Prop RPM during the approach.

[Chuck Ellsworth]

How's things Pig Boat?

Did you find a copy of that book I PMed you about? If not I can send you mine as I have finished reading it.

I would be very surprised if you did not use cruise RPM during the approach and move the the props to fine on touch down as it was the standard for operating those airplanes and worked just fine.

With the DC3 or the C117 you could just set a power setting once established on the glide slope and she would just drive right down to touch down with only one throttle movement needed..close them for touch down.....great birds and we were fortunate to have flown them.

Moose Murdock taught me how to fly both the DC3 and the PBY and he would have killed me if I brought the RPM up on approach unless there was a good reason to do so.

[flyboy2]

Cat amongst the pigeons!

You're all correct it seems, BUT there are some geared piston-engines that " de-tune" the crankshaft counter-weights if the pilot shoves prop-levers forward when throttles are closed ( or power setting is low).
To avoid damage it was 'procedure' to leave prop RPM at cruise setting until landed!
For instance the Lycoming GTSIO or the Continental GTSIO; they are fitted to types such as Rockwell Commander 680, Cessna 421 etc.
Fortunately these engines have priced themselves out of the market these days!
Any comments?

[privateer01]

Ya can't detune the GSIO by increasing the RPM after the throttles are at idle.

I've run QueenAires and 421's to TBO.

I know where Chucks coming from. As I've about 3000 hrs with the R1820, R1830, and R2800 too.

Consider the early jets if you will vis a vis needing the power immediately.

Spool time on the early jets could be as long as 21 seconds.

So...really if you've managed your energy as was mentioned the 1 second it takes to push the props up isn't going to save the bacon.

I think its all part and parcel of the dumbing down of aviation.

Someone (possibly during upgrade from a single to a twin) forgot to push the props up while attempting a go around......and students have beeen taught to push them up early ever since.

[Big Pistons Forever]

I have lots of GTSIO 520 time and that is one engine you do not be want to be running the props at low MP unless the props are all ready on the fine pitch stops (ie the aircraft is below 100 kts). In fact run this engine just like a big radial and it will reward you with a trouble free life. The 421C I used to fly was sold with 1400 hrs on the engines and with no cylinders or turbochargers requiring removal in the entire period since the engines were remanufactured .

There seems to be two procedures which are being mixed in the discussion. my experience is the generally standard flight training SOP is props to the climb RPM setting on downwind (VFR) or prior to intercepting the approach course inbound (IFR). I have not seen any school that mandated full fine (ie max RPM) at these points. if anybody does than I think they are being rather silly since climb RPM is plenty to climb away from a baulked approach

Anyway my experience is the farther folks are away from actaully having to teach (note the present tense) low hour pilots the easier they find it to pontificate on how it should be done.

The bottom line is for the simple direct drive non turbo charged engines in trainers where to bring the props up is purely a style point as the engines will not be affected either way.

[Chuck Ellsworth]

I have made it very clear that I have not instructed at the flight training school level for decades and will freely admit that I am out of touch with the teaching methods that have evolved since I let my rating lapse.

However I have witnessed the abysmal level of skills and understanding of how to operate aircraft that are to be found coming out of these training facilities.

I have no desire to get into no win arguments with anyone here on the Pprune instructors forum Big Pistons Forever as that is part of the reason I no longer post in the Canadian forum.

It has been so long since I held a Canadian instructors rating that my Flight Instructor Guide has the learning factors referred to as " The laws of learning ". In the laws of learning there is a one called " The law of Primacy " ( Teach it right the first time. )

I do not buy into the dumb it down to make it easier for the student to learn a given exercise mindset, so they can get a licence and be able to then get enough experience to learn to do it a different way that will work better.

My personal opinion is to teach them how to operate an airplane in the safest and most efficient way that I personally have found works best that is within the operating limitations of the pilot operating handbook for the airplane being flown right from the start of their training for any exercise.

Sorry but teaching pilots to increase propeller RPM some minutes before landing is not something I agree with nor teach as I take the position that going down hill requires a reduction in power and increasing RPM is an action that that can be performed safely when and if needed.

So lets leave it at that BPF because I have no intention of dragging our differences over to this forum from the Canadian one.

[SNS3Guppy]

Much as I hate to agree with Chuck, I've been operating piston engines the same way for decades. I teach it that way, and operate the airplanes that way. Regardless of whether it's a large radial piston engine or a smaller flat horizontally opposed piston engine. I teach keeping the props back and operate airplanes the same way.

Someone earlier indicated that certain flight manuals require the RPM to be placed forward, and this is not the case. Don't confuse a checklist or a procedure with an aircraft limitation.

Don't confuse a recommendation or suggestion with a limitation, either.

In general with aircraft utilizing a constant speed propeller, I don't increase the propeller until the power is retarded far enough that I won't hear or see an RPM increase.

In certain conditions such as an approach in ice, I will increase RPM early, and I'll do it when conducting an approach to minimums in which a missed approach is a liklihood...or I'll start increasing RPM earlier.

So far as the argument of not taking one's hand off the throttle or power lever...it's a non-issue.

One may ride the power quadrant on the way down the approach with the hand behind the lever, rather than grasping the top of it, so long as one can push the power up or control it...does it really matter if one is grabbing the lever or the knob on top of the lever? With this in mind, in most multi engine equipment, one can easily push up mixture, propeller, and throttle easily from behind the lever.

Flying an airplane is not simply a rigid discipline with only one way to get the job done. More than one technique may legitimately be used, and this is one such area.

Personally, I don't like to hear a propeller wind up as one enters a traffic pattern or turns final approach. It's a sign of an inexperienced operator. It's unnecessary wear and operation of the equipment, and it takes an air cooled engine already operating at low power creates a situation where the slipstream tends to drive the propeller even more. Leave the prop back unless it's absolutely needed...then use what's needed.

Now some airplanes very nearly need the prop up for the extra drag, to prevent having to pull the power back during the approach. In these cases, pushing the prop up means that the necessary drag is created in order to allow the pilot to carry enough power during the approach.

Then on the other extreme, I flew for one operator who taught and used power to idle, props full forward steep overhead descents in the dark to blacked out runways using piston engines. Never an engine problem, every engine to TBO, faithfully. It worked in that aircraft, though I wouldn't have thought it would...and I wouldn't try it in most others. I found in that aircraft, reduced power descents were nearly always in order due to the operating environment, and these involved low power and high RPM descents with gear and flaps out...and it worked. Again, I wouldn't do that in most other piston airplanes, but in that particular airplane, it worked very well.

[Chuck Ellsworth]

Why do you hate to agree with me SNS3Guppy when we both have exactly the same opinions on how to best operate piston engine airplanes?

Is there something about my background that you feel is lacking or is it just something you can't quite figure out?

For whatever it is worth I find the mechanical side of airplanes to be far more rewarding and enjoyable than flying the things. ( Well there were a couple of jobs that were not very pleasant that I can recall. The salvage of a DC3 in the high Arctic in 24 hours of darkness was very cold work and an engine change we did in Jeddah was just as bad comfort wise with temps sometimes over 50 C. outside on the ramp in the sun...but I degress...)

[DFC]

I am puzzled by the pre landing check that requires the props to be full fine before the landing gear is lowered.

I have read both debates in full and have not seen anyone say that.

I also have not seen anyone mention as you describe - "Full" fine.

You have gone off on a tangent to what was being discussed on the original thred and lost sight of the fact that there are very few students and low time PPLs with your experience.

Do you honestly expect me to give a nano second of thought to what a 10,000+ hour pilot would be capable of doing when deciding how to teach a 10 hour student?

Chuck, what would you expect a student to do when the recovery from a bounce is required on a short runway with obstacles at the end i.e. full power go-arround...........play with the levers that theya re not looking at while the aircraft gets ready to sit again even harder thanbefore?

------

Someone earlier indicated that certain flight manuals require the RPM to be placed forward, and this is not the case. Don't confuse a checklist or a procedure with an aircraft limitation.

The Arrow manual says select 2600, the Senneca says select 2500. There's two.

Please let me know how you select the 2600RPM (or any other RPM specified in the Flight Manual) setting when the prop is out of the governed range?

[Milt]

RPM or Pitch

Isn't it about time aviators handling props, having constant speed units, stopped calling the lever that sets a desired RPM a Pitch Control and isn't a setting of max RPM during a landing approach the worst position unless you want max drag.

The disadvantage is that at low airspeeds, during a landing approach, the prop will be at full fine pitch trying to reach max RPM. Then if you want some thrust in a hurry you won't get any until the RPM spins up to max with some overspeed before the CSU starts to coarsen the pitch. Not good.

Alternately with RPM set to around cruise RPM you can get a whole bunch of power and thrust much sooner which is what you want is it not? Of course if you want full power for a go round then you must know that the RPM setting has to go to Max in concert with the power lever. This operation then becomes optimumally close to the way FADEC works. .

[Chuck Ellsworth]

Naw Milt that line of thinking is just to logical and thus makes the subject to easy to understand.

You and I and a few others will have to get with the program to get any brownie points in today's flight training industry.

We have to quit thinking like this and get on board with the dumb'em down mindset driven by paranoia.

Somehow we just have not grasped the concept of teach e'm to set the airplane up so no matter how ham handed they are and how far behind the airplane they get they don't have to think about more than one task at a time.

Where do all these ideas like look at the far end of the runway during the landing come from?

Don't forget to wear your Hi Vis Vest and turn on those nav lights in bright sunlight....wouldn't want someone to run into you at the airport.

[Big Pistons Forever]

Here is two scenarios that I recently witnessed (VFR)

Scenario 1: As Joe pilot (fairly high time) flies toward the airport the altitude is wondering up and down because the airplane is not in trim. He is way too high because he has not planned his descent, prelanding checks are late rushed and incomplete and the final approach airspeed varies from - 5 knots to + 15 knots of the ideal speed because of the wobbly flight path down final.... BUT he keps cruise RPM set untill short final and then smoothly brings the props up just before starting the flare

Scenario 2: As John pilot (fairly low time) flies towards the airport the altitude is held perfectly. He intiates a descent at the perfect spot so a seamless transition is made from cruise to descent to final where he nails the speed and flies a constant flight path to the runway....But as part of the prelanding check as he rolls onto final he brings the props up to the climb setting.

According to Chuck, Joe pilot is doing it right and John pilot is a victim of the "dumb it down mindset driven by paranoia". I guess I was all wrong when I though Joe was just a lazy, crappy pilot, while John was a guy who was doing a good job and flying the airplane the best he could every single minuite he was in the air.

I think the is legitimate value in discussing technique on an instructor forum but there is seldom right or wrong absolutes, rather legitimate differances that stem from personal preferences and experiences. I have found generalizations seldom add much value to posts and I particularly dislike when the failure to apply your prefered method seem to inevitably become a diatribe about how flying instructors do not know anything about teaching piloting.

[Dudley Henriques]

Here is two scenarios that I recently witnessed (VFR)

Scenario 1: As Joe pilot (fairly high time) flies toward the airport the altitude is wondering up and down because the airplane is not in trim. He is way too high because he has not planned his descent, prelanding checks are late rushed and incomplete and the final approach airspeed varies from - 5 knots to + 15 knots of the ideal speed because of the wobbly flight path down final.... BUT he keps cruise RPM set untill short final and then smoothly brings the props up just before starting the flare

Scenario 2: As John pilot (fairly low time) flies towards the airport the altitude is held perfectly. He intiates a descent at the perfect spot so a seamless transition is made from cruise to descent to final where he nails the speed and flies a constant flight path to the runway....But as part of the prelanding check as he rolls onto final he brings the props up to the climb setting.

According to Chuck, Joe pilot is doing it right and John pilot is a victim of the "dumb it down mindset driven by paranoia". I guess I was all wrong when I though Joe was just a lazy, crappy pilot, while John was a guy who was doing a good job and flying the airplane the best he could every single minuite he was in the air.

I think the is legitimate value in discussing technique on an instructor forum but there is seldom right or wrong absolutes, rather legitimate differances that stem from personal preferences and experiences. I have found generalizations seldom add much value to posts and I particularly dislike when the failure to apply your prefered method seem to inevitably become a diatribe about how flying instructors do not know anything about teaching piloting.

I must be missing something in this thread. :-)

First of all, Joe Pilot, sounds to me like he shouldn't be in the airplane in the first place, let alone in any position that requires setting his props :-)

Secondly, where you bring the props up on landing isn't written in stone by any reasonable definition unless your aircraft calls for it being done at a specific time in the approach for specific reasons. You bring them up where recommended by the POH, Dash1, Natops, or whatever other source official information is available for your SPECIFIC aircraft/engine combination.

There IS no magic bullet answer for this question that fits every propeller aircraft out here. It's THIS simple folks!
I can go into the dash 1 for a Mustang and find it recommended that the prop be brought up immediately after the gear goes down.
On the other hand, you can fly many aircraft, INCLUDING the Mustang, through the approach carrying some power with the prop in cruise, then bring it up crossing the fence.
Haven't flown any airliners, but BOTH these scenarios work just fine in an F8F-2 Bearcat with an R2800!
So what's all the fuss about folks?
The bottom line on this entire issue isn't who's a good instructor and who isn't. It's simply following procedures IF RECOMMENDED by a specific manufacturer, or bringing the prop(s) up in the approach when and where the approach calls for it.
Dudley Henriques

[Chuck Ellsworth]

Thank you Dudley for reinforcing what I have been saying all along.

I have explained that increasing prop RPM on final should be done if there is a viable reason to do so such as it being called for in the POH ( although I do not recall any that state the RPM must be increased on final. ) or icing or turbulence or any other viable reason.

Once again let me be clear and point out that the issue of when to increase prop RPM is at the discretion of the pilot and I personally do not increase prop RPM unless there is a viable reason to do so.

Teaching increasing prop RPM early in the approach so the student will not forget to increase RPM should he/she decide to go around is not what I consider to be the best method of training a student because they will tend to maintain that habit regardless of what they are flying.

*****************************************************

Now allow me to comment on why I believe Big Pistons Forever has this misguided idea that I hold all flight instructors in contempt.

First off I am a flight instructor and was one probably before Big Pistons Forever was born and I have stated before I believe that being a flight instructor is the highest calling a pilot can attain.

I believe Big Pistons Forever and I first got on the wrong side of each other several years ago on the Canadian forum during a discussion about flying tail wheel airplanes the subject of brakes came up and me or someone else commented that one can instruct on tail wheel airplanes without the instructor needing brakes on his/her side of the airplane.

Big Pistons Forever jumped on that statement and said it was to risky for the instructor not to have brakes on their side when teaching on a tail wheel airplane and he said he would never teach on such an airplane.

When I mentioned that in that case he would not have made it as an instructor had he started teaching when I did because some of the airplanes did not have brakes on the instructors side a very strong disagreement ensued...the rest is history.

So having explained why I think Big Pistons Forever started disagreeing with me I will let it go at that and I will from now on just ignore any negative comments he may make regarding my thoughts on teaching flying.

[Terry_flyer]

I have 2000hrs + on GTSIO-520 engines amongst other variants of continental engines and our current company SOP is to fly the approach / landing phase with the props at the last cruise position selected. We only push the props forward once power has been removed and the aircraft has touched down. This has been taught for many years with no reported engine problems due to this method. The GTSIO is a geared engine and as flyboy2 mentioned another reason to leave the props at cruise setting until landing is to avoid" de-tuning" the crankshaft counter-weights if the pilot shoves the prop-levers forward when throttles are closed.

The only time we are advised to push prop RPM forward on approach is if we encounter turbulence or airframe icing.

During initial training as you all know were taught that when advancing power you work right to left on the throttle quadrant and therefore if the props aren't fully fine during approach and a go-around is initiated, they shortly will be and therefore performance isn't compromised and I don’t believe that the time delay in doing so is that critical, if it is then the situation has already developed to far!!!

Also I find that if your flying an approach with a constant power as soon as the props are selected fully fine the student / pilot has to reset the power to maintain G/P and speed; therefore it actually destabilise the approach!! Granted if the props are selected fully fine at height then that would be a suitable SOP to use, but I would be reluctant to do this on short finals as a lot of people teach / do.

Also as pointed out above with the props fully fine - noise levels increase dramatically and the likely hood of noise complaints will be increased if flying in the traffic pattern.

Finally on such a maneuver as a flapless approach with the props at a low RPM they are less responsive if power is required quickly but it does allow for a lower throttle position due to a higher MP for the same throttle position therefore sometimes its easier to achieve the required VAT. Our company SOP is to fly the approach with the prop RPM at the last cruise or selected position.

I believe that what ever students are taught they will do and there is no right / wrong answer to this thread. Of course you should always do what the POH/FM as this will give you the over riding information on the subject and may well indicate more information pertinent to the reasons why such a technique should be used over another.

TF

[pigboat]

Thanks for the offer on the book Chuck, but I had one of my nieces go through Corner Brook the other day. Santa Claus is supposed to drop the book down my chimney on Xmas eve.

[DFC]

Very interesting infor about

DC-3, C-46, PBY and Lockheed 10

as well as

GTSIO-520 engines

Hands up all the instructors who are teaching ab-initio students or low time PPL's on the above.

Very convenient for some to ignore what the POH for more common types say - as I have quoted previously.

Most of the posts seem to revolve arround a personal technique rather than thinking about what is going to fit the average student / PPL while complying with the POH / Flight Manual.

[Chuck Ellsworth]

Ahhhh we are back at that mantra about following the POH I see.

Have you read what has been said in this thread and missed the fact that I and most of the others who do not increase RPM until the power is at or below zero thrust just prior to the landing have said?

We point out that one should follow the POH recommendations and also use common sense with regards to when to increase RPM during an approach for landing.

Would you be kind enough to tell me if you think that a student learning to fly or a licensed pilot does not have the neurons to be able to understand a simple concept such as going down hill requires one to reduce power and if you want to go up hill you must increase power?

Are pilots dumber than people who drive cars and have no problem driving a standard shift car without an automatic transmission?

[Chuck Ellsworth]

Alister to answer your question lets ask one.

Should a pilot find them self twenty feet above the runway and fear they are approaching a stall and they have forgotten to move the prop pitch from cruise to climb or take off RPM and they applyl throttle to assist in flying out of a near stall situation what will happen?

Will the engine and prop produce enough power to help prevent a stall?

While we are in this position ( Twenty feet above the runway almost stalled ) what might be another concern if you quickly apply full power ?

[Chuck Ellsworth]

Alister you are reading things into what I have said that are not there.

No where have I said one should not have their hand on the throttle during the landing process, especially at the final segment of a landing which is the flare and the hold off just prior to touch down.

I can not think of a situation wherein one would be so far behind the airplane that full power is required to salvage a landing.

I can however think of many airplanes that would torque roll over on their back if full power is applied just prior to the stall.

To prevent or recover from a stall you first must reduce the angle of attack by moving the elevator control forward if the airplane is not in the inverted position.....the use of full power before reducing angle of attack can result in a torque roll that can kill you if it happens close to the ground.

Are you a student, PPL or a flight instructor?

[Chuck Ellsworth]

" So you idle the power at what height exactly? "

I generally close the throttle/s about a hundred feet above the landing surface in most airplanes I fly.