BFR question

Hey all,

I had my BFR yesterday and was e-mailed a short quiz to have ready in advance by the CFI. Some of the questions were kind of abstract, but all were easily found in the FAR/AIM.

Here is a question that was on the CFI's little quiz that seemed pretty bizarre to me.

"The pilot in command has the authority to make a decision to go or not to go if the barometric pressure reads 31.00" T/F

The answer is false according to the FAR's, but the thought slipped my mind to ask why? I ran it by a couple of pilots at work and we had guesses, but not a reasonable answer that we could buy off on. One was the altimeter doesn't have enough adjustment range to ensure flying at the proper altitude, and the other was the engine could make more than rated power. Both seem weak and unlikely as the real reason. So CFI's, weather gurus, professional pilots, etc...?

Hummmmmmmmmmmmmmmm

Bryan Wood said:

Hey all,

I had my BFR yesterday and was e-mailed a short quiz to have ready in advance by the CFI. Some of the questions were kind of abstract, but all were easily found in the FAR/AIM.

Here is a question that was on the CFI's little quiz that seemed pretty bizarre to me.

"The pilot in command has the authority to make a decision to go or not to go if the barometric pressure reads 31.00" T/F

The answer is false according to the FAR's, but the thought slipped my mind to ask why? I ran it by a couple of pilots at work and we had guesses, but not a reasonable answer that we could buy off on. One was the altimeter doesn't have enough adjustment range to ensure flying at the proper altitude, and the other was the engine could make more than rated power. Both seem weak and unlikely as the real reason. So CFI's, weather gurus, professional pilots, etc...?

Click to expand...

I am a CFI and ATP; I don't want to step on my schwantz here, but I'll go off the top of my head.


To answer the question the PIC can do a GO AROUND (correction see PS) at any time deemed necessary by the PIC for any reason. If you are VFR and physically can not set your altimeter (due to high ambient pressure beyond the altimeters capability, ie Kollsman window). You would just adjust altitude as needed. However VFR, who cares. So high BARO is no reason to do a go around. So it is false.

IFR I would be concerned. However with high ambient conditions and a kollsman setting lower than that, you are flying higher (agl). I have never been in this condition, but I recall vaguely ATIS or tower can issue a altitude correction or it is noted on the approach plate. Much more common in Alaska.

Now in general:

A BFR only requires one hour of ground and one hour of flight. There are some specified items to cover, but it is fairly general and left up to the CFI and the pilot, who may want to work on spacific things. In other words the BFR should be tailored to they type of flying the pilot does or will do.

A BFR does not require a written exam but I am all for a written exam. At least it gets the dust off the your AIM/FAR and demonstrates you can look stuff up.

Really I don't expect people to know everything by recall, but they should be able to put their hands on it quickly. So I'll follow my advice, I looked it up to be sure.

This is more an IFR question and its from the AIM Chapt 7, Sect 2
http://www.faa.gov/ATPubs/AIM/Chap7/aim0702.html
"Altimeter setting procedures- Below 18,000 feet - When the barometric pressure exceeds 31.00 inches Hg.

Unless you fly in COLD locations chance is you will not run into this. For a VFR pilot in Florida this is a frivolous question, unless the goal was to look up a obscure section in the AIM. In that case it was a success. The CFI should have gone over the questions and told you how it related to flying you do.


"From High to Low (press), to Hot to Cold (temp), look out below".

HOWEVER, IFR in Sub frigid temps does require corrections. Because the temp is extremely cold, you will be flying lower (agl). Again this is more an IFR procedures. It is all nice to know for VFR pilots if you plan on flying in -0C condtions (link above also shows temp / alt correction).


So back to the question if the pressure was 31.50 in-hg and we could only set 31.00 in-hg, we would be flying higher (agl). So we may not hit the ground but we may not break out on the approach if too high.

VFR 31.00 inches Hg is NO reason to GO AROUND (correction see PS) if in a position to land safely.

Why not LOW pressure correction. I think because altimeters have the ability to adjust and low pressure is not an issue unless you are making an approach in the middle of a hurricane (ie real low pressure).

George CFI (inst/me) ATP

PS: THANKS DAN, You are right it was GO / NO GO not GO AROUND, duaaa.
Yes Per 91.144 you can not fly, the pilot has no option uless given appoval from the FAA thru a Notice to Airman, which I think they tend to issue in such cases, if flight ops can be safely conducted.

I think Bryan meant GO or NO GO, not as in go around, but as in to take off or not to take off.

All I could find on this subject was stuff about ATC and what they're required to do. Sounded like if the pilot is going VFR, it doesn't matter one bit. Only for IFR would it matter. I look forward to hearing what the experts have to say about this.

And I friggin' hate CFIs who ask these ridiculously obscure questions and think they're Sierra Hotel because they stump the poor guy with some nugget of knowledge no pilot in his right mind would be able to whip out of the rectal database. I like CFIs who challenge me, but in the context of real world flying.

goodbye Mr. CFI

I had my BFR yesterday and was e-mailed a short quiz to have ready in advance by the CFI. Some of the questions were kind of abstract, but all were easily found in the FAR/AIM.

Click to expand...

That would be the last BFR that particular CFI and I would share.........I have more important things to spend my $$$$$$'s and time on than abstract written quizzes.

Sam Buchanan

31"?

Here is the FAR. As you can see it gives no reason either which just has me curious as to why. I agree with your conclusions that this was a ridiculous question to waste time on. The rest of the bi-annual went smooth and didn't seem to far out of the norm.


Sec. 91.144

Temporary restriction on flight operations during abnormally high barometric pressure conditions.

(a) Special flight restrictions. When any information indicates that barometric pressure on the route of flight currently exceeds or will exceed 31 inches of mercury, no person may operate an aircraft or initiate a flight contrary to the requirements established by the Administrator and published in a Notice to Airmen issued under this section.
(b) Waivers. The Administrator is authorized to waive any restriction issued under paragraph (a) of this section to permit emergency supply, transport, or medical services to be delivered to isolated communities, where the operation can be conducted with an acceptable level of safety.

Bryan Wood said:

(a) Special flight restrictions. When any information indicates that barometric pressure on the route of flight currently exceeds or will exceed 31 inches of mercury, no person may operate an aircraft or initiate a flight contrary to the requirements established by the Administrator and published in a Notice to Airmen issued under this section.

Click to expand...

Actually, I believe that this does not restrict your ability to fly at pressures greater than 31" at all. All it does is give the FAA authority to issue a NOTAM that restricts operations at these pressures.

Remember, the FAA is not a dictatorship and in general can't simply makeup whatever rules it feels like. For example, they can't simply say "Until further notice, blue airplanes with green stripes and red seats are grounded". In order to issue a flight restriction, they need to be given the authority to do so, and that's all this rule does, I believe.

The fact that they sometimes act like a dictatorship is beside the point

Well there you go

Thanks Dan and Bryan Wood, that is what I get by using my memory, which is rusty and illegal in 38 states and the District of Columbia.


First 31.00 in-Hg is rare at least in the lower 48 (USA). (Sorry international members but this topic is regarding FAA FAR's in the USA.)

The highest barometric pressure ever recorded in the USA, not in the lower 48 was 31.85 inches Hg, Northway, Alaska, in January 1989. If you noticed the date FAR 91.144 was amended, I believe it was to cover the 1989 high pressure event in AK.

91.144 (a) ".... no person may operate an aircraft or initiate a flight contrary to the requirements established by the Administrator and published in a Notice to Airmen issued under this section."

QUESTION:
"The pilot in command has the authority to make a decision to go or not to go if the barometric pressure reads 31.00" T/F (False)


With FAR 91.144, I agree you can not fly into an area greater than 31.00 if there are no "requirements" published via Notice to Airman or wavier; So you can NOT take off or GO based on your own judgment. I suspect a Notice to Airman "approval" will be published. I got it wrong on my first post. It is not just a IFR thing or airline thing.

In case of pressure if its above 31.00, it will be likely very cold and a rare extream high pressure wave. I guess most flying for fun will be suspended. In 20+ years flying all over the world I never saw pressure that high. From what I can tell the typical HIGH in the lower 48, plus Hawaii and Virgin Islands, is around 30.00-30.50 in-Hg, where 30.00 inHg is common. I think the lower 48 record is about 30.80-30.85 inHg.


GIVE HIM THE BOOT?
I would not ask this, in fact I would not administer a written exam. I find a general "guided discussion" is best. There was one guy who was way out of currency, and his 1 hours of ground, turned into many hours of ground over a week. That is the JOB of CFI's. This Gentleman had not flown since airspace transitioned into the ICAO Letter AIRSPACE. It took sometime. He flew fine after knocking to rust off with some practice. Think about it. It can be 1, 2, 5 or 10 years since your last flight, go get a medical, a flight review and you are good to go. Expect the flight review to be long. BOTTOM LINE, I tailor the Flight review to the pilots needs and usually high pressure op's are not something I included (or remember myself). With that said I have not thought about this in such a long time I learned something.

I agree this is obscure, not sure about giving the CFI the boot? I would not include this in my syllabus or lesson plan. HOWEVER it is interesting and to be fair I did not remember 91.144, so may be it is not a dumb question? It forced me at least to look it up and think about altimetry and Regs. I am sure many GA pilots think they can fly. I know I got it wrong, off the top of my head.

Mostly it shows if a pilot knows how to use THE PUBS. How many times can you ask about Class B airspace and when your medical is due to a point where that becomes trivial.

It be the FBO's "standard procedure" to give this written test? Hey if you don't want to answer it, leave it blank. You can not fail a Flight Review, you just don't get the log book endorsement that you completed it. I doubt you would get an UNSAT for not answering, but it should be explained to the pilot. The written deal may be to CYA / CTA. The only written a CFI needs to give is the pre solo written. There is no written Flight Review requirement, but hey its not a totally bad idea. Do you just want a pencil whip Flt Review, or do you want to have a fair evaluation of your knowledge and airmanship and learn. You want EASY!

Let's not persecute CFI's, they get payed poorly and work their tail off and all they get is pilot complaining about the question they where asked on a flight review. CFI's should charge $100/hr. A flight review should not be thought of as a hassle but key to keeping you and your passengers safe. (soap box off)


Now we know. George CFI/ATP

So here's a thought...

Everyone one of us that read this thread said to ourselves..... hmmm, Interesting information, I'll have to remember that.

While we may never have a scenario where we have to apply it, it's now data in our brains....

So.... Was I wonder, with all the "punt the CFI" comments..... Did yhe CFI accomplish his/her objective with the test and was it a good or a bad thing...

Interesting isn't it,

31.00 Altimiter Answer ! FAR 91.144

The answer is two fold, first of all: most altimiters do not correct, and indicate correctly above 31.00 inches of mercury due to scaleular calibration. Secondly, and more acurately, in a very high pressure enviornment, you must remember that your true altltude is lower than pressure altltude. To illustrate this, the altitude space from SL to 10,000 feet on your altitimter is actually less than 10,000 feet measured with a long ruler at any altimiter setting above 29.92. The 10,000 feet of pressure altitude spectrum may be compacted into 9,500 feet of actual altitude. The FAA has minimum altimeter tolerances so that two aircraft travaling 1000 feet apart in altitude, and one flying directly above the other, and the upper aircraft having the max altimiter tolerance error reading high, and the lower aircraft , also haveing the max altimiter tolerance reading low, would still pass at least 550 feet from each other. The FAA used a high altimiter setting of 31.00 to arrive at this, as the actualy vertical separation of two aircraft both using an altimiter setting of higher than 29.92 is always less then 1000 feet. The FAA had to prescribe maximum altimiter errors so that any two aircraft would still be at least 550 feet apart. Obviously, the FAA had to choose a max altimiter setting to do this, and they chose 31.00 inches. They could have chosen a higher pressure setting but then the altimiter max error would have to be reduced. The reason that there is no lower limit to altimiter settings, is that the FAA has never had anybody hit something by being too high or having too much separation (which is the obvious conclusion to am altimiter setting of 27.00 inches of hg).

Why cant the PIC say no to anything? If the tea leaves look blue today and it freaks him out, he can say no and sit and watch others fly. What am I missing here? PIC can decide to not fly for and good or bad reason he wants.

dan said:

And I friggin' hate CFIs who ask these ridiculously obscure questions and think they're Sierra Hotel because they stump the poor guy with some nugget of knowledge no pilot in his right mind would be able to whip out of the rectal database. I like CFIs who challenge me, but in the context of real world flying.

Click to expand...

I agree Dan,
I want to see good crosswind techniques, centered ball and coordinated flight. To h*** with all that other BS. So now the poor guy knows all about 31.00Hg and still can't do crosswind landings!!!!!!!!!!

Sheesh,

Lighten up on the CFI. Most try and at least make the BFR interesting and beneficial. Yes, sometimes they get sidetracked on issues that they "think" others might be interested in hearing about. Just talking about very basic VFR issues can be pretty boring. As others have mentioned, I bet the BFR recipient and otheres here now know what effect rising barometric pressue has on an altimeter.

And as for seeing crosswind landing technique, that's for the 1 hour in the plane. The above is part of the 1 hour of ground. Not to mention it's supposed to be a review. If he can't do crosswind landings, a 1 hr review probably isn't going to cut it.

Last, what's a Sheesh??