Introduction
This school assignment assumes I am a helicopter pilot and am required to make aeronautical decisions. The professor proposes certain information and criteria and I have to decide if I take the flight or not.
The rationale for asking
I have searched for some METAR on here and official FAA websites, but I can’t really find an answer that properly answers what I have in mind. I don’t have aeronautical friends so I thought coming back to ask here is a logical solution.
Question KCLS 31008KT 280V350 8SM FEW 55 22/11
The above is the assigned weather information. From above, I can learn the following:
Chehalis-Centralia Airport
Wind from 310, 8 knots
Wind variable between 280 and 350
Visibility 8 miles
Few clouds
Temp 22, dewpoint 11.
My question lies with FEW 55. In all documents and information provided here, the numbers after sky condition are denoted with 3 figures at all times. In this scenario, its FEW 55. Logically, I can assume the information to be FEW 055 and take it that clouds are few around 5,500 feet.
However, this being an aeronautical decision assignment, I have to make a stand on why and why not. Making an assumption is also a terrible human factor. I want to know if FEW 55 is considered an acceptable norm or that it is technically incorrect (and that I should clarify).
Assuming is definitely a bad thing to do in aviation. I’m sure you did NS already right, so the phrase “you think I thought who confirm” will come to mind.
Similarly in this case, If I were you, I’d suggest asking your prof to confirm that it is 055 first before giving your answer. Because in this case, I can only think of one answer available. It doesn’t make sense that the airport will be giving clouds at FL 550.
@N1DG@BadPlane However, when it comes to safety, does FEW 55 represent an erroneous way to represent the data. Since clouds are often depicted with 3 digits (FEW 055).
I have to decide if:
1)This is a norm, incorrect but done anyway
2)This is a norm, correct regardless of 3 or 2 digit representation.
3)In all technicality, it is incorrect and is best clarified despite the obvious answer being 5,500 feet.
Just by looking at the metar at anchorage (PANC), it shows BKN070 and OVC120 so I would assume a 3 digit value would be the norm since it could be confusing to have a FEW10, could be 1000 or 10000.
@Yunkeru. MaxSez: “FEW 55” appears to be missing a diget, erroneous or mis-printed in the METAR cited. METAR formats are governed by ICAO. The observation FEW like BKN for broken identify type cloud cover. The numbers measure the height to the base of the cloud/fog ect layer. This information is always listed as hundreds of feet above the ground (AGL) in three digits. Zero (0) always proceeds elevations from O to 999 Feet.
GOOGLE or National Federal Aviation Regulations (US-FAA FAR/AIM) are key resources to validate a correction, a private discussion outside of class with your Professor on this matter is suggested.
Good Luck, Max
Agreed Max, I was reading on FAA website about meteorology earlier.
As you have also included, AIM states that “Cloud bases are reported with three digits in hundreds of feet above ground level (AGL). (Clouds above 12,000 feet cannot be reported by an automated station).”.
In that case, since it is not represented in a manner correct to regulations, it cannot be a norm and it’ll be worth clarifying. Thanks for the detailed answer Max!
The correct way for clouds in the case would be few 055 (5,500 feet). Other examples would be like SCT 120. (12,000) feet BKN 030 (3,000 feet) or OV004 or overcast 400 feet
So, I think we are all squared away that the format is incorrect, but is that the question? Is that something you would question before flying in the area? If the assignment is deciding to make or not make the flight, would the answer be “not without first clarifying the ceiling” or something of the sort?
Of course, it’s entirely possible it’s just a typo on the assignment and not meant to be incorrect, but maybe it is intentionally incorrect to see if you note that or not.
Or maybe I just overthink academic questions too much.
Well, if I was an experienced pilot, I think I would make the flight. But this being academic and all, plus I am the student and the professor being a pilot of many years, I think it’s good to be on the careful side.
After all, its safety class xD A typo is after all, human factors. Maybe my professor haven’t been getting the proper rest he should be getting =p
It’s not the correct format but cloud heights are always measured in hundreds of feet so 55 hundred feet is 5,500 just the same as 055. Reference AC 00-45H Aviation Weather Services page 3-15
You’ll likely never encounter it in the real world since FAA Order 7900.5 keeps aviation weather observers from reporting anything other than 3 digits (Pg 115).
Also the National Weather Service uses the 55 format in an example on their Website for Aviation Weather Products. Which is still an incorrect format according to the FAA as referenced above.
Thanks for the insight ^^ Although I’ve since finished my final assignment for this module xD However, It’ll probably still come in handy for the next few subjects.