First Vac Pump Failure

[Vladimir Lenin]

I don't remember flying with two operational VOR's, an AI that didn't just spin (yes, spin on its axis) and a working DG and a TC...but, hey, it's only 65 bux an hour after a $1000 deposit

Plus, you should practice your compass turns and stay on yer toes anyway, right?

 

[Timebuilder]

Vac pump and the TC? Wow.

I had an AI take a dump right after rotation once. Like yourself, it was a severe clear day.

Needless to say, this instrument lesson became a "partial panel" lesson for my student.

 

[A Squared]

>>>>>Kudos to the awesome Chicago approach controller who sent me straight across the downtown area at 1900' into MDW to help me out.

I'm scratching my head wondering why you would need help, or even want help. So there you were in great VFR weather in an airplane without gyro instruments.....and you needed help to do what? I guess I'm missing something, a good portion of my time is in airplanes with no vacuum system or gyros and they seemed to fly just fine.

 

[dmspilot00]

I was wondering the same thing myself, but I figured I would leave it to someone else to ask. Thanks for clearing that up. Were you on an IFR flight plan? Flying without the DG would be rather annoying, I would think.

Anyway, how old is this plane? If you don't know you can look up the N# on the FAA database. Just curious.

The 172 I got checked out in after I got my private was a 1974 model, with original interior (but luckily not original avionics). Some of the comments I received from passengers (friends) I flew in it include: "this plane looks like it's gonna fall apart;" and one girl, after seeing the outside and saying, "its so cute!" said, "this plane needs to be retired!!" when I opened the door.

 

[bigD]

I've found that the actual age has less to do with the quality of the plane than the people responsible for maintaining it. One of the planes I'm most comfortable taking into low IFR is a '72 172.

For me, I've had more problems with the R models than anything else. Two alternator failures, an aux fuel pump failure, one vacuum pump failure in hard IMC at night (the plane was a month old), and just about everything in that god-forsaken avionics stack has failed at least once. I dunno if it's just been bad luck or what, but those friggin R models just don't like me. Of course, the passengers just love 'em.

 

[A Squared]

anyway, it's a good practical lesson. Vacuum pumps can and do fail. In about 1800 hours of flying airplanes equipped with vacuum pumps, I've had 5 failures. When you consider that about half of that time and four of the failures were in twins, my experience is in the ballpark of the conventional wisdom that dry vacumm pumps last about 500 hours. Be ready for it

 

[Hawker rider]

yeah yeah yeah

I currently fly a 1963 Learjet 23 converted to a 24, WITH some of the original instruments in it, I guess it's all just what you're used to. Most of the time not a big deal either.

M

 

[bunnyfufu]

God was watching over me and my passenger yesterday...

huh? by giving you a vacuum failure? you chose to fly in that weather.. and anyway, it's not like you were actually in any danger :\

 

[Timebuilder]

Now see what you did? You mention God and Bunny will certainly have something to say about it!

Thank Hillary that the NEA is still doing it's job of instilling political correctness in our young people today!!

and just about everything in that god-forsaken avionics stack has failed at least once.

Oh, no! That's TWO mentions of God. We'll never get past this thread!

Seriously, BigD, the new production Cessnas had a major problem with the new King stacks. I'm told they were built in Mexico (like the newer Zenith TV's) and suffered from a cold solder joint problem. Most all of those radios have been replaced from what I have seen.

I like the idea of a wet vacuum pump, but I like the idea of an electric AI, too.

 

[TurboS7]

I had wet-vacs on our 206's and also dry vacs, the wet outlived the dry 10 to 1 hours of operation.

 

[banned username 2]

Someone should shoot the plane and put it out of it's misery...

I feel your pain, I used to fly an old Falcon 20C that everytime I would walk out to the ramp, I would hope that to find a heap of molten metal on the ramp... But no such luck...

 

[CaptBuzzard]

I had my heading indicator fail in a C-402 last fall on a Part 135 flight. Luckily again it happened on a clear day. I did a little brush-up on compass turns however.

 

[metrodriver]

Big D, that's Cessna quality nowadays. I recently talked to a guy who 2 years back bought a brandnew 206. First the airplane leaked water, so much that during a heavy rainshower everything inside was wet, including avionics. Cessna gave him a hard time about fixing it and reimbursing travelcosts. Then he had something else (I forgot what), then he found out that his engine had a bad cranckshaft, one out of a series that has been recalled. He flew the airplane only 40 hrs in the first year and traded it in for a much better piper product.

Dry vacuum pumps are only guarateed for 700 hours if I'm correct. Most operators leave them on the plane till they fail.

I have seen a lot of problems with the Ford alternators on Cessna's. I had one fail where the stud on which you screw the cable broke out of the diode bridge and arced a big hole in this bridge. C172 RG in IFR. I left one com/nav and txpdr on, manual gear extension (just in case), no flap landing. Battery didn't need to be charged after replacing the alternator.
Second one was the standby alternator on a caravan, where ford didn't put enough resin in the receptacle on the inside of the alternator to keep the wires in place. When I touched the plug the whole thing fell out with the wires from the inside of the alternator attached to it.
I also have seen an alternator causing a total electrical failure to a pilot over Flushing Bay in NY, He decended to 400' before breaking out of the clouds (C172 RG)

 

[bin LAAidoff]

thread reminds me of a tip to pass on

beware of "dual vac" installtions. concept is splendid, but as pilot and MX I've seen more than one dual vac install s-h=i=* the bed. Vac line has a check valve of sorts, but when a pump fails, often impeller and assemly flies apart, and the "stuff" somehow gets in the other pump.

so...if you are flying along, fat dumb and happy, and one pump fails, be ready for the next to go withing ten minutes to the next two flights!

happy frying

 

[buzzer]

I lost my vac two days ago. I just turned on the electic driven standby pump and was on my way with a grin at having the back up in the most well equiped small airplane I have ever flown. This was my first flight in an airplane I purchased less than an hour before. I had just dropped off the salesman who sold it to me. The very next day (yesterday) the alternator belt gets tossed (without me knowing) and I end up loosing everything. The only vac drivin item was the AI and now that is gone since I'm on the standby eletric one. The airplane is loaded electically and I ran down the battery to the point where the gear barely made it down. It did come down, but it also drained what I had left in the battery (even after turning everything I didn't need off). So I get the gear down and loose my last radio. No green gear light. I'm on final (had been cleared to land) and an airplane takes off in front of me and I have to go around! I just turned out, wagged my wings, looked for a possible green light and landed.
My mechanic thought it was funny since he just did the prepurchase inspection and said the vac pump is 10 years old and the alt belt was looking bad..."both should be replaced". Good thing he is starting the annual next week. Weather wasn't a factor.

 

[generaltso]

No, by letting the weather be CLEAR. I'm saying if it wasn't clear, it would have been a really f-ed up situation... partial panel with no TC? Ouch.

You would have really taken that plane in IMC? It always amazes me how some low timers will take a PoS plane in to IMC. I've seen some guys take these planes in to solid IMC, at minimums. Scary stuff.

 

[flyby]

been there

funny you mention that, I had that exact thing happen in a seneca once. took off and on climbout noticed a button on the vac guage showing. sure enough, within a few minutes the other popped and both pumps were dead. lesson I learned is if I ever lose one vac. pump in a twin I'll expect the other will go shortly and act accordingly. good info.

good luck

thread reminds me of a tip to pass on

beware of "dual vac" installtions. concept is splendid, but as pilot and MX I've seen more than one dual vac install s-h=i=* the bed. Vac line has a check valve of sorts, but when a pump fails, often impeller and assemly flies apart, and the "stuff" somehow gets in the other pump.

so...if you are flying along, fat dumb and happy, and one pump fails, be ready for the next to go withing ten minutes to the next two flights!

happy frying

 

[mattfish42]

Speaking from my vast experience of slightly less than a year of both flying and fixing C172s, I gotta agree that the Ford alternators are cr@p and R models break down irritatingly often. My favorite airplane is a 1985 P model with 15,600 hours on the airframe. Fun to fly, and reliable; it's a great plane.