Diamond DA4X, 50, 6X stabilized approach criteria

[austropilot]

Hi,
I am looking for Diamond pilots who can contribute stabilized approach criteria for the DA40, 42, 50 and 62 models for implentation in FlySto.net

The idea is to get a better understanding of parameters and values for approach scoring and limits, see here for a sample flight
https://www.flysto.net/logs/1d2n6trv/ap ... /1?view=2d

Thank you for your contributions!

[waynemcc999]

Patrick, I really (really) like your FlySto.net !! Graphics and user interface are MUCH better than CloudAhoy.

At first glance I'd expect your parameters for the DA40 NG are quite reasonable... for the DA40-180 it seems that the IAS values would be say 5-to-8 knots less than the NG.

Keep up the excellent work!
Wayne

[Rich]

With respect to approach speeds I find it is good practice to vary according to weight. In my plane landing weights can easily vary by 500 lb. This results in appropriate speeds for normal approach varying by 10 KIAS: 70 at 2535 lb., 60 at 2000 lb. (me + half tanks).

[Boatguy]

I'm also a huge fan of FlySto and upload my flights every 28 days.

AGL approach altitudes are pretty much the same for all piston aircraft, but do vary based on pattern altitude and tower instructions. Sometimes we're instructed to make a "short approach" and sometimes we're instructed to extend the downwind at pattern altitude rather than begin a descent at the numbers.

I agree with Rich about approach speeds as the Diamond's are very sensitive to weight. The right speed at maximum weight is far too fast when light. Here I think your best guide is the AFM's Vref based on weight. You could capture the empty weight of our airplane in the aircraft profile, and you know the takeoff fuel in gallons so you can compute the weight based on fuel type. The missing datapoint for each flight is the passengers + cargo weight. You would need to capture that in order to accurately score approach speed.

[dant]

And don't forget wind conditions when scoring, gusting or otherwise turbulent conditions prescribe an increased approach speed.

And then of course some folks like to always come in high in singles so they stay close to / within glide range of the airport. I got hassled in my recent flight review for flying a perfect 3 degree straight in to KPAE.

[tjmoody]

H Patrick - For the DA42 VI, the numbers you already have in FlySto seem reasonable.

I like the idea of the approach score that you've included on this sample flight. Is that something you are planning on rolling out soon?

I purchased the AirSync box at AirVenture and have found it works very well. It is great to have the data immediately synced to FlySto immediately after each flight.

Trevor

[Tim H]

This is an amazing piece of software. Thank you for sharing.

[ingramleedy]

FlySto is amazing software - Thank you Patrick. I also got the AirSync box just to sync automatically to FlySto and to keep an aircraft log without manually doing it. It's nice, because it just happens without me thinking about it. In addition I get some richer data into ForeFlight too.

Patrick is looking to add ECU/dongle data too. I am sure he'd be interested in any data anyone can contribute.

-Ingram

[Ed McDonald]

I would suggest this for a generic stabilized approach criteria as well as DA62 specific:

Generic:
Stabilized at 1,000 ft above the runway (500 ft without an instrument approach loaded) - the "gates"
Maximum descent rate - 1,000 fpm
Descent rate - 5 times ground speed (assumes a 3 degree flight path angle which is a good assumption 99% of the time) +/- 100 fpm
Speed -5/+20 from Vref (see DA specific below)
Small heading changes (+/- 5 degrees from wind adjusted heading for runway track)
Small pitch changes (+/- 2 degrees) as final flap selection and the attendant pitching up should be completed before the stabilized approach gate (1,000 ft IFR, 500 ft VFR)
It is impossible to determine the aircraft configuration with the G1000 output nor whether checklists are complete

If there an instrument approach loaded and displayed (thus assuming an instrument approach is being flown)
no more than +/- one dot deviation laterally or vertically

DA62 Specific:

Vref varies with weight and flap selection. With landing flaps the Vref varies from 89 kts at max landing weight (2300 kg/5071 pounds) to 84 kts at the lowest published landing weight (1800 kg/3968 pounds). With T/O flap/no flap, the values are 91/95 to 88/91, respectively, at both landing weight extremes.

Flysto does have provision to input the aircraft ZFW so that plus the fuel weight (which Flysto records but does not seem to be able to account for auxillary tank fuel - perhaps they could get that from the G1000) provides the landing weight and it gives a Vref calculation based upon this with landing flap.

A feature that allows one to choose landing, take-off and no flap would be helpful and based upon this selection and weight a Vref computed. Then, an accurate assessment of the speed control noted above would be useful information. If this is not possible, I would suggest defaulting to a flaps take-off setting. Personally, I rarely use landing flap and even more rarely use flapless; 95% of my landings are with take-off flap as it makes virtually no difference in landing performance, it would make a huge difference if you had to overshoot, and rounding out is much easier.

Adjusting for wind would be tricky. The AFM is silent on any speed corrections except to say "in conditions such as (e.g.) strong wind, danger of wind shear or turbulence a higher approach speed should be selected. Personally, I use the airline rules - 1/2 of the steady wind component and all of the gust to a maximum of 15 kts.

The engine power settings vary with weight and wind so finding the steady state power setting would be challenging. If one could determinte this perhaps by a median power setting inside the approach gate (1000 ft/500 ft), then determining which are large fluctuations about that power setting can be calculated. I would say that +/-5 % engine load about this power setting would be stabilized, ie not wild flucuations.