B

[B @bpa331]

@BudaTxFrog @MyGolfSpy I'm a 9 and break 80 maybe a couple times a year out of around 40 rounds.

[KC-10 Driver ✈️ 👨‍✈️ B-737 Wrangler @MCCCANM]

I got a lot of questions about flying a “Cost Index” (CI) on an airliner.

Can’t blame you…I’d never heard of it until I got to the airlines. An explainer:

Airlines are concerned w/ keeping costs down. The margins in the industry are very low, so minimizing cost means you can keep ticket prices lower & stay competitive.

There are many costs to account for, but CI only relates to the airplane in flight. In this regard, the competing cost factors are fuel & time (time is cost of the crew…it actually includes other factors, but that’s too much info). You can save time by flying faster, but that burns fuel. You can save fuel by flying slower, but that burns time.

(That gets complicated…you can burn vastly more fuel by flying really slow, but that’s a lesson in aerodynamics & more than we need here. Just keep in mind we’re talking about trying to save a couple hundred pounds of fuel, which isn’t a lot on one flight, but if you’re airline does a few thousand flights a day, that’s a lot of money!)

So, the Cost Index is an attempt to balance the two competing costs to produce the most efficient result.

There is a formula involved, but I don’t know it & you won’t care, so we’ll skip that (but you can google it). Anyway, the Dispatcher (who builds the flight plan & checks the weather, etc.) selects a CI based on conditions. I imagine it’s probably automated, but I don’t actually know.

If the winds are favorable & you’ll be early, you’ll get a low CI. Usually a CI of 10. No need to burn extra fuel to get there even earlier…you’ll probably just end up waiting for a gate, anyway.

If you are late, you’ll get a high CI…like maybe CI 120. It’s basically “Go fast”.

The CI references can be different for different model jets. On the 737, the highest is usually 120…but other jets may be able to do CI 200 or more. The airlines may also regulate how high the CI can be set…at mine, on the 737 the highest CI is 80. It used to be 120, but they analyzed the data & backed it down. This is because anything over CI 80 produces speeds over .80 Mach (the 80 & .80 are not related!), and the maximum is .82 Mach. In the 737, if you hit a decent bump at .80 Mach, there is a good chance you will suddenly exceed .82 Mach & now it’s an overspeed, which requires an inspection (but almost never does damage unless it’s an egregious overspeed).

Anyway, you plug the CI into the computer. It runs the formula & decides the speed to fly, based on fuel burn. Now, the thing to know is that CI is *not* a speed. It produces a speed, but it’s based on the weight of the jet & efficiency. If you change the weight of the jet, you’ll get a different speed. Guess what happens as we fly? Yep, we burn fuel & our weight changes. So, the computer is re-running this formula & coming up with new speeds. You can start out flying at .76 Mach, but as you go along it will speed up to .78 Mach (or whatever).

The pilot can change the CI anytime they want. They can also just “hard code” a speed for the jet to fly. When crossing the ocean, I usually hard code the speed, rather than letting the jet modulate. This is because I have to meet certain times at each waypoint & don’t want the jet to change our speed (it wouldn’t be that dramatic to throw us off more than 2 minutes usually, but I don’t want it). When over land and in radar coverage, I let the CI run the show when it comes to speed.

CI is usually only a factor in cruise, but it does change how fast the jet will fly in climb or descent. A high CI can command a speed I don’t like in these phases of flight…like I won’t let the 737 climb at a speed faster than 325 knots, for the same overspeed reason described earlier. I go in & change the speed, which overrides the CI.

Ok, I’m about out of space. Hope that helps! As always, I’m simplifying things to try & give the layperson an understanding. Just remember that the CI produces a speed, but that’s not what it is. It’s fuel burn.

[B @bpa331]

@john_hersc79276 @JennyShin_LPGA I'm not sure either but that's what her caddie told her. I was actually surprised he said that because it seemed like everyone else was favoring short.

[B @bpa331]

@JennyShin_LPGA @john_hersc79276 But her caddie said long was better than short and anything that lands short of the green was stopping. It seems like the longer club was the clear choice then if they were unsure.

[B @bpa331]

@SmylieKaufman10 Why didn't he lay up? There was no way he pull off that approach shot.

[B @bpa331]

@GOLF_com No

[B @bpa331]

@MidwestGolfJake What do you need to capture your interest?

[B @bpa331]

@AB48420889 I'm pretty sure that's not unusual.

[B @bpa331]

@PennyJam_ Why?

[B @bpa331]

I'm pretty sure hail in Columbus in June is pretty common Jim.

[B @bpa331]

@ChetrosBakke @AdamKing10TV Wrong

[B @bpa331]

@AdamKing10TV I played it 2 weeks ago...90 degrees, firm, windy and rough longer than it is now. I can confirm is was by far the toughest round of golf any of us have ever played. If we had the energy to hug after that round we may have.

[B @bpa331]

@TourSwingsTommy @KevinPoppix5r5 @DocAmish0940 @TonySoprano1973 The doesn't stratify by age. There is a huge difference in a 25 year old 15 hcp and a 65 year old.

[B @bpa331]

@BreedsMNGolf @Steve_Swinger1 @Mike_kim714 I can confirm....and I'm also convinced the transfusions on tap at the lake house have 0 alcohol.

[Dan Patrick Show @dpshow]

"The best part about it was nobody knew who I was, and so they bullied me the whole time!" 😅

– @JoeyVotto on time spent in retirement as a sushi chef in Japan, among other travels.

[B @bpa331]

@SnobbyScheffler What's a divot?

[Adam Carolla @adamcarolla]

Funny

[B @bpa331]

@bscholl @greg_travis If they have yet to find a single use how are they eliminating jobs? Why are companies spending billions of dollars a year on tokens for coding assistance if they don't work?

[B @bpa331]

@acaseofthegolf1 I actually had his current caddie when I played Panmure and Carnoustie a couple years ago. Now I don't feel so bad that he had to chase around all my bad shots.

[Lou Raguse @LouNewsMan]

Nine people so far face new fraud charge in Minnesota, with more expected later today