Reliable Transport?

[spiderweb]

I have been thinking about how to make flying more reliable as a serious mode of transportation. In many cases, I've not used GA to get me where I want to go, because of my current situations. Adding ratings and capability in the form of better aircraft, though, helps with reliability. Here's how I feel about reliability of flying a 200-500 mile cross-country in the Mid-Atlantic region, based on different scenarios:

1) Proficient Pilot, single engine with no weather avoidance avionics or equipment: 40% chance of rescheduling.

2) Proficient Pilot, instrument rated, single engine with no weather avoidance avionics or equipment: 30% chance of rescheduling.

3) Proficient Pilot, instrument rated, single engine with good weather avoidance avionics like stormscope and radar, and medium to good deicing equipment: 15% chance of rescheduling (but maybe just to a different time of the same day).

4) Proficient Pilot, instrument rated, multiengine aircraft with no weather avoidance avionics or equipment: 25% chance of rescheduling.

5) Proficient Pilot, instrument rated, multiengine aircraft with good weather avoidance avionics like stormscope and radar, and medium to good deicing equipment: 10% chance of rescheduling.

That is probably as far as I'll ever get, but let's continue:

6) Proficient Pilot, instrument rated, turboprop aircraft with good weather avoidance avionics like stormscope and radar, and known icing: 5% chance of rescheduling.

And finally, the holy grail:

7) Proficient Pilot, instrument rated, jet aircraft with good weather avoidance avionics like stormscope and radar, and known icing: 3% chance of rescheduling.

Do you agree?

 

[Brian Austin]

You seem to give more weight to a multi-engine pilot being less likely to reschedule based on weather vs a single engine pilot. Why? More engines isn't going to change the weather and I can't see the correlation between engines and weather. And any mechanical issues that grounds a single engine plane SHOULD ground a multi-engine plane, too.

 

[Ken Ibold]

Depends on how risk-averse you are, I suppose. In four years/350 hours of owning my Mooney, which had no stormscope, I rescheduled exactly four legs for weather and three others for mechanical reasons. This was primarily flying in the TN/GA/KY/FL/AL region, although I did do some IL/IN/WI trips in it, too. I think I blew your 30 percent out of the water, but perhaps I was too stupid to know the risk I was taking.

However, when I talk about "rescheduling" I don't count the 1/2 to 1 hour delays to let a T-storm pass or fog to burn off. I'm talking delays of more than, say, 3 hours.

 

[ejensen]

I agree, all other things the same a well maintained single should have a slightly better dispatch rate then a twin. More stuff to go down with a twin.

Eric

 

[Ken Ibold]

I agree, all other things the same a well maintained single should have a slightly better dispatch rate then a twin. More stuff to go down with a twin.

Eric

Again, it depends on risk tolerance. Lot of people are comfortable departing in a twin when local weather is below approach mins whereas they won't go in a single. Lot of people won't fly night IMC or over open water in a single, but will in a twin.

I don't think generalizations about dispatch reliability can be made on a simple single/twin basis. I think a good Seminole would launch more predictably than a good Malibu.

However, what you meant is that, other factors equal, a twin has more to go wrong. That is, compare a Seneca and Saratoga and a Baron and a Bonanza. And yes, you might launch more in a single. However, after launch twins have redundancy that might let you carry on (dual vac pumps or alternators, for a couple of examples) when you'd be landing short of your destination in a single.

 

[jkaduk]

You seem to give more weight to a multi-engine pilot being less likely to reschedule based on weather vs a single engine pilot. Why? More engines isn't going to change the weather and I can't see the correlation between engines and weather. And any mechanical issues that grounds a single engine plane SHOULD ground a multi-engine plane, too.

Two engines reduces your risk in certain situations. IFR at night isn't grounding for a single per se, but some people won't take the risk. Same for mountainous terrain at night or IFR over mountainous terrain. Bigger twins can carry real RADAR too.

 

[ejensen]

All your points are true but how much do they really matter. I just don't think it measurably changes the percentage between the two classes. If YOU feel more comfortable in a twin then there will be a difference.

Throwing in a Malibu is playing dirty. I'll raise you a Queen Air or a Twin Bonanza

Eric

 

[bbchien]

Ben, disagree with item 5. Chance of rescheduling is about 1%, this over five years, meticulous proactive maintenance, and proficiency. But, I do some things that some pilots are NOT willing to do.

(1) I fly SLOW. 65% power is much less wear and tear on the equipment.
(2) I climb at 65% power. That's only 700 fpm at gross. Somehow pilots think they need 1000 fpm, or in my case 1450 fpm. Uh uh.
(3) I cool the turbos for all time below 5000 feet. Power settings are key.

 

[spiderweb]

You seem to give more weight to a multi-engine pilot being less likely to reschedule based on weather vs a single engine pilot. Why? More engines isn't going to change the weather and I can't see the correlation between engines and weather. And any mechanical issues that grounds a single engine plane SHOULD ground a multi-engine plane, too.

Ahh, but there is a correlation, especially in relationship to ice. Encountering ice in a 230 hp single, you are going down. Encountering ice in a combined 600 hp multi, you may be able to climb out of it.

 

[spiderweb]

Depends on how risk-averse you are, I suppose. In four years/350 hours of owning my Mooney, which had no stormscope, I rescheduled exactly four legs for weather and three others for mechanical reasons. This was primarily flying in the TN/GA/KY/FL/AL region, although I did do some IL/IN/WI trips in it, too. I think I blew your 30 percent out of the water, but perhaps I was too stupid to know the risk I was taking.

However, when I talk about "rescheduling" I don't count the 1/2 to 1 hour delays to let a T-storm pass or fog to burn off. I'm talking delays of more than, say, 3 hours.

Excellent point. When you are an instrument rated pilot, rescheduling might mean "two hours later." Thanks for pointing that out.

 

[spiderweb]

I agree, all other things the same a well maintained single should have a slightly better dispatch rate then a twin. More stuff to go down with a twin.

Eric

Ah, this is a good point, too. and I realize now that Brain was also saying this.

 

[spiderweb]

Ben, disagree with item 5. Chance of rescheduling is about 1%, this over five years, meticulous proactive maintenance, and proficiency. But, I do some things that some pilots are NOT willing to do.

(1) I fly SLOW. 65% power is much less wear and tear on the equipment.
(2) I climb at 65% power. That's only 700 fpm at gross. Somehow pilots think they need 1000 fpm, or in my case 1450 fpm. Uh uh.
(3) I cool the turbos for all time below 5000 feet. Power settings are key.

That's great to hear. But I think you are beyond "proficient." I'd certainly reschedule a trip much sooner than you, due to my experience. Also, I made a mistake in clarity inthe original post when I said "reschedule," because this word implies a day or more. You might wait a couple of hours.

 

[RobertGerace]

You seem to give more weight to a multi-engine pilot being less likely to reschedule based on weather vs a single engine pilot. Why? More engines isn't going to change the weather and I can't see the correlation between engines and weather.

Brian,

I respectfully and completely disagree with much of the above. I've sweated out two or three hours over low overcast. I've sweated out a load of ice with low overcast and reported tops un-reachable with limited power in a single. I've sweated out nights over dense cities, and nights over mountains -- both in IMC...wondering what on Earth I would do if the engine failed.

I've wondered what would happen if the *only* vacuum pump and/or alternator were to fail.

I've wondered what would happen if the *only* prop were to depart the airplane (or some part of it), or on constant-speed-props what would happen if it started to surge or overspeed.

None of the above changes anything about the weather (that much I agree with). But everything about redundant power, engines, vacuum pumps, alternators, and props changes my willingness to fly in it!

 

[Mark S]

I think you missed a catagory.

The proficient instrument rated pilot with weather detection equipment, but without de-ice. Both single engine and multi engine.

Other than that, your list looks good. I might argue with the rescheduling rate, but that will be more related to the pilot's experience level and confidence than the plane.

Mark

 

[Let'sgoflying!]

A good analysis Ben; you are a thinker.

And finally, the holy grail:
7) Proficient Pilot, instrument rated, jet aircraft with good weather avoidance avionics like stormscope and radar, and known icing: 3% chance of rescheduling.

make the H.G. --
"TWO jets and add another pilot." One jet won't go or whatever, just hop in the other one. Feeling ug? Stan can fly. (two more pilots, not just one if not SP certified jet)

 

[spiderweb]

I think you missed a catagory.

The proficient instrument rated pilot with weather detection equipment, but without de-ice. Both single engine and multi engine.

Other than that, your list looks good. I might argue with the rescheduling rate, but that will be more related to the pilot's experience level and confidence than the plane.

Mark

I guess I did simplify a bit. Most airplanes have at least pitot heat, but I realize that hardly qualifies. A hot prop helps. Heating the wings and tail feathers, etc.

 

[spiderweb]

A good analysis Ben; you are a thinker.



make the H.G. --
"TWO jets and add another pilot." One jet won't go or whatever, just hop in the other one. Feeling ug? Stan can fly. (two more pilots, not just one if not SP certified jet)

Right--good points1

 

[wsuffa]

Ben, disagree with item 5. Chance of rescheduling is about 1%, this over five years, meticulous proactive maintenance, and proficiency. But, I do some things that some pilots are NOT willing to do.

(1) I fly SLOW. 65% power is much less wear and tear on the equipment.
(2) I climb at 65% power. That's only 700 fpm at gross. Somehow pilots think they need 1000 fpm, or in my case 1450 fpm. Uh uh.
(3) I cool the turbos for all time below 5000 feet. Power settings are key.

Re: Item 2.

Somehow some controllers (Chicago) think they need you to climb at 1500 fpm. If you can't, it's the penalty box.

(Sorry, just based on my last experience out of Midway - "I need you at max climb to 10,000 for traffic").

 

[Brian Austin]

Brian,

I respectfully and completely disagree with much of the above. I've sweated out two or three hours over low overcast. I've sweated out a load of ice with low overcast and reported tops un-reachable with limited power in a single. I've sweated out nights over dense cities, and nights over mountains -- both in IMC...wondering what on Earth I would do if the engine failed.

I've wondered what would happen if the *only* vacuum pump and/or alternator were to fail.

I've wondered what would happen if the *only* prop were to depart the airplane (or some part of it), or on constant-speed-props what would happen if it started to surge or overspeed.

None of the above changes anything about the weather (that much I agree with). But everything about redundant power, engines, vacuum pumps, alternators, and props changes my willingness to fly in it!

So, knowing that ice was going to be a factor, you would have flown in it with two engines then?

Keep in mind, we're not talking about in-flight decisions. We're talking about go/no-go after talking to FSS. Re-routing is an option, as well as waiting a few hours, as someone mentioned.

 

[grattonja]

Winter vs Summer is a big difference, I think, here in Mid-Atlantic. Even with a certain amount of de-icing equipment, you still will want to be pretty conservative about launching into icing risk conditions. Winter IFR in the temps we have had this year basically grounds IR pilots like me, with not huge hours and no de-icing equipment, but I also know folks with twins with de-ice who say winter IFR is often still a "no-go".

On the other hand, the afternoon thunderstorms that we get out here can often be readily avoided by a short stop on the ground, and we can resume our trip after they are through. I think on board weather makes us better able to "debug" those storms and avoid them or perhaps get a bit closer to them before diverting. But summer IFR is definitely less of a "no-go" situation in my opinion than winter IFR.

Jim G

 

[spiderweb]

So, knowing that ice was going to be a factor, you would have flown in it with two engines then?

Keep in mind, we're not talking about in-flight decisions. We're talking about go/no-go after talking to FSS. Re-routing is an option, as well as waiting a few hours, as someone mentioned.

I see what you're saying Brian. Robert might have a different answer, but mine would be, "yes." Here's why: weather reports almost always mention a "chance of icing," so you have to go further to find out for yourself what you think that chance might be. Depending on the weather, you will note that there might be a chance for a bit of rime ice, or maybe a good chance for heavy clear icing. Those are the extremes. But if I'm flying a Cessna 172 over the Rockies, it isn't happening in the winter because I can't climb, even without ice! In something like a (turbo) Seneca with 460 combined horsepower and very good to known icing, I will launch unless moderate to bad icing conditions exist. I have a better chance of being able to climb.

 

[Brian Austin]

I see what you're saying Brian. Robert might have a different answer, but mine would be, "yes." Here's why: weather reports almost always mention a "chance of icing," so you have to go further to find out for yourself what you think that chance might be. Depending on the weather, you will note that there might be a chance for a bit of rime ice, or maybe a good chance for heavy clear icing. Those are the extremes. But if I'm flying a Cessna 172 over the Rockies, it isn't happening in the winter because I can't climb, even without ice! In something like a (turbo) Seneca with 460 combined horsepower and very good to known icing, I will launch unless moderate to bad icing conditions exist. I have a better chance of being able to climb.

A C172 has a better chance of going over the Rockies in the winter than the summer, ice not withstanding. DA issues.

You're also comparing apples to oranges.

Take the same scenario but substitute a T210 with K-ice for the 172. Still a turbo with known ice but now one engine instead of two. Same decision?

 

[gismo]

Excellent point. When you are an instrument rated pilot, rescheduling might mean "two hours later." Thanks for pointing that out.

I was thinking along the same lines. I can't really say how many times I had to "reschedule" a flight, when I was a strictly VFR ASEL pilot, but I do recall a few times when I was stuck somewhere for several days because of weather, some trips that were simply cancelled based on the forecast, and at least three times I had to land short of my destination (usually home base) and find alternate transportation. Once I got an IR I pretty much immediately added a stormscope so I've hardly ever been without some onboard TRW detection. I can remember two times I had to terminate a trip early for a solid line of storms with the flight continuing the next morning in one case and a couple hours after landing in the other. Personally I wouldn't call the latter a "rescheduling", just an inconvenience.

My experience in the Baron is better WRT completing trips on schedule. So far in 9 years I have yet to be seriously held up by weather. I have had to wait out TRW on the ground a couple times for an hour or two, and I'm pretty sure I've shifted my plans a day one way or the other a few times, but I normally try to build that kind of flexibility into my plans anyway. It's rare that I fly a trip where I "absolutely have to get there on time" FedEx like. Even for a business meeting, I've found that most business associates can understand the need to put safety above schedules, and anyone with many airline miles knows that their schedule reliability is far from flawless as well.

 

[wsuffa]

Ben,

It's all about the maintenance & aircraft reliability.

You learn to deal with the weather. In Texas, it's T-Storms, you have avoidance gear. Up north, it's ice - dispatch reliability requires K-Ice. Midwest can get both.

The best way to get reliability is to get a plane that is relatively common, with the features you require, and get a great mechanic. Tell the mechanic that your goal is dispatch reliability. Maintain properly. Something gets marginal, you replace it. Be proactive, not reactive. At annual, the instructions are that you want to identify stuff that's likely going to require work in the next year - and do the stuff now that's hard to fix along the way. Vacuum pump every 400-500 hours. Belts every year or two depending on usage (gotta pull the prop on most planes). Keep a running log of the approximate times that things require work on your plane.

And fly the plane often.

Stuff will still happen, but this kind of a process will keep unexpected/unscheduled down time to a minimum.

 

[spiderweb]

A C172 has a better chance of going over the Rockies in the winter than the summer, ice not withstanding. DA issues.

I would disagree, but I don't have the data to back that up. The reason I say this is that if there is a chance of ice, one wouldn't launch over the rockies in an NA 180 hp single without ice protection. Thunderstorm avoidance is easier, as long as you remain visual. Again, though, I wonder if anyon has numbers on this?

You're also comparing apples to oranges.

Take the same scenario but substitute a T210 with K-ice for the 172. Still a turbo with known ice but now one engine instead of two. Same decision?

Well, not for me. A KI T210 will have more climb capability.

 

[spiderweb]

Good points, all.

Ben,

It's all about the maintenance & aircraft reliability.

You learn to deal with the weather. In Texas, it's T-Storms, you have avoidance gear. Up north, it's ice - dispatch reliability requires K-Ice. Midwest can get both.

The best way to get reliability is to get a plane that is relatively common, with the features you require, and get a great mechanic. Tell the mechanic that your goal is dispatch reliability. Maintain properly. Something gets marginal, you replace it. Be proactive, not reactive. At annual, the instructions are that you want to identify stuff that's likely going to require work in the next year - and do the stuff now that's hard to fix along the way. Vacuum pump every 400-500 hours. Belts every year or two depending on usage (gotta pull the prop on most planes). Keep a running log of the approximate times that things require work on your plane.

And fly the plane often.

Stuff will still happen, but this kind of a process will keep unexpected/unscheduled down time to a minimum.

 

[gismo]

Well, not for me. A KI T210 will have more climb capability.

Methinks Brian meant substitute the T-210 w/KI for the 310, not the 172. Not many 172's with two engines.

 

[ggroves]

It is also very much about how much risk management are you willing/able to pay for. I too have debated the single vs. twin issue and have simply had to make choices. For me, I chose to spend extra money in other areas, specifically backup equipment, flying often, and being anal about maintenance.

- I pulled a perfectly performing engine @ 2,200 hours and had it overhauled for the extra peace of mind and all of the overhauled/new parts. Money well spent

- My bird is equipped with a backup electric AI, backup electric vacuum pump, TC driven autopilot, handheld gps, handheld navcom, flashlights, fresh batteries, etc etc. For that, I was willing to pay extra.

- I practice approaches and emergency procedures religously.

- I avoid night IMC in poor terrain / low ceilings. However, there are parts of WV/VA that I fly over that give me little/no options in VMC.

I accept the risk of a single engine aircraft.

Greg
182RG

 

[Brian Austin]

Methinks Brian meant substitute the T-210 w/KI for the 310, not the 172. Not many 172's with two engines.

No, I meant to substitute the 172. Ben was comparing a turbo, twin engine with known ice against a normally-aspirated, single engine without ice capabilities. My original argument was that, all things being equal EXCEPT engine count, I'm not sure I agree that two engines vs one is relevant to a go/no-go decision.

 

[gismo]

No, I meant to substitute the 172. Ben was comparing a turbo, twin engine with known ice against a normally-aspirated, single engine without ice capabilities. My original argument was that, all things being equal EXCEPT engine count, I'm not sure I agree that two engines vs one is relevant to a go/no-go decision.

After a re-read of the pertinent posts, I can't see what I thought I saw before. It all makes perfect sense now (except my own post), both what you wrote and Ben's response. So much for trying to straighten things out!

 

[spiderweb]

I guess it just boils down to power-weight ratio. A twin has more, and so is more able to climb. But as you point out Brian, if all things are equal except for this one element, the choice of a twin still wins, but probably not by much. (IMO.)

 

[Henning]

You seem to give more weight to a multi-engine pilot being less likely to reschedule based on weather vs a single engine pilot. Why? More engines isn't going to change the weather and I can't see the correlation between engines and weather. And any mechanical issues that grounds a single engine plane SHOULD ground a multi-engine plane, too.

2 factors for me on that. First, more twins out there Known Ice, that's a biggie in the winter. Second, lose one of two in the soup and you'll make the nearest ILS in most of the continental US, lose one of one...hmmmm... time to make teepees in the seat.
:dance: Now that dude is just too cool...

 

[Henning]

Brian,

I respectfully and completely disagree with much of the above. I've sweated out two or three hours over low overcast. I've sweated out a load of ice with low overcast and reported tops un-reachable with limited power in a single. I've sweated out nights over dense cities, and nights over mountains -- both in IMC...wondering what on Earth I would do if the engine failed.

I've wondered what would happen if the *only* vacuum pump and/or alternator were to fail.

I've wondered what would happen if the *only* prop were to depart the airplane (or some part of it), or on constant-speed-props what would happen if it started to surge or overspeed.

None of the above changes anything about the weather (that much I agree with). But everything about redundant power, engines, vacuum pumps, alternators, and props changes my willingness to fly in it!

Yep, that pretty much sizes it up for me as well, the redundancy and excess power, plus there aren't many known ice singles out there.

 

[RobertGerace]

So, knowing that ice was going to be a factor, you would have flown in it with two engines then?

Keep in mind, we're not talking about in-flight decisions. We're talking about go/no-go after talking to FSS. Re-routing is an option, as well as waiting a few hours, as someone mentioned.

Look, the thing of it is...

When you are learning to be a Private pilot, everybody tells you not to have 'get home itis' and to make no-go decisions. Then you get your instrument rating and they tell you the same thing...unless the weather is really tame.

Then you start trying to use GA for serious business transportation and you get a CFI who has 3,000 hours and you fly about 100 trips with him. On each of these trips you hear the scary 'Airmet for Icing' or the entire Eastern half of the country is red and there are thunderstorms expected everywhere.

Yet, you go...every single time. You might wait an hour (or three) but you go. There are ways that pilots navigate ice, thunderstorms, wind, turbulence, etc....safely...and you learn them. In one sentence the answer is, you go and you land short if it doesn't work out. You might turn around; you might turn towards vmc.

Then you get on one of these boards, and well meaning people tell you that you are wrong.

We all have to evaluate what risks we are willing to take. With the above profile, I know that I am assuming risk on some of those flights. I believe I can manage it.

I also know that I am only willing to take on just so much risk. Maybe for that reason I'm not willing to fly VFR. Others say that IFR does not afford much protection...and are probably right in some ways.

But the bottom line is...given my risk profile, I will not up the ante by doing it in a single, or under anything less than an IFR flight plan. So, yes, having two engines, turbo-chargers, known-ice, and and IFR flight plan I will fly bad weather in a get-home-itis kind of way. And no, I won't do it in a normally aspirated, or single, or non-known-ice, or VFR flight plan.

 

[spiderweb]

Plus with your bird, we're really talking as good as it gets in light piston aircraft:

Two powerful engines. You're an R model right? That's two turbocharged 285 or 300 hp per side. This will help tremendously to climb out of the slushies. The C310 I flew was incredibly powerful, and I could feel how this power opened up options.

You have the high standard of known icing, not "icing protection." This gives you more time to make your plan, and some help as you execute it.

Weather avoidance equipment on board. This helps you stay out of actual problem areas.

Those are the big three, and you got 'em.

The only upgrade I could think of would be the C340 which gives you pressurisation. But this adds complication and ups the operating cost. Anyway, the next upgrade after that has to be turbine.

 

[Brian Austin]

...
Then you get on one of these boards, and well meaning people tell you that you are wrong...

Actually, I never said anyone was wrong, just that I don't completely agree. And I asked for clarification more than anything.

You've got far more experience than I do in anything with wings. Just because someone questions the experience doesn't mean you're wrong, it could just mean they are trying to learn from it. My $.02.

 

[wsuffa]

And some of us have a slightly different risk profile than Bob. There are things that I'll fly in my turbocharged, de-iced single that he might not.

I cancel very few trips, though I've sat on the ground for a couple of hours or landed short waiting for a squall line to pass.

 

[bbchien]

Then you get on one of these boards, and well meaning people tell you that you are wrong.

We all have to evaluate what risks we are willing to take. With the above profile, I know that I am assuming risk on some of those flights. I believe I can manage it.

I think you can, too. It's sorta like the 375 hour CFI with no utility cross country time along for the ride. He's actually more work than value, while you struggle with Aviation Graduate School at the 400 level courses, live real time.

 

[ejborg]

When Lindbergh crossed the Atlantic he chose a single because, he said, a twin would double his chances of engine failure. Mathmatically, he may have been correct, but that was in the days when single engine ops in a twin was no less likely to end in an unscheduled off-airport landing than zero-engine ops in a single. If flying a reliable, known-ice twin changes your ability to tackle certain weather (and other added risks, like IFR over mountainous terrain), then adding a second engine sort of HAS changed the weather, in effect, hasn't it?

We live on the Pacific Northwest Coast. There are mountains and often nasty ice clouds between us and everywhere we'd like to go (and we lose a single out in the mountain icing conditions about once a year, sometimes more). When I sat down to decide what the minimum equipment would be for anything but hobby transportation around here, it all added up to one thing: a known-ice twin (Piper Seneca, in our case). Why? In 2 words: risk aversion. I got the bejabbers scared out of me once IFR over the mountains in a single (and vowed no more of that), and it's both illegal and foolhardy to penetrate forecast icing conditions in anything but a known-ice airplane. Voila! And step to the "pay window."

 

[bbchien]

The aircraft has to be capable of MEA on a single engine, somewhere around 13,000 feet is what's needed. If you have that, you have bought some reliability, in addition to systems redundancy. But you need fire-breathing engines to get this.