Night Flying

[gismo]

But for that to work I'd have to get the runway threshold into the GPS database as a user waypoint. I wonder if I could do that with the necessary precision in flight. If I knew exactly where the airport reference location was I could calculate it, but I'm not confident enough that I wouldn't overlook some correction that would put the waypoint far enough off to make it dangerous to fly for real.

I forget where I saw it but I could swear I once found a listing of lat/lon coordinates for the ends of each paved runway at all public airports. Baring that you could either measure the distance from the ref point to the runway ends on an airport diagram (AOPA as diagrams for most) or map it out on one of the online overhead image sites. In either case make sure you're using the same cartographic coordinate format (e.g. hh:mm:sec.tenths vs hh:min.hundredths). You'd also be pretty close if you added half the runway length to the distance from the reference since most ref points are near the middle of the airport.

OTOH, if the obstacles to be cleared are within 1nm of the airport reference location (so that the GPS is displaying the distance in hundredths), and as long as the reference location is somewhere well past the threshold, I don't see why I couldn't just use the reference location, noting the distance to that point along the extended centerline upon passing over the last obstacle and then when flying for real, beginning my descent from a predetermined "MDA" that has sufficient obstacle clearance (taking into account altimeter errors). That should definitely work at 3DA and probably at 76G too.

If I understand what you're describing it sounds OK. Sounds like it would require a trip to the same airport in visual conditions though (not a bad idea).

 

[azure]

I forget where I saw it but I could swear I once found a listing of lat/lon coordinates for the ends of each paved runway at all public airports. Baring that you could either measure the distance from the ref point to the runway ends on an airport diagram (AOPA as diagrams for most) or map it out on one of the online overhead image sites. In either case make sure you're using the same cartographic coordinate format (e.g. hh:mm:sec.tenths vs hh:min.hundredths).

I've never heard of a published listing of runway threshold coordinates, that would be a useful tidbit. I had thought of using Google Earth, but I don't know enough about how GE calculates lat/lon coordinates to be sure whether there wouldn't be some discrepancy between those coordinates and the ones used by the GPS.

The other problem with user waypoints though, is that every airplane I fly, other people do also. I once tried putting a user waypoint in the GPS in one of the rentals I flew out of 76G, only to find it was gone the next time I flew the airplane. I don't know whether that GPS stored user waypoints in volatile memory or if someone deleted it. But until I have my own plane or a very limited partnership, I'm just not inclined to go through the work of putting them in.

If I understand what you're describing it sounds OK. Sounds like it would require a trip to the same airport in visual conditions though (not a bad idea).

That's what I meant. I wouldn't consider trying this at night without first test-flying it in daylight and good visibility.

Thanks for the idea, Lance. Because of my previous experience with disappearing WPs I never seriously thought about using the GPS to solve this problem. You made me think some more and realise that I don't really need a user waypoint to do this, as long as I can align myself visually with the runway. Neat idea, I'll have to experiment with it.

 

[dmccormack]

And that's exactly why IMO it's easier to just know a "MSA" within a certain radius of the airport and descend to an "MDA" once aligned with the runway and past some visual reference point, using the homegrown "DME" to mark the invisible obstacle after which you can make a safe descent to the runway. Dive and drive, in other words, instead of a calculated glidepath descent.

Unless there's a VDP...

That would be illegal of course, not to mention pretty stupid.

Hmmm... If you are VMC, but use navigational data to set up your approach and landing, is that "illegal"?

Of course the only way it would be "legal" IMC is if you had the runway environment in sight and you could descend and land "normally."

 

[azure]

Unless there's a VDP...

On final to 22 & 76G at night, there just isn't any point you could call a "VDP" until you're directly over the approach end of the runway, and by then, you wouldn't make it even in a 172 without a pretty aggressive slip.

Yup, I've considered doing that too.

Hmmm... If you are VMC, but use navigational data to set up your approach and landing, is that "illegal"?

Of course not... I thought Lance said IMC?

Of course the only way it would be "legal" IMC is if you had the runway environment in sight and you could descend and land "normally."

Since the whole area is Class E above (at most) 700 AGL, how would you even get a clearance to try the procedure in IMC? The only ways I can think of would be to cancel IFR in the clouds (illegal), or declare an emergency.

 

[dmccormack]

On final to 22 & 76G at night, there just isn't any point you could call a "VDP" until you're directly over the approach end of the runway, and by then, you wouldn't make it even in a 172 without a pretty aggressive slip.

Yup, I've considered doing that too.


Of course not... I thought Lance said IMC?


Since the whole area is Class E above (at most) 700 AGL, how would you even get a clearance to try the procedure in IMC? The only ways I can think of would be to cancel IFR in the clouds (illegal), or declare an emergency.

A VDP is a marked point on a non-precision approach from which normal descent from the MDA to the runway touchdown point may be commenced, provided necessary landing criteria are met (the "runway environment").

Of course the AIM or CFRs don't define "normal descent," but the normal decsent angle for precision approaches is between 2.75 degrees and 3.75 degrees.

As far as canceling -- you can cancel IFR any time. It may not be smart, and in close conditions you may be better off requesting a contact approach.

 

[azure]

A VDP is a marked point on a non-precision approach from which normal descent from the MDA to the runway touchdown point may be commenced, provided necessary landing criteria are met (the "runway environment").

I know... I thought we were talking about a "homegrown" approach using user-inputted GPS data, not a real SIAP.

As far as canceling -- you can cancel IFR any time. It may not be smart, and in close conditions you may be better off requesting a contact approach.

Aren't you then operating VFR in violation of 91.155a if you cancel IFR in IMC in controlled airspace?

 

[JeffDG]

Aren't you then operating VFR in violation of 91.155a if you cancel IFR in IMC in controlled airspace?

Who said anything about canceling IFR. You're still IFR on a visual approach.

 

[dmccormack]

I know... I thought we were talking about a "homegrown" approach using user-inputted GPS data, not a real SIAP.


Aren't you then operating VFR in violation of 91.155a if you cancel IFR in IMC in controlled airspace?

Perhaps I wasn't clear -- you can cancel IFR at any time. The airspace will determine the VFR minima (not the weather).

It can be pretty lousy, crappy but if you have reference to the ground (runway environment) you aren't technically "IMC" anymore.

 

[azure]

It can be pretty lousy, crappy but if you have reference to the ground (runway environment) you aren't technically "IMC" anymore.

Okay, sorry to belabor the point, but I'm at the point where my CFII is talking about getting me ready for the oral, so I have to be sure I'm clear on this.

You're 400 AGL at MDA on a circling-only approach to a field with Class E to the surface, when you acquire the airport environment. You're maybe 150 feet below the ceiling, but you have good visual reference. You decide since you're not IMC anymore you can just cancel IFR in the air and circle to land VFR.

Is that legal? My understanding is no. Since you're in Class E 150 feet below a cloud layer, you're still technically IMC and cannot legally operate VFR.

If it's legal, what is the loophole in 91.155 that allows it?

Sorry to the OP for the thread hijack...

edit: since you wrote "runway environment" maybe it's different if you are on a straight-in approach and are in a position to make a normal landing? My understanding is still no, but I wanted to make sure we weren't talking apples and oranges (again).

 

[Greg Bockelman]

Is that legal? My understanding is no. Since you're in Class E 150 feet below a cloud layer, you're still technically IMC and cannot legally operate VFR.

You are correct. It is not. You must have VFR weather conditions for it to be legal and your scenario clearly does not meet that requirement.

I have heard stories (true or not, I do not know) about people getting violated for canceling IFR when they break out of the clouds on an approach into uncontrolled fields. Their intent was to free up the airspace for the next approach, but the FAA got wind of it and violated them.

 

[Capt. Geoffrey Thorpe]

I've never heard of a published listing of runway threshold coordinates, that would be a useful tidbit. I had thought of using Google Earth, but I don't know enough about how GE calculates lat/lon coordinates to be sure whether there wouldn't be some discrepancy between those coordinates and the ones used by the GPS.

Not that hard at runwayfinder.com
Example:

Find ONZ,
Switch to satellite view and max zoom, center the end of 35
click on "show link" you get:
http://www.runwayfinder.com/?x=-83.16364467144012&y=42.09323678907684&z=19&view=sat

you have to translate the coordinates a little:
x = 83.16364467144012 - take the .16364467144012 and multiply by 60 to get from decimal degree to decimal minute: 9.8186802864072 so the location becomes 83 degrees 9.8186802864072 minutes longitude in your GPS (assuming that your GPS uses the same format as mine) (and there is no need to punch in all 13 decimal points - about about three places to the right of the decimal point exceeds the accuracy of a typical GPS unit...)
Same thing to translate the y= to latitude.

I can't tell you EXACTLY how accurate the process is, but if I do the reverse starting with a waypoint from my GPS, I get the result in my .sig which pretty much zooms tp a point about 30 feet from where I was sitting in my back yard when I saved the waypoint...

 

[Capt. Geoffrey Thorpe]

Perhaps I wasn't clear -- you can cancel IFR at any time. The airspace will determine the VFR minima (not the weather).

It can be pretty lousy, crappy but if you have reference to the ground (runway environment) you aren't technically "IMC" anymore.

I have to unagree.

IMC is defined as "not VMC" - if you don't meet the VFR minimums you are still in IMC even if you are not navigating primarily by instruments.

If you are flying in unlimited visibility (and navigating by looking out the window) at 4500 feet below a 4600 foot overcast you are in "IMC" in most airspace.

Kinda like acting and logging PIC.

 

[dmccormack]

Request a Contact Approach and all you need is a mile vis and clear of clouds.

They can't give you a visual approach in the conditions Liz described (not 1000 and 3).

But once you are cleared for the approach often you'll hear "Cancel on the ground or with me."

 

[dmccormack]

I have to unagree.

IMC is defined as "not VMC" - if you don't meet the VFR minimums you are still in IMC even if you are not navigating primarily by instruments.

Right -- this slippery term was aptly discussed in this thread: http://www.pilotsofamerica.com/forum/showthread.php?t=3570

My very narrow -- not very clear -- point was that during a contact approach you are flying with reference to the ground (you have ground contact).

It's true you can't cancel IFR when conditions are less than VFR, but the airspace determines what constitutes VFR.

Hope that helps...?

 

[azure]

Right -- this slippery term was aptly discussed in this thread: http://www.pilotsofamerica.com/forum/showthread.php?t=3570

My very narrow -- not very clear -- point was that during a contact approach you are flying with reference to the ground (you have ground contact).

But IIRC, a contact approach can only be authorized if the airport has a SIAP. Neither of the fields I was using as examples has one.

And BTW, I'm with the majority in preferring to fly an approach to an unfamiliar field at night. For that matter, not long ago I flew the RNAV 9 into a very familiar field -- my home base -- even though it was still good VFR, because vis was going downhill.

This IR training is useful for more than just filing and flying IFR.

It's true you can't cancel IFR when conditions are less than VFR, but the airspace determines what constitutes VFR.

Hope that helps...?

Yes, I see what you're saying and that agrees with what I've been taught. Though I'd add, the airspace, altitude (above vs below 10,000 MSL), and day vs. night all contribute to determining whether conditions are legal for VFR.

 

[Ted]

And BTW, I'm with the majority in preferring to fly an approach to an unfamiliar field at night. For that matter, not long ago I flew the RNAV 9 into a very familiar field -- my home base -- even though it was still good VFR, because vis was going downhill.

If I'm coming into Williamsport from the east VFR at night, I'll routinely dial in the ILS and just follow that in. Good thing to do!

 

[SkyHog]

And BTW, I'm with the majority in preferring to fly an approach to an unfamiliar field at night. For that matter, not long ago I flew the RNAV 9 into a very familiar field -- my home base -- even though it was still good VFR, because vis was going downhill.

I don't believe that is the majority at all. I like doing it because it is fun, but I have absolutely no qualms about night flight into an unfamiliar airport without any approaches.

I've heard that the majority of people believe that night flight without the IR is dumb. I wish those people would stop saying that because they'll get it changed, and suddenly good pilots like me get screwed out of my favorite type of flying.

Night flight is safer than day flight, IMHO. How many midairs do you hear about at night? How about "I'm lost and can't find the gigantic flashing light at the airport?"

The only thing you lose with night flight is the ability to see emergency landing sites. With proper planning, night flight into an unfamiliar airport is perfectly safe.

 

[azure]

If I'm coming into Williamsport from the east VFR at night, I'll routinely dial in the ILS and just follow that in. Good thing to do!

Yup! I wish VLL had a precision approach. Or even an RNAV 27.

BTW on the subject of "homegrown approaches", another trick I sometimes use with Garmin GPSs is to dial in the runway heading on the OBS and hit the "OBS" button, then just fly the needle at a safe altitude until I have the runway in sight and intercept the visual glideslope (on runways with VASIs).

The 430 even gives you a digital readout of the desired bearing (very nice) and a <shudder> magenta line.

 

[azure]

I don't believe that is the majority at all. I like doing it because it is fun, but I have absolutely no qualms about night flight into an unfamiliar airport without any approaches.

Oh, don't get me wrong, as long as I have visual obstacle clearance, I won't avoid it either. But invisible power lines and trees (plus no VASI) give me the willies.

I've heard that the majority of people believe that night flight without the IR is dumb. I wish those people would stop saying that because they'll get it changed, and suddenly good pilots like me get screwed out of my favorite type of flying.

I wouldn't say that, but I do think that being able to fly the gauges is important when flying over remote areas at night. I'm sure there are a lot of non-IR pilots who can do it safely (I've done it, and don't think it was unsafe per se, though without partial panel training I really didn't have an "out" in case of vacuum system failure), but good training under the hood plus a lot of recent night experience make it a lot safer IMO. The rating, after all, is just words on your ticket.

The only thing you lose with night flight is the ability to see emergency landing sites.

Yup, that's the biggie. It's a risk I usually only take alone, or with passengers who understand that if the blower stops, our options are limited.

 

[dmccormack]

Night VFR can be "safe," as long as you have options.

Flying SEL over Baltimore I realized there weren't many.

Out here, in my home area, the options are limited -- even the fields are contoured along hillsides and ringed with tress, power lines, and gas wells.

I don't think IFR provides much more margin than VFR except in the rare case of inadvertent cloud penetration (you can't see them at night) and no-horizon scenarios (over the ocean or in very thick haze).

 

[RotorAndWing]

Night VFR can be "safe," as long as you have options.

True, it's all about risk management.

Personally, after 8,000 hours of night I'm going to try to make a point of never flying in the dark again.

 

[dmccormack]

True, it's all about risk management.

Personally, after 8,000 hours of night I'm going to try to make a point of never flying in the dark again.

All Single Engine?

 

[RotorAndWing]

All Single Engine?

No, most was either transport or multi piston or turbine.

At this point in my life I just enjoy day VFR down low.

 

[dmccormack]

No, most was either transport or multi piston or turbine.

At this point in my life I just enjoy day VFR down low.

You need an Aeronca!!!

 

[RotorAndWing]

You need an Aeronca!!!

That's for sure. I had a 7ECA back several years ago and a lot of time in a 7AC. Great airplanes for sure.

 

[gismo]

I don't think IFR provides much more margin than VFR except in the rare case of inadvertent cloud penetration (you can't see them at night) and no-horizon scenarios (over the ocean or in very thick haze).

IFR likely results in higher cruising altitudes and the resulting increase in options should a problem occur but that's probably not much of an effect.

I personally think the biggest VFR risk at night, especially a dark one is the inability to see and avoid clouds but I don't know if accident statistics support that feeling. I have flown into IMC while flying VFR at night on multiple occasions. In all but one, I was IFR rated/current but had some reason to attempt VFR along with a forecast that indicated it should have been easy. The one time when I was a VFR only pilot was a short flight between two airports in my home area. I had climbed into the cloud bases and as soon as I noticed the city lights getting dimmer below I descended back into the clear air beneath the clouds. That wasn't a big deal but might have been a lot worse if I had flown into the side of a cloud rather than the level bases.

 

[gismo]

Aren't you then operating VFR in violation of 91.155a if you cancel IFR in IMC in controlled airspace?...

But IIRC, a contact approach can only be authorized if the airport has a SIAP. Neither of the fields I was using as examples has one...

You're 400 AGL at MDA on a circling-only approach to a field with Class E to the surface, when you acquire the airport environment. You're maybe 150 feet below the ceiling, but you have good visual reference. You decide since you're not IMC anymore you can just cancel IFR in the air and circle to land VFR.

Is that legal? My understanding is no. Since you're in Class E 150 feet below a cloud layer, you're still technically IMC and cannot legally operate VFR.

Liz, I'm impressed. You obviously have been studying the regs and seem to understand some of the nuances that escape many an IR pilot. I predict you'll do very well on that oral (and the flying part as well).

 

[Everskyward]

I personally think the biggest VFR risk at night, especially a dark one is the inability to see and avoid clouds but I don't know if accident statistics support that feeling. I have flown into IMC while flying VFR at night on multiple occasions.

I agree. In my case it has usually been because I accepted the visual approach too soon. I can see the airport... oops maybe not. The other big risk is flying into terrain you can't see. That unlit area could be a number of things, including a hill. That's why it's nice to have a moon. When there is snow covered ground and a moon it's almost like day.

 

[Fast n' Furious]

http://www.ntsb.gov/ntsb/brief.asp?ev_id=20010109X00069&key=1

I'm not much for posting these unless there's something to be learned. Manage your risks accordingly. Please be safe.

 

[Ted]

I personally think the biggest VFR risk at night, especially a dark one is the inability to see and avoid clouds but I don't know if accident statistics support that feeling. I have flown into IMC while flying VFR at night on multiple occasions. In all but one, I was IFR rated/current but had some reason to attempt VFR along with a forecast that indicated it should have been easy. The one time when I was a VFR only pilot was a short flight between two airports in my home area. I had climbed into the cloud bases and as soon as I noticed the city lights getting dimmer below I descended back into the clear air beneath the clouds. That wasn't a big deal but might have been a lot worse if I had flown into the side of a cloud rather than the level bases.

I'm in agreement, Lance, and that's what I tend to tell VFR-only pilots. As an example, a primary student and I did a night XC from Lancaster back to Williamsport. METARs were reporting OVC060. I looked up at the sky and thought "I wonder when he's going to realize that the bases aren't 6000." It was a good lesson for him, and illustrated my point. I've had a few VFR into IMC experiences as well at night, but only as an instrument rated pilot. I almost always fly on an IFR flight plan for trips anyway, though.

 

[flyingcheesehead]

I've heard that the majority of people believe that night flight without the IR is dumb. I wish those people would stop saying that because they'll get it changed, and suddenly good pilots like me get screwed out of my favorite type of flying.

I don't think it's dumb, and I don't think that night VFR should be outlawed (like it is in most countries).

However, I *do* think that instrument *procedures* can greatly increase safety at night. As I've become older and wiser (and instrument rated) I've realized that things like obstacle departure procedures can GREATLY increase safety at night, especially at unfamiliar fields.

Night flight is safer than day flight, IMHO. How many midairs do you hear about at night?

Well, a lot less people are flying at night, too... But if two of them were approaching each other from opposite sides of an unseen cloud...

Yes, in severe clear planes are definitely easier to see... I don't think the risk of a mid-air increases at all, but many other risks are increased at night.

The only thing you lose with night flight is the ability to see emergency landing sites.

And see clouds (I know you don't have many of those in your area), and see terrain/unlit obstacles...

 

[chemgeek]

Night flight is safer than day flight, IMHO.

The accident statistics don't support this hypothesis. According to the AOPA Air Safety Foundation Nall Report, about 1/5 of daytime accidents result in fatalities, compared to more than 1/3 of nighttime accidents. Nearly half of the VMC night accidents resulted in fatalities.

I would not support an IR requirement for night flying privileges, but there is clearly additional risk associated with night flying, and pilots should plan and train accordingly.

Cheers.