I find it interesting to work out the numbers for myself from time to time, as it helps correlate with what I'm seeing. I'm not sure why everyone extrapolated the OPs posts to trying to rigidly adhere to these numbers while flying.
So am I…10 lbs of it.
This is your second post in the thread--do you feel sufficiently superior now?
Q.E.D.That reply was to answer Nauga’s some what question, odd that you think it’s about superiority.
Enjoy your 723.3 feet per minute descent rate.
A 3° glideslope is about 200 ft for every half mile. Makes for a long downwind and a wide pattern, because you'll need to fly 2.5 nm (± winds) to lose 1,000 ft.
We read it differently, apparently. He showed his work and asked "is [2000fpm] right?" He said nothing about flying to the tenth of a degree or tenth of a mile per hour. As some pointed out there was a flaw in his assumptions, not in his math. Others were not so forthcoming.
The math is right. I considered all legs of the pattern. I used statute miles for distances.
Beautiful way of simplifying the "problem"! From that, just play with different leg lengths that add up to about 2.5 miles. Done.
Guessing you're commenting about this post by me: "For a 1 mile pattern: the downwind 1 mile at 85 mph becomes 633 fpm descent at 4.8 degrees."
The original post considered 0.5 mile legs.
0.5 miles.
I got lucky. An instructor did it to me during a checkout within a year after I got my CFI and covering the instruments has been a staple for me ever since. I won't solo a student until they can land with the airspeed indicator covered. I also do it sometimes for flight reviews if the pilot hasn't done it before, and it's a staple when working with any pilot who has problems with landings.
Narrow minds.
Is the tach exposed?
When it was done to me. Instructor covered the whole panel with a newspaper on downwind. The flight school began using the technique when a renter pilot went off the end of the runway in a Tiger.
Thanks! And to add to the fun, I don't think the FAA or TC apply their silly new "stabilized approach" standards until you're established on final — perhaps any American or instructors can let me know if I'm wrong — so you can do a safer and more natural (for light pistons) 6° glidepath on the base leg and lose roughly 400 ft/mile.
While seat of the pants and hunting and pecking is a time-honored tradition, having power/configuration targets for various phases of flight is a good operating practice. It's often not specifically covered as such until instrument training but is useful much earlier than that.
Can't speak for TC, but the stabilized approach is described by the FAA in the Airplane Flying Handbook and elsewhere like this:
MPH or knots?
Nauga,
back to first principles
Obviously accuracy is not important, because you’re using the wrong formula…you cut your ground speed in half and add a zero to get VS.
My comment was tongue in cheek but for typical GA approach speeds the rule of thumb is off by ~9% if you use MPH and ~25% if you use knots. Since it's just a crosscheck for VFR you're almost as close or closer to just shoot for 250-300 fpm and adjust as you fly. *This* is just one reason why I think it's important to understand the math behind rules of thumb.The OP was in mph.
It works for either..just a rule of thumb to get you close without using a slide rule.
Yes, at the time I was assuming being as close to the 3 deg glide slope as possible once turning final. This is why I assumed trying to get to that slope and altitude before base. This is not my goal anymore.
