Would you have continued flight?

[Chrisgoesflying]

Although no longer a student, I see every flight as a training flight so I'm posting this here.

Today, I was on a long x-country flight that was cut short way too early. About an hour into the five hour flight, my tachometer became erratic in my Cherokee 140/160. I had it set to 2,400 rpm for cruise and suddenly it started jumping to 3,500, down to 2,000, back up to 3,000 and while doing so, making a strange, kind of grinding, noise. However, the engine appeared to be operating normal. I got good power and based on the engine sound, it responded appropriately to my power settings on the throttle.

To me it was an emergency (although I didn't declare one). Luckily, there was an airfield just a few miles south of my location so I pointed directly to the field. It's an airport pretty much in the middle of nowhere, small town, no services on the weekend, etc. so not a place I would normally land, especially not in the dead of winter at -17F. About an hour either way to the east or west, there would have been airports with services. Anyway, since I considered this an emergency, I landed at the tiny airport and I'm holed up with the family in a dingy little motel room where the heater is louder than the Cherokee without a headset on. I called my mechanic back home and he said it's most likely the tach cable that gave up. I then called a mechanic who is based an hour east at one of the larger airports and he said the same. He's coming over tomorrow to fix up the plane so we can get home. Both said since the engine wasn't revving up or down, I could have continued flight to a more preferred airport.

Question to some of the more seasoned pilots out there, would you have continued flight to another airport with services knowing there wouldn't be another airport for an hour either way or would you also have just landed at the nearest field even if that means landing in the middle of nowhere with no services?

 

[s35pilot]

I would have landed somewhere. I might have stretched it a little to get to an airport with services, but probably not an hour.

 

[Kritchlow]

I refuse to second guess what another pilot chose to do in an abnormal situation. So… absolutely no criticism h from me.

That said, if it were me, and all other indications were normal, I certainly would not have continued to destination, but may have aimed for a place with services as long as the engine was performing normally.

Again, I will not second guess your decision.

 

[Albany Tom]

I fly Cherokees from time to time, and I would have landed at a nearby airport, too. Having the engine running fine, but the tach being weird does sounds like just a tach problem. But I have no idea how the tach cable attaches to the engine, and if having that come lose represents a risk of either losing oil, or of having the lose cable bounce around and break something.

Way better to second guess a decision on the ground than find out you made too risky a choice in the air.

 

[Clip4]

91.205 says except anti collision lights, no person may operate a powered civil aircraft in any operation unless the airplane contains in operable condition the instruments and equipment required in that section. A tachometer is required equipment.

91.7 Requires the PIC to discontinue the flight if the aircraft is unairworthy.

 

[SkyChaser]

Luckily, there was an airfield just a few miles south of my location so I pointed directly to the field. It's an airport pretty much in the middle of nowhere, small town, no services on the weekend, etc. so not a place I would normally land, especially not in the dead of winter at -17F.

This right here is exactly why I wouldn't have continued the flight if I was worried about engine problems. Sure, you may have been able to make it to the larger airport, but for that hour, if the engine quits and you do a forced landing in the middle of a field, you have to wait for help to arrive. And -17F is a very bad temperature to be waiting for help, especially if you have to wait outside.

 

[kmacht]

I would not have considered it an emergency but would have landed somewhere convenient, checked under the cowl for anything obvious and given the mechanic a call for their opinion. I’m not sure I would have taken it to the extreme of getting stuck in the middle of nowhere overnight though. This is one of those things where it would have really helped to know the mechanics of your plans so you could know what the possible failure modes of a unstable tach were in order to make a more informed decision. You won’t likely get to the full knowledge level of an A&P mechanic but I would look at this as an opportunity to start learning more about your airplane and it’s systems

 

[k9medic]

I remember the statement "do not create your own emergency" very vividly pounded into my head when in initial training. You took the most conservative route and that's all that needs to be said, especially when the temp is -17 degrees (This Florida boy thinks you need to seek mental health though.)

It doesn't matter what we think our would have done. You and your family are safe rather than fighting off frostbite.

I have personally watched what appeared to be simple problems become compounded problems due to continues flight with a known issue.

 

[MauleSkinner]

It doesn't matter what we think our would have done. You and your family are safe rather than fighting off frostbite.

This.

having grown up with a few bad tach cables or the equivalent, I might’ve done something different, but I wasn’t the one responsible for your family’s well being.

 

[Brad Z]

Good discussion here…if you think your situation is critical, then it’s critical. Period. Don’t second guess your actions.

That said, I’ve gone through this before, and I know that on my airplane, the failure of the tachometer cable will not have an adverse effect on the engine. Once verifying with my ear that the engine was functioning appropriately, I would have continued on to the nearest practicable airport, which might very well be my destination or another maintenance base depending on what I’m flying.

 

[sourdough44]

I consider the inflight divert to be a great safety too, various reasons. I wasn’t there, not really strong about telling you to continue.

Yes one needs to evaluate the accuracy of a gauge, it all depends. Let’s say your oil pressure dropped to zero, do we wait for secondary confirmation or use those minutes to setup for a landing?

With your tach issue, the ear should tell you if the oscillations are real or not. Especially with the family onboard, keep it conservative.

 

[Half Fast]

This right here is exactly why I wouldn't have continued the flight if I was worried about engine problems. Sure, you may have been able to make it to the larger airport, but for that hour, if the engine quits and you do a forced landing in the middle of a field, you have to wait for help to arrive. And -17F is a very bad temperature to be waiting for help, especially if you have to wait outside.

Excellent point. Add to it the possibility of an injury in an off-airport landing, with the frigid temperatures complicating care and treatment. Also, a forced landing may cause significant damage to the plane, turning a minor problem into a major one.

Landing when you’re able to do so safely is never a bad decision.

 

[Rgbeard]

I won't second-guess your choice, nor do I know the exact locations available to you at the moment.

If I could have, I would have tried to get to an airport with some form of services. But I understand this isn't always possible.

You're on the ground, and can post about it. That's good.

 

[geezer]

Good choice. If you do not know, go safe, not convenient.

I have been there, done that, for other issues that I personally was not comfortable with.

Tachometer cables in specific, they are the same as speedometer cables, and are prone to go to the performance that you have described in cold temperatures. The OAT at altitude probably initiated your events. Cruising a couple of thousand feet lower, you may not have had the malfunction. Geezer is the name I go by, and my experiences with way more than a million miles of speedometers in a fleet of owned cars that were only half bought new, plenty of cable replacements.

Tachometer cables, the club has never bought a plane with less than 3,000 hours, and keep them through 2 engine replacements. We have replaced quite a number of cables. I personally would have continued an hour, but not to destination. That, I emphasize, is me personally, not you.

Without a great deal of experience with those symptoms, your choice was exactly right. You must be sure from your own experience that the plane is going to land safely, and when in doubt, any motel with heat is a good place to be.

I have made similar conservative choices, stayed in dumps, and never regretted it. The alternate is never a certainty for the outcome. 17 degrees would prejudice me very strongly, with an unfamiliar problem. The lack of a good airport with services within 100 miles makes the case clear that an off airport landing is not going to be a good idea.

My wife and I spent a night with our two sons in the last room available, one single bed, and four blankets on the floor for the boys. The room was less than 8 by 10, but it did have heat. The floor was linoleum over concrete, but with the blankets and snuggled together, the boys did fine.

Congratulations, that you are here to discuss the problem with us!

 

[luvflyin]

Although no longer a student, I see every flight as a training flight so I'm posting this here.

Today, I was on a long x-country flight that was cut short way too early. About an hour into the five hour flight, my tachometer became erratic in my Cherokee 140/160. I had it set to 2,400 rpm for cruise and suddenly it started jumping to 3,500, down to 2,000, back up to 3,000 and while doing so, making a strange, kind of grinding, noise. However, the engine appeared to be operating normal. I got good power and based on the engine sound, it responded appropriately to my power settings on the throttle.

To me it was an emergency (although I didn't declare one). Luckily, there was an airfield just a few miles south of my location so I pointed directly to the field. It's an airport pretty much in the middle of nowhere, small town, no services on the weekend, etc. so not a place I would normally land, especially not in the dead of winter at -17F. About an hour either way to the east or west, there would have been airports with services. Anyway, since I considered this an emergency, I landed at the tiny airport and I'm holed up with the family in a dingy little motel room where the heater is louder than the Cherokee without a headset on. I called my mechanic back home and he said it's most likely the tach cable that gave up. I then called a mechanic who is based an hour east at one of the larger airports and he said the same. He's coming over tomorrow to fix up the plane so we can get home. Both said since the engine wasn't revving up or down, I could have continued flight to a more preferred airport.

Question to some of the more seasoned pilots out there, would you have continued flight to another airport with services knowing there wouldn't be another airport for an hour either way or would you also have just landed at the nearest field even if that means landing in the middle of nowhere with no services?

Put me on the list of saying you done good. I think all the takes above about this are really good stuff. I couldn't answer the what would I have done question unless you tell me when. When in my experience as a pilot did it happen. Now you answer the question. You see a post with the same conditions as yours. What's your answer now?

 

[steingar]

A good friend of mine was flying a complex aircraft that lost its tachometer in the middle of a long flight. Just kept going on his merry. Thought was the tachometer was set, the only real worry was an overspeed and he'd have heard that.

 

[iamtheari]

"There are old pilots and there are bold pilots, but there are no old bold pilots." You chose the least bold option, which is how you get to become an old pilot whose experience allows a little more boldness. Next time this happens, maybe you will decide to fly the ~1 hour back home and fix the plane there and spend the night in your own bed, but that's next time when you are an older pilot with more experience (such as this experience) to draw on.

 

[MauleSkinner]

My wife and I spent a night with our two sons in the last room available, one single bed, and four blankets on the floor for the boys. The room was less than 8 by 10, but it did have heat. The floor was linoleum over concrete, but with the blankets and snuggled together, the boys did fine.

One of the things my wife and I don’t quite agree on is whether kids sleeping on the floor once in a while is an abnormal hardship or part of a normal, healthy childhood.

 

[Lndwarrior]

Happened to me once. Same thing. I landed and an A&P on field quickly determined it was a loose tach cable. He tightened it and we were back on our way in about an hour.

 

[SkyChaser]

One of the things my wife and I don’t quite agree on is whether kids sleeping on the floor once in a while is an abnormal hardship or part of a normal, healthy childhood.

I slept on hotel floors at least once per family vacation. It's really not bad for one or two nights. In more recent years, my family would bring along those mats that you can blow up by mouth and the floor sleepers got one of those. We rented a house in the OBX once and when we arrived, there was only sleeping for 8 and there were 10 of us. Sleeping out on the covered porch was awesome! It's one of my favorite memories. LOL

 

[MauleSkinner]

I slept on hotel floors at least once per family vacation. It's really not bad for one or two nights. In more recent years, my family would bring along those mats that you can blow up by mouth and the floor sleepers got one of those. We rented a house in the OBX once and when we arrived, there was only sleeping for 8 and there were 10 of us. Sleeping out on the covered porch was awesome! It's one of my favorite memories. LOL

Same here. Christmas at my grandparents’ usually involved at least six of us on the floor. The most desirable spot was under the dining room table, because nobody tripped over you when they got up to go to the bathroom.

that said, I can easily see my wife’s position. Her dad spent a good chunk of his childhood bouncing around between relatives (his sister got adopted out), and my wife and the girls had to live with friends for a while after her divorce.

 

[Timbeck2]

I had the same thing happen to me on the last flight I took a girl up in my plane. For some reason, Broom Hilda does NOT like it when I fly females. It happened when I was about twenty miles from landing at my home airfield. In my situation, it was the tach itself and not the cable.

 

[luvflyin]

Same here. Christmas at my grandparents’ usually involved at least six of us on the floor. The most desirable spot was under the dining room table, because nobody tripped over you when they got up to go to the bathroom.

that said, I can easily see my wife’s position. Her dad spent a good chunk of his childhood bouncing around between relatives (his sister got adopted out), and my wife and the girls had to live with friends for a while after her divorce.

 

[Zeldman]

Question to some of the more seasoned pilots out there, would you have continued flight to another airport with services knowing there wouldn't be another airport for an hour either way or would you also have just landed at the nearest field even if that means landing in the middle of nowhere with no services?

Since you asked....

You did what you felt was right and I am not disputing that one bit. You had family onboard and therefore your actions need no explanation.

For me, I wasn't there. But going off your description I probably would have headed for a more convenient airport with services available. My back ground includes flying desolate areas of Alaska in dark of winter in single engine planes. I was very aggressive, bold, and now I am old. What I would have done might not have been the right decision for you. What you did was right for you and your family and no further discussion is needed.

One of the things my wife and I don’t quite agree on is whether kids sleeping on the floor once in a while is an abnormal hardship or part of a normal, healthy childhood.

As a kid of the 60s, I have slept in a number of places besides a bed, like floors, an ironing board set up between 2 chairs, under a table, car seats on the floor, even a covered wagon a few times. Great memories.!!

 

[Tantalum]

I had it set to 2,400 rpm for cruise and suddenly it started jumping to 3,500, down to 2,000, back up to 3,000 and while doing so, making a strange, kind of grinding, noise.

However, the engine appeared to be operating normal.

You 100% made the right call. We're flying (mostly) single engine piston planes, if I saw a jumping tach and heard funny noises I'd be getting on the ground ASAP as well.. it's all about breaking that accident chain. Even if it just something simple, like a tach cable nearing the end of its life you never know for sure while in the air or what other downstream (or upstream) failure points could be

I also wouldn't want to habitualize flying with funky mech things.

Nice work! and thanks for sharing!

 

[MauleSkinner]

That’s not my FIL, btw.

 

[Jeff Oslick]

"It is better to be on the ground, wishing you were up there, than to be in the air, wishing you were on the ground". - Someone with prior experience in these matters

I would not have continued flight for an hour over hostile terrain/weather with an uncertain problem. I would have made the same choice you did.

 

[bflynn]

This one is hard for me to say because I've never flown where the next airport is 100 miles away. Around here, they're usually ~25 miles between airports with service facilities, so you're never more than 12.5 miles away. Climb to 10,000' and you're within gliding distance if the engine quits. I'm having trouble putting myself in that situation.

That said - it's not dumb to get on the ground, even if you think it's just instrumentations. Far better to be on the ground in the cold than in the air wondering if you're going to live through the crash.

 

[Rushie]

I would have done what you did. The outdoor temp makes it a no brainer.

 

[coma24]

When a gauge starts acting whacky, the big question is, "is the gauge hosed, or is the underlying system having a problem?"

Had it been an oil or fuel pressure gauge, then I'd put it down in somewhat of a hurry as it would be tough distinguish between the two possible outcomes. The tach, however, is a bit of a special case in that your ear can 100% tell you if the RPM is changing. I would've reduced power slightly to verify operation of throttle control and to verify that I could audibly hear the RPM change with each power change. If so, and if the audible pitch was absolutely stable despite massive changes in the tach indication, then I would surmise with confidence that it was a gauge issue.

That being the case, I would have likely continued to a field with services in this specific instance as there wasn't reason to think the problem was any more than the gauge, or the connectivity between the gauge and the engine. However, it's not a bad outcome to be down, safely on the ground, even if it takes a bit longer to get it fixed.

 

[Ed Haywood]

This is one of the reasons helping your A&P do your services is so valuable. As you gain more understanding of your aircraft systems, your ability to interpret and judge mechanical situations is greatly improved. In this case, you might have learned the routing and connection of your tach cable and how to decowl your aircraft, so you could land and troubleshoot it yourself, using the mini tool bag you helpfully brought along. If you didn't, don't worry, everything you need is for sale at the nearest Walmart.

IMO the primary safety concern with a malfunctioning tach would be inaccurate power settings resulting in fuel burn rates different than predicted. While you can hear if the engine is operating correctly, your ear cannot gauge whether you are flying at 65% or 75% power. Armed with that knowledge, you could plan a sufficient fuel reserve to get you to somewhere with services, so that you could order a new tach cable overnight from Aircraft Spruce and find an A&P on site to install it.

That does not mean you are SOL. Your A&P might be able to talk you through replacing the cable or lubricating the existing one. Take a few pictures for him to verify it's good, do a runup on the ground to confirm proper operation, then fly to somewhere with services to have it checked out more thoroughly.

Also, don't assume that just because there are no services on site that no A&P is available. Ask around. A lot of times there will be an A&P in the area who does house calls, or is like the old "circuit rider" judges of the wild west.

 

[Half Fast]

While you can hear if the engine is operating correctly, your ear cannot gauge whether you are flying at 65% or 75% power.

True, but if you're familiar with the plane you can make a decent guess from your airspeed in level flight.

 

[Brad W]

I'm in the camp of "probably continuing or back tracking the hour to a field with services". This based on a fair bit of experience with bad speedo and tach cables.
The probably...because I would have doubts since I'm not familiar with how that cable in your plane (or any plane really) is connected and how it may be different from cars, tractors, etc... which points to what others have said about learning systems, going through stuff with your mechanic, etc...
and during/after that hour re-evaluate as I go...re-routing to keep airports under me, etc.... and possibly but doubtfully would then continue to the destination.
one thing is for sure I'd be listening extra careful and watching everything else for a hint of a problem, and would likely throttle back a bit and take it easy...
and another thing is for sure....it's dang easy for me to write all this sitting here in my office chair and a whole other thing when looking at what you were seeing with the family in the back seat

 

[brcase]

Not enough information.
I assume excellent VFR and wind conditions.
In flight how confident where you that it was just a tach issue, with minimal side affect (leaking oil?)
What was terrain like back to your next choice of place to land.

If I was pretty confident it was just the tach and I could airport hop (gliding range of airports or great landing areas) I might have flown back to my home airport for repairs.

If a good stretch of unlandable terrain or I don't know much about how tach connection works I might have done exactly what you did.

And of course a whole bunch of in between answers depending the situation. As the pilot you are the only one that can make a real time decision based on all the available information on what the best course of action and what the risks are vs the reward for your decision. This is called being Pilot in Command.

It should always be hard to criticize the ultra safe decision even if it isn't what most pilots would do.
Some day I hope to be sitting in my retirement home thinking I may have been to conservative in my flying.

Brian
CFIIG/ASEL

 

[Plano Pilot]

Using what the OP stated and my few thousand hours/years of experience. I would have returned to home base and slept in my own bed. I am assuming home base is where they departed from

 

[Ed Haywood]

I'm not familiar with how that cable in your plane (or any plane really) is connected and how it may be different from cars, tractors, etc...

Function is exactly the same, assuming it is mechanical. Simply a cable in a sheath that runs from the back of the gauge to the tach drive fitting on the back of the engine near the oil screen or filter housing. Don't even need tools, just strong hands or maybe pliers. On a lot of them you can pull the cable out from the engine end, lube it, and stick it back in.

 

[idahoflier]

I think you did the right thing. -17° isn't something to mess with when you have your family on board...

 

[David Lloyd]

Flying not new airplanes all my life, I found that sooner or later everything fails. Not a matter of if, but when. Make some decisions on the ground what you will do when various things quit working properly. Fouled plug on runup, don't go. Big mag drop, don't go. Running rough during climb out, turn around. Vac pump, alternator, various engine instruments, have some plan thought through. Sometimes the answer is land ASAP, other times land somewhere better suited to the problem. Sometimes, go back home or continue to your destination. Sometimes some in-flight analysis is in order: Fuel gauge suddenly reads 0, did it suddenly all drain out or did the gauge quit working? Do you continue to fly if the fuel gauge quit working?
Things that happened to me. Vacuum pump fails on top of a layer, solid clouds below for next 200 miles, good weather at destination 400 miles away. Alternator fails 100 miles from destination (Carlsbad, NM) in clear weather. Alternator fails receiving vectors for a 600' ceiling approach into Linden, NJ that would probably result in a missed. Tach cable suddenly shook so violently a radio vibrated out of the panel. Alternator failed between Naples and Key West in good weather. Oil pressure (electric gauge) jumped from normal to 150PSI and back repeatedly and quickly. One cylinder temperature jumps from normal to off scale repeatedly and quickly.
I would regard landing anywhere other than my destination or large, well equipped airport when it is -17F as a life threatening emergency. No, I'm to southern to even imagine that.

 

[Daleandee]

Won't judge your decision. When oil pressure went high on a previous plane I owned some years ago (pegged to it's max reading) I landed at the nearest airport, about 12 miles in front of me. Turned out to be nothing but I'd rather work on the thing on the ground ...

 

[Chrisgoesflying]

Wow, so many responses to my post. Thank you so much! I'm a relatively low time pilot (138 hours PIC) so all of this is still very much a learning experience for me, albeit one without a CFI in my ear yelling to use more rudder lol.

Some clarifying information that were asked throughout this threat.

Weather conditions were cold as hell (-17F) but perfectly VFR, sunny with 30 kts headwind aloft but only about 5 kts of wind on the ground.
Terrain was flat with little to no trees but every field had a few feet of soft powder snow. I was loosely following a major highway I would have been within gliding distance of at all times.
No other airports besides the one I'm now stuck at for an hour either way. It's VERY rural out here.
Departure airport was not my home airport. My home airport is five hours from here. We were on our way home.
Airplane is new to me so not 100% familiar with the airplane just yet. I mean, I am in terms of flying it, but you know what I mean, I don't know the plane like the back of my hand, or like I did with my last plane which I've flown for nearly 100 hours. I've only flown the Cherokee for about 10 hours since I bought it last month.
I was 90% certain it's just an instrument issue and nothing wrong with the engine. Originally, I was setting up for a landing right besides the highway in a field but I played around with the power settings and the engine responded as expected based on engine sound. Based on that, I decided to not go down in a field but instead head to the airport that was nearby. I think the one thing that startled me the most was the strange grinding sound I heard. Without it, I might have continued flight to a more suitable airport I guess. Hard to tell sitting on a sofa indoors though.

Update about the situation.

I found a mechanic who works on ag planes here during the winter and he looked at it today. The tach cable is shot beyond repair. We ordered a new one which should have arrived same day via courier but it didn't so we're stuck for another night at least. Apparently the tach itself is also on its last leg so once home I'll change that as well. My local mechanic has a tach sitting around that fits the Cherokee.

Well, another crazy aviation story to tell I guess. I like the boring stories that go like "well, we took off, and landed at our destination three hours later..." much better than the crazy ones.

To everyone from further south: Yes, -17F is really cold, inhumanely cold and it should be illegal for anyone to live in climates that cold. This entire region should just be evacuated from November until March. We'll voluntarily evacuate next month and head down to Florida for a little while. Hopefully all my flying stories flying to Florida and then back north a few weeks later will be of the boring kind.