Odd? landing technique (PA28) wanted by school
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I agree with most of what has been said here, in fact if someone was using this schools technique I would be wary of signing them off.
One bit I do disagree with though is
, nothing I can see in the POH that says this and my understanding is that you leave power on during the flare to give some slipstream effect over the tail, thus increasing the effectiveness of the elevator - one reason you use a higher speed on a glide approach.
One bit I do disagree with though is
Don't forget, though, that to achieve the POH landing performance, you will need the correct speed/height at the threshold, and the throttle at idle from there on.
One bit I do disagree with though is
Quote:
Don't forget, though, that to achieve the POH landing performance, you will need the correct speed/height at the threshold, and the throttle at idle from there on.
, nothing I can see in the POH that says this and my understanding is that you leave power on during the flare to give some slipstream effect over the tail, thus increasing the effectiveness of the elevator - one reason you use a higher speed on a glide approach.
Quote:
Don't forget, though, that to achieve the POH landing performance, you will need the correct speed/height at the threshold, and the throttle at idle from there on.
, nothing I can see in the POH that says this and my understanding is that you leave power on during the flare to give some slipstream effect over the tail, thus increasing the effectiveness of the elevator - one reason you use a higher speed on a glide approach.
http://http://www.desu.edu/sites/default/files/u725/Warrior%20161%20Section%205%20Performance%20Landing%20200%20 pbi.pdf
'ASSOCIATED CONDITIONS: POWER OFF, FLAPS - 40, PAVED LEVEL DRY RUNWAY, MAXIMUM BRAKING.'
MJ
Last edited by Mach Jump; 6th Jul 2015 at 22:19.
Aeroplane gust response is proportional to the square of airspeed (source, any good university textbook on flight mechanics). So, adding (say) 10% to IAS, will add 21% to the airframe response to a gust. That has never seemed to me to be particularly wise in a conventionally configured aeroplane.
G
I would be interested in knowing your authoritative source for this.
Aeroplane gust response is proportional to the square of airspeed (source, any good university textbook on flight mechanics). So, adding (say) 10% to IAS, will add 21% to the airframe response to a gust. That has never seemed to me to be particularly wise in a conventionally configured aeroplane.
G
Aeroplane gust response is proportional to the square of airspeed (source, any good university textbook on flight mechanics). So, adding (say) 10% to IAS, will add 21% to the airframe response to a gust. That has never seemed to me to be particularly wise in a conventionally configured aeroplane.
G
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I don't know what the physics looks like and I don't really care, but adding a LITTLE speed in gusty conditions reduces the one armed paper hangar demands in my experience. I'm guessing it's airline practice because jet engine throttle response isn't as rapid as piston engine.
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Several comments if I may ..
Your version was what they termed a "performance landing" as it resulted in a shorter roll
Generally a reference to "performance landing" infers max effort, min distance from the screen. This infers min POH approach speed, generally 1.3Vs, min flare distance and max braking. GTE knows all about that stuff.
While there may be operational reasons to add a bit of fat to the approach speed going into the flare, in general, ANY extra speed is counterproductive if the aim is to achieve a min distance landing ... you have some concern about what lies past the runway head ...
Re speed adjustments if the POH doesn't provide guidance, one should check the PEC .. just to make sure you don't get into tiger country .. not usually a problem unless you are back near the stall.
add half the gust factor to the POH speed
Perhaps misheard in respect of common OEM heavy guidance, which is half the steady wind plus all the gust to a maximum additive of 20kt.
Reasoning is
(a) steady wind is predictable and the low level gradient, in the absence of obstacles and the like, is fairly predictable ... usually following something approaching the usual FT and AFM 1/7th power relationship. Adding half the steady wind is an attempt to model this in a simple manner for line operations.
(b) gust is statistically unpredictable .. so it follows that a more conservative approach to additive be followed.
(c) max 20kt is a sanity check on the normal landing factor for heavies of 1.67 .. be careful with lighties as the factors are generally somewhat smaller. 20kt also reflects an old (ancient ?) UK BCAR AFM requirement which imposed that as a maximum additive.
Some discussion can be found in various threads including this old one ...
nothing I can see in the POH that says this
The POH should have words of wisdom regarding the technique upon which the landing distances are scheduled. Otherwise a read of the Flight Test Guide might be useful.
and will also dictate a performance penalty to the landing charts.
Generally none .. that's the reason for the 20kt limit.
jet engine throttle response isn't as rapid as piston engine
That problem went away years ago following a number of approach prangs where engine RPM was allowed to be too low. The simple expedient of requiring the engines to be spun up (typically above bleed valve closure) gave good response.
Your version was what they termed a "performance landing" as it resulted in a shorter roll
Generally a reference to "performance landing" infers max effort, min distance from the screen. This infers min POH approach speed, generally 1.3Vs, min flare distance and max braking. GTE knows all about that stuff.
While there may be operational reasons to add a bit of fat to the approach speed going into the flare, in general, ANY extra speed is counterproductive if the aim is to achieve a min distance landing ... you have some concern about what lies past the runway head ...
Re speed adjustments if the POH doesn't provide guidance, one should check the PEC .. just to make sure you don't get into tiger country .. not usually a problem unless you are back near the stall.
add half the gust factor to the POH speed
Perhaps misheard in respect of common OEM heavy guidance, which is half the steady wind plus all the gust to a maximum additive of 20kt.
Reasoning is
(a) steady wind is predictable and the low level gradient, in the absence of obstacles and the like, is fairly predictable ... usually following something approaching the usual FT and AFM 1/7th power relationship. Adding half the steady wind is an attempt to model this in a simple manner for line operations.
(b) gust is statistically unpredictable .. so it follows that a more conservative approach to additive be followed.
(c) max 20kt is a sanity check on the normal landing factor for heavies of 1.67 .. be careful with lighties as the factors are generally somewhat smaller. 20kt also reflects an old (ancient ?) UK BCAR AFM requirement which imposed that as a maximum additive.
Some discussion can be found in various threads including this old one ...
nothing I can see in the POH that says this
The POH should have words of wisdom regarding the technique upon which the landing distances are scheduled. Otherwise a read of the Flight Test Guide might be useful.
and will also dictate a performance penalty to the landing charts.
Generally none .. that's the reason for the 20kt limit.
jet engine throttle response isn't as rapid as piston engine
That problem went away years ago following a number of approach prangs where engine RPM was allowed to be too low. The simple expedient of requiring the engines to be spun up (typically above bleed valve closure) gave good response.
We are good for up to 7 kts additives but beyond that we have to add a percentage to the landing distance required. Max total additives (gusts and icing) 14 knots. That's for a BAe146 which is a bit different due to its low speed wing.
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So we're all agreed that:
a) The original poster is right and his instructor is wrong
b) There might be a case for adding a little bit of speed in gusty conditions but it's a matter of personal taste or comfort in light aircraft.
a) The original poster is right and his instructor is wrong
b) There might be a case for adding a little bit of speed in gusty conditions but it's a matter of personal taste or comfort in light aircraft.
A light aircraft with a lower approach speed, and without the susceptibility to windshear doesn't want the same magnitude of speed change, if any at all.
G
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We are good for up to 7 kts additives but beyond that we have to add a percentage to the landing distance required.
Now, had I taken up the command slot I relinquished on the Quadrapuff all those years ago .. I would have known that Type requirement. Learning requirements still operative ...
Now, had I taken up the command slot I relinquished on the Quadrapuff all those years ago .. I would have known that Type requirement. Learning requirements still operative ...
Also a part 25 aeroplane like a 146 has a lot of inertia, and a high approach speed. The first creates windshear risk, and the second makes say 10kn speed increment a relatively small percentage change.
A light aircraft with a lower approach speed, and without the susceptibility to windshear doesn't want the same magnitude of speed change, if any at all.
G
A light aircraft with a lower approach speed, and without the susceptibility to windshear doesn't want the same magnitude of speed change, if any at all.
G
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Thanks
Thank you all for your replies so far folks.
I'm glad to hear that I've not gone crazy and that the CAA haven't instituted some mad policy in my absence from these shores.
As some of you point out it, this (incorrect) technique I'm being told to use probably stems from the fact that the school is geared towards airline wannabes. I find it quite ironic that in training people to "fly like the big boys" they are missing the point that the big boys fly exactly as per the manufacturer's manuals! The post by Sir Niall Dementia re the two techniques taught by the big schools explains all the firewall problems a certain school had in their 172s at an airfield I have flown at.
Prior to my next session I'll have a chat with the instructor in question with POH in hand. I'll also try to figure out why I was told that "we don't touch the mixture below 3,000ft", why I haven't seen W&B/performance charts and why we haven't bothered to dip partially full tanks prior to flying (whole another stories).
I'm hesitant to walk away from the school as I am limited for choice (the next nearest is an extra 45min drive) and they seem to have a good reputation. I'll canvas more instructors at this school to see if this is limited to a subset of instructors or a real policy. However, if they aren't going to operate the aircraft in the correct way I'll take my hard earned money and good looks elsewhere.
I'm glad to hear that I've not gone crazy and that the CAA haven't instituted some mad policy in my absence from these shores.
As some of you point out it, this (incorrect) technique I'm being told to use probably stems from the fact that the school is geared towards airline wannabes. I find it quite ironic that in training people to "fly like the big boys" they are missing the point that the big boys fly exactly as per the manufacturer's manuals! The post by Sir Niall Dementia re the two techniques taught by the big schools explains all the firewall problems a certain school had in their 172s at an airfield I have flown at.
Prior to my next session I'll have a chat with the instructor in question with POH in hand. I'll also try to figure out why I was told that "we don't touch the mixture below 3,000ft", why I haven't seen W&B/performance charts and why we haven't bothered to dip partially full tanks prior to flying (whole another stories).
I'm hesitant to walk away from the school as I am limited for choice (the next nearest is an extra 45min drive) and they seem to have a good reputation. I'll canvas more instructors at this school to see if this is limited to a subset of instructors or a real policy. However, if they aren't going to operate the aircraft in the correct way I'll take my hard earned money and good looks elsewhere.
Last edited by gfunc; 7th Jul 2015 at 10:13. Reason: typo
In my opinion:-
Lack of W&CG/Perf access: knowledge that you are a licenced pilot, and that 2-up with partial tanks from a known and fairly long runway, they're irrelevant anyhow.
No mixture below 3000ft: This is a common UK view: some aircraft (I have a 1969 Condor which actually placards this) do recommend this approach, but in reality it's just burning fuel for no good reason in a long cruise. Also nervousness of low ability student pilots damaging the engine through misusing it. If you understand it, use the mixture, it's what it's for.
Dipping tank: Probably because they know the aeroplane well enough, are flying relatively short sorties, and are always flying with good fuel reserves. When I used to part-own a Warrior II and flew it regularly, I was pretty good at telling within 20 litres or so how much fuel was in the tanks by sight.
An obvious question for you - if you are a reasonably experienced pilot, why not look to local syndicates, rather than pay commercial rates in a school which will be very restrictive of aircraft access anyhow.
G
Lack of W&CG/Perf access: knowledge that you are a licenced pilot, and that 2-up with partial tanks from a known and fairly long runway, they're irrelevant anyhow.
No mixture below 3000ft: This is a common UK view: some aircraft (I have a 1969 Condor which actually placards this) do recommend this approach, but in reality it's just burning fuel for no good reason in a long cruise. Also nervousness of low ability student pilots damaging the engine through misusing it. If you understand it, use the mixture, it's what it's for.
Dipping tank: Probably because they know the aeroplane well enough, are flying relatively short sorties, and are always flying with good fuel reserves. When I used to part-own a Warrior II and flew it regularly, I was pretty good at telling within 20 litres or so how much fuel was in the tanks by sight.
An obvious question for you - if you are a reasonably experienced pilot, why not look to local syndicates, rather than pay commercial rates in a school which will be very restrictive of aircraft access anyhow.
G
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Hi Genghis,
I get your points about my other "disappointments" about my experience thus far. I would agree with them all in the case of you and I going for a local flight in your lovely privately owned Condor.
However, in my opinion at this stage (me rocking up as an unknown quantity) an instructor should be setting an example and insisting on high standards. From viewpoint of a student, at worst quickly going over the W&B and perf would refresh my memory, and at best would highlight any deficiencies in my knowledge. Again the not dipping tanks is setting a poor example - it literally takes seconds during the walk around and is again another opportunity to check my knowledge. Flight training is predominantly a case of "monkey see, monkey do"; visual guestimation plus an inexperienced PPL has the potential to line up several slices of Swiss cheese.
The mixture issue...it seems a UK oddity that I'll live with!
With regards to your question - two issues are (i) I have to convert my overseas CPL, so I'm stuck in the training environment for a while (thanks CAA!) and (ii) I seemed to have moved to a part of the country with a paucity of airfields and I would be looking for something aerobatic with the little wheel at the correct end of the aircraft.
I get your points about my other "disappointments" about my experience thus far. I would agree with them all in the case of you and I going for a local flight in your lovely privately owned Condor.
However, in my opinion at this stage (me rocking up as an unknown quantity) an instructor should be setting an example and insisting on high standards. From viewpoint of a student, at worst quickly going over the W&B and perf would refresh my memory, and at best would highlight any deficiencies in my knowledge. Again the not dipping tanks is setting a poor example - it literally takes seconds during the walk around and is again another opportunity to check my knowledge. Flight training is predominantly a case of "monkey see, monkey do"; visual guestimation plus an inexperienced PPL has the potential to line up several slices of Swiss cheese.
The mixture issue...it seems a UK oddity that I'll live with!
With regards to your question - two issues are (i) I have to convert my overseas CPL, so I'm stuck in the training environment for a while (thanks CAA!) and (ii) I seemed to have moved to a part of the country with a paucity of airfields and I would be looking for something aerobatic with the little wheel at the correct end of the aircraft.
Can't you do recreational VFR flying with PPL privileges on your ICAO CPL?
Yes, I take your point about demonstrating gold standard flying - something that was certainly strongly emphasised on my instructors course.
G
Yes, I take your point about demonstrating gold standard flying - something that was certainly strongly emphasised on my instructors course.
G
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It's all been said already but the taper wing Cherokees are very sensitive to carrying excess speed on the approach. 70kt+ will easily see you floating off the end of the runway at many smaller UK GA airfields.
In strong gusty conditions I might fly the approach at 70kt, but in that situation, I'd be leaving the flaps up & landing clean.
In strong gusty conditions I might fly the approach at 70kt, but in that situation, I'd be leaving the flaps up & landing clean.
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On the Warrior I flew for a few years, we had 3 options - full, tabs, flight time since full or tabs.
The dihedral on a PA28 means that dipping will give you different values depending on how level the ground is, and will mean that you can't have a gauge with a straight scale but need a specifically calibrated one. So quite common to not use dipping on a PA28 due to its inaccuracy.
The dihedral on a PA28 means that dipping will give you different values depending on how level the ground is, and will mean that you can't have a gauge with a straight scale but need a specifically calibrated one. So quite common to not use dipping on a PA28 due to its inaccuracy.
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Every landing I do in every type I fly will be a full flaps landing. If the crosswind is such that I cannot safely fly the approach and landing, I will not land on that runway then. Every landing I do will be flown with the intent that the mainwheels touch gently first, and then the nose or tailwheel later in the rollout, unless there is a specific reason for a different technique. That is my personal preference, and in 40 years of flying, I have never been unhappy with it, and never damaged landing gear (or a plane, for that matter). I have only flown partial flap landings under instruction from much more competent pilots on type (Beaver and Twin Otter), or in the case of mechanical failure.
If you have a landing technique which works for you, and results in a controlled, stable, gentle landing, then do that. If a check pilot does not like it, ask to be referred to an authoritative document which says it should not be done that way. On the ever so slight chance there actually is a reference to not doing it that way, consider it! Otherwise, flyi the plane as though you own it, and would have to pay for wear&tear, and damage!
I once had to be checked out in a DA-42 for some flying I had to do. The check "Instructor" resisted my flaring for landings, rather wanting a three point landing. I don't like three pointing nosewheel planes for wheelbarrow risk, and damage to the nose strut. But, I did not have time to argue with him. so, I did a couple of nice three point landings, just touched the nosewheel, then held it light. Once he left, I flew it the right way, and held the nosewheel off 'till much later in the rollout.
If you have a landing technique which works for you, and results in a controlled, stable, gentle landing, then do that. If a check pilot does not like it, ask to be referred to an authoritative document which says it should not be done that way. On the ever so slight chance there actually is a reference to not doing it that way, consider it! Otherwise, flyi the plane as though you own it, and would have to pay for wear&tear, and damage!
I once had to be checked out in a DA-42 for some flying I had to do. The check "Instructor" resisted my flaring for landings, rather wanting a three point landing. I don't like three pointing nosewheel planes for wheelbarrow risk, and damage to the nose strut. But, I did not have time to argue with him. so, I did a couple of nice three point landings, just touched the nosewheel, then held it light. Once he left, I flew it the right way, and held the nosewheel off 'till much later in the rollout.
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I've always believed that landing flapless gives you better gust control, particularly in the flare, at the expense of needing a little more pavement.
I'm sure someone more technically expert than myself can explain it in terms of wing loading, but I think of it as reducing the gust component expressed as a percentage of the stall speed.
IIRC on a warrior, landing flapless gets you about a 15% increase in stall speed.
I can't imagine any situation where I'd ever attempt to three point a tricycle light aircraft and would regard such a landing as a major fail.
I suppose if you're using a warrior to train someone to operate an A320, teaching them not to hold off might just prevent a tailstrike incident further on down the line, but IMO it's no way to fly a light aircraft.
I'm sure someone more technically expert than myself can explain it in terms of wing loading, but I think of it as reducing the gust component expressed as a percentage of the stall speed.
IIRC on a warrior, landing flapless gets you about a 15% increase in stall speed.
I can't imagine any situation where I'd ever attempt to three point a tricycle light aircraft and would regard such a landing as a major fail.
I suppose if you're using a warrior to train someone to operate an A320, teaching them not to hold off might just prevent a tailstrike incident further on down the line, but IMO it's no way to fly a light aircraft.