Developing procedures

[jdwatson]

Greetings !
Each time I flew a new type of plane, I get to learn some new procedures but there seems to be some "general" ones that can be made common. The trouble is how does one go about plugging in the correct numbers.

For instance:

0) IFR configurations
How does one go about figuring out what airspeed & pitch to use for approach level, non-precision descent, precision descent & etc.

1) Traffic pattern
What speed to fly downwind, base & final.

Usually a CFI gives me the "numbers" and I fly them, but what if I wanted to do this for myself in some other aircraft ? Do the same principles apply to procedures for getting into/out-of slow-flight (MCA), stalls and other BFR maneuvers ? The POH does give some clues, is there a formula of sorts that you can take a plane's POH and come out with a good set of procedures ?

 

[Dave Krall CFII]

Flying by numbers is very nice, as long as one realizes the numbers are fluctuating constantly. I've seen good "numbers" flying pilots go to pieces when in a non-standard situation such as an unusual pattern into a mountain strip or in strong, variable winds.

The numbers aren't usually etched in stone either, and otherwise good pilots get in trouble when they're flying their usual numbers right down to the last nanoknot but, the flight situation is actually demanding a changed set of numbers at that instant, regardless of aircraft being flown.

Greetings !
Each time I flew a new type of plane, I get to learn some new procedures but there seems to be some "general" ones that can be made common. The trouble is how does one go about plugging in the correct numbers.

For instance:

0) IFR configurations
How does one go about figuring out what airspeed & pitch to use for approach level, non-precision descent, precision descent & etc.

1) Traffic pattern
What speed to fly downwind, base & final.

Usually a CFI gives me the "numbers" and I fly them, but what if I wanted to do this for myself in some other aircraft ? Do the same principles apply to procedures for getting into/out-of slow-flight (MCA), stalls and other BFR maneuvers ? The POH does give some clues, is there a formula of sorts that you can take a plane's POH and come out with a good set of procedures ?

 

[jdwatson]

Dave,
I don't disagree, but the numbers are a great place to start from when creativity is necessary. I like to have a stable known set of configurations and procedures for the tasks and aircraft I fly.

I was curious how CFIs come up with in the BugSmasher 2000 you fly downwind at 100kts, 10 degrees of flaps abeam, pitch for 80kts, drop in 20 degrees of flaps on base, trim for 70kts, fly final at 62kts...

 

[gismo]

Greetings !
Each time I flew a new type of plane, I get to learn some new procedures but there seems to be some "general" ones that can be made common. The trouble is how does one go about plugging in the correct numbers.

For instance:

0) IFR configurations
How does one go about figuring out what airspeed & pitch to use for approach level, non-precision descent, precision descent & etc.

1) Traffic pattern
What speed to fly downwind, base & final.

Usually a CFI gives me the "numbers" and I fly them, but what if I wanted to do this for myself in some other aircraft ? Do the same principles apply to procedures for getting into/out-of slow-flight (MCA), stalls and other BFR maneuvers ? The POH does give some clues, is there a formula of sorts that you can take a plane's POH and come out with a good set of procedures ?

0> Just go out and try it VFR. It doesn't take very long to discover what power setting will result in a proper approach speed for level, descending, and climbing flight.

1> Typically I'd start with the bottom of the green on the MP and cruising RPM (typically mid range or top of the green on the tach) for level pattern flight. Base and final targets should be 1.3 Vso (possibly a little higher on base especially if you are using less flap there).

I don't know of any simple formula. You could calculate good targets using the relationship of power to climbs and descents (1 HP = 33,000 ft-lbs/minute) and you might be able to graph the power required for level flight by plotting the power vs IAS from the charts in the POH, but I think that would take much longer and be far less fun than "learning" them in the actual airplane.

BTW, don't you expect to be taking a "checkout" flight with a CFI before tackling a new plane on your own? This would be the time to figure what speeds and power/pitch/configuration settings to use.

 

[gismo]

I was curious how CFIs come up with in the BugSmasher 2000 you fly downwind at 100kts, 10 degrees of flaps abeam, pitch for 80kts, drop in 20 degrees of flaps on base, trim for 70kts, fly final at 62kts...

If you really want the truth, I think you'll find that many of those numbers are pulled out of someone's nasal passages. Some actually have some basis in carefull testing, but a lot is just plain made up by someone and then "standardized" for consistency.

 

[Dave Krall CFII]

Yep, they are a good place to start. That's what I use 'em for, & then see what I need in numbers to end up right for the proceedure being flown.

Dave,

I don't disagree, but the numbers are a great place to start from when creativity is necessary. I like to have a stable known set of configurations and procedures for the tasks and aircraft I fly.

I was curious how CFIs come up with in the BugSmasher 2000 you fly downwind at 100kts, 10 degrees of flaps abeam, pitch for 80kts, drop in 20 degrees of flaps on base, trim for 70kts, fly final at 62kts...

 

[poadeleted20]

To a certain extent, whoever checks you out in the plane should provide that information. However, there are certain rules of thumb that work out very well for nearly all light aircraft. For example:

VFR traffic pattern:
Downwind -- 18 inches/2500 RPM or bottom of the green arc for fixed pitch and pitch about 3 degrees nose up, flaps 1/3 and 15 inches or 1500 RPM abeam touchdown lowering the nose to about zero pitch.
Base -- Zero pitch, flaps 2/3
Final -- Zero pitch, flaps full, power as required to maintain desired touchdown point.

In each case, speed will take care of itself.

 

[bbchien]

Occasionally I have been in the situation where I HAD to fly an aircraft in which I had not been checked out. Usually these are single seaters, of course. They are all from the days when the POH was a phamphlet.

I usually do a high speed taxi no flaps, tailwheel up, for sight picture and "feel". Then a slightly lower speed taxi full flaps (if any), tailwheel up. The next maneuver occurs at 3000 AGL and is a stall series, after slowflight. Then, 400 fpm descent at 1.3 vso as I've determined indicated Vso already. Whatever power setting accomplished the latter is my "on final" power setting.

This is why we teach de novo pilots (PVT ASEL) in simple aircraft. Mike A will attest to how lonnnnggg it takes when you have numbers in addition to mastering the sight and feel at the same time. Primary in an Arrow? Yes you can do it, just plan on 90 hours.

 

[Dave Siciliano]

Like Lance, I've checked a lot of settings VFR, then gone right back to those adjusting for wind or traffic conditions. In the B-55, 16 to 17" of MP 2500 RPM and approach flaps gives me good approach speed for an instrument approach. At glide slope intercept, gear down gives me very close to a perfect rate of descent in no wind conditions. Then, one learns to adjust for winds and traffic. I've come down the GS at 150 knots to make way for following traffic and normal is just above blue line.

The A-36 is almost the same except no approach flaps and just a tad more MP. Comes in a little slower. May have to adjust just a little more if I'm trying to legally fly category A.

I'd suggest you find normal settting VFR; then adjust them to see if you can safely slow a little and safely speed up a little to know where the margins are if you need to adjust. Over time, one developes a real 'feel' for a plane. You can tell when the controls are getting little mushy or where you've got to slow a little to stay at maneuver speed in bumps.

So Cal really slam dunked me into Gillespie last weekend on a localizer approach in IMC and short cut the initial intersection. Because I knew the modus operendi there, I had already reduced power to an approach setting and was below gear speed so, as Monte Hall used to say, "Come on Down".

Best,

Dave
A-36TN ADS