Sticky Situation - Need Advice

[Roger Wilco]

... I'm here asking if pushing this further is worth the trouble it might cause for me over something that might be more widespread and commonplace (and insignificant) than I realize.

From my perspective, the answer is no. The incident you shared is just one single incident. As such, it reveals only that the flight school owner, and the other CFI, made a mistake in assessing the risks posed by (what we presume to be) a defective p-lead.

Is grounding your aircraft over a bad p-lead the correct "by-the-book"

Not just by-the-book, but also an exercise of sound judgement with regard to safety.

rule the FAA requires CFIs to teach but one that no one in the real world of aviation really follows?

You cannot infer much from this incident about the rest of the "real world." Some in aviation are overly cautious while others are foolishly cavalier; some strive for compliance while others seek to circumvent standards and regulations whenever they become inconvenient or burdensome. In the real world of aviation, you will encounter all of that and more. You can only exercise control over your own operation.

To me its not just an issue of telling him how to run his business;

To you, perhaps, but have you considered his perspective? To him, it may seem that you are attempting to do exactly that. Consider also that the loss of revenue that might have occurred due to the p-lead issue is absolutely a business matter (as well as a safety matter). I will assume that, like many small flight school owners, yours is an experienced pilot. He understands the ramifications of a defective p-lead as well as you. In his judgement, the p-lead did not create an unsafe condition while the airplane was being flown, so it was okay to fly like that. He must also have assumed that the risk created, while the airplane was shutdown on the ramp with a live mag, was insignificant or could be mitigated by awareness. And herein lies a little piece of advice that I would like to share with you, an aspiring professional aviator:

When it comes to safety, NEVER trust anyone who flies a desk.

The scenario you provided is but one example of why I say this. By now you should have been exposed to a bit of human factors training, so that you are aware of the many cognitive biases that can influence our decision-making as aviators. And you are aware of the potential negative consequences that may occur when we allow those biases to exert influence on our better judgement. I suggest to you that those in management, whether a flight school owner, the chief pilot of a 135 operation, or the director of operations for an airline, are all subject to the subtle influence of subconsious biases. Two of those bias factors are financial metrics and career goals. Either or both of those can exert influence on the desk pilot's judgement, influence that affects their perception of the ways that their decisions impact safety. Your flight school owner is a perfect example of this. Due to the fact that he is, as you put it, "hard up for cash," the prospect of grounding the airplane and losing revenue while repairing the p-lead almost certainly influenced his judgment, and his decision to continue to fly the airplane clearly reflects that.

I can avoid flying the airplane and I don't mind telling him that I wont fly it until its fixed

In the real world, that is the answer. Don't be the local safety tyrant. Except in egregious and dire circumstances, your best course of action is to follow Ed Haywood's sage advice:

Worry about yourself and let others make their own decisions.

Thanks for your input.

You're welcome. As I suggested previously, keep calm and carry on.

 

[Sonny225]

If you shut off with mixture, it really can’t burp. AND ANYONE should assume prop is hot when they touch it anyway.

That being said, ANYONE who touches it should know the mag is hot. If he’s HIDING that fact, THAT is the attitude I worry about.

I can mitigate all sorts of issues if I’m informed and not worrying about what is DELIBERATELY HIDDEN.

I have always been told that even if you shutdown by pulling the mixture there is still a chance of the prop advancing or kicking back with a hot mag, particularly with a fuel injected engine (which this is). Even if that's wrong we always talk about the "Swiss Cheese holes" lining up in risk management and mitigation and, to me, knowingly handling and flying an airplane with a hot mag is allowing one of those swiss cheese holes to line up with disaster and makes the consequences of someone making a normally minor mistake potentially much more serious. To be fair, I don't think he's hiding issue from anyone per se but 1) the school has never been very good at circulating even critical maintenance information so an uninformed student or line guy going out without knowing about the hot mag is far from unthinkable (however unintentional) and 2) whatever risk a hot mag may or may not present to ground crews is only half the equation. A correctly functioning ignition system is required to fly by the aircraft's TCDS.

 

[Clip4]

If you shut off with mixture, it really can’t burp. AND ANYONE should assume prop is hot when they touch it anyway.

That being said, ANYONE who touches it should know the mag is hot. If he’s HIDING that fact, THAT is the attitude I worry about.

I can mitigate all sorts of issues if I’m informed and not worrying about what is DELIBERATELY HIDDEN.

So you are placing a hot mag sign in the windscreen, but the aircraft isn’t grounded?

 

[Dan Thomas]

Note that, on many light piston-engine airplanes, there is a step in certain emergency checklists that calls for the mags to be switched off—kinda hard to do with a defective p-lead.

Yes. That. As below:

If the mag with the broken P lead malfunctions and is firing out of time, how do you propose turning it off in flight?

Inside the mag are plastic gears that drive the spark rotor, sending spark to the right cylinder at the right time. If those gears fail, the gearing slips a bit and now the mag starts sending spark to the cylinders at the wrong time, which can shuts the engine down altogether. A busted P-lead means you can't shut off that rogue mag, and it keeps the engine dead until the crash.

Imagine the spark going to a cylinder that has just started it compression stroke. Massive overpressure. Or is on its intake stroke. Blows the whole induction system.

A poorly-maintained airplane probably isn't getting 500-hour mag inspections, so worn gears are not an impossibility.

We teach students to check the mags on the runup, but they really aren't taught why. Sure, we want to know if they're both working, but we also want to know that we can kill one if it gets out of hand. I remember an RV flying over the city with a really rough engine, headed for the airport. Probably mag gearing.

 

[Larry in TN]

Airline Interviewer: "Tell us about a time that you felt undermined?"

Now you have an answer. Make it an answer with what you learned for it and how you'd handle it even better in the future.

FWIW, that is a question that I was asked at my current airline's interview.

 

[Tarheelpilot]

Airline Interviewer: "Tell us about a time that you felt undermined?"

Now you have an answer. Make it an answer with what you learned for it and how you'd handle it even better in the future.

FWIW, that is a question that I was asked at my current airline's interview.

I was given a scenario. After being hired I’m at a social gathering of my spouses coworkers and someone there is being very negative about my employer. Worst airline ever blah blah blah. I was asked how I would respond. My response? “I’m not sure, how much have I had to drink.”

Love airline interviews. Lol

 

[Gilbert Buettner]

I've been a CFI for 25 years, and I have the luxury of not really needing to work. But I am pretty sure if this happened to me, I would immediately start looking for a new job. I would not want to be associated with a flight school that allowed students and instructors to fly unsafe airplanes. There is a very good reason the mag check is in the checklist.

 

[Plano Pilot]

How would you feel if you were parked someplace and some Line Kid went to move your prop so he could move the plane and the prop kicked them HARD? Possible death, serious and/or perminate injury.

Just confirming, you remember that if there is a P-Lead issue, that is the same as leaving the Mags ON.

All I did was supply an alternate way to kill the engine. I did not get into the debate.

 

[Ed Haywood]

All I did was supply an alternate way to kill the engine. I did not get into the debate.

New to the Internet, are ya?

 

[Racerx]

I left out of my post that it is standard procedure to do the hot mag check at low RPM before shutdown after every flight (or attempted flight) at this school and when I performed that check (by switching the ignition to OFF) I got an RPM drop (as you would expect with one mag grounding) but the engine continued running again indicating a broken p-lead.

I'm actually impressed the hot mag check is sop. Quite a few have never heard of it.

 

[M20K]

All I did was supply an alternate way to kill the engine. I did not get into the debate.

Ah, no... you just confirmed you don't understand the danger. Even turning off the fuel selector will NOT stop a cylider from firing.

A broken P-Lead is not something to be ignored. It needs to be repaired as soon as it is discovered.

 

[Roger Wilco]

If it was own plane, I wouldn't hesitate to fly it

Why not just get it fixed first, and then fly it?

 

[Roger Wilco]

Yes. That. As below:

Inside the mag are plastic gears that drive the spark rotor, sending spark to the right cylinder at the right time. If those gears fail, the gearing slips a bit and now the mag starts sending spark to the cylinders at the wrong time, which can shuts the engine down altogether. A busted P-lead means you can't shut off that rogue mag, and it keeps the engine dead until the crash.

Imagine the spark going to a cylinder that has just started it compression stroke. Massive overpressure. Or is on its intake stroke. Blows the whole induction system.

A poorly-maintained airplane probably isn't getting 500-hour mag inspections, so worn gears are not an impossibility.

We teach students to check the mags on the runup, but they really aren't taught why. Sure, we want to know if they're both working, but we also want to know that we can kill one if it gets out of hand. I remember an RV flying over the city with a really rough engine, headed for the airport. Probably mag gearing.

Thanks for that reply, Dan. I am not surprised that you caught the significance of my reference to inflight emergencies in post #4. My post was intentionally general as I don't know every ignition system and every emergency checklist on every airplane, but you provide a nice description of some potential failure modes/scenarios without getting too technical.

 

[OneCharlieTango]

The best advice you've gotten is to keep a close eye on preflight checks, refuse to fly when the airplane is unairworthy, update your resume, and jump as soon as you can. Ideally, when you interview at the next school, you'll be able to compliment the new place without insulting the old one: "Why do I want to come here? I've seen your operation. . . professional.. . blah,blah. . . .WELL MAINTAINED. . . It looks like a desirable next step." You don't want to leave in a huff and you sure don't want to be fired.

 

[Lindberg]

Why not just get it fixed first, and then fly it?

Why bother? If not getting it fixed is merely an "error in judgment" and not indicative of a major safety issue, as you seem to be suggesting, then who cares if it's fixed?

 

[Dana]

Why not just get it fixed first, and then fly it?

Might need to get it to somewhere it can be fixed. I wouldn't fly it "just because", though, or if it was already at home, or let anybody else fly it.

 

[Half Fast]

Might need to get it to somewhere it can be fixed. I wouldn't fly it "just because", though, or if it was already at home, or let anybody else fly it.

That’s why God and the FAA gave us ferry permits.

 

[Roger Wilco]

Why bother? If not getting it fixed is merely an "error in judgment" and not indicative of a major safety issue, as you seem to be suggesting, then who cares if it's fixed?

Operating an aircraft with a safety issue is an error in judgement.

 

[sarangan]

Hello all,

First time I've posted on here and I'm looking for some advice; kind of a long story so bear with me.

I'm a flight instructor working toward a job in the airlines and I have more than 1400 hours so I'm almost there. I have, however, got this situation and I'm looking for advice on how to handle it. Just yesterday I was supposed to pick up one of my students in another city and fly with him back to our home airport; during the run up I noted that setting the ignition switch on the right mag didn't produce an RPM drop or a rise in EGTs. The POH called for performing an additional mag check at higher RPM to verify a suspected broken p-lead on the left magneto, which gave me exactly the same results. So, having determined the aircraft to not be airworthy, I taxied back to the hanger, texted the owner of the flight school (and the instructor who was supposed to fly the airplane later that day) about the issue and jumped in the schools other plane to complete my flight. However, as I prepared to enter the pattern on the way back home I was surprised to hear the airplane with the mag issue doing laps in the pattern with the instructor and his student onboard. When they landed I asked the instructor if he had seen the same issue with the no drop on the left mag and he said he had. I then asked him how he was able to safely and legally fly an airplane with a clearly faulty ignition system and he said he was told by management that since it was "just a p-lead" and the magneto itself was working fine it was ok to fly and we just needed to be careful around the prop on the ramp. This did not sit well with me so after I got home I called the owner of the flight school thinking that maybe he was unaware of what was happening. To my chagrin, he confirmed that he was aware and had approved. He stated that they had been able to run the airplane and "do some more testing and troubleshooting and send more data to maintenance" and that "maintenance" (note that we use three different maintenance facilities depending on the situation and he didn't say which maintenance facility he had consulted) had determined that it was "just a p-lead" and was safe to fly. This flies in the face of everything I have ever read, heard or been taught about how to handle a broken p-lead. So my question is what do I do about this? I firmly believe that the owner (who also happens to be hard up for cash) just doesn't want to ground half his fleet of airplanes over a busy weekend and I suspect that he never even consulted "maintenance" because, based on what I have read, no A&P would sign off on it and take on that kind of liability. Is this par for the course for flight schools? Is not flying with a broken p-lead just a thing you say you would never do to a DPE but done regularly in real life? Am I making a mountain out of a molehill? Is this what I should expect in my aviation career? Should I push this issue or let it drop and hope nothing bad happens?

I welcome any advice!

If it is indeed a broken P lead, then it is a bigger hazard while parked on the ramp than when flying. In that situation, I would have done some extra things when parking, such as put a note on the prop saying "hot mag - do not touch", and also turn off the fuel valve. A pilot unable to shut down a running engine is one thing, but a kid playing around getting hit by a prop is an entirely different matter.

 

[KE5BM]

...but 1) the school has never been very good at circulating even critical maintenance information so an uninformed student or line guy going out without knowing about the hot mag is far from unthinkable (however unintentional) and 2) whatever risk a hot mag may or may not present to ground crews is only half the equation.

The outfit I take lessons from today has impeccable maintenance standards and I know the most of the maintenance crew. In addition, most of the maintenance guys also serve as CFIs and sight-seeing tour pilots. If the plane is active on the line, I have no doubt as to its airworthiness. The first flight school I worked with kept the squawk list with the aircraft binder. So the pilot checking out the plane could see the last several weeks - if not months of maintenance issues. Reading through this, I'm honestly a bit surprised that there are flight schools out there that don't adhere to similar standards. Hell, even the flying club I'm with has exceptional transparency on maintenance issues and routine scheduling and thorough explanations for anything that is deferred.

I'm actually impressed the hot mag check is sop. Quite a few have never heard of it.

As a sub-200 hour pilot I had not heard of this so far as I can recall. It has me looking it up now to learn more about it.


This has been a great conversation about risk management

 

[flyingcheesehead]

I hear what you are saying about my place in the landscape of the industry. I realize I'm still a baby pilot in the grand scheme of aviation which is why I'm here asking if pushing this further is worth the trouble it might cause for me over something that might be more widespread and commonplace (and insignificant) than I realize. Is grounding your aircraft over a bad p-lead the correct "by-the-book" rule the FAA requires CFIs to teach but one that no one in the real world of aviation really follows?

The NTSB database is full of stories about dead pilots who learned that it was okay to fly unairworthy aircraft somewhere along the way.

The rules are a pain in the @$$ sometimes, but they're written in blood. If you don't follow them, the next one may be written in YOUR blood.

Yes, this is a small industry and you don't want to earn a reputation as someone who's a giant PITA - But you also don't want to operate unairworthy aircraft and have some sort of incident that either injures or kills you, or ruins your career because of an enforcement action. Again, unless you can get a better explanation from the owner, I'd be polishing up the resume and looking hard for your next gig. I'd also ensure that your students are made aware of any aircraft issues so they don't accidentally solo an unairworthy aircraft.

You cannot infer much from this incident about the rest of the "real world." Some in aviation are overly cautious while others are foolishly cavalier; some strive for compliance while others seek to circumvent standards and regulations whenever they become inconvenient or burdensome. In the real world of aviation, you will encounter all of that and more. You can only exercise control over your own operation.

After I became Director of Safety for a 135, I went and learned as much as I could about it. One of the best expert quotes I heard during that process was:

"Safety is easy until it's hard."

People will talk the talk all day long, but when you find out whether they're really operating safely is when they make a call that would be easy to NOT make. "Well, we can just fly it back to base with a broken P lead" is the start of a normalization of deviance that will eventually lead to flying with worse things broken, possibly ending up with something that causes an incident or accident.

To you, perhaps, but have you considered his perspective? To him, it may seem that you are attempting to do exactly that. Consider also that the loss of revenue that might have occurred due to the p-lead issue is absolutely a business matter (as well as a safety matter). I will assume that, like many small flight school owners, yours is an experienced pilot. He understands the ramifications of a defective p-lead as well as you. In his judgement, the p-lead did not create an unsafe condition while the airplane was being flown, so it was okay to fly like that.

It's not up to the flight school owner to decide whether it's OK to fly with a broken P lead. It's up to the FAA. So no, it was not okay to fly like that.

When it comes to safety, NEVER trust anyone who flies a desk.

Great advice - Especially if that desk has a big calculator on it, or the person has any responsibility for money, cost, or profitability.

 

[Roger Wilco]

The NTSB database is full of stories about dead pilots who learned that it was okay to fly unairworthy aircraft somewhere along the way.

The rules are a pain in the @$$ sometimes, but they're written in blood. If you don't follow them, the next one may be written in YOUR blood.

Yes, this is a small industry and you don't want to earn a reputation as someone who's a giant PITA - But you also don't want to operate unairworthy aircraft and have some sort of incident that either injures or kills you, or ruins your career because of an enforcement action. Again, unless you can get a better explanation from the owner, I'd be polishing up the resume and looking hard for your next gig. I'd also ensure that your students are made aware of any aircraft issues so they don't accidentally solo an unairworthy aircraft.

Since you quoted my earlier post, let me clarify that I do not endorse or support the flight school owner's position. The OP received replies with different perspectives on the best way to deal with the "sticky situation," which, we hope, he will find useful.

"Safety is easy until it's hard."

Or, safety is easy until it costs money. The OP's sticky situation stands as an example.

People will talk the talk all day long, but when you find out whether they're really operating safely is when they make a call that would be easy to NOT make. "Well, we can just fly it back to base with a broken P lead" is the start of a normalization of deviance that will eventually lead to flying with worse things broken, possibly ending up with something that causes an incident or accident.

We in the aviation industry habitually tell the public that "safety is our number-one priority." But we don't always mean what we say, and we don't even realize that we don't mean what we say when we say it. The role that human factors play in safety is not limited to the flight deck.

It's not up to the flight school owner to decide whether it's OK to fly with a broken P lead. It's up to the FAA. So no, it was not okay to fly like that.

My perspective is that it is up to the PIC. It was not okay to operate the airplane with a defective ignition system component, and the final decision to fly belonged to the PIC (CFI), not the owner or the FAA.

Great advice - Especially if that desk has a big calculator on it, or the person has any responsibility for money, cost, or profitability.

It took a couple of decades of observing the various maneuvers performed by desk pilots, before I came to that realization.

I appreciate your perspective and hope that the OP gains something from this discussion (which I find rather interesting).

 

[flyingron]

I'm actually impressed the hot mag check is sop. Quite a few have never heard of it.

A hot mag check guarantees nothing. I fail to see what it does that isn't detected in a regular mag check.

The mag switch in my plane would kill the engine in the off position, but you removed the key (or just jiggled it) and at least one would go hot again.

 

[rockyfatcat]

A hot mag check guarantees nothing. I fail to see what it does that isn't detected in a regular mag check.

The mag switch in my plane would kill the engine in the off position, but you removed the key (or just jiggled it) and at least one would go hot again.

You discovered that issue…. When are you changing out that switch?

 

[Dana]

A hot mag check guarantees nothing. I fail to see what it does that isn't detected in a regular mag check.

It's done at shutdown, and detects that the switch or P-lead hasn't fixed during flight, verifying it's safe when you put the plane away.

The mag switch in my plane would kill the engine in the off position, but you removed the key (or just jiggled it) and at least one would go hot again.

Then the switch is bad and should be replaced.

 

[DFH65]

The OP failed miserably on this one. Obviously the proper thing to do was to slash the tires. That way nobody could fly it.

 

[Half Fast]

A hot mag check guarantees nothing. I fail to see what it does that isn't detected in a regular mag check

Well, it does check one additional switch position, and I imagine that’s why there’s an AD for the Bendix switches. I don’t know the internals of this switch, but I suppose it could test okay in the L and R positions during a regular mag check yet fail in the OFF position.

 

[flyingcheesehead]

Or, safety is easy until it costs money. The OP's sticky situation stands as an example.

Yup.

We in the aviation industry habitually tell the public that "safety is our number-one priority." But we don't always mean what we say, and we don't even realize that we don't mean what we say when we say it. The role that human factors play in safety is not limited to the flight deck.

Same guy who said "safety is easy until it's hard" said that we have two competing priorities: Safety and profitability, and our job is to go right down the middle between them. Sacrifice safety for profitability too much and you have an accident. Sacrifice profitability too much and you're out of business. Steering down the middle is the hard part when most "safety departments" are one person or less (someone who has other responsibilities) and the company is small/new/poorly run enough that profitability may be in question and thus there may be pressure to "move that equipment" (bonus points if you know where this came from) or otherwise skimp on safety.

My perspective is that it is up to the PIC. It was not okay to operate the airplane with a defective ignition system component, and the final decision to fly belonged to the PIC (CFI), not the owner or the FAA.

It's the FAA's decision whether or not the defective ignition system is legally airworthy or not. It's the PIC's decision whether to fly an unairworthy airplane or not.

I appreciate your perspective and hope that the OP gains something from this discussion (which I find rather interesting).

Same!

A hot mag check guarantees nothing. I fail to see what it does that isn't detected in a regular mag check.

Well, it'll tell you if something failed during the flight that you just operated. I would have at least one more flight in my logbook if I religiously checked mags after flight...

 

[Half Fast]

Same guy who said "safety is easy until it's hard" said that we have two competing priorities: Safety and profitability, and our job is to go right down the middle between them. Sacrifice safety for profitability too much and you have an accident. Sacrifice profitability too much and you're out of business.

One of the engineering teams I led had a safety engineer who seemed to think his job was to put up obstacles when he perceived some design element to be unsafe. I finally sat down with him and explained, "Your job is to help us find safe solutions, not just shoot down somebody else's recommendation. When you think an approach is unsafe, I expect you to consider the overall objective and tell us how to alter the approach to render it safe."

He was a sharp guy who took it to heart, and he became much more effective after that.

In the same way, a boss might be more inclined to listen to a pilot who doesn't just say "I won't fly that plane" but instead helps him to figure out a way to solve the problem. "I'll catch a ride to XXX with Bob, and fly Joe back up here so he can work on it, then bring him and the plane home." Or "Let me get started on getting a ferry permit, and I'll use it to bring the plane back to XXX." Or whatever.

Bosses tend to like employees who bring them options and answers, not just problems.

 

[Roger Wilco]

It's the FAA's decision whether or not the defective ignition system is legally airworthy or not. It's the PIC's decision whether to fly an unairworthy airplane or not.

It may be a matter of semantics, but I have to disagree. Or maybe I have to agree. Let's see...

There's a definition of airworthy hiding in Part 3.5: "...the aircraft conforms to its type design and is in a condition for safe operation." Conformance with type design essentially means conformance with the TCDS, which is generated and maintained by the manufacturer or TC holder, and conformance with applicable STCs and relevant ADs.

With that in mind, the FAA does not decide whether a defect in an ignition system renders an airplane unairworthy, at least, not in the way that I think you intended (and I know you'll correct me if I'm wrong). Should the issue come to their attention, they will refer to the TCDS, STCs, ADs, etc. to determine whether the defect results in non-conformance with the type design. Separately, they will make their own determination as to whether the aircraft was in a condition for safe operation, and that, I think, is consistent with what you wrote.

As we all know, the responsibility for determining the airworthiness of an aircraft for a given flight operation falls on the PIC, ref. 91.7 and 91.3. The responsibility for maintaining an aircraft in airwothy condition falls on the owner or operator per 91.403.

 

[luvflyin]

It may be a matter of semantics, but I have to disagree. Or maybe I have to agree. Let's see...

There's a definition of airworthy hiding in Part 3.5: "...the aircraft conforms to its type design and is in a condition for safe operation." Conformance with type design essentially means conformance with the TCDS, which is generated and maintained by the manufacturer or TC holder, and conformance with applicable STCs and relevant ADs.

With that in mind, the FAA does not decide whether a defect in an ignition system renders an airplane unairworthy, at least, not in the way that I think you intended (and I know you'll correct me if I'm wrong). Should the issue come to their attention, they will refer to the TCDS, STCs, ADs, etc. to determine whether the defect results in non-conformance with the type design. Separately, they will make their own determination as to whether the aircraft was in a condition for safe operation, and that, I think, is consistent with what you wrote.

As we all know, the responsibility for determining the airworthiness of an aircraft for a given flight operation falls on the PIC, ref. 91.7 and 91.3. The responsibility for maintaining an aircraft in airwothy condition falls on the owner or operator per 91.403.

?? Part 3.5 of what?

 

[luvflyin]

A hot mag check guarantees nothing. I fail to see what it does that isn't detected in a regular mag check.

The mag switch in my plane would kill the engine in the off position, but you removed the key (or just jiggled it) and at least one would go hot again.

Way it was explained to me, the reason to do a turn both to off during shut down is in case a p-lead broke during the flight. Typically the last time you did a mag check was before departure. I figure just doing a left off/right off check during shut down might not be a bad idea. The both off thing followed by a back on can cause back fires sometimes. That’s not good for the engine.

 

[AvNavCom]

Same guy who said "safety is easy until it's hard" said that we have two competing priorities: Safety and profitability, and our job is to go right down the middle between them.

Some years ago, a squadron CO of mine got bent out of shape when the Admin officer posted a bunch of "Safety is our Number One Priority!" signs around the spaces. The CO made it very clear that in fact getting the mission done was our number one priority. Safety was integrated into everything we did, with risk identified, removed, mitigated, or accepted as appropriate. Safety cannot be the number one priority in aviation, because it is inherently hazardous and we'd never leave the ground.

 

[AV8R_87]

The both off thing followed by a back on can cause back fires sometimes.

My IA told me it's not an issue at idle and recommens I check the ignition switch on a regular basis. Only time the exhaust went bang was when I accidentally went to off during a mag check (2000 rpm) and back to on (didn't know any better at the time). Never heard even the faintest pop when checking it at idle.

 

[Lindberg]

My IA told me it's not an issue at idle and recommens I check the ignition switch on a regular basis. Only time the exhaust went bang was when I accidentally went to off during a mag check (2000 rpm) and back to on (didn't know any better at the time). Never heard even the faintest pop when checking it at idle.

Aviation in itself is not inherently dangerous. But to an even greater degree than the sea, it is terribly unforgiving of any carelessness, incapacity or neglect. — Captain A. G. Lamplugh

 

[flyingron]

Some years ago, a squadron CO of mine got bent out of shape when the Admin officer posted a bunch of "Safety is our Number One Priority!" signs around the spaces. The CO made it very clear that in fact getting the mission done was our number one priority. Safety was integrated into everything we did, with risk identified, removed, mitigated, or accepted as appropriate. Safety cannot be the number one priority in aviation, because it is inherently hazardous and we'd never leave the ground.

We used to have posters that said "Strike up the band for safety." I always wondered if these sort of "awareness" campaigns actually accomplish anything.

When the security office started putting security slogans in our message of the day, I thought it was equally stupid. It took them a while to realize I was inserting my own slogans. They completely missed my "Security is good" entry. They caught on when I put in "Even the ears have walls."

 

[Dan Thomas]

There's a definition of airworthy hiding in Part 3.5: "...the aircraft conforms to its type design and is in a condition for safe operation." Conformance with type design essentially means conformance with the TCDS, which is generated and maintained by the manufacturer or TC holder, and conformance with applicable STCs and relevant ADs.

With that in mind, the FAA does not decide whether a defect in an ignition system renders an airplane unairworthy,

The TCDS is a summary of vital specifications for the airplane. You could not build a 172, for example, from the design info in its TCDS. There will be a mass of drawings and instructions for the airplane, all of them approved by the FAA.

FAR 23 is the regulation under which the OP's airplane was built. We find this in the historical FAR 23:

Sec. 23.1145 — Ignition switches.​

(a) Ignition switches must control and shut off each ignition circuit on each engine.


(b) There must be means to quickly shut off all ignition on multiengine airplanes by the grouping of switches or by a master ignition control.

(c) Each group of ignition switches, except ignition switches for turbine engines for which continuous ignition is not required, and each master ignition control must have a means to prevent its inadvertent operation.

The first requirement, that the ignition switch must control and shut off each ignition circuit, was not met with a broken P-lead or whatever defect was in play at the time. Therefore, the airplane was not airworthy.

I figure just doing a left off/right off check during shut down might not be a bad idea. The both off thing followed by a back on can cause back fires sometimes. That’s not good for the engine.

It won't do that at idle. I've done that check many times with no ill effect. You just don't do it at runup power, that's all. We taught the technique to all our students. It catches the defect before the next flight, and allowed us to fix it immediately so that no flights were lost.

The big bang when someone switches off during runup, and then back on again, is not a backfire. A backfire is back through the induction system. The big bang here is an afterfire, and it can crack exhaust components. I have also found induction elbow gasket blown out from it when the concussion and flame travels back into a cylinder during valve overlap and the whole induction system goes off. That's a combination afterfire and backfire.

 

[Ed Haywood]

Some years ago, a squadron CO of mine got bent out of shape when the Admin officer posted a bunch of "Safety is our Number One Priority!" signs around the spaces. The CO made it very clear that in fact getting the mission done was our number one priority. Safety was integrated into everything we did, with risk identified, removed, mitigated, or accepted as appropriate. Safety cannot be the number one priority in aviation, because it is inherently hazardous and we'd never leave the ground.

Reminds of when Doolittle changed the signs at 8th Air Force fighter command from "bring US bombers home" to "destroy German fighters."

 

[Roger Wilco]

The TCDS is a summary of vital specifications for the airplane. You could not build a 172, for example, from the design info in its TCDS. There will be a mass of drawings and instructions for the airplane, all of them approved by the FAA.

Yes. Conformity with the TCDS is required in order to be airworthy.

FAR 23 is the regulation under which the OP's airplane was built. We find this in the historical FAR 23:

Part 23 governs design and certification. It’s not relevant to us mere pilots. But it may be an interesting read for pilots who are gearheads.

 

[Roger Wilco]

?? Part 3.5 of what?

Maybe 14 CFR?