Savin' the Prop

[C.W.E.]

We should try and be more sympathetic with these guys shimmy, they can not really be blamed for what they don't understand or know.

We used to describe them as either " Children of the magenta line " or " Paint by numbers zombies "

[jakeandelwood]

Reading this is really depressing to know that there are people that do not have the experience or self confidence to set the airplane up so you do not do unnecessary damage to your prop and engine.

It is people ( notice I said people, not pilots. ) like some here who are so lacking in flying skills they can't perform a simple basic task like such we are discussing.

No wonder insurance is so expensive and the properly trained pilots have to pay for the incompetent ones.

Just because a pilot chooses not to shut down their engine, fly close to a stall to stop the prop from windmilling and play with the starter to get it horizontal all while on short final doesn't mean they are a bad pilot. I recently witnessed a 172 take off from an uncontrolled airport while another plane, a Bonanza I think was on final behind it, the 172's engine quit and it it did a 180 turn back to the one runway, the other plane was in his flare and the 172 veered over and landed on the taxiway beside the runway to avoid a collision, I dont know what was said on the radio because I wasn't in a plane at the time. I'm just saying you never know when you may have to go around. I doubt the conversation with your insurance company would go well after you had a runway collision with another plane maybe a fuel truck in that mistakenly crossed the runway or whatever and that you couldn't go around because you thought that shutting down you perfectly good engine was a great feat of piloting skill.

[photofly]

I’m curious... is there something to stop you restarting the shut-down engine if you need to go around?

[PilotDAR]

I doubt the conversation with your insurance company would go well after you had a runway collision with another plane maybe a fuel truck in that mistakenly crossed the runway or whatever and that you couldn't go around because you thought that shutting down you perfectly good engine was a great feat of piloting skill.

If you're compelled to land with unsafe landing gear, and shut down the engine short final to prevent more damage and expense, you're insurance company would be sympathetic to you, if someone else's emergency, or mistake caused a yet bigger problem. Recall that the air regs do say that other aircraft shall give way to an aircraf they know is committed to land. if two aircraft are committed to land on the same runway, at the same time, by their respective emergencies, then make the best or it - that's exactly what insurance companies are there for!

If a pilot is simply not confident to commit to an engine stopped landing under those circumstances, then that pilot should keep it running. However, if that pilot is not confident to land engine off in any circumstances, that pilot should seek more training!

Nudging the starter to try to make the prop horizontal is a nice idea, though probably not worth the distraction when you're crossing the threshold to a short runway. 50/50 the prop would want to windmill anyway, and prematurely approaching a stall to try to get it to stop would be foolish. If the engine is not running, and the prop is gently windmilling when a blade touches the runway, you can be proud of a good job - the scraped prop/blade might still survive. If you can get it horizontal, how nice, but don't create an unsafe situation trying. The one time I though I was having to do this, I aimed for a very long runway, planning to cross the threshold faster, to give time over the runway to get shut down. But with two three blade props, I knew I would not get it ideal. Happily, the gear did come down at the last minute instead.

On that occasion, though it all worked out fine, my error after landing was that I taxiied in. I should have stopped on, or just off the runway. If you got down and stopped on three wheels, you did your job well. If in doubt, have the gear safely locked down before you taxi in! How stupid would I have felt if I'd collapsed a gear leg on the taxiway, and took out prop(s) and engine(s) anyway!!

[C.W.E.]

Deleted

[C.W.E.]

I doubt the conversation with your insurance company would go well after you had a runway collision with another plane maybe a fuel truck in that mistakenly crossed the runway or whatever and that you couldn't go around because you thought that shutting down you perfectly good engine was a great feat of piloting skill.

It would seem that I was poorly trained and my decision making skills are lacking in your opinion Jake ??

[cncpc]

I’m curious... is there something to stop you restarting the shut-down engine if you need to go around?

You haven't got a large time window to do that.

My view of this technique is that you don't shut down until you know you aren't going around for runway remaining or any other visible cause, i.e. other aircraft getting in the way on the ground. If it is a main gear indication, then just before the roundout when you can accurately predict your touchdown point. If it is nose gear, then I wait till wheels are down but there is still enough elevator authority to hold the nose up and cut then. So you're down, you haven't bounced or ballooned, and you are holding the nose off with a stopped engine.

This is up for discussion, but in a twin, it helps to know your prop clearance in different gear problem situations. It may be that one type of failure may not lead to a prop strike, so no need to shut down. Nose gear won't affect some aircraft, and some aircraft may not contact even with a main failure. Similarly, if you have a main indication on a single, but the nose is green, you can shut down in the rollout just to have fewer moving parts if it starts to slew around.

I don't think it's a good idea to just shut one down on a twin, unless circumstances are that you are already rolling out and you know you aren't going to have to apply power on the other.

I don't know if there is any mechanical reason for this, but it seems some props always end up in the same place on shutdown. If that seems to be true, you may have advance knowledge about that, and the starter thing may not be necessary. As Pilot Dar says, it isn't really necessary as you only get a scraped or bent blade. However, this discussion has been here before and someone commented that even non moving but unusual force on a prop requires a teardown. So that's the other side of the story.

You have to bring the nose up on a 172 to stop the prop, but its 10-15 knots above stall speed. Once you get into higher compression, it stops at a higher speed.

On the twins, it was mixture and feather.

One of two issues in which people here seem divided. The other is whether to choose trees or water (shoreline) in the event of total power loss.

[cncpc]

Reading this is really depressing to know that there are people that do not have the experience or self confidence to set the airplane up so you do not do unnecessary damage to your prop and engine.

It is people ( notice I said people, not pilots. ) like some here who are so lacking in flying skills they can't perform a simple basic task like such we are discussing.

No wonder insurance is so expensive and the properly trained pilots have to pay for the incompetent ones.

I doubt the conversation with your insurance company would go well after you had a runway collision with another plane maybe a fuel truck in that mistakenly crossed the runway or whatever and that you couldn't go around because you thought that shutting down you perfectly good engine was a great feat of piloting skill.

Let's look at the logic of that scenario. It implies that you haven't told anybody inbound that you have a gear emergency. Or communicated at all. It implies that you were texting on final with eyes inside, just prior to shutting down. Or catching a quick nap. Anything but looking out the goddamn window to see what situation you were descending into while you still had power. If you weren't napping or texting, you'd be on your A game for this event, and you'd know there wasn't another plane active on the field,or had communicated with it, and you'd know there was no fuel truck. You'd land in the first 1000 and you'd squeek it on. All of these harum scarum scenarios, plus that of a naked orange orangutan president with a toadstool pecker running across the field, won't cause you to go around. Nada.

Insurance companies should have a question on the application form. "If you have a gear indication problem on a light aircraft, what you gonna do?". If the answer is going to cost them 30 grand or more because you didn't learn anything from this thread, you likely aren't getting insurance. If you say, "But hey I didn't hit that imaginary fuel truck that was paying even less attention to what was going on than I was.", you'll be going in a database.

[jakeandelwood]

I’m curious... is there something to stop you restarting the shut-down engine if you need to go around?

I don't think it's good for piston engine to shut it down in the air in the 1st place, it could shock cool, you probably aren't going to have time to get a cold engine started on short final while you are flying a plane at the same time.

[cncpc]

Perfect. Doesn't get better than this. Go around option was there until about 10 seconds before touchdown.

https://www.youtube.com/watch?v=uSEZ8cgGHgo

[cncpc]

Very professional, but not perfect. The chop was way too soon, and the two bladers weren't moved horizontal. Lots of time for that.

https://www.youtube.com/watch?v=Jl5n8ircdPg

[cncpc]

A thing of beauty from a Mountie pilot

https://www.youtube.com/watch?v=50_OWeaGkR4

[C.W.E.]

I don't think it's good for piston engine to shut it down in the air in the 1st place, it could shock cool, you probably aren't going to have time to get a cold engine started on short final while you are flying a plane at the same time.

I am interested in this subject and am wondering how long it takes a small piston engine to cool down to the point it is difficult to restart it.

Can you elaborate on this opinion you have?

This idiot obviously was very fortunate not to have killed himself wouldn't you say Jake?

https://www.youtube.com/watch?v=bQWXMLtR-LA

[photofly]

I’m curious... is there something to stop you restarting the shut-down engine if you need to go around?

I don't think it's good for piston engine to shut it down in the air in the 1st place, it could shock cool, ...

I guess, as you replace both prop blades, the hub, the crankshaft and the valve train due to a sudden stoppage as the blades hit the tarmac, you can always console yourself with the thought that you kept the cylinders warm. All the way until the engine stopped turning on impact.

[C.W.E.]

This subject and the opinions about the subject shows just how important it is for those who are new to aviation making sure they research the subject and not assume all posters know what they are talking about.

[cncpc]

I don't think it's good for piston engine to shut it down in the air in the 1st place, it could shock cool, you probably aren't going to have time to get a cold engine started on short final while you are flying a plane at the same time.

I am interested in this subject and am wondering how long it takes a small piston engine to cool down to the point it is difficult to restart it.

Can you elaborate on this opinion you have?

This idiot obviously was very fortunate not to have killed himself wouldn't you say Jake?

https://www.youtube.com/watch?v=bQWXMLtR-LA

He was some fella, that idiot.

[cncpc]

This subject and the opinions about the subject shows just how important it is for those who are new to aviation making sure they research the subject and not assume all posters know what they are talking about.

Learn first, then know everything. Not the other way around.

Still learning here.

[C.W.E.]

Everyone should have a benchmark for what they want to be.

Bob Hoover was my benchmark and even if I made it to half his flying skills level I would have been very happy.

In person he was so unassuming and soft spoken you would have never even dreamed he could fly like he did.

Looking back on my life in aviation having admired and known Bob it gives me pleasure to think about how lucky I was to have known him.

My other hero was Ernest K. Gann and I was fortunate to have gotten to know him personally and been invited to his home to talk about flying.

In my opinion he was the best story writer about aviation we ever had.

[switchflicker]

I’m curious... is there something to stop you restarting the shut-down engine if you need to go around?

I don't think it's good for piston engine to shut it down in the air in the 1st place, it could shock cool, you probably aren't going to have time to get a cold engine started on short final while you are flying a plane at the same time.

I'm kinda thinking that if I was to be required to grind my engine nacelle and all the associated plumbing within onto a cement surface, the one thing I'd really like is a stone cold engine. I'd like it to be totally without fuel in it too if I could.
But that's just me.

[PilotDAR]

I don't think it's good for piston engine to shut it down in the air in the 1st place, it could shock cool, you probably aren't going to have time to get a cold engine started on short final while you are flying a plane at the same time.

Shock cooling is a risk to cylinder health when rapidly going from high power settings to idle, particularly if a speed increase at idle is an element of that. So climb with full power, then suddenly close the throttle and dive creates a risk of cylinder damage. Smacking a running engine/propeller into the ground creates a certainty of much more expensive damage. I'd rather the risk of cracking a cylinder or two, than the certainty of a prop and everything which turns in the engine being ruined.

While we're at it, the "cold" of shock cooled is not the same as the cold of 'been sitting at -25C for a week. Aircooled cylinders will cool quite quickly when the heat is taken away. That won't prevent them from turning over well enough for a quick restart. The engine case, on the other hand, is not specifically cooled, and will hold heat nicely for a long time. Restart will not be a problem at any point during a glide which any light GA airplane can achieve.

But, as said, if you the pilot cannot satisfy yourself that your landing path is sufficiently clear and will remain so, to conduct an abnormal condition landing, you're doing it wrong! If a meteor smacks a hold in the runway right in front of you, and you wreck the plane because of that, the insurance will pay (except for the gear malfunction itself, see the September COPA magazine).