Levelling off from the Climb - Trim Technique
Levelling off from the Climb - Trim Technique
When teaching the level off from the climb do you teach to make an initial trim immediately after selecting the attitude and then refine after cruise speed attained and selection of power or select attitude, wait for target speed, select power and then trim?
I have my own views on the best technique but am interested to hear the different views. Why do you think your preferred technique is better than the alternative?
I have my own views on the best technique but am interested to hear the different views. Why do you think your preferred technique is better than the alternative?
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Progressively Adjust Attitude and Trim. At top of climb adopt the level flight attitude for the climb speed (say 70 kts - the nose will be a little higher than at cruising speed) leaving the power at full, and trim. As the aircraft accelerates the nose will need to be lowered porgressively to maintain level flight, trimming all the time, until you reach cruise speed whereupon the power is reduced to the cruise and a final trim is performed. Easier on aircraft with electric trim. Basically your former technique, with a bit more trimming. The latter technique does not teach the student to stay in trim all the time and on some aircraft the forward pressure that has to be maintained during acceleration can considerable if you don't trim, then as soon as you reach for the trim wheel you have to hold it with one hand, nose leaps up, height goes haywire, mayhem mayhem etc.
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FFB, depends upon the A/C. In a Warrior I advocate one 'back to front' on the trim wheel at same time as pitching forward to the cruise attitude for climb speed. This helps overcome the excessive force required on the yoke to aviod climbing as the A/C accelerates to cruise speed. From here on it is a matter of progressive forward pressure on yoke, then trim for attitude.. .. .By the way when I say 'back to front' I mean holding the trim wheel at the rearmost position then moving forward until fingers contact front of trim panel (OH hell, this sounds grim doesn't it??!!) I am sure you know what I mean though.. .. .Also to refine the attitude I suggest keeping an eye on VSI as this will show the trend.. .. .Principally I agree with with DB6. .. .JWF <img border="0" title="" alt="[Big Grin]" src="biggrin.gif" />
Leave full power, progressively adjust power as IAS increases, set power then trim to hands off with the proviso that a couple or few trim adjustments to lighten the workload while still accelerating is perfectly OK as long as the student knows that this is not the same as trimming to hands-off in stable flight.
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The RAF way of teaching this (on the Grob anyway) is to anticipate the level off (50'), select hold and trim for straight and level at 80 kts (climb speed), leave the power and progressively adjust the attitude and trim until approaching cruise speed then set cruise power, rudder to prevent yaw, adjust and trim for s&l as req'd.. .. .Seems to work and we have no electric trim.. .. .Tonks
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Agree with Titch, set attitude, wait for the speed to increase, reduce power, then trim. If you can't hold a basic trainer straight and level while the speed increases then perhaps you should consider joining a gym. Heavier aircraft with more power may require a slightly different trimming technique, but I presume we are talking ab-intio trainers here.. .. .Kermie <img border="0" title="" alt="[Razz]" src="tongue.gif" />
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Sorry for intruding (just a lowly student) but my instructor teaches the titch method - set attitude, let the speed increase, reduce power then trim. Have to confess I don't find it too hard to hold attitude on the PA38, but wouldn't want to try it on anything heavier.
Well I suspected this issue would cause some interesting debate!. .. .DB6 I am with you on this one.. .. .In some light aircraft (especially at higher altitudes) it can take quite a long time to accelerate to cruise speed and I cannot see the point in sitting there pushing more and more when we have surely already taught the student in Effects of Controls to Trim!. .. .If you had an aircraft that climbs at 100 kt and cruises at 300 kt would you wait until you have set the power at 300 kt before applying any trim? I think not. We should as far as is possible be teaching techniques which are not type specific.. .. .I think the best way is to teach to trim whilst accelerating rather than wait till cruise speed achieved etc. All this presupposes the student is able to achieve and maintain the correct attitude.. .. .However, if I came across a pilot who could level out competently (how many of those are about!?) then I would not go wading in suggesting that he changes his system but I might suggest it would be easier if he did!
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titch - why???? What's the point in holding, in a Warrior at least, large out of trim forces as the aircraft accelerates from climb speed to cruise speed? When you do S & L 2 surely you teach PAAT (progressively adjust attitude and trim) so why aren't you teaching the same thing for the same circumstance at TOC (apart from the "well that's what my old dad /CFI/someone I met down the pub did")?
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I still prefer the way we do it. You can so easily see those students who don't trim or progressively adjust the attitude as the ac just keeps going up and the speed never reaches cruise.. .. .This technique works on the Grob and the VC10 so I will stick with it.. .. .Tonks <img border="0" title="" alt="[Smile]" src="smile.gif" />
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Well.. I have been taught both methods during my past training.. .. .I would advocate making it as simple as possibe on basic light aircraft such as C152 and PA28 etc, especially for a new student. .. .Attitude. .Power. .Trim.. .. .with the proviso that its ok to relieve some of the stick forces if necessary.. .. .Of course on something larger and more powerful the stick forces become much greater and then it would certainly be worthwhile trimming progressively. I used to trim progressively on the PA-34 as it is very hard to resist the stick forces whilst accelerating from 100 in the climb to 140-150kts cruise. . .. .As long as a student trims correctly, understands the corect operation of the trimmer and why it needs to be used correctly then I'm happy that they will be able to fly and trim more or less any light aircraft safely, accurately and correctly.. .. .LP. .. .(edited for keyboard gremlins). . . . <small>[ 05 March 2002, 18:57: Message edited by: Loony_Pilot ]</small>
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As some of you have said, 'it's horses for courses' but I would urge those who did not insert 'speed' before power reductions to be cautious - after a go-around, for example, in a draggy machine, students get embarassed when they reduce power having forgotten they have some residual flap still there - there are other cases, too, but my suggestion is attitude, speed, check flaps and gear,power, trim - there is then an 'inertia' period, so it will be back to attitude for the new established cruise speed, fine power correction, then final(hopefully) trim.. .Also, of course, as some of you have said, if you are working too hard at any stage, that's what trimmers are for, so use them but not if you start looking inside and lose the picture - ab initio, or not - always fly the picture, whether that's out the window or on the panel <img border="0" title="" alt="[Big Grin]" src="biggrin.gif" /> ATTITUDE PLUS POWER EQUALS PERFORMANCE ( GOD, I'M BORING!)
PAAT every time!! Incidentally, 'Attitude, Power, Trim' results originally from some civil FI's misunderstanding of the CFS litany 'PAT' and it has infected civil teaching ever since.. .. .Not difficult. Anticipate, select attitude, Progressively adjust attitude to maintain level flight whilst accelerating to cruise speed, adjust power to maintain cruise speed when achieved.. . . . <small>[ 07 March 2002, 14:23: Message edited by: BEagle ]</small>
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Why does there have to be acronyms for every possible thing we do in aviation?. .. .Is it not possible to teach using a logical thought process?. .. .For instance I have transitioned or am about to transition from the climbing attitude to the crusing attitude, for some reason I am having to hold pressure on this stick, wheel, side controller, to make this thing do what I want it to do. Hmmmmm maybe if I use this trim thingy here and with a little playing around with it I can relieve the pressure on the stick, wheel, side controller. Hey magic it works!!!!!!. .. .Whow what a concept.. .. .Lets look at Attitude - Power - Trim.. .. . I am in cruise and want to decend... sooo attitude nose down wait a minute the airspeed is increasing Hmmmm O.K reduce power and trim... s**t that is not the right speed. Hmmmm O.K. Attitude, nose up now should I add or reduce power?? Oh well re trim , naw thats wrong to, oh well close enough for this approach.. .. .............. . <img border="0" title="" alt="[Big Grin]" src="biggrin.gif" /> The hardest thing about flying is knowing when to say no. <img border="0" title="" alt="[Big Grin]" src="biggrin.gif" />. . . . <small>[ 07 March 2002, 19:10: Message edited by: Cat Driver ]</small>
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Haven't heard the PAAT thing before but I do use AAPT (Attitude, Accelerate, Power, Trim). Nothing wrong with teaching a student to hold excessive control forces early in their training. Makes them appreciate the Trim and they will use it sub-conciously even doing a few turns whilst they are accelerating.. .. .S2K
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Before teaching this, one should refer back to the 'Effects of Controls' exercise. We all know that as airspeed increases so does the effectiveness of each aerodynamic control. Rarely refered to or taught, is the fact that THIS ALSO INCLUDES THE TRIM TAB.. .. .Therefore, when teaching the level off from the climb the procedure should be:. .. .Attitude - Maintain level flight. .Airspeed - Allow to rise. .Power - Reduce to cruise power when. . approaching cruise airspeed. .Trim - When at constant airspeed. .. .Trim can not be set correctly when the aircraft is accelerating as the effect of the trim tab is changing.
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Trim cannot be set correctly when aircraft is accelerating??. .. .I guess I have been doing it wrong all these years.. .. .Any aircraft I have flown that require any signifigant control pressure to maintain level flight while the airplane is accelerating I have progressively trimmed.. .. .If by some strange chance I were to have to take a check ride from a Certified Flight Instructor would he / she mark me down for poor airmanship due to my not knowing you cannot trim while accelerating?. .. ......................... . <img border="0" title="" alt="[Big Grin]" src="biggrin.gif" /> The hardest thing about flying is knowing when to say no. <img border="0" title="" alt="[Big Grin]" src="biggrin.gif" />