Instrument rating in 2 days, chump this stump
Posted by johnisom@reddit | flying | View on Reddit | 102 comments
I’m taking the checkride for instrument rating airplane Wednesday morning. I’m flying a Cherokee 180 with Dual G5s and a GNX 375, no autopilot.
I’ve already read through the previous instrument stump the chumps, give me your realistic and interesting questions.
roundthesail@reddit
Hey, cool G5s! Very futuristic. I noticed the altitude isn't exactly the same as the old-timey round-gauge altimeter next to it.
Why is that? Is it okay? How much of a difference between them would you accept? When ATC says "maintain 5,000," which altimeter are you going to use?
johnisom@reddit (OP)
Wow, I wasn't even aware that the G5 would possibly not be certified as a primary altimeter until you asked this question. I dug in, and it's only certified as a secondary one.
It's going to be different just because different altimeters on the same airplane always give slightly different values. Also, the G5 takes data from 3 sources: the pitot-static system, GPS, and it's internal accelerometers and gyros, so the altitude displayed is typically more accurate than the old, crusty altimeter that is technically the primary.
As long as both are within 75 feet of the reference altitude (typically the surveyed field elevation on the ground, with the airport's altimeter setting), we're good to go, and I will mostly rely on the G5's altimeter while occasionally referencing the analog one as part of my cross-check, making sure that their difference is stable. If the G5 altimeter is not within 75 feet, I'll fly with the analog one.
The max difference between them could be potentially 150 feet, as they could each be 75 off in opposite directions.
roundthesail@reddit
Good answer! One nitpick:
Actually, it doesn't -- it's a common misconception that the G5 shows the GPS altitude, but it really is only the static source. (Which you know, because the displayed altitude changes when you change the altimeter setting. The GPS altitude wouldn't be affected by the weather.)
So why else might they be different? (Small hint if you need it: >!It's to do with only one of them being a certified altimeter.!< Bigger hint if you need it: >!Is there anything that's required to happen periodically with one but not the other?!<)
Good plan, just make sure to verbalize it for checkride purposes especially. You want the DPE to be looking at the same altitude you are. And particularly when it comes to your MDA, if the G5 happens to read higher, you might not want to let the round-gauge altimeter exceed the -0' standard.
johnisom@reddit (OP)
Oh wow, thank you for the explanation. For the question about why else they might be different, I didn't get it until I read the hints. The non-certified G5 altimeter doesn't need to undergo the 24 calendar month altimeter/pitot/static inspection. So that's another reason it could be inaccurate and should always be cross checked against the known elevation figure and the primary analog altimeter.
roundthesail@reddit
How'd it go?
johnisom@reddit (OP)
Passed! The reddit chump stumper was way harder than the real thing lol
roundthesail@reddit
Hell yeah, congratulations!
roundthesail@reddit
Yep, exactly! It's the same static system, so it benefits from that inspection, but the instrument itself isn't required to be tested and adjusted, so it usually isn't. They'll typically match when the G5 is first installed, but then they might drift apart over time.
You're in good shape, good luck on the ride!
roundthesail@reddit
How'd it go?
adrewishprince@reddit
Here is a report on common IR checkride questions students miss.
Flaps3please_@reddit
What differentiates emergency fuel and minimum fuel based on 91.167? When do you technically need to declare an emergency?
Marko1st@reddit
This will definitely stump you, but you won’t get asked this on a checkride.
You’re crossing STRDP on T328 at the posted MCA of 8,800 MSL W bound. The MEA for the segment immediately west of STRDP is 10,800 MSL.
How long from crossing STRDP at 8,800 do you have until you need to be at 10,800?
johnisom@reddit (OP)
Hm, this is stumping me. I know we're expected to climb/descend at at least 500fpm. But that associated climb gradient could really be anything. I would guess it requires the standard departure climb gradient of 200ft/NM to assure obstacle clearance, so I have 10 miles to make the climb, but I'm really not sure.
Marko1st@reddit
You’re very close! But MCA’s are designed to slightly shallower climb gradients which also depend on your altitude. Check out section 15-3 in the TERPS. Seems like a very small climb gradient, but depending on your aircraft type it might not be!
Love the way you’re thinking though. & from these comments of yours, I honestly think you’ll do fine
johnisom@reddit (OP)
Wait, how do I find section 15-3 in the TERPS, could you link a reference? All I’m seeing is that the TERPS was replaced by the TPP, and I cannot find a reference to the climb gradients. All I’ve found online are 150 ft/NM below 5000 MSL, 120 ft/NM 5001-10000 MSL, 100 ft/NM above 10000 MSL. But this references an outdated FAA publication and I haven’t found anything in anything modern.
randombrain@reddit
The TPP is the pilot-facing document, you're correct. They were talking about FAA Order 8260.3, United States Standard for Terminal Instrument Procedures (TERPS), which is the reference guide that the airways & procedures guys use when designing stuff.
johnisom@reddit (OP)
Wow, good stuff
Marko1st@reddit
This is absolutely correct. & thank you for catching my error!
sleepingorangutans@reddit
where’s the FAF on an ILS approach?
johnisom@reddit (OP)
Where the lightning bolt points. The point where the glideslope intercepts the minimum glideslope intercept altitude, which is written as a step down altitude in the side profile view
figure-9rock@reddit
A technicality- the lightning bolt denotes the elevation of glideslope intercept, but this isn’t an exact “point” in space because the elevation is based on your altimeter, which will read lower than your true altitude on days above standard temperature, and higher than your true altitude on days below standard temperature.
johnisom@reddit (OP)
Could you elaborate? Are you talking about crossing over the outer marker? The final approach segment starts at the lightning bolt intercept, so that would be where the PFAF is.
In Utah, there are approximately 0 ILSs with OMs so I’m not sure, and this would be great to know
figure-9rock@reddit
I’m not talking about the outer marker (my area also doesn’t have any ILSs with one, at least that I’ve flown!)—I’m talking about a difference in your position over the ground at the moment you intercept the glideslope at the published altitude. Remember that you’re flying based on indicated altitude, and indicated only equals true at standard temperature. If it’s warmer than that, your true altitude is slightly higher, so you will intercept the glideslope slightly further away from the threshold than if it were colder. Link to diagram illustrating this point. ILS glideslope intercept point varies with temperature
johnisom@reddit (OP)
I think we're both talking about the same thing.
It is true to say that the precision final approach point is where you are when you are centered on the glide slope at the minimum glide slope altitude, indicated by the lightning bolt. And yes because of this it differs slightly depending on the exact aircraft and the conditions of the day.
Like the MAP on an APV is where you are when you hit the DA/DH.
Unhappy-Ostrich7445@reddit
You are on the localizer. The final approach course is 260, but you accidentally set 160 what will happen to the localizer needle ?
johnisom@reddit (OP)
Nothing happens to the localizer needle when setting the OBS, it acts exactly the same. It just might be confusing since the course you put in the OBS is 100 degrees off of your heading/course.
If on an HSI, then it'll still act as normal but point not in the direction of your actual course
figure-9rock@reddit
You’re going on an IFR flight during the day, and on preflight notice one nav light is out. Can you fly? If so, what action needs to be taken?
johnisom@reddit (OP)
The man light is required by VFR night equipment, which ifr also needs if it’s at night, but not during the day.
So to determine if I could fly without it, I would follow this order: - if there is an MEL, follow that - if there is a KOEL, follow that - if it’s required in the POH, follow that - we already established it’s not required by the FARs
If the above checks deem it’s not required, I can disable it (switch it off) and placard it inoperative, deem it safe to fly, and go on flying.
figure-9rock@reddit
That’s a great by-the-book answer; I looked up a Cherokee 180 POH/AFM and don’t see any KOEL or reference to required lights so it’s likely that you can fly without it if your manuals are the same. MEL’s are rare for piston singles. But by discovering it on preflight you do now have to deactivate and placard it! Good luck on the ride tomorrow
johnisom@reddit (OP)
Yes, for my plane we don’t have anything other than the FARs for required equipment. It was certified in 1965 😮
cookie7754@reddit
Do you have to go missed at the VDP?
johnisom@reddit (OP)
No, you do not have to commit to going missed once you reach the VDP as long as you can still satisfy 91.175 and land using normal maneuvers using a normal rate of descent. One way I could do that is since I’m flying under part 91, I don’t have to land in the touchdown zone. But it’s not advisable.
randombrain@reddit
Well if you've read the previous stumps you may have seen my questions, but here I am, so here you are.
This is a real-world scenario that happened to me during the second week after I was certified to work radar. Details changed, of course.
You have filed a flight plan from Ionia County Airport (Y70) to South Bend via VIO V274 PMM V55 GIJ direct with a filed altitude of 060. Pretend all the airway segments are usable.
The AWOS at Y70 is reporting ceiling OVC015 and visibility 10SM—marginal VFR, to be sure, but still legal VFR.
Your cell carrier has poor coverage near Ionia, so you elect to depart VFR. You take off from Runway 28. Because you are VFR, you maintain 500' below the cloud layer—1000' AGL, 1800' MSL. You call Great Lakes Approach airborne to pick up your IFR clearance.
The Great Lakes Approach controller issues your squawk code and identifies you on radar. They give you the Grand Rapids altimeter setting and confirm that you are at 1800' MSL. Then they say this:
What do you say, and why?
figure-9rock@reddit
Other options: look at the takeoff minimums for Y70 and notice that there’s no nonstandard climb gradient or ODP published for runway 28, so a 200fpnm climb should guarantee obstacle clearance for a straight out departure. Further confirmation could be found in the missed approach procedure for the rnav to 28, which is a straight-out climb.
randombrain@reddit
Also true. Note that the RNAV missed approach has you starting at 1240' MSL over the numbers, but that isn't a consideration for the standard departure procedure; the 200' climb gradient still holds, the "cross DER at least 35' AGL" is apparently old info that is soon to be removed from the AIM, and if you're going straight-out then you don't care about the "get to 400' before starting a turn" thing.
You just need to make sure, at the point when ATC asks the question, that you definitely are still within the procedure's protected airspace. I said in the scenario that you were 1000' AGL, 1300' MSL. Climbing at 200 FPNM gets you five miles from the DER before you need to be that altitude. Maybe that's realistic; maybe it isn't. Depends how fast you're going and how long it took to call ATC and have this back-and-forth with them.
Of course, if you have gotten beyond five miles from the DER, you could always go back to the airport and overfly the runway at pattern altitude... now you've turned the 35/400/200 into 1000/1000/200. Just make sure you coordinate that with ATC before doing it, because once you say "yes" they're going to issue your IFR clearance and you'll be bound to fly the route they give you.
Naive-Caterpillar309@reddit
Ooohhhh. I want to know.
randombrain@reddit
OP answered, so here you go. Bear in mind I am not a pilot myself, nor a DPE, ASI, or FAA lawyer. Opinions are my own and not necessarily those of the FAA, and all that.
Step 1 is to calculate your height below the referenced MVA (700'), and compare that to your height below the clouds (500') and the difference in those two numbers (200'). That's how long you'll be in true IMC before the FAA assumes responsibility for your terrain/obstacle separation.
Step 2 is to compute the distance that it would take you to fly (at Vx, I would assume, but I'm not a pilot—you do you) in order to climb all the way to the MVA. And then remember to put that in statute miles, because the next step is going to involve visibility.
Step 3 is to use your Mark I eyeball to scan the area in front of your plane for two things: First, do you agree with the ASOS machine that visibility is good, specifically is it at least the distance you computed in Step 2. And second, within the area that you can see, are there any mountaintops or radio towers poking into the cloud layer.
If there are no obstacles below the clouds, then there won't be obstacles in the clouds either. (Unless you're near the Mexican border, or the Florida Keys, and there's a tethered surveillance balloon nearby. But those will be in their own restricted areas, for very good reason.) So you can tell ATC that you can, in fact, accept responsibility for your own terrain and obstruction clearance up to 2500, knowing that ATC will then issue you an IFR clearance and keep you separated from any mobile objects (other IFR aircraft).
This is all very dependent on the specifics of the situation: The cloud bases, the visibility, the time of day (you did read each and every unlit obstacle NOTAM, right?), your climb performance, and probably your familiarity with the area. If something doesn't feel right, tell ATC "unable," maintain VFR, and pull out Plan B.
johnisom@reddit (OP)
If I really can guarantee my own terrain and obstacle clearance for that 700’ climb, then I can say yes, get my IFR clearance and climb into the clouds, receiving only traffic separation u til I’m at 2500 MSL. Only 200’ of the climb is actually in the clouds. If I’m familiar with the area, the charts, and the terrain and obstacles immediately in front of me, which I’d be able to see before going into the clouds (unless it’s at night and the obstacles are unmarked), I could do it.
So if I’m already familiar and comfortable with the area, “Great Lakes Approach, affirmative, I can maintain my own obstacle and terrain clearance to two thousand five hundred, Cherokee 345”.
randombrain@reddit
However you feel comfortable answering "yes," as long as you understand that it is entirely on you and you alone to analyze the situation! I like to emphasize the visibility aspect; make sure you agree with the machine that visibility is good below the layer.
(Also, if you're less than 1000' from the MVA, then in theory you're already within the MVA buffer zone. That can help give you confidence in your "yes" answer, but if it isn't good enough for ATC, it shouldn't be good enough on its own for you either.)
johnisom@reddit (OP)
This is something they don’t teach you in school, I learned it by reading previous stumps
randombrain@reddit
This is a really tricky question that the examiner probably won't ask you, and probably won't ever be a factor in your IFR flying career... until the day that it is.
Compare and contrast:
How do you safely navigate yourself from 0' AGL to the minimum safe IFR altitude?
johnisom@reddit (OP)
Y70 has instrument approaches, which means the FAA has evaluated the area for instrument approaches and departures. There are no published takeoff procedures or minimums for 10/28, so it passes the diverse departure assessment. As long as I can meet the standard takeoff climb gradient of 200ft/NM, cross the DER at 35 AGL, and fly runway heading to 400 AGL before making any turns, I will get obstacle clearance. Well, as long as I take off runway 10 or 28, of course.
On the other hand, C43 hasn’t been evaluated for a diverse departure, there are no IAPs or departure procedures published for that airport. It’s totally on me to avoid obstacles until I’m at MVA, but I don’t know what that MVA is. Other than knowing the area intimately and keeping situationally aware, how can I ensure obstacle clearance while in the clouds at 700 AGL?
randombrain@reddit
Perfect!
Aside from local knowledge of the area, you can't ensure obstacle clearance in the clouds. For example, this pilot's personal procedure is "turn over the ocean, not over the mountains." But it's their procedure, not the FAA's.
If you don't feel like you are extremely familiar with the airport's surroundings, you probably don't want to depart into a low layer. And if you aren't sure what the MVA is, you probably want to ask ATC before taking off.
The tricky part here is that our procedures on the ATC side don't make any distinction between a Class G airport with IAPs/TPP info, and a Class G airport without IAPs/TPP info. If you ask for a clearance, we'll issue you a clearance. It's on you to understand what that means for you.
randombrain@reddit
You're departing Capital Region Airport (LAN) on a flight plan to Indianapolis Metro Airport (UMP) via direct FWA, direct. Weather is solidly IMC, bases OVC008, tops reported around 5300, negative ice.
In your clearance, you were issued "maintain 3000, expect 7000 one-zero minutes after departure."
Lansing Tower gives you "Proceed direct Fort Wayne, cleared for takeoff." You take off and you turn direct FWA. Then they issue "Contact Great Lakes departure," but when you flip the switch you can't get a response. Going back to Tower, also no response.
What is your game plan? (I'm specifically curious about your altitude, but really the whole scenario is important to think over.)
johnisom@reddit (OP)
First, I try to troubleshoot the radio. I double check the frequencies to make sure I didn't fat finger the freqs. If the freqs are right and I don't hear anything, I'll try out my second comm. If that also fails, I'll squawk 7600 and continue to troubleshoot. Meanwhile, I'm going to have to stay IFR since I'm in the clouds.
I need to then follow lost-comms procedures. If it's been 10 minutes after departure, I'll climb to 7000. Until then, I'll maintain the highest of my assigned 3000 or the OROCA of my direct routing. For the entire route, this is just 7000.
For routing, follow the cleared direct routing to the clearance limit, then proceed to a fix for an instrument approach and execute the approach including the vnav.
Since the cloud tops are 5300, I'll end up in VFR conditions and fly an appropriate VFR altitude of 8,500. If I see a break in the cloud layer near a good diversion airport, I can divert there under VFR. If it's just a sea of clouds, I'll continue to my clearance limit as described above.
Realistically, while I do the above, I'll call ATC on my cell phone.
Funny enough, I don't think the lost comms procedures cover the particular case where you're VFR above the clouds but with no way to the surface under VFR. Unless I've missed it.
randombrain@reddit
Ha, good catch on the altitude for direction of flight. I had you going to a different airport at first, and then I changed my mind to UMP. My mistake.
I will point out that the 3100' OROCA is not, technically speaking, the 91.177 minimum altitude and therefore is not, technically speaking, the 91.185 minimum altitude. As best as I can tell from the VFR sectional, the highest obstacle in the quadrant is the 1956' tower just South of Eaton Rapids. That would correspond to a 91.177 minimum altitude of 3000' (after rounding). I'm not sure how the OROCA gets to 3100'. It's possible I'm missing something, though.
But very good job on not falling for the misconception that some people have; the "expect 7000 in ten" (which should be 8, you're right) does not apply until that ten minutes are up! And the rest of your answer is solid as well. Remember that even if you file, and are cleared over, an IAF, your clearance limit is still the airport. But also remember that 91.3 exists, and the AIM basically says "the PIC may decide to pull the 91.3 card and deviate from 91.185 if necessary." What "necessary" looks like is between you, the situation at hand, and your DPE.
When you call ATC on your cell phone (good!!), how do you know what number to call?
johnisom@reddit (OP)
Just read 91.177. Good point, the OROCA isn’t the minimum, the minimum is based off of obstacles within 4 NM horizontally of my track. But, to reduce my mental load while I fly, I would exercise 91.3 and use my emergency authority to go to the OROCA
randombrain@reddit
Solid answer. Just know that using the OROCA is, in fact, exercising 91.3, because the OROCA—by definition—is "for general situational awareness, flight planning, and in-flight contingency use."
johnisom@reddit (OP)
I would try to call Cleveland center since I’m in their airspace at the time of the comms failure. I’m having trouble finding a phone number , but I found a Cleveland center clearance delivery phone number by looking in the chart supplement of one of the small untowered airports along the route of flight. If I couldn’t find one, I’d call at least an ATC facility and ask them to relay me the phone number while I aviate, navigate, communicate in that order.
randombrain@reddit
At 7000 (or 8000) you shouldn't be in any Center airspace anywhere along that route... at least not during the daytime. Great Lakes Approach and Grissom Approach do close overnight, but Toledo, Fort Wayne, and Indianapolis are all 24/7.
But yes, that is exactly the way to go. Find the closest non-towered airport, ideally with an IAP but I don't think it necessarily needs to have one, and look in the Chart Supplement. Whatever the "for clearance delivery, call XXX" number is, that goes to the ops room floor and they can figure it out from there.
johnisom@reddit (OP)
Oh, interesting I didn’t know you’d just be with approach. I fly in Utah, and the only approach facility we have is salt lake approach, and once we’re usually kicked over to salt lake center pretty quickly once out of the 30NM vicinity of the airport, even at the lower altitudes of like 3000 AGL
randombrain@reddit
Yep, if you click through that link you'll see some (old-ish) maps depicting Approach airspace. With one or maybe two exceptions, an approach control will own up to at least 10k MSL; 12 or 15 if the airspace is busy, and a couple own as high as FL230.
As you can see from the maps, on the East Coast and well into the Midwest the approach control coverage is relatively extensive. Less so as you get into the Mountain West where you are.
14Three8@reddit
If you lost your pitot static/adc instruments in imc, what kind approach would you want to shoot?
If you lost your gyro/ahrs instruments, what kind of approach would you want to shoot?
Explain why pls
johnisom@reddit (OP)
For the first, something like ILS, RNAV LPV or LNAV/VNAV since I’d be unable to safely fly without vertical guidance.
For the second, honestly I’d take the same. Luckily with the G5 and my GNX 375 I still have ground track even without gyro/ahrs. That is very useful, and I can use that to get established on an approach with vertical guidance and use the needles from there. But a non precision approach wouldn’t be a big deal to execute given my gps on board
40KaratOrSomething@reddit
Your on an IFR flight plan to KOCF, ATC cleared you direct to KOCF, you are on the OCF VORTAC 178 radial headed noeth. ATC says to expect the VOR 36 approach. You're at 2,000 feet, 15 miles out, told to contact tower. Tower says cleared for the VOR 36 approach. Describe the route flown.
johnisom@reddit (OP)
This procedure is not authorized on airway radials 129 CW 208. I'm no radial 178, which isn't an airway radial. OCF is the only IAF, which is awkward. How do I turn around?
I would ask tower for radar vectors to final or a straight-in approach clearance. If they can't, I will tell them unable and request a different approach such as the RNAV RWY 36.
40KaratOrSomething@reddit
Not authorized 129 CW 208 in this instamce means not authorized on airway radial 129 clockwise to 208 from OCF VORTAC. You're coming in on R178 so this procedure is not authorized from that direction. Otherwise yes, contact tower ask for vectors, straight in, some other approach.
randombrain@reddit
I know you and /u/johnisom are being informal here, but you wouldn't be talking to Ocala Tower here and they wouldn't be giving you vectors to final. It would be Jacksonville Approach.
40KaratOrSomething@reddit
Maybe. Last time I flew this Jacksonville told me to talk Ocala about getting vectored/straight in.
randombrain@reddit
...and you were IFR at the time? Because that is absolutely not how things work if you're IFR. Unless they didn't understand your question and thought you were talking about a circle-to-land.
40KaratOrSomething@reddit
Filed KSPG to KOCF. Nice layer from about 1,500 to 3K on an IFR plan. Had me at 5K for the most part. May be they did get confused but told me to talk to tour after they pass me off. Not saying they did the right thing woth how busy they were but that's how that went down.
randombrain@reddit
If it were me flying, with my knowledge of the NAS, that would warrant a question on the frequency and a call to the facility after I landed.
Towers can relay approach clearances ("anything is possible with coordination," as we say) but they definitely should not have the responsibility of getting you aligned with the final approach course and issuing a PTAC all on their own. Something got mixed up.
johnisom@reddit (OP)
OK, I was confused by the wording since it says NA ... "airway" radial ... And I'm not on an airway but i am tracking a radial on that range.
randombrain@reddit
Yeah, the wording on the plates is old and doesn't account for the possibility of someone approaching via "direct." But the point is that the interception angle is too great if you're anywhere in that pie slice.
40KaratOrSomething@reddit
That is the catch on that approach.
randombrain@reddit
You're going in to GRR. You get the ATIS, which has 05016KT SCT013 BKN035 and says that both the ILS RWY 08R and the ILS RWY 35 are in use.
You're cleared the ILS RWY 08R. Brief the expected immediate/initial response from ATC if something happens and you report going missed, or get sent around, on short final.
Note: The answer is NOT "turn right direct Victory VOR." Explain why.
sforzapop@reddit
Why would ATC wait until going missed to give those instructions? If there is a possible conflict, wouldn't it make more sense to give alternate missed approach instructions before clearing them so that if there is lost comms or something, it isn't going to be an issue?
randombrain@reddit
Fair point, and I don't actually know myself how GRR does things. They may actually assign the alternate missed of KNOBS if the weather is bad, although that would be unusual. In order for a real conflict to occur, someone would have to go missed, AND lose comms, AND there would have to be a 35 arrival at the same time.
There have been one or two times in my career when the weather was absolutely terrible and I did give someone "in the event of a missed approach, fly heading XXX" but in the vast majority of cases we don't bother doing that.
The underlying point, as I told OP, is that you should always be prepared to receive a heading and altitude if you go missed at a towered airport. The published missed is generally designed in a vacuum, assuming non-radar one-in-one-out procedures, and almost never works well with our standard traffic flows.
johnisom@reddit (OP)
The ILS RWY 08R published missed has you holding over VIO at 3000. The ILS RWY 35 has you crossing VIO at 2412. Since the ILS RWY 35 is in use, ATC will likely not allow me to execute this missed procedure as published since it would put me in direct conflict with traffic. I would likely be given either radar vectors, or told to climb 3000 direct KNOBS, the alternate missed approach fix, and hold.
randombrain@reddit
105% chance it will be vectors, not KNOBS, unless you specifically request(ed) KNOBS for some reason. But yes!
The underlying point here is that even if there isn't such an obvious conflict, you should always be prepared for Tower to issue a heading-and-altitude at a towered airport. At least at any Class B or Class C airport, and at more than a few Class Ds as well. It's not common for the published missed to line up well with our traffic flows—not even a "straight out to hold at the reciprocal IAF"—if there's any other traffic around you.
Marko1st@reddit
You’re very close! But MCA’s are designed to slightly shallower climb gradients which also depend on your altitude. Check out section 15-3 in the TERPS. Seems like a very small climb gradient, but depending on your aircraft type it might not be!
Love the way you’re thinking though. & from these comments of yours, I honestly think you’ll do fine
VileInventor@reddit
You flew 2 approaches in February, 2 in March, 1 in July and 1 in August. Your flight is in September, can you do it? and if not how can you go about being able to do it.
johnisom@reddit (OP)
No, I cannot do it as I am not current by performing the 6 HITS in the past 6 calendar months. This is the grace period, so I can go up with a safety pilot and knock them out.
If my flight is in September, the 6 calendar months are April-September, so I still need to fly 4 approaches with a safety pilot under the hood.
VileInventor@reddit
“Within the 6 calendar months preceding the month of the flight” So If my flight is September, the month before is August. March - August. Not April - September.
johnisom@reddit (OP)
Wow, I previously glossed over this detail and my instructor and the one giving me a mock checkride didn't dig in more on my answer of "6 months". Thanks. So the correct answer is I need to do 2 more approaches under the hood.
johnisom@reddit (OP)
Well, how does that work?
Take this example. It's already September. My IFR flight is in a week. I only have 4 approaches March-August. If March-August is the time frame (6 calendar months preceding the month of the flight), then it's already too late. No matter how many approaches I do in this upcoming week, it's not in the March-August time frame and I'm just sore out of luck, I have to postpone to October.
I don't believe this is the consequence that the FAA intended. Given this information, my interpretation of 61.57(c) is the preceding 6 calendar months April-September. That is what the FAA means when it comes to the 12 calendar months of an annual inspection.
Do you have a resource explaining why it wouldn't include the current month?
VileInventor@reddit
It’s not day based, you’re good all of September. In October if you didn’t do more approaches then you’re no longer instrument current. The day of the week in September doesn’t matter. You can do some research on it if you want. Currency starts the month before the month of the flight. If you use YOUR interpretation you’re still current but cutting yourself out of approaches.
johnisom@reddit (OP)
so basically "Within the 6 calendar months preceding the month of the flight" means from the last 6 full months that have passed plus the current partial month, so just March-present day
VileInventor@reddit
Basically yeah.
VileInventor@reddit
What’s the FARs wording say.
SnarfsParf@reddit
You pop into a cloud you probably shouldn’t have and start getting kicked around to an alarming degree. What are you doing and what things are you keeping in mind?
johnisom@reddit (OP)
First, I need to make sure I'm at a safe airspeed, below Va. Depending on how severe the turbulence is and how large the cloud is, ask ATC to deviate left or right, or even turn around. I don't believe descending below or climbing above the cloud would help much, as turbulence happens above and below these cumulus clouds too.
If it's cold, I could expect freezing rain or hail coming down from the higher altitude portion of the cloud, and overall many of the nasty things that come with convective activity.
SnarfsParf@reddit
Nice!
Just to emphasize (and I think this is what you meant), if the situation is severe enough to require immediate deviation, I’m deviating and informing ATC what is happening.
Follow up question, what does Va protect from and under what circumstances?
Also, would hail only be present in “cold weather”? Could it be 90° on the surface and still have hail present?
johnisom@reddit (OP)
Va protects the aircraft from structural damage at full control deflection. Va depends on the weight, the Va that is usually placarded is at MGTOW. It's lower at lower weights. When you're below Va, the aircraft surfaces stall before enough load factor can be applied to damage the airframe. While flying through turbulence isn't applying full deflection of the controls, you're probably safe at or below Va.
Hail forms in the upper part of a cumulonimbus/towering cumulus cloud, so if it's below freezing up there, you could get it on the surface even if it's quite warm.
SnarfsParf@reddit
Great!
Just a little tweak. Va protects from structural damage at full control deflection in ONE direction. To my knowledge (and someone can check me here), it doesn’t necessarily mean structural damage will occur if full deflection of more than one surface happens, it just means it was untested during development of that aircraft. In other words, they tested deflection of each surface in one direction, just not a combination of more than one at once.
LikenSlayer@reddit
What causes surface winds to flow across the isobars at an angle rather than parallel to the isobars?
johnisom@reddit (OP)
Due to friction against the surface. Why, i only know it has to do with earth rotating underneath the winds
VileInventor@reddit
Read the longer answer that’s not enough
johnisom@reddit (OP)
I get it now, i replied to the longer answer with my understanding
Thomas-Ligotti97@reddit
I recommend students to actually read how the cause of this affects it because some DPE’s hit them with the ‘why?’ And it always stumps them
LikenSlayer@reddit
Because of surface friction. Isobars of differing air density, like in a high or low pressure system, cause winds to flow perpendicular to them. Coriolis force causes these winds to then veer parallel to the isobars. Close to the surface however, friction from the ground slows down wind speed and weakens the Coriolis effect, causing these winds to back into the isobars at an angle.
johnisom@reddit (OP)
Thanks, makes sense. The reason we have the Coriolis effect is because the air is moving with the rotation of earth. At the equator, it's the fastest, and at the poles it's 0, with an even gradient inbetween. Wind is just air masses moving about. If we have air masses moving from the pole(s) to the equator, it's velocity with the rotation of the earth is near 0, so it seems like it's shooting to the west, when simply the earth is rotating underneath it. When an air mass moves from the equator toward the pole(s), it has a high velocity with the rotation of the earth, so it seems like it's now rotating faster than the earth near the poles, shooting to the east.
Ultimately, this is why in the northern hemisphere, the air moving out of a high pressure system rotates clockwise with earth as the reference frame, and low pressure systems counterclockwise. Because of the friction at the surface, the wind there isn't just slipping around independent of earth's rotation any more, and accelerates/decelerates east/west with the earth now, so the airflow flows less parallel/more perpendicular with the isobars.
Thomas-Ligotti97@reddit
100% spot on. I was just saying it’s a pet peeve of mine when students don’t progress past rote memorization. I’ve delayed submitting a checkride for one guy and had a 3 hour ground because of that.
It’s brutal but you never know what DPE’s are focusing on nowadays
johnisom@reddit (OP)
can you link to a good resource explaining this? I'm trying to visualize it
johnisom@reddit (OP)
OK, it all makes sense
Thomas-Ligotti97@reddit
Literally just understanding what stages of learning there are. Rote is memorizing basic facts, (ex: V speeds) but application is the last stage (ex: when and how to use V speeds regularly and automatically)
You’ll learn stages of learning in FOI but it literally boils down to whether you can answer ‘why?’ To any question
pilot2647@reddit
You lose comms on climb out, filed for 10k, told to expect 7k, and MSA is 8k. Which altitude do you level at?
randombrain@reddit
Compare and contrast:
I'm specifically wondering what is the same, and what is different, about your approach to the airport and your selection of landing runway.
johnisom@reddit (OP)
Both of these are visual approaches, so you’ve already reported field in sight. Or for the second one, since it’s towered, you could have reported preceding traffic in sight.
The first one is a visual approach clearance to the airport, you can circle any runway. The second one is a clearance to only runway 28L.
Farmerhardy@reddit
Can you fail an IPC?
johnisom@reddit (OP)
No, it’s like a flight review. You receive instruction, and they pass you off when you’re ready and met requirements
rFlyingTower@reddit
This is a copy of the original post body for posterity:
I’m taking the checkride for instrument rating airplane Wednesday morning. I’m flying a Cherokee 180 with Dual G5s and a GNX 375, no autopilot.
I’ve already read through the previous instrument stump the chumps, give me your realistic and interesting questions.
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