Off the charts?

Any DA40 related topics

Moderators: Rick, Lance Murray

Post Reply
User avatar
Rich
5 Diamonds Member
5 Diamonds Member
Posts: 4592
Joined: Mon Aug 30, 2010 12:40 pm
First Name: Rich
Aircraft Type: DA40
Aircraft Registration: N40XE
Airports: S39 Prineville OR
Has thanked: 145 times
Been thanked: 1180 times

Off the charts?

Post by Rich »

There is a school of thought that one flies by the numbers. Using the POH, one figures out stall speed and divines appropriate approach speeds from there. For example, when I got my CFI these many decades ago, the examiner was of the Air Force school, where you flew at 1.5 downwind, 1.4 on base, 1.3 on final - times stall speed on approach. Not unreasonable rules of thumb, I suppose. But stuff happens and sometimes you fly by feel. The DA40 lends itself to that, really, given the light control forces.

Today I was on downwind, intending to land full stop. But the pattern was sort of busy, with 2 planes waiting to depart, another behind me in the pattern and one about to enter the pattern (both from a flight school that routinely trains their students to make 777-style approaches in Cessna 150's). So I decided to be a minor hero and perform a nice tight pattern, suggesting using lower speeds than I ordinarily use. Working in my favor I'm flying light with about 24 gal. of fuel and just me inside - something like 2,020 lbs. Diamond does not have stall speeds published below 2161 lbs., if you're wondering. 60 knots in the turns, a base leg straightening out about 1,000 ft. off the threshold felt about right, and touch down about 1,000 ft. down the runway, to expedite turnoff at the first available exit. For the record, 60 knots at this weight is a bit much. I did touch down well down the runway after considerable float, but in retrospect I should have simply aimed further down the runway and been at maybe 50-55 entering the flare, spending less time/distance in ground effect. I need to practice this more. It's not really a short field approach because I wanted to minimize the time to the exit. True short field needs to be much slower.

In the past it's often occurred that I need to slow down below my typical 90-knot downwind in the pattern to give room for something like a 150 in front of me flying halfway to Idaho before turning base. So it's somewhat routine to be schlepping along downwind at 65 knots waiting for the magic moment when they finally decide to turn base and final :tap: . Luckily I'm not renting :thumbsup:
2002 DA40-180: MT, PowerFlow, 530W/430W, KAP140, ext. baggage, 1090 ES out, 2646 MTOW, 40gal., Surefly, Flightstream 210, Orion 600 LED, XeVision, Aspen E5
User avatar
YCCA
3 Diamonds Member
3 Diamonds Member
Posts: 96
Joined: Sun Jul 15, 2018 3:44 am
First Name: Jeffrey
Aircraft Type: DA40
Aircraft Registration: N209DS
Airports: B19
Has thanked: 22 times
Been thanked: 11 times

Re: Off the charts?

Post by YCCA »

At that weight and 60kts try pulling the power earlier to avoid the float
User avatar
Rich
5 Diamonds Member
5 Diamonds Member
Posts: 4592
Joined: Mon Aug 30, 2010 12:40 pm
First Name: Rich
Aircraft Type: DA40
Aircraft Registration: N40XE
Airports: S39 Prineville OR
Has thanked: 145 times
Been thanked: 1180 times

Re: Off the charts?

Post by Rich »

YCCA wrote: Wed Mar 20, 2019 1:25 pm At that weight and 60kts try pulling the power earlier to avoid the float
Power was at idle long before the threshold. It was the speed. Needed to be slower over the fence. Probable actual stall speed (indicated) at that weight: 40 knots. Stick back a bit after turn to final would have done it, thereby flying a little further on the back side of the drag bucket.
2002 DA40-180: MT, PowerFlow, 530W/430W, KAP140, ext. baggage, 1090 ES out, 2646 MTOW, 40gal., Surefly, Flightstream 210, Orion 600 LED, XeVision, Aspen E5
Post Reply