How do you guarantee finding that airport

[pelmet]

You are flying along in a small airport in a remote area over featureless terrain on a long VFR cross country in an old Piper Cub with nothing more than the basic flight instruments. Unfortunately the overcast cloud layer is quite low at about 800 feet. Your handheld GPS batteries died a about 30 minutes ago so it is dead reckoning using your paper chart. Fuel is tight and you don't have much reserve fuel but you should be OK with perhaps your barely legal 30 minute reserve.

You lost exact positioning a while back but you have one thing going for you. Your destination airport is on an unmistakeable river that crosses almost 90 degrees to your track(or maybe it is a shoreline of a large lake). Unfortunately, it is a fairly straight shoreline river with few identifying features. You are certain that you are off course but not sure if it is left or right of track. Then again, maybe you are on track. You would hate to turn the wrong direction upon reaching the shore and run out of gas prior to finding the airport.

What do you do to guarantee finding the airport?

[AirFrame]

Make a course correction to one side, let's say to the right, enough that makes you certain that you would come out well to the right of your destination. Then fly up the shoreline until you find the airport?

[Tips Up]

And I assume no local radio station? Radio contact available with FSS?

[youhavecontrol]

Make a course correction to one side, let's say to the right, enough that makes you certain that you would come out well to the right of your destination. Then fly up the shoreline until you find the airport?

Exactly what I would say too. The whole situation is perplexing in that, someone would have to be dumb enough to choose a flight like that with no equipment and poor weather forecasting, yet smart enough to get themselves out of it.

[dogfood]

A used smartphone which you can probably get for around 50$ will have GPS and the ability have offline maps. anybody that puts themselves in that situation is an idiot

[Schooner69A]

From the narrative:

“You are certain that you are off course but not sure if it is left or right of track. Then again, maybe you are on track”

Can’t put yourself off well off track if you don’t know roughly where you are already…

[Hilroy]

Wish thay guy never took off...

[PilotDAR]

What do you do to guarantee finding the airport?

The described conditions suggest that your poor preparedness and fuel planning prevents your guaranteeing finding the airport for yourself (though Airframe's method would be the best hope). So, should you run out of fuel, the guarantee will best be fulfilled by SAR, when they fly you from your crash site, to their airport.

For flights like that, it's worth the cost of a paper chart with all the planning lines you learned in ground school, and then as you fly, mark on it features you've passed, and the time. I did this lots, back when charts were 50 cents a piece, and the planes I flew maybe had a Comm.

[No Smoke, No Fire]

Find a decent enough of a spot to put it down, go get fuel, try again another day.

[avsteve1]

Flying in a Piper Cub with an overcast layer at 800ft...Wow.

[C.W.E.]

How do you guarantee finding that airport

The answer is obvious if you read what you posted.

You are flying along in a small airport in a remote area over featureless terrain on a long VFR cross country in an old Piper Cub with nothing more than the basic flight instruments.

You don't need another airport, you are flying in one.

[pelmet]

Make a course correction to one side, let's say to the right, enough that makes you certain that you would come out well to the right of your destination. Then fly up the shoreline until you find the airport?

Correct. Interestingly, instead of having a solution, some seemed to become totally focused on why the Piper Cub pilot got into this situation instead of recognizing that the point of the question is of course, a navigation exercise. It could be a trans-oceanic flight with an electrical failure where you do actually need to find an airport.

According to the article I read(which I found interesting), turn 30 degrees left or right of present track half an hour prior to reaching the river. You then know which way to turn when reaching the river. It is a dead-reckoning procedure called 'Making Landfall With a Known Error".

Who knows, maybe someday for some bizarre reason, you will have need to use it.

[Beefitarian]

I don't like the sounds of 30 degrees intentional off course for a half hour, when you're worried about making it on your self described barely legal reserve.

If you were on track you might be flying out of range of that destination. Sounds scary.

[PilotDAR]

The 30 degree off track idea is not new. We applied a variation of the concept back in the 70's for our solo cross country flights. Our destination was Goderich, which when approached from the east, brings you to the shore of Lake Huron, perpendicular to the shoreline. If the airport is not in sight, you have to decide which way to turn - north or south. For whatever reason, some pilot would turn north along the shore to look for the airport. The problem was that there was less choice, at a greater distance, of suitable airports north, rather than south. I heard of a few precautionary landings, necessitating skilled airplane recovery.

So the drill became to deliberately aim a little bit north of the planned course, and if upon arrival to the shoreline, Goderich airport was not in sight, to expect it to be south of you. If you were right, you'd find it. If you'd been wrong, and arrived to the south of Goderich, and then turned to fly more south, you weren't going to get to Goderich, but there were more suitable aerodromes on your path, so you'd be less likely to have to pick a field.

The reliance upon GPS has lulled pilots into thinking that preplanning for "what could go wrong" is no longer needed, but a paper chart used properly is still more dependable than a GPS! It just takes more skill and discipline to use!

[photofly]

If you were dead on track, and in the absence of wind, heading thirty degrees off track 30 minutes before arrival and flying the hypotenuse and short side of the right triangle, you’d be airborne 19 minutes and 1.1542 seconds longer than if you continued straight.

[digits_]

That's an awfully accurate calculation for a question without a specified airspeed. Did you take the curvature of the earth into account?

[photofly]

That's an awfully accurate calculation for a question without a specified airspeed. Did you take the curvature of the earth into account?

I'm in pedant mode, so I'll point out that it's a very precise (lots of digits) answer, but not an accurate (close to the correct answer) one.
Yes, I accounted for curvature of the earth, Special Relativistic time dilation, and I also included the time dilation effects predicted by General Relativity at an altitude of 800'.

More seriously, if you head off 30 degrees, 30 minutes to prior to arrival, it doesn't matter how fast you're flying, the detour will always take the same amount of time. A faster airplane will execute the turn further away from the destination and have further to fly, but it exactly makes up for it by flying at a faster speed.

It's very similar to the "an aircraft with an NDB exactly on its beam crosses 10 degrees of bearing in so-many minutes. How many minutes flying time from the beacon is it?" questions so beloved of written exams. I did actually try that out one day.

[digits_]

[photofly]

Interesting rule of thumb though, isn't it? 30 degrees off at 30 minutes out means 20 minutes extra flying (if you were on track to start with). If my geometry is right, anyway.

[digits_]

It honestly is, yes.