Checking Engine Oil Levels
Thanks for the article on preflight inspections (June 2024 Accident Probe, “Preflight Inspections 101”). I know I have not been diligent in looking for liquid spills under the aircraft. I will try to improve my process.
I’m wondering about the statement “always a good idea to check engine oil levels before any flight.” I had stopped doing that after short stops as I recall reading that the measured level is only accurate after so many hours of engine rest (I vaguely recall 12 hours). I have found that levels are hard to quantify after short stops. Thoughts?
—Andrew Doorey, via email
Good question. A major engine oil leak normally would leave visible evidence, either on the aircraft’s belly, around the cowling or, as we saw in that accident, on the ground. So, unless you see some evidence of it during a quick turn, it’s a good bet there’s not a problem. Normally.
However, checking the oil level in an engine you shut down, say, just 30 minutes ago is simply good airmanship. You need to confirm adequate oil is still in the engine. Timing is everything: The accident aircraft’s engine seems to have sprung its leak in the last few minutes of its previous flight.
Yes, some oil will still be draining from the upper levels of the engine, making the dipstick reading appear slightly low. Whether it’s too low is a judgment call. Aside from not checking the oil, the greatest danger is burning your fingers: use a paper towel or a glove.
In our experience, a typical Continental or Lycoming engine will blow out a quart or more if it’s filled to the dipstick’s capacity. With our IO-520, which has a 12-quart capacity, we only put in nine quarts at an oil change (plus a bottle of CamGuard). If we see only eight quarts on the dipstick at a fuel stop, we’ll add another one.
GA Vs. Military Training
The articles on GA versus military training and the transition issues of Air Force pilots are interesting and good reading. As an old, retired Naval Aviator and CFI, here are some comments.
In the Navy, pilots are the people who guide ships in and out of port. Therefore, we are aviators. In the AF, a precision landing is anywhere in the first third of the runway. At NAS jet bases, they have to close runways to scrape the build-up of rubber from the touchdown point. Naval aviators are by definition crazy because they have to want to fly at night on carriers.
—LCDR Paul Meinhardt, USNR Retire, via email
Ditching: Gear Up Or Down?
I was surprised to read that there was no statistical evidence to justify a recommendation of landing gear up. Not enough data or other facts? Could we get more on this topic? Did the crew of the PC-12 that ditched put the gear down?
—Jim Zimmerman, via email
The PC-12 that was on our May 2024 cover was ditched with its gear up. After seeing videos of amphibious airplanes touching down on water with their gear extended, we consider ditching with the gear up a no-brainer. If you’re flying a fixed-gear airplane, you don’t have much choice, of course. The bottom line in our 2002 article is that there’s just not enough data for an informed answer.
Are Hangars Safer?
Is a hangar a convenience or a safety issue? Is there any data on the accident rate for hangared versus non-hangared light aircraft?
Interestingly this was an AOPA poll a few days ago. It seems that most pilots (by a large majority) consider a hangar more important than a second engine or even a ballistic chute.
Could be a great topic for exploration by one of the magazines, i.e., Aviation Safety or Aviation Consumer.
—Daniel Spitzer, M.D, via email
We’re pretty sure the NTSB doesn’t have meaningful data on the accident rates involving hangared versus non-hangared aircraft. Some insurance companies might, though, and we’ll take on asking them as a project.
The economics of hangaring versus tying down are interesting, though. We once queried an owner on why he preferred tying his airplane down instead of putting it in an available hangar. He told us it was cheaper to get it painted every 10 or 12 years than to rent a hangar for the same length of time.
In our experience, airplanes that sit outside require more maintenance. And in addition to aging the paint, sunlight can deteriorate various synthetic materials, including the transparencies. They also obviously see more rain, which leads to corrosion. All of which can increase the cost of ownership and, if taken to extremes, increase risk.
Officially Holding
You wrote in a November 2019 article titled, “Hold Everything,” the following, “You’re officially ‘established’ in the hold upon crossing abeam the holding fix outbound.”
I would agree you begin the timing of an outbound leg when “abeam” the holding fix if it can be determined, but I would not agree that this is “officially established in the hold.” I have searched all the FAA guidance and don’t find “abeam” being used anywhere other than as the point to begin the timing of the outbound leg. Can you provide an FAA reference that makes this “official.”
—John Collins, via email
There’s no such reference. In fact, the FAA does not define when we’re “established in the hold.” The AIM says we should report reaching or leaving a holding fix or point to which we’ve been cleared, which implies that crossing the fix is when we’re “in the hold.”
Our thinking is that we’re really not “established” in a hold until rolling out abeam the fix on the first course reversal after crossing it, since, as you point out, that’s when our timing begins, along with figuring our wind correction angle. To which we can add confirming our fuel remaining, ensuring the power is set and that the airplane and its panel are properly configured.
When rolling out abeam the fix, that’s when the real holding begins, at least in our mind.
Send your thoughts, comments or questions to avsafetymag@gmail.com
