Pilots cutting corners

bnt83

bnt83

Final Approach
Joined
Dec 31, 2012
Messages
9,980
Location
Lincoln NE
Display Name
Brian
Home Airfield
KLNK
Yep, who needs standards?

And I bet that pesky insurance company even wanted the pilots to attend recurrent training!

Yep, just trying to kill off GA, nothing more! :rolleyes2:
 
Sigh...the one time I noticed someone not do a good control check..in a 172.. and didn't make them do one, was the one time that the controls were jacked up and we had one hell of an arrival when there wasn't enough elevator authority to flare. I watch every pilot like a hawk on checks now...

For those that are curious, after the arrival, I crawled under the panel to look and see what was wrong. A mechanic that recently replaced the DG routed the vacuum cable in a way that interfered with the yokes ability to travel back. Completely stopping it without a LOT of force and then jamming it back without a LOT of force forward. It could have been bad...
 
I just cut a corner this week. The new cylinders and the baffling didn't match up real good, so I took a pencil grinder to a corner of the baffling so it would fit.
 
EdFred said:
I just cut a corner this week. The new cylinders and the baffling didn't match up real good, so I took a pencil grinder to a corner of the baffling so it would fit.
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You're so bad!
 
Cutting corners probably cost a couple lives in the Ebsol/St James crash at Montrose. And they did put it on the pilots.

"included the flight crew's failure to ensure that the airplane's wings were free of ice or snow contamination that accumulated while the airplane was on the ground, which resulted in an attempted takeoff with upper wing contamination that induced the subsequent stall and collision with the ground. The NTSB also stated that a factor contributing to the accident was the pilots’ lack of experience flying during winter weather conditions."
 
Not long after purchasing my 172, I completed my preflight including checking the controls. It was a little chilly so I pulled the cabin heat for the first time. After the run up, I checked the controls again and had very limited movement of the ailerons. Having the cabin heat knob pulled out interfered with a yoke mounted GPS unit on the copilot side. I hate to think what could have happened after take off had I not made just one last check of the controls. :mad2:
 
They proved 174 times that it was safe not to do the preflight safety checks.
I have this discussion with myself often.
Just because it didn’t kill me doesn’t indicate it was safe.
Just because I don’t find anything in my preflight safety checks doesn’t mean preflight is not necessary.
Just because I can see the sky over my destination airport doesn’t mean I don’t need to call Lockheed Martin.
There is risk in aviation and I work to mitigate that risk.
Hopefully I will live long enough to get better.
 
During my flights last night I saw for the fist time ever low oil pressure on startup. Shut down, unloaded everybody, walked back to the hanger, got oil, walked back to the aircraft, added oil, loaded everybody back in and fired back up.
 
steingar said:
During my flights last night I saw for the fist time ever low oil pressure on startup. Shut down, unloaded everybody, walked back to the hanger, got oil, walked back to the aircraft, added oil, loaded everybody back in and fired back up.
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I assume you are implying that you didn't check the oil as part of your pre-flight?

How low was it/How much oil did you add?

For low oil quantity to be the cause of low oil pressure, I'd think you'd need to be pretty dang low to begin with.
 
Fearless Tower said:
I assume you are implying that you didn't check the oil as part of your pre-flight?
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Of course I did.

Fearless Tower said:
How low was it/How much oil did you add?
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Oil was just a tad low, thought it was fine. Start up proved otherwise.

Fearless Tower said:
For low oil quantity to be the cause of low oil pressure, I'd think you'd need to be pretty dang low to begin with.
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From the looks of it I was a quart low, since a quart fixed it. First time I ever saw such a thing.
 
steingar said:
During my flights last night I saw for the fist time ever low oil pressure on startup. Shut down, unloaded everybody, walked back to the hanger, got oil, walked back to the aircraft, added oil, loaded everybody back in and fired back up.
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BAD idea. Glad you got lucky.

Running the engine with no oil pressure can easily cause damage that doesn't get undone by adding oil. The worst case is tossing a piston overboard.

Talk to an A&P, but if you did this to your car, I would strongly suggest not starting the engine until the oil has been changed AND you have had a used oil analysis that indicates no excessive bearing material. Bearing scrapings can plug oil passages, and worse, jam connecting rods. When that happens, the weakest point gives, usually the connecting rod bolt or bearing cap. This is a catastrophic failure. And it will happen with NO warning beyond what you have already had.
 
MAKG1 said:
BAD idea. Glad you got lucky.

Running the engine with no oil pressure can easily cause damage that doesn't get undone by adding oil. The worst case is tossing a piston overboard.

Talk to an A&P, but if you did this to your car, I would strongly suggest not starting the engine until the oil has been changed AND you have had a used oil analysis that indicates no excessive bearing material. Bearing scrapings can plug oil passages, and worse, jam connecting rods. When that happens, the weakest point gives, usually the connecting rod bolt or bearing cap. This is a catastrophic failure. And it will happen with NO warning beyond what you have already had.
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He said 'low oil pressure' after startup (presumably at under 1000 RPM) not NO oil pressure.
 
I leave the aux fuel pump running while I do the walk around.

I try to stay in one spot with engine running and doing all the preflight items including run-up prior to rolling away. The idea is I can look at the ground behind me while rolling away to see if the airplane is leaking anything.
 
steingar said:
Dah, at low rpm was just barely outside the green. I might have missed it but my pax (with a head on view) caught it.
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Yeah, you didn't do any damage. Depending on the airplane/engine, that may not even be considered 'low oil pressure'. On some aircraft, the green arc is the required oil pressure limits for flight not idle.
 
Fearless Tower said:
He said 'low oil pressure' after startup (presumably at under 1000 RPM) not NO oil pressure.
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Low oil doesn't cause low oil pressure. It causes no oil pressure. If it really was "just" low, that's not explainable by low oil.

There are some benign things that can cause low oil pressure, but once again, the worst case is a piston thrown overboard. Like a pressure regulator (or bypass) tuned incorrectly. Some common reasons are incorrect oil grade, fouling, or just excessive bearing wear.

Oiling systems should not be taken lightly. A failure there is the most likely reason for an engine to blow up.

Engines usually start with high oil pressure, not low. Cool oil has much higher viscosity (even with multigrades) than warm. I'll suggest that you really do want to understand this.

If it was actually in-spec due to the low RPM (and it is quite normal for low RPM pressure to be proportionally lower than high RPM, at a given temperature), then that's another story. But, out of spec is out of spec, and the spec is there for a reason, and I'd really want to know what happened, especially if the engine was cool.
 
MAKG1 said:
Low oil doesn't cause low oil pressure. It causes no oil pressure. If it really was "just" low, that's not explainable by low oil.



There are some benign things that can cause low oil pressure, but once again, the worst case is a piston thrown overboard. Like a pressure regulator (or bypass) tuned incorrectly. Some common reasons are incorrect oil grade, fouling, or just excessive bearing wear.



Oiling systems should not be taken lightly. A failure there is the most likely reason for an engine to blow up.



Engines usually start with high oil pressure, not low. Cool oil has much higher viscosity (even with multigrades) than warm. I'll suggest that you really do want to understand this.



If it was actually in-spec due to the low RPM (and it is quite normal for low RPM pressure to be proportionally lower than high RPM, at a given temperature), then that's another story. But, out of spec is out of spec, and the spec is there for a reason, and I'd really want to know what happened, especially if the engine was cool.
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I understand plenty. My point was that you are reading things into Steingar's post that aren't necessarily there.
 
MAKG1 said:
If it was actually in-spec due to the low RPM (and it is quite normal for low RPM pressure to be proportionally lower than high RPM, at a given temperature), then that's another story. But, out of spec is out of spec, and the spec is there for a reason, and I'd really want to know what happened, especially if the engine was cool.
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This is interesting. Actually, the engine was hot, second sortie on a hot day.
 
steingar said:
This is interesting. Actually, the engine was hot, second sortie on a hot day.
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Well, that changes a lot.

Oil pressure is lowest when hot and low RPM. But is it in spec or not? If out of spec, it's important to understand what's going on. If in spec, it's fine.

Oil viscosity is generally measured at 100 C, or 0 C for "W" weights. It gets a lot thinner at higher temperatures.

By dumping a quart or two in, you probably cooled the oil down significantly.
 
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Yep, oil pressure on hot days was a problem with my old engine and single weight oils. I ran 40 in the winter and when a hot day came around, it read low.
 
It's quite common (and normal) for my Cardinal's oil pressure to be well into the green when starting cold, but then when warm to read below the green at idle, and only get comfortably into the green at run-up RPM. I have not noticed this in 172s, but both Cardinals I have flown behave this way quite consistently. Not sure whether the difference is in the engine, the oil pressure gauges, or in the oil used - the 172s I have flown all used single weight oils, but multi weight (15W50) in both Cardinals.

That said, I would be concerned any time a gauge read significantly differently under what seemed to be the same conditions.
 
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