly pointed out, the aircraft shoud fly over the threshold at Vref (based on weight), with full flap and at idle power. If flying to a PAPI or T-Vasis that should have you aiming for the 1000 foot markers (which equates to 3 degrees). I think the US use a slightly shallower ILS approach (maybe 2.7 degrees?) Unsure.
It's actually a really good argument the whole touchdown point thing. I worked at a company once that encouraged a high approach that would permit a landing from anywhere in the circuit - including a base or final. Other schools encouraged the Airline approach utilising the PAPI or T-vasis for guidance. Other taught reference points on the nose (i.e. threshold on the nose to touchdown on the numbers). It's all up to the operator. Our copmany policy has the MetroIII and other larger turbines fly at 3 degrees but we teach abinitio students in Cherokees to come in at closer to 4 degrees.
Each to their own I say. If it's in your SOPs, if you can justify it and you always thrive to improve your standards and consistantly account for the way you do things then you're doing it right!
<font face="Verdana, Arial, Helvetica" size="2">During the rollout we take carb heat off then raise the flaps</font>
Retracting flap on the roll has it's time and place but certainly not under normal operating conditions.
<font face="Verdana, Arial, Helvetica" size="2">In a Go-around, our procedure is nose up, then full throttle, then carb heat off, then flaps 20.</font>
Second, you should really apply carby heat to the off position prior to applying full power. Full power (when carby heat is on) may possibly result in detonation (i.e. very high CHTs and low approach speeds).
Correct use of carby heat
The correct use of carby heat is defined differently in different climates, condtions and countries. Where you may not use carby heat ever in Central Australia, for example, you may find yourself using it often on the South Coast of OZ.
Use Carby heat when either:
a)The Aircraft's Flight Manual Dictates its use at a particular power setting or particular climatic conditions;
b)The Conditions are conducive and you suspect that Carby Ice will form - this is open to interpretation from pilot to pilot. Most people generally use RH 50% or greater and a temp range of -10 degrees to +25 degrees celcius. There is an excellent chart produced from CASA that, based on current conditions, assess your carby ice risk. I'll try and locate it soon...
c)You have ice and want to remove it.
Our own Operations Manual requires carby heat to the OFF position by 300'agl if it was applied so maximum power is available in a go-around. Keep in mind though that although you want maximum power available to you in the missed approach - that does not mean that carby ice will not form with full power set. You must stil keep a good lookout out for the symptoms of the formation of ice.
Minimising the use of Carby heat will undoubtedly increase the life of your engine. Remember that's it's hot unfiltered air that's making its way into the cylinders - not a good thing!
Bottom line. Read your Copmany SOPs, Flight Manual or Pilot's Operating Handbook. If it has been written up correctly then there is a relevant section explaining your company procedure on the above matter.
Touchdown Point
As -Y- correctly pointed out, the aircraft shoud fly over the threshold at Vref (based on weight), with full flap and at idle power. If flying to a PAPI or T-Vasis that should have you aiming for the 1000 foot markers (which equates to 3 degrees). I think the US use a slightly shallower ILS approach (maybe 2.7 degrees?) Unsure.
It's actually a really good argument the whole touchdown point thing. I worked at a company once that encouraged a high approach that would permit a landing from anywhere in the circuit - including a base or final. Other schools encouraged the Airline approach utilising the PAPI or T-vasis for guidance. Other taught reference points on the nose (i.e. threshold on the nose to touchdown on the numbers). It's all up to the operator. Our copmany policy has the MetroIII and other larger turbines fly at 3 degrees but we teach abinitio students in Cherokees to come in at closer to 4 degrees.
Each to their own I say. If it's in your SOPs, if you can justify it and you always thrive to improve your standards and consistantly account for the way you do things then you're doing it right!
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Capt Crash
As JF eloquently points out, there's a major difference between teaching your students to fly accurately and teaching them to land at the end of the runway.
Landing short on 05 at Cambridge is a fairly high-risk venture. You have a choice between Sainsbury's car park and the sewage works. If you land very short, you'll take out my house! So I have a personal interest.
Given that there's some 1670m from the threshold, and that Cessna 152s taking more than 1200 m to land are even rarer than engine failures on final, wouldn't you agree that it's sensible to pick an aiming point some way in to the runway (taxiway D always seems sensible to me)?
As JF eloquently points out, there's a major difference between teaching your students to fly accurately and teaching them to land at the end of the runway.
Landing short on 05 at Cambridge is a fairly high-risk venture. You have a choice between Sainsbury's car park and the sewage works. If you land very short, you'll take out my house! So I have a personal interest.
Given that there's some 1670m from the threshold, and that Cessna 152s taking more than 1200 m to land are even rarer than engine failures on final, wouldn't you agree that it's sensible to pick an aiming point some way in to the runway (taxiway D always seems sensible to me)?
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Turbine the procedure I described was for a C172, I agree about the flaps/gear problem with other types (saw an Aztec crew raise gear on R/W during a touch-and-go). Raising flaps during the rollout is useful primarily on short runways, by transferring weight from wing to wheel thus improving braking action (which is mentioned in the Flight Training Manual- Aeroplane in Canada). I should have been a bit more specific about the sequence we use in the go-around- we raise the nose to a level pitch attitude (similar to the flare) while simultaneously applying full power, i.e. we've got max RPM just as the nose is passing the horizon. Not sure exactly why, but I would guess that being nose-down at full throttle only a couple of hundred feet up would be considered by some to be a tad riskier than a stall. We do our approaches at 60-70 KIAS, and with a clean stall speed of 47 one would have to be pretty slow on the controls to stop flying. Once we have full power we adjust the pitch to get our climb speed.
Code Blue my instructors always warned me about carb heat in extreme cold- if the OAT is below the carb ice range then carb heat could warm the air up to the point where carb ice can form. I was taught to bring the carb heat on before bringing power below the green arc as a precaution, because if it's needed later the engine will be too cold for it to be effective.
Code Blue my instructors always warned me about carb heat in extreme cold- if the OAT is below the carb ice range then carb heat could warm the air up to the point where carb ice can form. I was taught to bring the carb heat on before bringing power below the green arc as a precaution, because if it's needed later the engine will be too cold for it to be effective.
Guest
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>if the OAT is below the carb ice range then carb heat could warm the air up to the point where carb ice can form. <
I seem to recall a mention of this but it was then almost dismissed with comments about very low humidity with the cold temps.
>I was taught to bring the carb heat on before bringing power below the green arc as a precaution, because if it's needed later the engine will be too cold for it to be effective<
Moi aussi.
Perhaps some of the comments here relate to vastly different climates and humidities.
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I seem to recall a mention of this but it was then almost dismissed with comments about very low humidity with the cold temps.
>I was taught to bring the carb heat on before bringing power below the green arc as a precaution, because if it's needed later the engine will be too cold for it to be effective<
Moi aussi.
Perhaps some of the comments here relate to vastly different climates and humidities.
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Guest
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I'm sure they do, Bluedude. Humidity is definitely the biggest factor in carb ice- I remember those graphs that show carb ice danger at temps of 20c when the humidity is high enough; basically the more humid the air, the further from freezing (above or below) carb ice can happen. I'd wager that at this moment the risk of carb ice is higher in Florida than it is in Toronto. If any of the scientifically inclined out there wish to sponsor me on an expedition to test the hypothesis I suppose I could make the effort All in the name of research, of course 
All in the name of research, of course
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Going back to the discussion of runway touchdown/aiming points, surely the "one technique fits all runways" approach must be too simplistic, because there is a wide variation in runway lengths and associated approach paths/obstacles out there. Each approach to each runway needs consideration on its own merits. This is something that every pilot surely learns as he/she progresses after gaining a licence, assuming that the pilot does more than just fly around their local strip.
For example, at the grass strip where I did much of my PPL training, the longest runway is 1800 feet. Landing on one end, with a significant downslope, you need to fly the final approach close to Vref (say 60 kt in a PA-28, 55 kt in a C152, plus any gust correction) and touch down close in to the threshold. Landing from the other direction is quite different. The touchdown point is one-third of the distance down the runway. Reason: If you try to touchdown closer to the threshold, you might end up in a stand of big oak trees conveniently located under short finals!
The technique in this situation is to use full flap, closely controlled airspeed, and lots of throttle control to carefully control the glidepath. Oh, and I forgot to mention the deep valley just before the trees, where you usually get a nice bit of sink at the wrong moment. Not to mention the "interesting" gusty winds that invariably blow in from the Atlantic most days.
Just cruising down finals with the engine idling isn't a realistic option here!
PAPI's and VASI's?? Forget it! No such high-tech gizmos!
For example, at the grass strip where I did much of my PPL training, the longest runway is 1800 feet. Landing on one end, with a significant downslope, you need to fly the final approach close to Vref (say 60 kt in a PA-28, 55 kt in a C152, plus any gust correction) and touch down close in to the threshold. Landing from the other direction is quite different. The touchdown point is one-third of the distance down the runway. Reason: If you try to touchdown closer to the threshold, you might end up in a stand of big oak trees conveniently located under short finals!
The technique in this situation is to use full flap, closely controlled airspeed, and lots of throttle control to carefully control the glidepath. Oh, and I forgot to mention the deep valley just before the trees, where you usually get a nice bit of sink at the wrong moment. Not to mention the "interesting" gusty winds that invariably blow in from the Atlantic most days.
Just cruising down finals with the engine idling isn't a realistic option here!
PAPI's and VASI's?? Forget it! No such high-tech gizmos!
