Dive and Drive or CDFA? | KRNT Renton, Washington RNAV 34

Let's shoot this non precision RNAV into KRNT at Renton to look at different ways to descend on the approach.

[AlexGac]

I think you nailed it with the avionics choices in your video!
With minimal automation, I like to chop and drop. I get under any cloud bases quicker (if bases are high enough at all), and it's easier for me to maintain an MDA _while looking for the runway environment_ then it is for me to make a constant descent towards the MDA while looking.
With more automation, and especially with a coupled AP, a CDFA feels like a light workload even while scanning for the runway environment.

[seattleraf]

My home airport!! :D

I’m finishing up instrument training and tend to prefer “dive and drive” (though don’t love that term). My flight school has G1000s and the fake glide path has caught me out and busted step-down altitudes including on this very approach. I know it’s something I can just learn to be aware of - but keeping it simple and just flying the step downs manually reduces workload for me and also constantly remind me that I’m flying an approach with an MDA and not a DA.

[JakeSpeed]

I dive and drive. I can hopefully get under the cloud layer faster and have more time to spot the runway.

[gonetoearth]

Nice video as usual! One thing I would add is there are MANY advantages to Jepp charts one of which is that the approach plates will have the decent rate in ft/min depending on GS and in some cases WHERE to initiate the CDFA decent so you don't bust the altitudes....This is a VERY IMPORTANT point as the ADVISORY GS on these approaches could cause you to be lower than charted.

[thebadgerpilot]

4:25 I think you have a slip in your verbiage there. 1000fpm is an aggressive descent, but it's stable as long as it remains a consistent 1000fpm. "Destablized" or unstable would be if you're aiming for a 1000fpm descent but it's fluctuating between 800-1200fpm. You can just as easily be unstable when aiming for a docile 300fpm descent. Known pitch/power settings are quite helpful here.

[jimallen]

“Dive and drive” is a misnomer. The stepdown is really descend and drive and it is still stable. We should properly distinguish between climbs and zooms and descents and dives. Climbs and descents involve power differences such that chemical energy rates impact potential energy. Accelerations and decelerations do chemical to kinetic. Zooms and dives, however, are unique in that these are the trades potential and kinetic. You don’t “dive and drive” an approach.

[bludybrains]

CDFA absolutely the easier and safer approach. Plus you can always dip below GP as you approach MAP so that you have a little bit of time at the MDA before going missed.

[dragoclarke]

CDFA whatever I'm flying. But I did fly a B752 for 20 years so that may have influenced my thinking 😊

[knackeredish]

Don’t land too long at KRNT. You’ll go down the seaplane ramp and into the water!

[johnhowardyt]

Refer to AIM 7-3-1 for guidance on effect of non-standard temperature on actual/true height above the ground.

[mikoajjozwiak]

Is RNAV still NPA approach? Thought its APV now

[vissj]

CDFA and I add 50ft to the published minima

[victorchang]

why is it possible to be on the glidepath but cross the fix below stepdown altitude on hotter than standard days?

[jimallen]

Increase your power to keep your speed up? How about add power to level off.

[notsoancientpelican]

GA is not airline flying. GA's utility comes from ability to fly into all kinds of little airports that have all kinds of NP approaches. The BEST way to fly an NP is Dive and Drive. D & D gives you then BEST chance of seeing the runway with adequate time to make a good landing. If you aren't able, comfortable, confident and proficient doing D&D, you should take up boating as a hobby. GA Flying: It's not for everybody.