Not so good solo

[Blueadventures]

2 hours ago, RFguy said:

I nose over,  (end climb)  then let the plane accelerate to desired cruise speed, reduce throttle as necessary, and then trim for zero stick forces. 

With my rotax 912 ULS 100hp before nose over to cruise or if still in a long climb to a high altitude (say to clear mountain height, etc) after about minute or two I will reduce rpm from maximum by at least 100 rpm. Then settle on planned / desired cruise speed.

[facthunter]

That's engine handling though isn't it. Who has their cruise power figure handy in a small plane? It can be done with planning. Any turbulence or control inputs of any magnitude will cause extra drag. at the time.  Nev

[RFguy]

Per my post about 5 posts back....

I thought my flying would be all over the shop with the bumps but wasnt so bad.

left hand circuits on 33..

(red arrow)  I flew right over the same course on those two normal approaches. I did that just by looking over my shoulder and judging where base and final should be , didnt look at the ground, too busy looking for the other two aircraft in circuit. no GPS or tablet....  just a good compass. quite surprising how precise you get at your home AD.

200+ hours now. 65+  in the piper I think.    

not much wind though.. 5-10 kts down the runway.

My downwind altitude hold was awful ....

 

 

Edited February 13 by RFguy

[Methusala]

Back 'in the old days' (late 80's - early 90's) used to fly my Pteradactyl or the club's Robinson B1RD. Both trimmed out naturally to 35mph per the simple ASI. In calm air would add a little power without touching the controls, the aircraft would transition to a gentle, nose up climb with no effect on airspeed. Conversely, a gentle reduction of power would translate to a gentle nose down with again, no change in airspeed. Direct confirmation that power affects ascent/descent and that it is angle of pitch surface that controls airspeed.

[aro]

10 hours ago, facthunter said:

Strongly disagree. You don't get speed in cruise by pitch changes and mentioning trim only confuses what's happening ,Trim only relieves stick forces. You  accelerate due to leaving climb power on for long enough.

You might disagree, but physics says you can't fly at a different speed at constant G without changing AOA.

 

"Stick forces" are an indication of changing AOA. At cruise it might only be fractions of a degree and too small to call a pitch change, but the AOA is changing.

 

Power is only a measure of energy input. If the AOA stays the same, power causes you to climb. If you change the AOA i.e. with nose down stick force to prevent the climb, speed increases.

 

[facthunter]

Everything you say there is correct ARO but we must be crossing wires somewhere. Power changes your speed in level flight.

 Methusala That's only the way your plane is balanced with centre of lift thrust /drag  changes. . IF you hold your level, thrust will change your speed.. Power can get you out of a stall or prevent it. You put power on more in a level turn to overcome the extra drag and  increase speed to keep a stall margin and take a bit off when you come out of the turn.    Nev

 

[aro]

12 minutes ago, facthunter said:

we must be crossing wires somewhere. Power changes your speed in level flight

Yes, but "level flight" requires AOA changes as the power changes. So yes, the speed changes if you change the AOA to maintain level flight as the power changes.

You are talking the practical technique rather than aerodynamics, and you are correct UNLESS you actually want to argue whether AOA or power controls the speed.

[spacesailor]

The difference could be what caused the " Max " problem. 

Centre line of thrust above wing or below wing .

More engine power on a " Thruster " will surely push the nose down.

Same power increase on a " Jabiru " will rotate nose high .

Just my ' penny ' worth .

spacesailor

 

[BrendAn]

1 hour ago, spacesailor said:

The difference could be what caused the " Max " problem. 

Centre line of thrust above wing or below wing .

More engine power on a " Thruster " will surely push the nose down.

Same power increase on a " Jabiru " will rotate nose high .

Just my ' penny ' worth .

spacesailor

 

On my jabiru powered xair if you push the throttle quick it will compress the nose wheel suspension.  And you can make it hop off the ground by cutting the throttle abruptly at about 20 knots. There is lot of leverage when the engine is mounted so high.

[facthunter]

Everything you say there is correct ARO but we must be crossing wires somewhere. Power changes your speed in level flight.

 Methusala That's only the way your plane is balanced with centre of lift thrust /drag  changes. . IF you hold your level, thrust will change your speed.. Power can get you out of a stall or prevent it. You put power on more in a level turn to overcome the extra drag and  increase speed to keep a stall margin and take a bit off when you come out of the turn. 

 Power went off in the middle of this and was off for about 20 hours. I'll post it anyhow.  Nev

 

[Methusala]

My point bring that in order to change airspeed following the addition of thrust (power) a change in stick position is required.  Otherwise speed won't cha ge, only altitude. 

[facthunter]

Depends on things like thrustline, Centre of drag. If the defining condition  is level flight or a specified glidepath, Power  controls speed.. You covered this in your straight and level lessons (I hope)  Nev

[Methusala]

"All things being equal..." My point is valid, no doubt.

[BrendAn]