Pitch or power?

[BigEndBob]

Do you pitch up or power up to initiate a climb?
One method is rarely taught the other just thrashes and can overspeed engines, destabilise the climb entry and create out of trim forces which have to be held until the aircraft settles.
PAT has a lot to answer for.

[homeguard]

I have the unfortunate disabilty of being able to say only one word at a time.

Therefore; Power-attitude. But I do it simultaneously or at the same time, whatever you prefer.

This debate will without doubt lead into the stall recovery arguement. The answers is simultaneous, reversed; Attitude-power.

[BEagle]

A lot of this is due to the total misunderstanding of 'PAT' by civil FIs. It started when someone got their hands on a CFS document and misunderstood it; then it spread like a cancer from places like CSE and is now firmly entrenched. But the way it's taught is bolleaux.

PAT applies only during a change of power setting. You set the power, control the attitude and trim for the effect of the changed power setting. That's 'PAT'. But then you 'Select Hold and Trim' the climbing attitude, check it and re-trim as needed. When levelling off, you anticipate slightly, Select Hold and Trim the straight and level attitude, then Progressively Adjust Attitude and Trim as you accelerate back to cruise speed, followed by another 'PAT' as you reset cruise power, controlling the attitude and trimming as you do so.

And there is simply NO SUCH CYCLE as the 'APT' about which some people talk!

[homeguard]

Thats it in a nutshell!

Funny you should mention CSE. The first time I came across this 'APT' thing was from someone who had 'done time' at Oxford.

Didn't eat with a knife and fork and hid his bumph under the mattress. Strange how it gets to some people.

[Field In Sight]

Power + Attitude + Trim = Performance. That is all we really do as pilots to control aeroplanes. So I place great emphasis on this to my students.

BEagle is quite right in saying that even during the acceleration to cruise speed after levelling out from a climb it is PAT followed effectively by a continuous set of smaller PAT’s until cruise speed is reached. Then setting cruise PAT.

All that I can say is that the number of people who I see reducing power to cruise as soon as they level off show’s to me that it is generally not being taught (or emphasised) properly. I know I used to do it in exactly the same way.

At the top of climb I teach “Set Attitude & Trim” followed by “progressive changes of Attitude” whilst the aircraft accelerates and then a final PAT when cruise speed has been achieved. It seems to fix the problem.

That’s my two pennies worth.

FIS

[FlyingForFun]

And there is simply NO SUCH CYCLE as the 'APT' about which some people talkHope you guys don't mind if I stir things up a little ;)

I was taught APT when leveling off at the top of the climb. Set an attitude which will give me level flight, and gradually adjust the attitude as the aircraft builds up speed. Once at (or approaching) cruising speed, reduce the power to cruise power, let everything settle down, and then trim. This technique seemed to work pretty well in a PA28 out in the practice area where I was taught it.

Then, as I gained experience, I started to learn that one technique doesn't necessarilly work in every case. When levelling off in the circuit, it was very handy to "coarse trim" before everything settles down. So the sequence is now Attitude, (course trim), Power, Trim.

On the PA23, I found that the only way of levelling off was to begin to wind the electric trim nose-down as soon as you start to change the attitude - a development of the coarse trim that I used in the PA28 in the circuit. The trim forces involved are just too great to be able to hold the nose down as the aircraft builds speed otherwise.

Then I started flying a Europa with a manually-adjustable variable pitch (i.e. not constant speed) prop. The technique for levelling this aircraft off and accelerating to cruise speed is to lower the nose and immediately coarsen the prop. (To do anything else will result in an engine overspeed.) With one hand on the stick and one on the prop switch, I don't have a free hand to be able to trim until after achieving the correct prop pitch. So the sequence is Attitude, (prop), Power, Trim.

I guess that, what I'm saying in a long-winded way, is that teaching APT as a basis seemed to work well for me. Since then, I've developed other techniques to suit different aircraft and different circumstances - but they are all, essentially, based on the APT technique that I was taught.

Any thoughts on this from the experienced guys out there?

FFF
-----------------

[homeguard]

before we move away from the original point.

I came across the idea of pitch before power to enter the climb, some years ago.

If I remember the arguement correctly; PITCH to climb atttitude, as speed settles to the correct climb speed progressively add POWER (balance) to the correct setting for the rate of climb required and TRIM.

I added; check that you rear seat passengers haven't thrown up!

[Say again s l o w l y]

I personally like students to add power gradually until they can reach full power without overspeeding the engine. I prefer this to any other method since adding power produces an initial pitch up anyway, in the same way when descending, a reduction in power causes the nose to pitch down, so why not use these natural movements and give everyone a smoother ride? It also helps students understand the forces that effect the a/c.

It all helps conserve energy as well. With titchy(power wise) engines and not alot of mass, light a/c slow down pretty quickly, so having full power added asap is very useful.

[Field In Sight]

Back to the original point.

I teach simultaneously set full power and set the climb attitude then HOLD it whilst the speed decreases. Trim off continuous pressure as needed.

I do this because it is simpler.

However, I agree with you that setting the climb attitude first and not changing the power until at the desired climb speed. This allows you to be in a hands off trimmed climb in a shorter period of time as the aircraft slows more quickly.

I don't teach it though because I don't want to have easily distracted low hour students with the nose high unless full power is applied.

FIS

[M.85]

Easy...if your pitch is out of service..use power..
if your engine quits ..use pitch.
If both are **** call mayday.
If both work..use them both at the same time if you have nothing else to do.

Ok..just felt like talking rub***
M.85

[DFC]

BEagle said;

"You set the power, control the attitude and trim for the effect of the changed power setting. That's 'PAT'. But then you 'Select Hold and Trim' the climbing attitude, check it and re-trim as needed"


Am I reading that correctly?

Are you really saying that to enter a climb from cruise the following actions should be made;

1. Apply full power
2. Apply forward pressure to prevent the nose rising due to increased power.
3. Trim nose down to remove the force from the control
4. Apply rearward pressure (against that trim) to select the climbing attitude
5. Trim back nose up (past the point where the trim was in the cruise).

If that is what was put forward by the above quote then IMHO we are increasing the workload for a simple manoeuvre unnecessarly.

---

The nose doesn't always pitch up when power is applied - it depends on the thrust-drag lines. In some aircraft adding power causes the nose to lower. No problem as long as the pilot is aware of it.

---

This idea that we should not teach APT because "there is no such cycle as APT" IMHO is rubbish. Perhaps the RAF instructor manual does not use such a method but that is for the RAF not the rest of the world.

Who cares what work cycles that the instructor uses to teach safe efficient operating practices as long as they get the message across.

Personally, I teach PAST for the entry to the climb - Power, Attitude, Speed, Trim. (the trim refers to the final trim not the coarse trim that may be required on some aircraft).

I teach ASPT for the exir from the climb - Attitude, Speed, Power, Trim.

Of course, I could use "wink, cough and scratch your ass" to assist a student in remembering a work cycle......but no doubt that isn't in the RAF manual either!! :D

Regards,

DFC

[squeakyunclean]

Keep it simple!

[mad_jock]

There is always PAT the CAT you daft ****.

Have to watch that one. Sometimes forget the student is 14 years old.

[G-SPOTs Lost]

MJ

Me thinks I know who did your FI Rating...........

Wouldn't be a balding squash player from EGNM would it????

;) ;)

[Slow-Rider]

DFC

My interpretation of Beagle's post is PAT:
P - Full power
A - Attitude - climbing attitude (smoothly)
T - trim the climbing attitude.

Directly after this and some checks then its SHT to refine.

Select climb attitude (visually) should be there or thereabouts from entry to climb anyway.

Hold adjusted attitude (if adjusted)

Trim - refine trim or retrim as required to maintain the selected climb attitude.

This is the way I understand it from Beagle's post and indeed my QFI.

The drill is then Lookout Attitude Instruments to maintain climb. Any deviation from the Tutor's set climb attitude or speed of 80kts is adjusted with SHT.

Hope that clarifies!

[homeguard]

You cannot trim ATTITUDE


TRIM SPEED!

[BEagle]

What utter rubbish!

I do hope that you're not a FI!

[homeguard]

If you think it's rubbish BEagle then explain yourself

[BEagle]

Just go back to EofC 1.

"To use the primary flying controls in order to select, hold and trim the datum attitude"

[homeguard]

Indeed!


The elevator (stabiliser) is used to PITCH the aeroplane not the trim!. The effectiveness of the elevator control is dependant on airspeed.

Following a pitch up to a required attitude the airspeed will decay. The deflection of the elevator that achieved our required ATTITUDE is no longer sufficient owing to the reduction in airspeed that follows. A further increase in elevator deflection is required. This process will continue until the four forces are in equilibrium.

At the point of equilibrium the 'stick' forces being applied by the pilot may be impossible to maintain but at the very least will certainly be uncomfortable and require constant attention. It is these forces that we need to trim, by a resetting of the 'trim tab' or 'balance tab', such that the re-positioning of the trim/balance tab will aerodynamically relief the pilot of 'stick' load.

Assume weight is constant, the three other forces are; thrust (by diving in the case of a glider), drag and lift and all three are a product of AIRSPEED.

It is the forces resulting from AIRSPEED that we TRIM using a flap attached to the elevator (conventionally) The trim, be it a stabilator or fixed tailplane/elevator arrangement is dependant on airspeed for effect as are all other aerofoils sections.

It is therefore the FORCES developed from AIRSPEED that we trim and not the attitude.

Put simply we trim for AIRSPEED whatever the ATTITUDE.

[Propjet88]

Sorry! When I read the title of this thread, I though that it was going to be about the final approach technique. i.e.

1) Attitude to control IAS / Power to control Rate of Descent

or

2) Attitude to control aiming point / Power to control speed

We all know that whilst technique 1) is used in a glide, 2) is a better technique for powered approaches and is fully transferable between A/C typres from light a/c, through fast jets toheavies.

Surprising how many F/Is still teach 1) for powered approaches!

(Retires to safe distance, fingers in ears, awaits explosion)!

[BEagle]

Control effectiveness is indeed dependant upon dynamic pressure. This may be a product of both IAS (as taught during EoC 1) and slipstream (as taught on EoC 2 except by the RAF who, perplexingly, attempt to teach 'effect of slipstream' before they teach 'use of engine controls'!). The attitude is controlled by the pilot selecting, holding and trimming the aircraft to maintain a desired attitude. Whether that attitude is correct for the desired flight stage is then assessed by reference to the instruments (Lookout, Attitude, Instruments); thus if S&L flight does not result from the selected attitude, the attitude is adjusted and re-trimmed until S&L flight is achieved. If that is not at the correct IAS, then thrust is adjusted, together with a progressive adjustment of attitude and trim, until it is.

Thrust is not normally considered to be a direct function of airspeed as such; the ram effect may modify it for jet engines and any propellor efficiency will certainly be affected by airspeed, but as a secondary effect only.

When an equilibrium of forces exists, only nett acceleration will be zero; dynamic stability will dictate the response to small perturbations as the ac is more than a mere frictionless particle in a steady state of equilibrium.

In a descent with idle thrust, if the IAS is incorrect, the pilot selects a new attitude and trims it, then rechecks whether that attitude has resulted in the correct IAS being achieved - Select, hold, trim, check, re-adjust, re-trim. Pilots who simply push or pull until they see the correct IAS on the ASI and then trim to relieve stick loads have not been taught the correct sequence of attitude flying. This 'head-in needle-chasing' is an obvious sign of poor initial instruction.

The principles of aerodynamics do require a particular trimmed state for airspeed in order to compensate for pitching moments; however how the pilot achieves that trimmed state is by deliberate selection and trimming of attitude initially (by reference to the horizon in VMC or artificial horizon in IMC), then correcting that attitude to achieve the desired IAS. It is not by selecting an IAS and then relieving stick force loads with pitch trim.

And yes, 'point and power' is indeed fully transferable from light ac to heavy and/or fast jet ac! It also results in pilots going solo earlier than if they are taught the 'old' technique.

[Say again s l o w l y]

If there wasn't a b*oody great prop throwing air over the elevators at differing speeds, then Homeguard would have a point, but since we do, then BEag's has it right.

Propjet88, you should know better than that! Point and power works for high inertia a/c, but in little bugsmashers then the 'old' technique works best.

[Send Clowns]

Hate to contradict BEagle, but APT is the correct sequence for leveling off, according to CFS. I was taught by CFS-trained instructors in the Air Squadron, the Navy and at CPL (by chance) and to level out at the top of climb was always taught to set the attitude, allow the aircraft to accelerate then set power, then trim the correct attitude (found by select - hold - adjust, of course). This was in contrast to the initiation of climb, descent or straight and level flight which were PAT.

[BEagle]

Not by CFS you weren't - you would have been taught SHT followed by PAAT in acronymish!

And that's a fact. If I'd tried to teach 'APT', I'd have failed my B1. Let alone my A2!

[Big Pistons Forever]

While the fore going debate has been very interesting, from my POV the challenge in the early PPL stage is to get the student to recognize the attitude of the airplane when they are looking out the windshield. I put most of the emphasis on the first few flights into getting students to be able to repeatedly and consistantly atttain and hold a level flight and normal climb and decending attitude. My experience when flying with students who are not progrssing is almst invariably been they cannot recognize the attitude of the aircraft.:(

[BEagle]

Big Pistons Forever - amen to that! How right you are!!

I had a pilot freshly back from one of those American 3-week PPL places:yuk: who said that he'd never heard of selecting attitudes. That was blindingly obvious from his head-in needle chasing antics in the circuit etc. He had no idea where to look in the circuit to assess tracking or spacing as he had always just turned over ground features. It took us 5 hours of re-training before we'd let him fly solo - and this was a so-called licensed pilot!!

[homeguard]

Whatever the arguements re the trim and I still stand my ground. Before I say anymore, I would like to here more imput on this complex issue from other contributors.

Re the last two submissions. I agree 100%. I regularly cover the ASI, when needs must, to stop students becoming mesmorised by it and I always empasise it's shortcomings and it's real purpose. I am a firm believer in working outside, setting attitudes by visual reference (VMC) and the power to be set initially by sound. Both to be followed by a refinement, by cross-reference to instruments. but once again using the outside references and engine sound to correct followed by a further check inside for confirmation, and as BEagle has said repeating the process until the aim is achieved. Then fine trimming (maintaining attitude by outside reference) but only when the aim is achieved and the process is stable.

Since the Seminar process has been in place I have now attended two Seminars and have been astonished by the wide differences in the use of words and approaches to patter and briefing. My mentors of old. Frank Morgan, Hector Taylor and Les Rackham to mention only a few,would, if I had followed such techniques as I have heard expounded, have dragged me over the coals.

Yet I have not, to date, witnessed a full and challenging debate on dynamics, the root of it all. David Scouler has a wonderful and illuminating lecture on the 4 forces throughout the approach and landing, by the way.

[Chuck Ellsworth]

As each " new " generation of regulators and flight instruction " experts " get into a position of power where they can re invent how to teach people to fly airplanes, we shall continue to see the dumming down of pilot skills as evident from a visit to any local airport.

God help us and protect us from these incompetents.

Chuck

Flight controls simplified:

Throttle :

A device that determines if the aircraft will leave the surface of the earth and fly.

Elevators:

Devices that determine at what angle the aircraft will leave or return to the earth in.

Trim :

A device that releives the pressure required to maintain the last attitude / airspeed change, Which of course is related to continuing to fly or return to earth.

Note:

If you crash the flying machine back onto the earth all three devices will probably become inoperative.

Chuck