What if... Modernizing GA

[MauleSkinner]

Yes, book number. Takeoffs could use actual performance to some extent, maybe even have an abort warning, but with landings the actual performance depends on how hard you hit the brakes.

Except when you deal with truly short fields, you’re also dealing with runway conditions that may not be charted (if the airplane even has performance data) like soft or rough fields.

Landing performance also depends on where and how fast you touch down, as well as the surface type.

There are just too many variables in light airplane GA operations to be able to apply commercial jet requirements reasonably.

 

[flyingcheesehead]

Except when you deal with truly short fields, you’re also dealing with runway conditions that may not be charted (if the airplane even has performance data) like soft or rough fields.

For takeoff, if you're not at 71% of liftoff speed by 30% of the runway, you're not going to be off the ground by 60% of the runway, so that's still reasonably simple to deal with.

Landing performance also depends on where and how fast you touch down, as well as the surface type.

You could monitor this and have a system call "Go around! Go around" if you haven't touched down either in the touchdown zone, or early enough on the runway to allow a safe stop, whichever comes first...

There are just too many variables in light airplane GA operations to be able to apply commercial jet requirements reasonably.

That was merely a starting point... And the variables can be dealt with. An 80/20 sort of solution (or really, 20% of the variables cause 80% of the problems) is reasonable. Tires that are 2 PSI low or grass that's 1/8" of an inch too high are the reason you only use 60% of the runway.

 

[MauleSkinner]

For takeoff, if you're not at 71% of liftoff speed by 30% of the runway, you're not going to be off the ground by 60% of the runway, so that's still reasonably simple to deal with.

You could monitor this and have a system call "Go around! Go around" if you haven't touched down either in the touchdown zone, or early enough on the runway to allow a safe stop, whichever comes first...

That was merely a starting point... And the variables can be dealt with. An 80/20 sort of solution (or really, 20% of the variables cause 80% of the problems) is reasonable. Tires that are 2 PSI low or grass that's 1/8" of an inch too high are the reason you only use 60% of the runway.

So you’re actually advocating restrictions in excess of what commercial operators have to do.

 

[flyingcheesehead]

So you’re actually advocating restrictions in excess of what commercial operators have to do.

No, I'm suggesting that using 60% of the runway is a good starting point and there are various ways that could be done.

Also, are you talking simply about the planned vs actual?

 

[MauleSkinner]

No, I'm suggesting that using 60% of the runway is a good starting point and there are various ways that could be done.

Also, are you talking simply about the planned vs actual?

Not just planned vs actual. The 60% rule doesn’t apply to takeoff distance at all, and only applies to landing distance for planning purposes…once you get to the destination, your book landing distance can be the entire runway if conditions require it. And, of course it doesn’t apply at all to 135 in prop airplanes less than 12,500 pounds, which is pretty much what we’re talking about here.

And then it gets into 60% of what? As I mentioned, data probably doesn’t exist for takeoff and landing distances on truly short runways, so what are you going to use to determine whether or not you can takeoff, much less apply the 50/70 rule to?

Applying the 60% rule in the manner you’re suggesting also propagates the myth that a runway is the only suitable surface, and I’ve seen more than one airplane wrecked because the pilots didn’t consider simply rolling off the end and stopping on a suitable surface there.

Generating more restrictive rules doesn’t necessarily enhance safety…I know of one company that, in the event of an engine failure in takeoff requires their pilots to fly as much as 15 minutes before they pick up a checklist. I don’t think that’s a good thing. Part 135 and 121 OP’s are safer than Part 91, but a big part of that is also the fact that 500 hours minimum is required to fly VFR, and 1200 minimum to fly IFR, not to mention the operational control issues and additional training/checking requirements. If you want safer private pilots, you have to convince them to want to learn enough to be safer, not add operational burdens.

 

[flyingcheesehead]

Not just planned vs actual. The 60% rule doesn’t apply to takeoff distance at all, and only applies to landing distance for planning purposes…once you get to the destination, your book landing distance can be the entire runway if conditions require it.

Again... It was merely a starting point.

And, of course it doesn’t apply at all to 135 in prop airplanes less than 12,500 pounds, which is pretty much what we’re talking about here.

Really? I had to apply it on our TBMs.

And then it gets into 60% of what? As I mentioned, data probably doesn’t exist for takeoff and landing distances on truly short runways, so what are you going to use to determine whether or not you can takeoff, much less apply the 50/70 rule to?

If you mean TORA, TODA, ASDA, LDA then yes many runways don't have those. But I'm talking about TORA which is pretty much just runway length and LDA which is runway length minus a displaced threshold.

Applying the 60% rule in the manner you’re suggesting also propagates the myth that a runway is the only suitable surface, and I’ve seen more than one airplane wrecked because the pilots didn’t consider simply rolling off the end and stopping on a suitable surface there.

Absolutely... There's the difference between planning and execution, and it's obviously better to roll off the end of most runways at 30 knots than it is to risk crashing into trees at the other end. I'm merely offering a starting point and saying that there are ways of dealing with the variables.

Generating more restrictive rules doesn’t necessarily enhance safety…I know of one company that, in the event of an engine failure in takeoff requires their pilots to fly as much as 15 minutes before they pick up a checklist.

I don’t think that’s a good thing. Part 135 and 121 OP’s are safer than Part 91, but a big part of that is also the fact that 500 hours minimum is required to fly VFR, and 1200 minimum to fly IFR, not to mention the operational control issues and additional training/checking requirements. If you want safer private pilots, you have to convince them to want to learn enough to be safer, not add operational burdens.

That last part is the real sticking point... But if you were able to get 1/3 or even 2/3 off the price of a brand new airplane by doing that, I would think that would stimulate a lot of "want".

 

[MauleSkinner]

Really? I had to apply it on our TBMs.

Show me the reg.

If you mean TORA, TODA, ASDA, LDA then yes many runways don't have those. But I'm talking about TORA which is pretty much just runway length and LDA which is runway length minus a displaced threshold.

No, I’m talking about airplane data.

That last part is the real sticking point... But if you were able to get 1/3 or even 2/3 off the price of a brand new airplane by doing that, I would think that would stimulate a lot of "want".

But it’s “want” that probably doesn’t understand the consequences involved in getting the cost savings.

 

[flyingcheesehead]

Show me the reg.

I think it was in the OpSpecs. We didn't have to do it until we got the 135 cert.

No, I’m talking about airplane data.

We've gone in so many circles on this now I don't know what you're talking about any more. Gonna have to take a trip back through the thread again later.

But it’s “want” that probably doesn’t understand the consequences involved in getting the cost savings.

My want is to come up with new ideas that could help get the cost of GA airplanes to a more reasonable level. Liability is a big piece of that.

 

[MauleSkinner]

My want is to come up with new ideas that could help get the cost of GA airplanes to a more reasonable level. Liability is a big piece of that.

I’d like that, too…I just don’t think restricting operations is going to be effective.

If a manufacturer was willing to reduce prices based on such criteria, more power to ‘em. I wouldn’t buy an airplane subject to that, though.