IAP speeds

[ESbuilder]

Does anyone here fly their profiles at speeds adjusted for the weight of the aircraft (talking smaller acft not turbines).

Asking b/c I'm going to be an instructor soon, and I don't want to suck... if theres a better way to do it than just flying 90kias @ 2100 RPM then I'd like to know. example: My instructors always told me 65kias in the 172 regardless of weight (for regular approach speed, not IAP), but when you run the #'s you get speeds that work better.

Related, does anyone have a table (or know how to figure out without going up and doing it for real) a list of power settings that will give you certain speeds @ specific weights at 3 degree descents

THX

 

[EdFred]

I fly the IAP speeds pretty much at cruise speed regardless of weight. I adjust my landing speed for weight.

You can fly pretty much any speed at any weight at a 3 degree descent by varying the AoA. You shouldn't be messing with approach speeds because of weight. When you go visual THEN clean it up and adjust as necessary. Plus atmospheric conditions are going to affect those power settings way more than a hundred or two hundred pounds will.

And your instructor who says 65KIAS no matter what should be dragged behind a 172 at 65KIAS.

 

[Danos]

I learned the 90kt setup but circumsatances may call for you to do it differently (faster traffic behind you, gotta pee,etc). It's not always going to be the same. I'd say practice in a range of different speeds so you're comfortable with them.

 

[TMetzinger]

When you're cleared for an approach, it's YOUR airspace. You should be considerate of others who are waiting (either behind you for the approach or on the ground for a departure), but don't let your "helpfullness" lead you into doing something unsafe.

With that said, I try to fly at 120 or greater during the initial phases of the approach, and cross the FAF at no less than 90 in something like a 172 to 120 in a faster airplane.

Every airplane is different - you can go 150 to short final in a 182, then pull the power back, add the flaps, and be at 70 and slowing over the numbers. You can do something similar in a Mooney if it has speed brakes, but if it doesn't you need to have a plan for slowing down.

Practice flying approaches at higher speeds in good weather with a safety pilot, as you can always slow down if things don't feel right, but a fast approach is appreciated by everyone (still, see the first paragraph of this response).

 

[poadeleted20]

I don't think weight makes as much difference when it comes to IAP speed as it does for final approach to land, so I don't bother with it in instrument approaches. As for a table of speeds/power settings, that's something you really have to put together yourself in your aircraft. In fact, that's one of the things we do on Day 1 of the PIC program.

 

[ESbuilder]

As for a table of speeds/power settings, that's something you really have to put together yourself in your aircraft. In fact, that's one of the things we do on Day 1 of the PIC program.

I'm just looking to suck up some gouge. I havent seen/met anyone that I know of that has different speeds/power settings for descents beyond what you need for basic IAPs.

I'm sure I could use some math/physics voodoo and create a table... I guess thats why I go to college

 

[flyingcheesehead]

With that said, I try to fly at 120 or greater during the initial phases of the approach, and cross the FAF at no less than 90 in something like a 172 to 120 in a faster airplane.

Do you do anything specific to avoid airspeed changes unnecessarily adding to your workload? I like to use one speed from "base" leg or approaching the IAF until I transition to landing, whether that's 90 knots or...

Every airplane is different - you can go 150 to short final in a 182, then pull the power back, add the flaps, and be at 70 and slowing over the numbers.

I started practicing this after I did a crappy job on an approach where I was asked for best forward speed. I've got it down to where I can go 140 to 325 AGL on the ILS glideslope, throttle idle, prop flat, full flaps (40) at the white arc, touchdown at the numbers. Cessna should have called the 182 the drag-o-matic.

Hmmm, I wonder how low I could go if I added a slip to the equation...

Practice flying approaches at higher speeds in good weather with a safety pilot, as you can always slow down if things don't feel right, but a fast approach is appreciated by everyone (still, see the first paragraph of this response).

 

[flyingron]

I fly my approaches at the top end of the gear extend speed (which is pretty low, 87 knots). The last thing I want to do late in the approach is slowing the airplane down so I can get the gear out.

 

[Dave Krall CFII]

Does anyone here fly their profiles at speeds adjusted for the weight of the aircraft (talking smaller acft not turbines).

Asking b/c I'm going to be an instructor soon, and I don't want to suck... if theres a better way to do it than just flying 90kias @ 2100 RPM then I'd like to know. example: My instructors always told me 65kias in the 172 regardless of weight (for regular approach speed, not IAP), but when you run the #'s you get speeds that work better.

Related, does anyone have a table (or know how to figure out without going up and doing it for real) a list of power settings that will give you certain speeds @ specific weights at 3 degree descents

THX

The weight can affect my speed in as far as Va considerations if it's turbulent and on touchdown of course. Otherwise after the pilot becomes comfortable with lower speed approaches, we tell ACT we'll be flying the next one at x knots, all the way up to just safely under airframe and engine max speeds.

There's lots of times when you'll be asked for max forward speed (if able) and practicing it when the pilot is ready is fun and saves time. If they're not ready, then just plug along slower, and/or demo a faster approach.

 

[midlifeflyer]

Weight as a function of IAS is primarily used with load-limited speeds - speeds that are based on the stall speed (which does change by weight). So, for example, the recommended IAS to use for short final, 1.3 Vso changes by weight because it's based on a multiple of a weight-determined speed.

IAS for an instrument approach isn't based on a multiple of the stall speed.