Point & Power - Will somebody explain

[G-SPOTs Lost]

Whats it all about then????? An RAF technique I hear

All stems from a thread on Private Flying about trim on final.

I got tempted into giving some of the chaps the benefit of my inexperience and somebody discussed using this technique which I know nothing about.

Please feel free to enlighten me.

[DB6]

It's a descent technique which you can use if you have a fixed point to aim at e.g. a runway threshold. Attitude controls flightpath and ideally now remains fixed relative to the aiming point, and power is used to control airspeed. It does rather hinge on achieving a fixed point on the glidepath (400' point in RAF teach or 500' point otherwise [or letterbox, having now read the other thread]) which sets you up at the correct angle (3 degrees or so) but thereafter it's an effective technique which I believe translates well onto larger and heavier aircraft. I haven't read all of the other thread (but will in a moment) but you do still have to trim if you vary power.

[LeadSled]

Folks,

This is another version of the US Navy "point of no relative movement" approach, developed for training on early jets.

This is the first application I know of, but it is virtually univesal as the technique for all large aircraft.

It post dates the venerable " elevators control airspeed. power controls rate of climb and descent" , see also a debate Techead forum.

Tootle pip !!

[BlueLine]

Roll out on a Final at say 1 nm and 500 ft, select the attitude /power combination that you require for the approach.

Note where the landing point is in the windscreen - by maintaing this in the same position you musy fly a straight line towards it.

If everything else remains constant, the IAS will also remain constant however, in practice it will vary due to changing Met; maintain IAS with throttle.

The net result is a smoother, easier to fly approach with a linear descent path.

[BEagle]

Plus for the student, a small IAS change is much easier to spot and correct using 'point and power' than a glidepath error is using the 'old' method.....

But like other newer, easier advances in flying (such as SCA for visual navigation), it isn't in some dusty old tome written by Pontius' FI - so it remains a mystery to those still trained by The Ancients!

To remind everyone,

1. Roll out of final turn at right height.
2. Select landing flap.
3. Adjust to Aproach Speed and TRIM.
4. NOW Point at touchdown spot, keep it nailed under the same dead fly spot in the windscreen.
5. Scan TD point - IAS - TD point - IAS continually on the approach.
6. Make small constant power corrections. Minor re-trimming might be needed.
7. Approaching impact, select landing attitude and close throttle. Hold it off until it kisses the runway smoother than a politician with a baby!

[GT]

And anyway, isn't 'point and power' how we fly the ILS? Glideslope with elevator and speed with power.

Regards, GT.

[G-SPOTs Lost]

Interesting in theory...

Im thinking more about airplanes with a narrow speed range nothing heavier than say a light twin and a student in the ab initio phase.

GT

Certainly dont teach the ILS like that in a warrior, am I missing something?

[DB6]

Works just fine in anything from a Tipsy Nipper upwards, G- old bean :cool:, and gets taught to ab-initio RAF students at JEFTS and UAS's. You can fly the ILS the same way - it was taught that way at Prestwick when I did my IR - or the other way, which the RAF do currently. Take your pick.

[I Fly]

I hear what a lot of you are saying and I'm sure it works very well for 'experienced' pilots. However I think it must be a bit confusing to early students. We teach them Effects of Controls, Straight and Level, Climbing and Descending, Turning, Stalling, Circuits. We teach 3 types of climb - in each elevator controls speed and power controls rate of climb. We teach them 3 types of descent and again - elevator controls speed and power controls rate of descent. Then we put them in the circuit and say "this is no longer true, we now do it different"???? When you teach circuits emergencies, how do you teach that? Point at what? Perhaps I have been trained the 'old' way but I think the first thing we need to teach the early student is to get the attitude correct (=correct speed) so that they can see the 'picture' and they can see whether they are high or low, then they can fix that. I agree with the statement "we fly the ILS that way". By the time a pilot flies an ILS they should have quite a bit of experience and the 'picture' is presented on the instrument, not outside. I think the point and power methodology got developed when the military flew turbine engines that were very slow to respond and you did not get the power when and as needed. Piston engines do not have that problem. A 400 ton juggernaut does not respond so fast either. If a 'mature' type person wants to learn in a Superpup purely for fun I find the 'old' method works better.

[juggernaut]

The problem with the point and power technique is that it was brought in by CFS in order to prepare students for fast jet training. If you are approaching at 120knots then using the elevator to reduce speed means a large divergence from the glide path, this is due to the much greater inertia In most light aircraft however, this is not a problem and I suggest that for PPL training that the tried and tested method of elevator for airspeed and power for ROD doth apply, if I ever get to fly a Hawk then I will use the CFS method!

[DB6]

The last two posts make valid points however I will say that we taught point and power to ab-initio teenagers at Tayside on the Flying Scholarship scheme and they had no trouble with it. I don't think it's any more difficult, just slightly different. I personally don't have a preference but have probably forgotten how to do it the other way ;) .

[BlueLine]

I Fly,

And what do you teach them in the turn?
Elevator controls........?

And power controls..... could it be speed?

[fibod]

This has nothing to do with aircraft size, or the 'experience' of students. The technique works very well on light aircraft and with ab-initio students. I know, because I have been teaching it for years. The disadvantages of the 'other' method are:

a. It teaches a technique that has to be unlearnt later, because it doesn't work on real aeroplanes.

b. Taken literally, to extremes, it can encourage inappropriate (even dangerous) handling close to the ground (student lets the speed get a little low, realises and responds by shoving the nose forward. Unchecked result - a steep approach to short of the threshold, where extra power was what was really called for. I've seen it, many times, on tests, at the CPL and later.)

[bluskis]

I think something has to explain the increase in landing accidents, particularly involving wheelbarrowing.

I Fly has it right when he cites the poor response of jet engines of 'real aeroplanes' as the reasons for jet pilots to learn point and power.

I firmly believe PPL piston pilots should think power controls descent and pitch controls speed.

They should then think speed is the vital ingredient, and in sticking to the correct speed they should use power to control their arrival at the appropriate point on the runway.

No doubt relearning will be required for the transition to'real aeroplanes', instruments and jet power, but in the mean while the PPL pilot will have achieved feel for flying, and safe landings will have been made.

I post the above secure in the knowledge that I will be in the minority.

[moggie]

Elevator for speed, power for ROD - tosh!

Why use power to control ROD when this technique only works on props? The point and power "jet" technique works on everything with an engine (helos and airships excepted) - regardless of what type of power unit it is.

On a jet aeroplane (e.g. any jet airliner) the only technique that works is point and power - so if that is the ultimate aim for a student, why teach one technique on ab-initio and then have them re-learn how to fly on a type rating?

Use the pitch attitude to make the aeroplane fly the desired flight path and use power to control speed (after all, this is what you do when flying level!). It works for all approaches - instrument and visual, precision and non-precision.

One problem - no offence intended - is that a HUGE proportion of FIs have never flown big aeroplanes and don't realise that point and power is essential.

[Blue Hauler]

I have to disagree with the ‘point and power’ (gun-barrel or ballistic) approach technique, particularly at ab-initio stage. And I do fly jets!

The technique sets the student up for disaster in short-field approaches. If at 1.3 Vs the student recognises that he/she is falling below the approach path and attempts to recover by back pressure, speed will rapidly reduce as induced drag takes over. At this point the student should have corrected with power.

In a jet aircraft the situation is different. Because of the low drag profile a change of attitude will have little effect on speed, but a major diversion from the flight path. Therefore elevators are extremely effective to recover to the flight path without upsetting the speed. Small adjustments of Ng are very effective at maintaining air speed.

The technique will work on many of the performance twins and I guess that transitioning during multi-engine conversion or instrument rating training is valid.

[BEagle]

So long as the final approach path is commenced from an acceptable approach point, 'point and power' works very well in any aeroplane. I teach it on the PA28, I teach it on the VC10.

During Descending 2, the final exercise should show the student the acceptable limits for the approach path from which 'point and power' is commenced.

CC for IAS and power for ROD works until you are aiming at a fixed point on the ground! - after which 'point and power' takes over. Everyone who has tried it agrees - it's MUCH easier and more logical!

[Blue Hauler]

Beagle

I agree that the technique works in any aircraft but that was not my point. In teaching the ‘point and power technique’ we are programming students to check approach path with elevator – therefore speed becomes a secondary consideration. If the aircraft descends below flight path and attitude is increased to recover, speed will decrease. The rate of decrease is dependent upon angle of attack, the greater the angle the more rapidly speed will reduce. On short field approaches where speed is targeted at the minimum approach speed there is not much margin for error.

On the other hand students trained in the conventional manner will recover from a below flight path or high ROD situation with power, a pre-requisite to going round which will be the next step if the ‘swimming in glue’ syndrome continues.

I worked for a school that taught the ‘point and power’ technique exclusively. One of my students during STOL practice failed to recognise a low-speed high ROD situation because he was too intent on pinning the aim point with elevator. My calls for ‘power’ went unheeded until I slammed the throttle forward. We landed softly with full power!

Low time students just don’t have the experience to put it all together, all of the time. Training should therefore safeguard the student until the basic skills and situation awareness are developed. In training pilots onto turbo props/jets I have never had a problem introducing the ‘point and power’ technique. To most experienced pilots the approach and landing just seems to happen with no conscious thought until taught an alternative method.

Our company operates a diverse turbine fleet including Cessna Caravans. The latter regularly operate into 420 metre strips. I note that in STOL operations our pilots make a conscious effort to fly the traditional method with the aircraft trimmed for speed and the power varied to achieve the flight path. Therefore turbines – small ones at least – do not have to be flown using the ‘point and power technique’.

[G-SPOTs Lost]

Moggie



errrr... everybody learning to fly doesn't want to fly Big Jets....


You have to teach the lowest common denominator at ab initio level, you cant ask everybody whether they have considered a career in commercial aviation when they are booking a trial lesson.

Im not disagreeing with your point of view about the technique point and power just your motives for teaching it to ab initio private flying types and having gone as far as saying that iit also needs to be said that there is a pattern emerging here, anybody else spot it? ;)

[bluskis]

Just a thought, not intended as a diversion, do you teach pitch for speed in stall recovery, as the first action that is?

[BEagle]

BlueHauler - no, we are insisting that pilots refer constantly to both speed and touchdown point throughout the entire approach. Keeping the aim point nailed, any IAS change is rapidly noted and corrected, the magnitude of any errors and rate of corrective power changes become less as experience is gained so that they become virtually seamless.

And it's SO VERY EASY!!

[Blue Hauler]

BEagle


I agree that both parameters must be monitored but when one parameter deviates from the target, it is corrected, possibly at the expense of the other and that was my experience. I subsequently compromised by teaching point and power in normal circuits but reverted to the traditional technique for STOL. Point and power will not work in glide approaches as attitude controls air speed not rate of descent. At the bottom of the glide power is used to arrest the rate of descent and also to climb. Therefore sooner or later you must revert to the traditional method.

The traditional method is also easy if you instruct the student to pin speed with attitude and then trim. Speed is maintained with elevators. If the aiming point moves up the windshield put the power up…if it moves down, put the power down. Now that is not too hard is it?

I would be interested in your method for STOL or are you folk fortunate enough to not have to deal with short bush strips?

[BEagle]

The whole idea is that one parameter remains fixed - aiming point. The other is continually corrected.

If an approach angle is flown to an aiming point which allows the required constant approach speed to be maintained with a power setting somewhere between idle and max, then the technique can be used. It worked quite happily in the Bulldog when we were teaching 'short landing' technique with the IAS very close to the 'wrong side of the drag curve' - it just neede rather more prompt power application and more frequent IAS cross-checking.

[Blue Hauler]

Thanks Beagle,

The interesting issue is that for every adjustment of power there needs to be a corresponding adjustment with elevator to achieve the profile, whether we use traditional or point and power technique. In other words point and power is not a change in aerodynamics but a change in the state of mind of the pilot!

In my country CFI’s fly with the regulator (Flight Operations Inspector) three times every two years. Two Instrument Rating and one Instructor Rating renewals. My FOI (ex-military) was adamant that point and power was not a technique to be taught ab-initio. In some ways I agreed but argued along the lines of most of the ‘pro’ posters above – and lost.

I then had to convince the troops, many of whom were experienced airline captains (the school is voluntary, training air minded youth) and as most readers will realize there are two distinct camps of ‘compartemtalised’ individuals. Those who would not succumb to cognitive dissonance just had to be pressured.

My own opinion is that ‘point and power’ simplifies early circuit training but undoes some of the skill that can be applied to short field landings. Beagle thanks for the discussion. I suspect we have just created more questions for the poster and readers.

[Aerobatic Flyer]

I would be interested in your method for STOL or are you folk fortunate enough to not have to deal with short bush strips?

The technique taught flying to mountain strips in France is exclusively "point and power" - and the strips can sometimes be exceptionally short.

The view is that for a short landing, nothing is more important than an accurate touchdown point, which can only be achieved using a fixed aiming point and stable speed. If pitch is used to control airspeed, it becomes impossible to focus on the aiming point - and consequently you will miss the touchdown point, which on the shortest strips means you will break something.

[Blue Hauler]

Aerobatic Flyer

The view is that for a short landing, nothing is more important than an accurate touchdown point

The overiding factor on a short field landing is speed. If the approach speed is higher than published then the distance from fifty feet above the surface to touch down will be greater. If touch-down speed is higher then the ground roll will also be greater. Even if the aiming point is achieved the upwind fence becomes an arrestor cable – not so good.

If approach speed is controlled using the traditional technique and the aiming point is overshot then one simply applies full power and goes ‘round - not so bad.

The downside of point and power for STOL is that if rate of descent increases, casuing the aircraft to drop below the glidepath then the initial reaction is to increase nose pitch. This causes an increase in drag and a rapid reduction in airspeed. An adept pilot will quickly apply power to recover speed. The student will not be quick enough and the result will be a heavy landing or stall from low altitude.

[I Fly]

This argument seems to go on and on. I'm sorry for prolonging it. A couple of answers first.
blueskis - pitch at stall is to reduce Angle of attack, nothing to do with speed (in a 4 g manoeuvre your stalling speed will be twice the normal Vs).
Blue line - What do you do when after take-off the aircraft appears not to climb as desired at blue line? Point to where you want it to go??????????
I thought I better go and consult 'the bible'. In Australia we have what used to be called Pub 45 (I don't know it's current number). It is written by our Regulator for the guidance of Instructors. Our Regulator states "speed must be controlled with elevator and the rate of descent and thus the approach path, with throttle". Perhaps I'm a weaklings but I do as they suggest. And it has worked well for my for the last 35 years. It also works, for me into strips that are to the meter the minimum calculated. (many times I have to reduce the load to just fit). In fact I think I'd be in trouble if I used the point methodology on short strips.

I'd be interested to hear what does your Regulator suggest / require. Perhaps we are just a victim of history or geography.

[DB6]

Whichever method you use you will become competent in its execution, it generally doesn't matter which. The difference I think comes with the size and speed of the aircraft you're flying; the point and power mothod becomes more and more the one to use. On smaller aircraft it's purely a matter of choice. Try both and see which one you prefer. Just don't get evangelistic about it :D .
We don't have a single 'bible' as such. The RAF 'bible' pronounces that point and power shall be the method thou dost use, the civil world is left to follow its own messiah and beware false idols as best it can. For it is written.

[40 yearflyer]

Yes,it is 'horses for courses'. Having in the past been an enthusiastic exponent of point and power I am not so sure anymore. I agree the amount of inertia/weight of your particular steed probably determines the best method to use. I have seen drawbacks to both methods when applied to light aircraft.
The average student struggling to maintain a constant glidepath (why do we call it that ?) using the 'old method' is often reluctant to change his approach path in the last 100ft and goes where the aircraft takes him -usually to the middle of the runway where he feels pressurised into completing his landing before he runs out of runway. For this problem I have introduced point and power in the 'last 100ft'
The reason I no longer advocate 'point and power' earlier (higher) is that our average (non RAF selected) student seems to cope better with the old method. It also gets him out of trouble when he hits the wrong side of the drag curve and and elevators will restore the speed by reducing induced drag faster than the power input he is likely to make'

It is also better in the strong wind gradient situation.

It also makes sense when teaching to maintain two reds and two whites -PAPIs.

However, remember, that you cannot, in a light aircraft, expect to make any change to pitch without a corresponding change to power and vice versa - all other things being equal. A experienced pilot is seamlessly using the two together.

If you teach the 'old method' a competent student is in fact using point and power in the latter part of the approach to bring his speed back to the Vat - and he is doing this without realising it has a name.

Sorry to preach. I only have 14,000 hours but something like 25,000 approaches and landings - not to count the bounces !

[Aerobatic Flyer]

Blue Hauler

You're right, accurate speed control is essential landing on a short strip, as is touching down at the correct point.

If approach speed is controlled using the traditional technique and the aiming point is overshot then one simply applies full power and goes ‘round - not so bad.

Usually, yes. But in the mountains, this just isn't an option. Nor is undershooting. If things go wrong, the best you can hope for is a low-speed impact at the uphill end of the strip.

There is not really a lot of difference between the two techniques, however. On an approach to a mountain strip, final approach is initially flown at a level attitude until the glideslope is intercepted, then approach power is set and the aiming point is aimed at. If speed is too high, you reduce power.... but, if you always fly approaches in the same way, the only reason for the speed being too high is that your approach is too steep and you are above the glideslope.

The power reduction that I use to control speed is therefore effectively controlling my height!

[Blue Hauler]

Aerobatic Flyer

Years ago I flew Cessna 180 aircraft in and out of short strips, clay-pans and sometimes just rough clearings in remote areas of the country. Some were one-way strips due to the slope or terrain. Our technique was to approach at 1.1 Vs. The full flap stall speed of the aircraft was 36 KIAS therefore approach with full flap was flown 40 KIAS. In such a scenario the final approach required much control with the throttle to keep the aiming point correctly positioned – we had the throttle friction backed right off. As angle of attack was just below the stall there would have been no room to manoeuvre with nose pitch if the aircraft slipped below the flight path. The aircraft was stabilised at 40 KIAS in pretty much the three-point attitude and being a tail wheel type required little or no further flare. However sometimes conditions could inflict a higher rate of descent just prior to ‘impact’ and this was corrected with power!

My philosophy on the technique centred on a right-angle triangle. The baseline representing horizontal speed, the perpendicular representing ROD and the hypotenuse the TAS. If ROD could be increased for a given TAS then the baseline would reduce and so would ground-roll! In such a technique the use of power is the only way to arrest ROD.

I don’t advocate STOL at 1.1 Vs. If the strip is too short to approach at 1.3 Vs then simply reduce payload until it fits – particularly since a Cessna Caravan costs many times more than a C180. I would advise any non-instructor types to use the technique they were taught and stick with what works best.

My commentary on the topic was more aimed at instructors and the need to consider all teaching options as many students progress into various types of flying. We should therefore not only teach both techniques but also ensure the student is fully conversant with the logic of each. My preference is to delay the 'point and power' technique until it fits the scenario i.e.: high inertia, low drag airframes.

[fibod]

Hmm 40 Year Flyer, we're the same vintage (and a damned fine wine it is too!). Maybe that is why I agree with much of what you are saying. However, I 'switch' earlier in the approach: when comfortably lined up and a touchdown point can be properly selected.

It's interesting how polarised views are on this topic. The truth is, that both teaching methods work; otherwise 50% of students would be in smoking holes!

:)

[martinidoc]

Whilst in an ideal world both techniques could be taught, in reality for ab initio training, the time (and cash) constraints mean that to attempt to teach two different techniques might well cause confusion, and would certainly reduce the students experience at flying one type of approach

[fibod]

Martini (I used to know a girl by that name; probably a grandmother by now) I don’t think anyone is suggesting teaching both methods as a landing technique. In my book, one is a technique for a powered decent (power controls, indirectly, RoD). That technique is employed to control the decent in the pattern until the landing point can be selected. The other is a technique for landing an aircraft (point the aircraft where you want to land and control the speed with the throttle).

It’s a simple proposition, and intuitive. I’ve taught it for years to both those who are gifted, selected, and bound for jets, and those who are struggling, without aptitude, and bound nowhere. I’ve also attempted to employ the ‘theory’ model. Personally, I’ve had less success with it. I’ve found the gifted students learn whatever (i.e. despite me), but those who struggle, struggle more with the “power controls RoD” model.

After years of discussion and practice, I’m comfortable with the way I do it and I regard it as a safer technique for the less able/experienced, as discussed earlier.

But that’s just my opinion.

[40 yearflyer]

Fibod.
Thanks for that. I agree the 'switch' has to made higher than 100ft otherwise there isn't time to adapt to the new technique. I tried out my 100ft this week and it is too late.
I can no longer criticise a student who uses the old method o maintain a good visual approach path, or papis, and decides to go 'point and power' in the last part to achieve a possible touchdown 'just after the numbers'. However this can produce a 'banana' shape to the approach profile particularly if he has been using papis (which are set up for a touchdown beyond the numbers).
I cannot resist telling the tale of how I had to impress my CFI (Boss to Americans - not certified flying instructor). This was a short field pattered landing. He had a cold so the upper work was 'binned' which suited me fine as I always felt sick after the mandatory spin aeros etc, Suffice to say I really worked hard in the Chipmunk to land it next to the 'caravan' . There was NO POINT AND POWER in this approach - I could see nothing of the windscreen in the back seat and it was all 'along the side' of the left fuselage. I managed to achieve the 'increase of power' to reduce the vertical component in the approach path so that a touchdown was achieved in the right place at an incredibly low speed. If the runway caravan had been a 'snowbird' size mobile home (minus compact car at the back) I would have claimed a landing to full stop in the length of the caravan. Nothing to boast of here-just bringing the two threads that have been running here together.