TOGA attitude for IF

[Barneyw]

Hi All

Just wondering if anyone has some ball park figures for attitudes for IFR takeoff and missed approach.

The avionics folks set my TOGA button FD attitude for 7 degs NU and would like to know if that is correct. In the absence of any book figures I'd be interested to here what people's IFR experience is in the Mooney in particular one fitted with a Johnson bar.

Cheers

Barneyw 

[201er]

AOA is a much better target than attitude. Heavy Mooney or high DA climbs at a pretty flat attitude compared to light.

[dzeleski]

15 minutes ago, Barneyw said:

Hi All

Just wondering if anyone has some ball park figures for attitudes for IFR takeoff and missed approach.

The avionics folks set my TOGA button FD attitude for 7 degs NU and would like to know if that is correct. In the absence of any book figures I'd be interested to here what people's IFR experience is in the Mooney in particular one fitted with a Johnson bar.

Cheers

Barneyw 

I believe that setting is mandatory and not adjustable. At least for the GFC 500 its called out in the STC for the airframe.

Page 7-5:
https://static.garmin.com/pumac/190-02291-20_02.pdf

[WilliamR]

45 minutes ago, 201er said:

AOA is a much better target than attitude. Heavy Mooney or high DA climbs at a pretty flat attitude compared to light.

Agreed.

So, is there an interconnect of some type between your AOA (assuming you have one) and the flight director (again assuming you have one) when you hit your TOGA button?

Thanks!

William

[dzeleski]

19 minutes ago, WilliamR said:

Agreed.

So, is there an interconnect of some type between your AOA (assuming you have one) and the flight director (again assuming you have one) when you hit your TOGA button?

Thanks!

William

Assuming its a GFC, no there isnt. But the GFC also wont let the airspeed decline below the ESP minimums. So it will maintain 7 degrees until the airspeed gets to the warning threshold in which case it will announce "air speed" and the nose will start to lower to avoid a stall.

On page 3-3 of the above pdf I linked there is note for min speed: "Autopilot Underspeed Protection Mode provides a pitch down command to maintain 80
KIAS."

[WilliamR]

@dzeleski, thanks. Very familiar with those GFC 500 limitations and functionality.

@201er gave me the impression that there was an interconnect between his AOA and FD when pressing the TOGA button given his answer. Interested in how that works and the equipment.

William

[Barneyw]

Thanks for the replies thus far.

I guess what I was driving at was the raw data figures. The TOGA button is coupled with the FD and nothing really to do with AoA and as mentioned assuming you have one. Weight, altitude and temperature aside assuming an ISA day at SL what are the figures to get the climb performance required. I can make the necessary adjustments from there noting that a lot of weather occurs in the colder months.

dzeleski I believe I saw a selectable pitch attitude in the settings on the G3X but will recheck. Do you have a reference for it being mandatory?

Cheers

[201er]

2 hours ago, WilliamR said:

@dzeleski, thanks. Very familiar with those GFC 500 limitations and functionality.

@201er gave me the impression that there was an interconnect between his AOA and FD when pressing the TOGA button given his answer. Interested in how that works and the equipment.

William

I dunno all these terms but simply put when I go missed or around, I pitch up to the AOA that gives best angle or best rate of climb. No speeds, flight directors, or buttons to fiddle with.

[PT20J]

2 hours ago, Barneyw said:

Thanks for the replies thus far.

I guess what I was driving at was the raw data figures. The TOGA button is coupled with the FD and nothing really to do with AoA and as mentioned assuming you have one. Weight, altitude and temperature aside assuming an ISA day at SL what are the figures to get the climb performance required. I can make the necessary adjustments from there noting that a lot of weather occurs in the colder months.

dzeleski I believe I saw a selectable pitch attitude in the settings on the G3X but will recheck. Do you have a reference for it being mandatory?

Cheers

Most parameters of the GFC 500 are adjustable in G3X configuration mode including the GA pitch attitude. The STC addendum for each aircraft type specifies how these settings are to be entered for a specific aircraft. For the Mooneys, the GA attitude is 7 deg. That's an initial setting for the go around. It is expected that you will soon chose a different vertical mode, usually IAS.

[dzeleski]

1 hour ago, Barneyw said:

Thanks for the replies thus far.

I guess what I was driving at was the raw data figures. The TOGA button is coupled with the FD and nothing really to do with AoA and as mentioned assuming you have one. Weight, altitude and temperature aside assuming an ISA day at SL what are the figures to get the climb performance required. I can make the necessary adjustments from there noting that a lot of weather occurs in the colder months.

dzeleski I believe I saw a selectable pitch attitude in the settings on the G3X but will recheck. Do you have a reference for it being mandatory?

Cheers

As said above its of course "adjustable" because different STCs have different values, but the STC states it must be set to 7 degrees for a Mooney.

 

Page 7-5 of the pdf I linked above has a table with the reference.

Edited September 17 by dzeleski

[midlifeflyer]

1 hour ago, PT20J said:

Most parameters of the GFC 500 are adjustable in G3X configuration mode including the GA pitch attitude. The STC addendum for each aircraft type specifies how these settings are to be entered for a specific aircraft. For the Mooneys, the GA attitude is 7 deg. That's an initial setting for the go around. It is expected that you will soon chose a different vertical mode, usually IAS.

I think you nailed it. It's part of the STC for the airframe.  It's a setting for the flight director for a go-around or missed approach, although many also use it for the post takeoff climb as well. With a GFC 500 or 600, it's also contemplated you are flying that missed coupled, so it's not surprising if its choice is a compromise number that does not reflect what an AoA indicator might tell you is optimum.  

[Marc_B]

20 hours ago, PT20J said:

For the Mooneys, the GA attitude is 7 deg. That's an initial setting for the go around. It is expected that you will soon chose a different vertical mode, usually IAS.

+1.  I think of the TOGA as a transition mode.  You're never in it long, but it gets you away from the ground safely.  If you push the TOGA button on an approach, you'll soon need to either configure heading or GPS mode, and will be further tailoring your climb out and altitude capture.  If on take off, I'm usually climbing out in IAS so that I can keep my speed exactly where I want it.  With a fixed pitch climb your airspeed will continue to decay as you get higher (probably not what would be ideal in any situation).

Bob Kromer (Mooney test pilot and former executive VP/general manager) presented this slide (above) at MooneyMax this year, as well as at previous MooneySummits.  Basic gist, get some altitude fast, then configure for a faster cruise climb for better cooling, better speeds, and only slight to moderate change in your climb rate.  I find the TOGA roughly prescribes to this.  I've also found that my VSI climb rate isn't as impacted by a 115-120kt climb as you'd expect plus your forward speed is much better and much more airflow over the engine. 

So for what it's worth, on takeoff I quickly move to an IAS climb shortly after departure (above 1000 feet AGL or so) and typically start off in HDG mode. 

For missed approach, I press the TOGA button which allows me to transition the aircraft/engine followed by navigation to the missed and then transition from TOGA button mode to the climb out and missed approach.

[Marc_B]

As an aside, for those of you with GFC500 in other models of Mooneys, what average airspeed are you finding the 7deg nose up usually gives you.  I'll have to confirm next time I fly but IIRC I believe it puts me somewhere between Vx and Vy, right around best glide.

[Barneyw]

Some interesting points being made.

At the risk of being controversial which I am not attempting to do Garmin are not the authority for the aircraft and I guess I was looking for the Mooney figure which begs the question where did Garmin get 7 deg from.

I have some misgivings about using the AoA as a means of setting an attitude on the ADI as it appears to be performance flying. I've never heard AoA being used for departure but willing to listen to how that works practically and what training is required as opposed to basic IF flying technique.

Interesting to see a multi-engine construct being used to describe single engine climb in the slide above.

With respect to the TOGA being adjustable I probably wasn't clear enough - I meant pilot adjustable. 

[Will.iam]

In the tanker world where we would do multiple touch and go landings the setting for going around was 66% thrust and 6 degrees pitch this gave us a nice 1000ft per min climb fast enough to avoid obstacles but slow enough to not rush check list and bust through pattern altitude. On any go around you are way ahead of a plane that is taking off as you are already off the ground and at flying speed at the beginning of the runway compared to the plane taking off so to go full power and climb like for takeoff just invites vertigo if you are truly IMC which would be the main reason you are going around in the first place. I will add power about 65% and the plane will naturally pitch up i start trimming off the nose up pressure while getting the gear up check the vvi for about 500ft per min adjust pitch as necessary by this time the trim is starting to get too much nose low to which i raise the flaps. This put the trim at about where it needs to be for climbing out again. If i need more the 500ft per min i now add more power and trim off that as well. Much smoother transition and greatly reduces if not totally illuminates  acceleration vertigo which you do not want to be fighting while low to the ground. 

[Marc_B]

@Will.iam With the GFC500 and GTN there are multiple ways to sequence missed approach.  So you don't always have to use the TOGA button.  By simply activating the missed approach in the GTN you can navigate this a little more smoothly if something happened early in the approach that required a go around.  You can do this from the "splash screen" when you pass the missed approach point, from the flight plan page selecting the approach, or from the procedures page at the bottom.

I'd probably be reserving this for something like an unexpected downgraded approach that I haven't briefed...

 

[PT20J]

3 hours ago, Barneyw said:

At the risk of being controversial which I am not attempting to do Garmin are not the authority for the aircraft and I guess I was looking for the Mooney figure which begs the question where did Garmin get 7 deg from.

Well actually, for certified aircraft, the FAA is the final authority. The FAA approves Mooney’s TC and the AFM and Garmin’s STC. Garmin would likely have flight test data to support 7 deg when applying for the STC.

[Barneyw]

39 minutes ago, PT20J said:

Well actually, for certified aircraft, the FAA is the final authority. The FAA approves Mooney’s TC and the AFM and Garmin’s STC. Garmin would likely have flight test data to support 7 deg when applying for the STC.

Fair enough It seemed like a simple question to start with and yes ultimately the FAA would give the final tick but Mooney did the test flights and collected the data to provide to the FAA.

Anyhow we could go around in circles here it appears there is no official data for the early Mooneys that one could put their finger on.

Thanks

 

[Barneyw]

On 9/18/2024 at 12:29 AM, dzeleski said:

I believe that setting is mandatory and not adjustable. At least for the GFC 500 its called out in the STC for the airframe.

Page 7-5:
https://static.garmin.com/pumac/190-02291-20_02.pdf

Further to my last and I apologise because I hadn't quite got around to reading the AFM Sup for the GFC 500 concentrating more on the GTN and G3X Pilot Guides and as you can appreciate there is a lot to read. I opened the link on your post  dzeleski and realised it was for a M20J so I looked and my AFM Sup and this is my table for the "F" You will notice that the "F" is set at 5 deg which is interesting because my aircraft has been set at 7 deg which a few seem to agree with and I think 5 deg seems a little low.

Cheers