Why don't they...?

[Methusala]

I have transitioned, in the past 6 months, from flying my Thruster to the club Jabiru J-170. Never before having to manage flaps this is the major change for me. So, when doing touch & go circuits, sometimes need to pull off full flap after touchdown to 1/2 flap for take-off. Why not have a detent flap switch enabling selection of full/half/no-flap relieving one of the chore of a)holding the stick, b) managing throttle and, c)holding flap switch to re-set 1/2 flap while being busy managing the take-off? And, for that matter, why is there no friction nut on the throttle? Just askin'.

[Ryanm]

I've never flown a Jabiru, but I'd imagine it's like most Aircraft. The general idea is to Land- Rectract the flaps to what ever setting is recommened- Apply T/O power.

It all happens very quick, but there is a method to the maddness.

[facthunter]

Think situational. What do you need?   Reconfigure flaps, retrim, apply full power and check carb heat cold and then it's like a normal take off from there. Nev

[Old Koreelah]

2 hours ago, Methusala said:

…Why not have a detent flap switch enabling selection of full/half/no-flap…

I’m sure that would be possible; I’ve flown Technams with flap buttons on the stick. Just remember that electric flap controls are not foolproof. I’ve had one fail me at a critical moment.

A manual flap lever lets you rapidly make changes as needed and you get a good feel for the airflow. 

I’m quite happy to juggle controls (I also have no mic button on my stick, so left hand needs to leave throttle to press talk switch on radio). Maybe we rely too much on technology to make life easier; the occasional high task load does us good.

[Methusala]

Thanks for your thoughtful and helpful replies. My problem is that by the time I am stabilised following touch-down the flaps need retracting and the switch is located directly in front of the stick. Just when application of take-off power is required my left hand is off throttle and on the switch. I agree that a flap switch on the stick grip would help. Had a ride in a Bonanza the other day and flaps were :- Up;  Aph (approach),and : Dn. with a light for "in transit". Something like that would do.

I agree that mechanical flaps would be simpler and more tactile.

Edited December 20, 2021 by Methusala

[Yenn]

Manual flaps are simpler and give you feel, but you still need to know exactly what to do and when. It is all part of flying, or do you want it all automated in a similar way to an airbus. I cannot see that happening in a Thruster.

My RV4 was so heavy to apply flaps at the top end of the allowable speed scale that I had to use two hands sometimes, that made it interesting and in a go round if I didn't get them up quite quickly enough I had to haul the nose up to slow down and reduce the pressure, or just climb away with full flap.

[turboplanner]

1 hour ago, Methusala said:

Thanks for your thoughtful and helpful replies. My problem is that by the time I am stabilised following touch-down the flaps need retracting and the switch is located directly in front of the stick. Just when application of take-off power is required my left hand is off throttle and on the switch. I agree that a flap switch on the stick grip would help. Had a ride in a Bonanza the other day and flaps were :- Up;  Aph (approach),and : Dn. with a light for "in transit". Something like that would do.

I agree that mechanical flaps would be simpler and more tactile.

Agree with you on the J170, and being electric flaps without position stops you have to focus on the flaps for way too much time. Have a look in a Cherokee at the handbrake type flap lever where you can really DUMP flaps if you need to, but you can go for flap increments while still focussed ahead.

[Thruster88]

Cessna have that type of switch, it still requires one to look while resetting, the flaps then travel to that position. Unless your first name is Dan. 

Edited December 20, 2021 by Thruster88

[APenNameAndThatA]

This is what you want to do. 

Touch and go: flaps THEN full throttle

Go around: full power THEN WAIT for full throttle. 

 

You only need to use two controls at once. 

 

(I have 140 hrs and am not a flying instructor: disclaimer.) 

 

The ergonomics of aeroplanes can be really bad. In a Foxbat, the carby heat and cabin heat controls are the same shape and are right next to each other. In a Decathlon, the Throttle and trim controls are both on the left wall and the knobs are the same size and shape, and not really where you look! Those things are called “latent errors”, which is technical speak for “accidents waiting to happen”. 

[Methusala]

1 hour ago, APenNameAndThatA said:

This is what you want to do. 

Touch and go: flaps THEN full throttle

Go around: full power THEN WAIT for full throttle. 

 

You only need to use two controls at once.

Only have 2 hands. Need to : a) Pick up 1 notch of flap,

                                                 b) Add power, and

                                                 c) control pitch and perhaps roll (in x-wind),

All simultaneously before the end of the strip. Been flying for most of my adult life and yet to come to grief.

Seriously, this thread is mainly to draw peoples' attention to an ergonomic problem in the J-160 - 170 Jabirus which are mainly well designed and straight-forward to fly. Don

[Roundsounds]

14 hours ago, Methusala said:

I have transitioned, in the past 6 months, from flying my Thruster to the club Jabiru J-170. Never before having to manage flaps this is the major change for me. So, when doing touch & go circuits, sometimes need to pull off full flap after touchdown to 1/2 flap for take-off. Why not have a detent flap switch enabling selection of full/half/no-flap relieving one of the chore of a)holding the stick, b) managing throttle and, c)holding flap switch to re-set 1/2 flap while being busy managing the take-off? And, for that matter, why is there no friction nut on the throttle? Just askin'.

Just use 1/2 flap for the approach when doing touch and goes.

When I had a flying school I banned flap retraction on the runway when moving (mitigates the risks associated with inadvertent gear retraction and ground loops) . I had a standard operating procedure to use takeoff flap when conducting touch and goes, but also taught full flap go-arounds including after touch down. The aircraft are certified for full flap go arounds.

Edited December 20, 2021 by Roundsounds

[walrus]

Methusala, a Cessna  electric flap switch almost killed me. It failed as we attempted to retract to  half flap during a STOL touch and go. With full flap a fully loaded C150 WILL NOT climb out of ground effect and we only escaped by a low level (30 feet) 180 turn with stall warning blaring. So when I hear about your problem I am aroused to post this.

 

First of all, will a fully loaded Thruster (MTOW) easily climb at better than 3% out of ground effect with full flaps out? If the answer is yes then have at it with your electric switch because all you are going to do if the switch fails or you have finger trouble is embarrass yourself.

 

If the answer is no, then please, please follow Roundsounds advice above and DO NOT practice Touch and go's involving retracting to half flap while moving because you are asking to become a statistic.

 

Whatever you do, DO NOT practice any form of STOL  work with a touch and go procedure.  Always make a full stop, backtrack and configure the aircraft while stationary.

 

Yes, I know about go arounds, but that is a different procedure mentally.

[KRviator]

On 21/12/2021 at 5:06 AM, walrus said:

With full flap a fully loaded C150 WILL NOT climb out of ground effect and we only escaped by a low level (30 feet) 180 turn with stall warning blaring. So when I hear about your problem I am aroused to post this.

Does that not put the PIC in breach of CAO 20.7.4 for trying to land at too high a weight to satisfy the 3.2% climb gradient requirement while in the landing configuration??

[facthunter]

It wouldn't make it if you took off with full flaps either. To comply, you reselect flaps to a lesser setting when you go around Nev

[walrus]

KRAviator, the C150 POH is mute on the subject of climb with 40(?) degrees of flaps and meets the FA specs in force circa 1960. As for that CAR, who would know and how old is 7.1 regarding climb in landing configuration??

 

In any case 3.2% is marginal and doesn't get you over a gum tree in front of you. The POH calls for ZERO flaps on takeoff and if you don't have zero and sufficient runway you are SOL.

 

Hence my warning: do not practice touch and go on small STOL strips like YCEM. Do a full stop. Backtrack. Reconfigure and go again. Otherwise you are one error from being in the trees.

[KRviator]

9 hours ago, walrus said:

KRAviator, the C150 POH is mute on the subject of climb with 40(?) degrees of flaps and meets the FA specs in force circa 1960. As for that CAR, who would know and how old is 7.1 regarding climb in landing configuration??

 

In any case 3.2% is marginal and doesn't get you over a gum tree in front of you. The POH calls for ZERO flaps on takeoff and if you don't have zero and sufficient runway you are SOL.

 

Hence my warning: do not practice touch and go on small STOL strips like YCEM. Do a full stop. Backtrack. Reconfigure and go again. Otherwise you are one error from being in the trees.

You're right, of course, about the lack of POH data, but what that means - to me at least - is you need to operate with the data you do have. Eg, the stall speed difference between F40 & F20 is 1KIAS (48 vs 49), & the balked landing procedure is to set F20 immediately after applying full power. So why not approach at F20, ensuring you can climb if you need to? IF you're flying solo and just come back from a XC with minimum fuel, then that's the time you can use F40 and can be assured of being able to climb in the landing configuration after a go-around.

Using F40, two up, on a hot day is asking for trouble - as is trying T&G's on a short or otherwise performance-limiting runway.

I tried to find an old DCA-approved C150 POH in the hope it would have "Australian-ised" performance charts with F40 landing climb weight limits, without success - but the absence of that chart doesn't absolve a PIC of the requirement to be able to comply with that CAO - which has been around for yonks, IIRC. To use the example given, a low-level 180, if you'd stalled & spun in, or hit the windsock pole halfway through the turn, the PIC would have been hanged, drawn & quartered, though the ATSB would likely find the lack of the landing climb weight limit chart as being a contributing factor, it's still the PIC's head on the chopping block.

[kgwilson]

The best flaps by far IMO are those on the Cherokee with the 10, 25 & 40 deg notches and the handbrake style which is manual and foolproof. You can select any amount of flap or dump it all in a second. If doing T&Gs your left hand is on the yoke the whole time, once on the ground full throttle with the right hand on the quadrant & the hand can drop naturally to the flap lever. I've never found a better system. 

 

The flaps on my aircraft are electric & as it is a low wing how many deg you set can be seen at a glance of the actual flap position. I put my flap switch on the throttle binnacle which is located on the cabin side wall aft of the panel in a natural position not requiring any reach. I don't bother with intermediate amounts & just flick the switch which will then move the flap to max of 30 deg and stop. Carb heat is also in this binnacle directly below the throttle. The setup is the most ergonomic I could create. For a T&G it is full throttle & immediate flap switch up. Full travel takes a few seconds.

 

Ergonomics of panels on many light aircraft are bloody atrocious. The Jabiru is terrible but it is a compromise for being able to be operated from either seat. It wouldn't cost too much more to have a left and right switch. It is a press and hold switch so you have to keep pressure on it while looking at the indicator to work out the amount of flap you have.

[walrus]

KR, I agree with you, I was a student at the time and my newly minted grade 3 instructor didn't know any better. She now flies for Qantas....

[Yenn]

I do not have an old C150 POH, but I do have a note book with info taken from all over the place and included in that is notes on the C150.

Approach full flap 50kts.

Overshoot Full flap 50kts, best rate of climb 60kts.

I remember in training that one day I forgot to lift the flaps. This resulted in me pushing the nose down lower and lower in an effort to increase speed. I was not climbing and then I looked round ans saw the barn door hanging there, so up with flaps and keep pulling the nose up as the sped increased. It had me worried for a few moments.