ILS Emergencies OEI

I don't know what you guys are talking about. If you lose an engine you only lose half the power and performance so going around shouldn't be an issue.


:stirpot:

; )
 
I can expand on that too. I sat behind the pilot in an Aerostar one hot July evening during a checkout. We almost wiped out the tower on a single engine go-around. Never, EVER get in the back seat of a multiengine training flight!

dtuuri

We didn't do single-engine go-arounds.
 
We didn't do single-engine go-arounds.
Well, I was speaking more to the young skulls out there. I know of an instructor and several observers in the back seats who perished when their 400 series Cessna (401?, 411?) hit a barn on a single-engine approach.

Still, at several hundred feet in the air in a clean configuration in a light twin, you're positioned much better than after takeoff for an engine failure. If the plane is documented to be capable of it, the pilot should be able to perform it.

Setting aside any flight test no-nos I've not kept up with, such as minimum altitudes, etc., and giving an opinion based on just my experience, it seems reasonable to me that a normal approach ending with a miss is a valid place to fail an engine, say due to a simulated blown jug, on a checkride and a good reason for the applicant to keep the flap configuration clean until the runway's in sight and a commitment to land on it is made. A single-engine approach is even better than a normal miss with an engine failure because the gear can be kept retracted as well, who's going to argue with that decision? Going around could be the better choice than 'landing at all costs'--say you're just too damn high, for instance.

Flat, spring-loaded, canned responses can be a good thing or a bad thing. Double engine flameout? Good thing. Strange noise at V1? Maybe a bad thing. Landing no matter what on a single-engine approach? Good if the plane can't go-around, bad if it can and if it should.

dtuuri
 
I don't know what you guys are talking about. If you lose an engine you only lose half the power and performance so going around shouldn't be an issue.


:stirpot:

; )

As I recall in a light twin when you lose one engine, you lose 85%, or so, of your performance.
 
Well, I was speaking more to the young skulls out there. I know of an instructor and several observers in the back seats who perished when their 400 series Cessna (401?, 411?) hit a barn on a single-engine approach.

Still, at several hundred feet in the air in a clean configuration in a light twin, you're positioned much better than after takeoff for an engine failure. If the plane is documented to be capable of it, the pilot should be able to perform it.

Setting aside any flight test no-nos I've not kept up with, such as minimum altitudes, etc., and giving an opinion based on just my experience, it seems reasonable to me that a normal approach ending with a miss is a valid place to fail an engine, say due to a simulated blown jug, on a checkride and a good reason for the applicant to keep the flap configuration clean until the runway's in sight and a commitment to land on it is made. A single-engine approach is even better than a normal miss with an engine failure because the gear can be kept retracted as well, who's going to argue with that decision? Going around could be the better choice than 'landing at all costs'--say you're just too damn high, for instance.

Flat, spring-loaded, canned responses can be a good thing or a bad thing. Double engine flameout? Good thing. Strange noise at V1? Maybe a bad thing. Landing no matter what on a single-engine approach? Good if the plane can't go-around, bad if it can and if it should.

dtuuri
Do you have any data that suggests this training scenario is likely in real life or is this training based on tradition and OWT? Just asking...
 
On one engine. It's 2.1%, IIRC. It's 3.3% @ 200'/nm.

You're confusing second minimum segment certification climb performance criteria with missed approach climb gradient (in this case, diverse climb criteria).

A Part 23 airplane isn't required to exhibit a positive climb gradient with an engine out. A part 25 airplane is.
 
I don't know what you guys are talking about. If you lose an engine you only lose half the power and performance
Not so. The issue isn't how much of your total power you're losing, it's how much of your excess power you're losing. Typically, in light twins, losing half your power costs you 80% of your climb performance, and that only at SL/std day. You also generally lose 100% of your takeoff performance, as few if any light twins can take off from a standing start on one engine.
 
You're confusing second minimum segment certification climb performance criteria with missed approach climb gradient (in this case, diverse climb criteria).

A Part 23 airplane isn't required to exhibit a positive climb gradient with an engine out. A part 25 airplane is.
Padon me? I'm confusing nothing. Approach climb is 2.1%. That pertains to the missed approach you were supposed to be doing and I was relating it to a Part 25 airplane because aterpster asked me to expand on it. But apparently to placate you, the examiner chose to fail an engine after a touch and go and just call it a missed approach. That's a takeoff configuration and should be 2.4% in a Part 25 turbojet. Both are below the 'diverse' criteria of 3.3% of an IFR departure or missed approach which your post earlier implied, to me at least, might be required of a Part 25 airplane, but not of a Part 23 plane.

As for your comment now about a multiengine Part 23 airplane not being required to climb at a positive rate, that may be true, but you didn't say yours couldn't, only that YOU wouldn't. Not exactly conducive to a safe operation, IMO.

dtuuri
 
I can expand on that too. I sat behind the pilot in an Aerostar one hot July evening during a checkout. We almost wiped out the tower on a single engine go-around. Never, EVER get in the back seat of a multiengine training flight!

dtuuri
Sometime ago (2010) on the Redboard, a Florida Inst. of Tech. student was bemoaning the crash on real OEI and death of four FIT students in a Seminole on a 3600 ft runway, with LE inop shortly after rotation.

I could not make Dan understand the problem with excess load, still under legal Max Gross, but close. His response was, "it was legal". Yes it was.

That is what we are training for the future.
 
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Do you have any data that suggests this training scenario is likely in real life or is this training based on tradition and OWT? Just asking...
OWT? The reason for not 'failing' engines on flight tests below some arbitrary altitude have nothing to do with the validity of the task, but everything to do with risk vs. the reward of doing it during a test. That doesn't change my opinion that the pilot should be able to get the job done if it's possible, but I wouldn't stray outside the boundaries of the official safety protocols on a flight test either.

Even single engine planes crash during real missed approaches. Pilots have to demonstrate they can handle it on flight tests though. If enough crash during flight tests, I suppose the FAA will remove it from the PTS, wouldn't you? :rolleyes:

dtuuri
 
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If enough crash during flight tests, I suppose the FAA will remove it from the PTS, wouldn't you? :rolleyes:
That's been their past response, viz, the old Vmc cut at 400 AGL. Now there are a lot of restrictions in the PTS about how and when engines are cut on ME rides, and the aforementioned allowance on the ATP-ME ride to let the airplane get up and climbing before killing the engine on the OEI missed approach.
 
That's the point I've been trying to make. There is no reason to die in training practicing a scenario that is statistically unlikely to happen, and if you compare training accident to real world, there must be a point where sanity causes a reconsideration of the risk-reward.
 
That's the point I've been trying to make. There is no reason to die in training practicing a scenario that is statistically unlikely to happen, and if you compare training accident to real world, there must be a point where sanity causes a reconsideration of the risk-reward.
All scenarios are statistically unlikely. I'd go so far as to say most or at least many real abnormal and emergency events aren't even covered by the POH/AFM. So we should not train for the ones that are? Nah. Just make sure you do your homework and keep on asking those questions.

Before I could teach in an Apache, the Chief Flight Instructor took me up for a checkout. I was pretty concerned about the performance on one engine and did lots of studying and asked lots of questions. So, he makes me sit there and watch as he throttles an engine back on a go-around and then slowly and effortlessly describes the procedure. "No reason to hurry, just be methodical," he said, "You can see once it's cleaned up it can climb over 200'/min." (it was 160 hp/side, no passengers.)

I had to admit, at the Apache's slow blue-line speed, 200'/min seemed like marching right up there. The guy welded the nose on the centerline too. The only way you could tell an engine 'failed' was by the reduction in noise and lower pitch attitude. It was just the right thing for me to experience at the time to assuage my deep concerns. Those 'concerns' are every bit still there to this day in the form of meticulous planning, but now I know what it takes, what it looks and feels like when done right. I'm trying to pass it on.

dtuuri
 
But apparently to placate you, the examiner chose to fail an engine after a touch and go and just call it a missed approach. That's a takeoff configuration and should be 2.4% in a Part 25 turbojet.

To placate me? Show me where an engine-out missed approach is required in a Part 23 airplane for a Part 135 check ride. It isn't. Show me where a Part 23 King Air 90 (BE9L) is required to be capable of such performance. You can't. It isn't.

Placate me? Hardly.

The fool demanded that I do something not required by the regulation, not within the capabilities of the aircraft, and outside the bounds of safe operation. He was warned. He tearfully learned the hard way, and was fired shortly thereafter.

Before I could teach in an Apache, the Chief Flight Instructor took me up for a checkout. I was pretty concerned about the performance on one engine and did lots of studying and asked lots of questions. So, he makes me sit there and watch as he throttles an engine back on a go-around and then slowly and effortlessly describes the procedure. "No reason to hurry, just be methodical," he said, "You can see once it's cleaned up it can climb over 200'/min." (it was 160 hp/side, no passengers.)

I had to admit, at the Apache's slow blue-line speed, 200'/min seemed like marching right up there. The guy welded the nose on the centerline too. The only way you could tell an engine 'failed' was by the reduction in noise and lower pitch attitude. It was just the right thing for me to experience at the time to assuage my deep concerns. Those 'concerns' are every bit still there to this day in the form of meticulous planning, but now I know what it takes, what it looks and feels like when done right. I'm trying to pass it on.

Was this little exercise in foolishness done close to sea level on a standard day? You're doing no one a favor by passing it on, nor should anyone be encouraged to think about going around on one engine in an Apache, or any other light twin.
 
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To placate me? Show me where an engine-out missed approach is required in a Part 23 airplane for a Part 135 check ride. It isn't. Show me where a Part 23 King Air 90 (BE9L) is required to be capable of such performance. You can't. It isn't.

Placate me? Hardly.

The fool demanded that I do something not required by the regulation, not within the capabilities of the aircraft, and outside the bounds of safe operation. He was warned. He tearfully learned the hard way, and was fired shortly thereafter.
I don't keep up on this 135 stuff, but a quick check turns up these possible requirements. It's your attitude that bugs me. Let's leave it at that.

135.293(b)
The competency check may include any of the maneuvers and procedures currently required for the original issuance of the particular pilot certificate required for the operations authorized and appropriate to the category, class and type of aircraft involved.​

ATP PTS
F. TASK: MISSED APPROACH
REFERENCES: 14 CFR part 61; POH/AFM; AIM; Standard
Instrument Approach Procedure Charts (SIAP); FAA-H-8083-15,
FAA-H-8261-1.
NOTE: The applicant must perform two missed approaches with one being from a precision approach (ILS, MLS, or GLS). One complete published missed approach must be accomplished. Additionally, in multiengine airplanes, a missed approach must be accomplished with one engine inoperative (or simulated inoperative). The engine failure may be experienced anytime prior to the initiation of the approach, during the approach, or during the transition to the missed approach attitude and configuration.

dtuuri
 
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It's your attitude that bugs me. Let's leave it at that.

Let's not.

You appealed to the ATP PTS (http://www.faa.gov/training_testing/testing/airmen/test_standards/pilot/media/FAA-S-8081-5F.pdf) which clearly stipulates that "All TASKs are required, except as noted. When a particular element is not appropriate to the aircraft or its equipment, that element may be omitted."

An aircraft which lacks the performance capabilities to go around on one engine, and for which the certification criteria doesn't include a requirement or ability to go around on one engine means that a PTS requirement to do so isn't appropriate to the aircraft or it's equipment. It's not required.

I once had an FAA inspector demand that I demonstrate a missed approach in a Seneca II on one engine. I informed him that it would not happen. He told me he would fail me. I asked him if he'd like to get out now, or wait until we got back on the ground. He relented, and completed the ride, passing me. He was an idiot.

That this may "bug" you pleases me.

I don't keep up on this 135 stuff,

Clearly.

Generally, where a single engine missed is to be demonstrated in a Part 23 airplane, the check airman or examiner will retard power at a minimum above 400.'

The examiner on my ATP practical test did so after executing a VOR approach, and when he retarded the power, we were unable to maintain altitude at 400'. We made a continuous descent to another runway.

To require an applicant on a practical test to execute a maneuver for which the aircraft is not designed, nor capable is foolish.

Certainly in type rating practical tests in Part 25 aircraft, we do engine-out missed approaches, but many of the transport category aircraft that I've flown will do several thousand feet per minute with an engine out. An examiner once came unglued when I retarded the power on the good engine during the missed approach from an engine-out ILS. We had excess climb performance on one engine in the airplane, let alone two. The excess thrust, climb rate, and speed, was unnecessary.

An engine-out go-around or missed approach in a light twin is unwise, and has often proven fatal.

You seem to believe and perhaps even teach otherwise. You do no one any favors.
 
Max Gross weight comes from the marketing department!

You ain't a-kiddin'. And that's not the only thing marketing departments do...
 
You ain't a-kiddin'. And that's not the only thing marketing departments do...

I thought he was. I believed (prior to this) That a certified design was required to be able to demonstrate all performance capabilities at all weights up to and including MGW.
 
I thought he was. I believed (prior to this) That a certified design was required to be able to demonstrate all performance capabilities at all weights up to and including MGW.
Jay, it can be demonstrated, by an ACE test pilot who has had about thirty runs to get it right. The OEI engine climb table can be obtained, if your equipment is recent, and you are top gun.

Me, not so much, maybe on a good day. "Is today a good day for an engine failure?"

That's why I fly 200 undergross, routinely, and "THINK!" when I am not.

KASE requires 400 undergross, which for me is 60 gallons of fuel. Enough to depart the Front Range, climb to FL 19, do the approach, and missed, go OEI, and go to GJT without a lot of sweat.

You might be more capable.

But if you're not the factory test pilot, I'd love to give you a BFR and have you show it to me. It will be at Max GW. If you can demonstrate it, it's on me.

THAT is the meaning of "the book was written by the "markenting department". Normal pilots have no business expecting the same results.
 
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I believe you and also don't believe in pushing the limits of the book. I use it as a hard limit then find the real limits based on that and experience in that airplane. I've once experienced an airplane meeting spec (???) and refusing to perform. Don't wanna do it again if I can help it.
 
You appealed to the ATP PTS (http://www.faa.gov/training_testing/testing/airmen/test_standards/pilot/media/FAA-S-8081-5F.pdf) which clearly stipulates that "All TASKs are required, except as noted. When a particular element is not appropriate to the aircraft or its equipment, that element may be omitted."

An aircraft which lacks the performance capabilities to go around on one engine, and for which the certification criteria doesn't include a requirement or ability to go around on one engine means that a PTS requirement to do so isn't appropriate to the aircraft or it's equipment. It's not required.
I don't think the FAA shares your interpretation of that statement. It does not say a TASK may be omitted, just an element of a task. For example, one element of the Area I, Task A, is "hydraulic system." If the aircraft for the task doesn't have a hydraulic system, then that element is omitted. In order for a TASK to be omitted, then there must be a specific note allowing that omission, such as Area II, Task A, where the Note says the visual inspection may be omitted when a Flight Engineer is a required crewmember on that type, or for Area III, Task B, where the Note says glassy water operations may be covered orally if no glassy water is available for an AMES/ASES ride.

In the case of the OEI Missed Approach task, there is no such Note allowing its omission. It is the applicant's responsibility to provide an aircraft which can perform that task, albeit perhaps with the understanding that the examiner will delay the failure in accordance with the Note to that TASK saying the failure may be experienced during the transition to the missed approach altitude rather than before the missed approach point.

I once had an FAA inspector demand that I demonstrate a missed approach in a Seneca II on one engine. I informed him that it would not happen. He told me he would fail me. I asked him if he'd like to get out now, or wait until we got back on the ground. He relented, and completed the ride, passing me. He was an idiot.
Just what certificate/rating was this for? If it was for a PP or CP ME rating, then yes, he was an idiot, because a single engine missed approach is not part of that PTS.

Generally, where a single engine missed is to be demonstrated in a Part 23 airplane, the check airman or examiner will retard power at a minimum above 400.'
That is covered in the ATP PTS:
In a multiengine airplane certificated under 14 CFR part 23, (for
which no V​
1, VR, or V2 speeds are published) the failure of the most
critical powerplant should be simulated at a point after reaching a
minimum of V
SSE and, if accomplished in the aircraft, at an altitude
not lower than 400 feet AGL, giving consideration to local

atmospheric conditions, terrain, and aircraft performance available.

The examiner on my ATP practical test did so after executing a VOR approach, and when he retarded the power, we were unable to maintain altitude at 400'. We made a continuous descent to another runway.
If that is true, then you violated 14 CFR 61.45 by not providing an aircraft capable of performing all required tasks in the PTS, and the ride should have been discontinued until you came back with an appropriate aircraft.

To require an applicant on a practical test to execute a maneuver for which the aircraft is not designed, nor capable is foolish.
Whether it is foolish or not, it's the applicant's regulatory responsibility to provide a "suitable aircraft," and there is no authority for examiners to waive tasks if the applicant fails in that responsibility.

An engine-out go-around or missed approach in a light twin is unwise, and has often proven fatal.
I can't argue that, but if you want to complete your ATP practical test in one, you'd best bring one which can perform that task under the conditions of the test (environmental as well as load). That's a regulation, not a choice.
 
I thought he was. I believed (prior to this) That a certified design was required to be able to demonstrate all performance capabilities at all weights up to and including MGW.

As Bruce said, these specs were performed by a factory test pilot in relatively ideal conditions. Us mere mortals (of which Bruce includes himself, and I include myself - note we both have a good bit of multi-engine time and are very safety conscious) can not expect to get the same results.

Also keep in mind that back 40 years ago when many of these planes were being certified, the burden of proof wasn't quite as strict as it is today. Some numbers in there were definitely optimistic, and remain so today.

As I've said, in the 310 with the upgraded engines, I have enough power where, if I do everything right, I should be able to survive an engine failure right as the gear comes up. There's a big if there, because I am mortal, even though I prepare for it every flight. Less weight and cooler temperatures helps my odds, more weight and higher temperatures hurt them. I'd like to pretend that I'm a constant, but I'm not. Being human, some days I'm sharper than others, and so my reaction time may vary. I can only hope that, if I have an engine failure at rotation, that it be on a good day, when I'm lightweight, and it's cold out.

In the Navajo, if I lose an engine at rotation, I'm in a world of ****, unless I'm pretty light. Place the Aztec somewhere between the two.

Marketing has meddled in numbers a bunch of times. Any look at the Duke or Malibu performance specs (especially fuel burn) tells you that marketing got in the way. Perhaps the aircraft can do those numbers, but not with engines that will last very long.
 
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Do you have any data that suggests this training scenario is likely in real life or is this training based on tradition and OWT? Just asking...
Here is a special study by the NTSB from back in the 1970s. Plenty of data to gnaw on: http://libraryonline.erau.edu/online-full-text/ntsb/aviation-special-studies/AAS79-02.pdf

See conclusion #10 and especially read Appendix C--an article written in 1973 which I still keep on hand.

That article, Always Leave Yourself An Out, has been more or less adopted by the FAA as a standard for light twin operations and is the basis for many beliefs expressed in this thread. I recommend reading it.

But I don't agree with the article's notion of extending the gear at the 'normal' place, say the FAF, on a single-engine approach. That's an SOP for a Part 25 aircraft. [EDIT: Apologies to Richard Aarons. He didn't write that. It was in this otherwise agreeable treatise: https://www.faasafety.gov/files/gslac/courses/content/30/248/FlyingLightTwinsSafely.pdf] What if you need to level off at MDA for a while? With 80% of your climb performance gone, do you really want to drag your gear in the breeze? Same goes for making a circling approach. Keeping a light twin clean as long as possible leaves you with a much better 'out'. You only need to extend the gear like the space shuttle--in time to land. You most likely don't need flaps at all.

In this thread the term 'go-around' appears to have different meanings for different folks or circumstances. It's a general term that can apply to single engine airplanes too. In multiengine discussions the critical factors are the configuration at the start of a go-around and the point of thrust loss. Those important nuances can be lost on the uninitiated.

A 'rejected landing' is a form of a 'go-around' that specifically means 'all engines operating' and a certified 'balked landing climb gradient' for transport aircraft when in the 'landing configuration' of gear down, flaps down. A single-engine missed approach is different: the gear is up and the flaps are at the aproach setting for Part 25 airplanes.

When speaking of light twins, simply saying 'go-around' doesn't convey the critical facts well enough--it could be from a clean or a dirty configuration which makes all the difference in the world. I'm sure we all agree that a light twin can't go-around from the landing configuration from 20' above the runway--or at least agree it shouldn't. Breaking out high on a non-precision approach in a clean configuration, though, is another story for many twins, and "going around" doesn't necessarily mean climbing back into the clouds, it may mean leveling off and circling the airport.

To fly a light twin safely, you need to think like Dr. Bruce. It helps to know Part 25 performance standards and then try to come up with personal limitations and procedures that are similar, although obviously they can't be the same.

As an example, adding takeoff distance to landing distance gives you a quasi-balanced field, but puts 'V1' in the air, something not allowed under Part 25. But it's better than the silly 'accelerate-go' distances published in the AFM.

Gotta go. ;)

dtuuri
 
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Depends on the King Air. In a 90 in most cases, I wouldn't go around.

I took a 135 check ride in a BE9L, and the chief pilot giving the ride told me I'd have to do a single engine missed. I told him that wasn't going to happen, and he told me I wouldn't pass the ride if I refused. I told him we ought not waste our time then, but he'd be talking with the FAA in the morning. I also asked him if he'd do a single engine missed with a patient on board. He quickly said he would. The general manager was standing nearby, listening. He was one of our chief medics. I asked if he'd do it with the GM on board, and the chief pilot assured me he would go missed on one engine.

The following day we assembled in the airplane and went to go fly. I told him pointedly that if he pulled an engine below 400' he wasn't getting it back, and that he would be deeply sorry if he attempted to force a single engine missed. Toward the end of the ride, after an ILS to a touchdown, he told me to go. As I began the climb, he slowly retarded one power lever to idle, and informed me that this would simulate our single engine missed.

Having already informed him that it wasn't required in a Part 23 airplane, I didn't feel like providing an education. I began a drift down to a field south of Reno. The chief pilot asked me how I was going to return to Reno. I told him we weren't. He asked me where we were going. I pointed to the field and said "over there." He said I couldn't; there were power lines. I told him we'd be landing under the lines, in the field. He said it would cause aircraft damage. I told him he was right. He told me to push the power back up, and I said no.

I reminded him that he had been told that if he pulled the power below 400' he wasn't getting the engine back. I reminded him that failure to listen had consequences. He began to cry. He begged for the power. Eye level to the power lines, he became nearly hysterical. Below the altitude of the power lines, he was very unhappy. He demanded, begged, pleaded in a shrill voice for the power lever. I told him to push it up if he wanted, but that I wasn't going to do it. He pushed up the power, and we climbed out, then headed back to home plate.

He said nothing on the ride back, other than asking if he could fly for a while. Once on the ground, he signed off my check ride, got in his truck and left. He didn't want to hear "I told you so," and I didn't feel like telling him. A few weeks later he was fired for two incidents involving exceptionally bad judgment, all in one day, with patients aboard or waiting. He went to another operation, where he was also fired. He's an FAA inspector, now. Go figure.
This sounds like two bull-headed guys playing some misguided game of chicken. Would it have been worth it to land in the field or hit the power lines?
 
Here is a special study by the NTSB from back in the 1970s. Plenty of data to gnaw on: http://libraryonline.erau.edu/online-full-text/ntsb/aviation-special-studies/AAS79-02.pdf

See conclusion #10 and especially read Appendix C--an article written in 1973 which I still keep on hand.

That article, Always Leave Yourself An Out, has been more or less adopted by the FAA as a standard for light twin operations and is the basis for many beliefs expressed in this thread. I recommend reading it.

But I don't agree with the article's notion of extending the gear at the 'normal' place, say the FAF, on a single-engine approach. That's an SOP for a Part 25 aircraft. [EDIT: Apologies to Richard Aarons. He didn't write that. It was in this otherwise agreeable treatise: https://www.faasafety.gov/files/gslac/courses/content/30/248/FlyingLightTwinsSafely.pdf] What if you need to level off at MDA for a while? With 80% of your climb performance gone, do you really want to drag your gear in the breeze? Same goes for making a circling approach. Keeping a light twin clean as long as possible leaves you with a much better 'out'. You only need to extend the gear like the space shuttle--in time to land. You most likely don't need flaps at all.

In this thread the term 'go-around' appears to have different meanings for different folks or circumstances. It's a general term that can apply to single engine airplanes too. In multiengine discussions the critical factors are the configuration at the start of a go-around and the point of thrust loss. Those important nuances can be lost on the uninitiated.

A 'rejected landing' is a form of a 'go-around' that specifically means 'all engines operating' and a certified 'balked landing climb gradient' for transport aircraft when in the 'landing configuration' of gear down, flaps down. A single-engine missed approach is different: the gear is up and the flaps are at the aproach setting for Part 25 airplanes.

When speaking of light twins, simply saying 'go-around' doesn't convey the critical facts well enough--it could be from a clean or a dirty configuration which makes all the difference in the world. I'm sure we all agree that a light twin can't go-around from the landing configuration from 20' above the runway--or at least agree it shouldn't. Breaking out high on a non-precision approach in a clean configuration, though, is another story for many twins, and "going around" doesn't necessarily mean climbing back into the clouds, it may mean leveling off and circling the airport.

To fly a light twin safely, you need to think like Dr. Bruce. It helps to know Part 25 performance standards and then try to come up with personal limitations and procedures that are similar, although obviously they can't be the same.

As an example, adding takeoff distance to landing distance gives you a quasi-balanced field, but puts 'V1' in the air, something not allowed under Part 25. But it's better than the silly 'accelerate-go' distances published in the AFM.

Gotta go. ;)

dtuuri
I had a rather long exchange of emails with Richard Aarons on the subject of the extended gear having a "keel effect" in an engine-out situation. He told me that a lot of the information included in that article was based on conversation with factory pilots and not on any kind of performance testing. He did not seem happy that the FAA had latched onto his article as the gospel truth.

Bob Gardner
 
I can see a young man full of p_ss and vinegar doing what Douglas relates. But as a more mature airman, I think there was misconduct on both sides.

Let me tell you a story, from my district.
About 10-12 years ago a young man was on a part 135 ride, FSDO ops examiner, in an Aerostar 600. When they were basically done (after the OEI miss, and were on downwind with two operating, the young pilot says to the examiner (there's an observer in the back seat....)"would you like the landing". The examiner says, "my aircraft". Whereupon the young pilot pulls the fuel from the left engine.

After a great bit of confusion, the examiner cobbs the good engine, cleans up the frame, identifies, feathers, and brings the AStar around for a long final. Trouble is, neither pilot remembered to put down the gear.

The Examiner retired. The 135 Candidate was busted down to PVT ASEL and enjoined from reapplying for a year. The insurance company scrapped the bird.

Good decisionmaking, huh............not.

Then there's the matter of posting it.....sigh.
"Senior Airmen are senior because they know where the bones lie and refuse to disturb them".
 
I can see a young man full of p_ss and vinegar doing what Douglas relates. But as a more mature airman, I think there was misconduct on both sides.

Let me tell you a story, from my district.
About 10-12 years ago a young man was on a part 135 ride, FSDO ops examiner, in an Aerostar 600. When they were basically done (after the OEI miss, and were on downwind with two operating, the young pilot says to the examiner (there's an observer in the back seat....)"would you like the landing". The examiner says, "my aircraft". Whereupon the young pilot pulls the fuel from the left engine.

After a great bit of confusion, the examiner cobbs the good engine, cleans up the frame, identifies, feathers, and brings the AStar around for a long final. Trouble is, neither pilot remembered to put down the gear.

The Examiner retired. The 135 Candidate was busted down to PVT ASEL and enjoined from reapplying for a year. The insurance company scrapped the bird.

Good decisionmaking, huh............not.

Then there's the matter of posting it.....sigh.
"Senior Airmen are senior because they know where the bones lie and refuse to disturb them".

That story is so jacked up I believe every word.
 
I am not incentivized to get a twin.

Here is a special study by the NTSB from back in the 1970s. Plenty of data to gnaw on: http://libraryonline.erau.edu/online-full-text/ntsb/aviation-special-studies/AAS79-02.pdf

See conclusion #10 and especially read Appendix C--an article written in 1973 which I still keep on hand.

That article, Always Leave Yourself An Out, has been more or less adopted by the FAA as a standard for light twin operations and is the basis for many beliefs expressed in this thread. I recommend reading it.

But I don't agree with the article's notion of extending the gear at the 'normal' place, say the FAF, on a single-engine approach. That's an SOP for a Part 25 aircraft. [EDIT: Apologies to Richard Aarons. He didn't write that. It was in this otherwise agreeable treatise: https://www.faasafety.gov/files/gslac/courses/content/30/248/FlyingLightTwinsSafely.pdf] What if you need to level off at MDA for a while? With 80% of your climb performance gone, do you really want to drag your gear in the breeze? Same goes for making a circling approach. Keeping a light twin clean as long as possible leaves you with a much better 'out'. You only need to extend the gear like the space shuttle--in time to land. You most likely don't need flaps at all.

In this thread the term 'go-around' appears to have different meanings for different folks or circumstances. It's a general term that can apply to single engine airplanes too. In multiengine discussions the critical factors are the configuration at the start of a go-around and the point of thrust loss. Those important nuances can be lost on the uninitiated.

A 'rejected landing' is a form of a 'go-around' that specifically means 'all engines operating' and a certified 'balked landing climb gradient' for transport aircraft when in the 'landing configuration' of gear down, flaps down. A single-engine missed approach is different: the gear is up and the flaps are at the aproach setting for Part 25 airplanes.

When speaking of light twins, simply saying 'go-around' doesn't convey the critical facts well enough--it could be from a clean or a dirty configuration which makes all the difference in the world. I'm sure we all agree that a light twin can't go-around from the landing configuration from 20' above the runway--or at least agree it shouldn't. Breaking out high on a non-precision approach in a clean configuration, though, is another story for many twins, and "going around" doesn't necessarily mean climbing back into the clouds, it may mean leveling off and circling the airport.

To fly a light twin safely, you need to think like Dr. Bruce. It helps to know Part 25 performance standards and then try to come up with personal limitations and procedures that are similar, although obviously they can't be the same.

As an example, adding takeoff distance to landing distance gives you a quasi-balanced field, but puts 'V1' in the air, something not allowed under Part 25. But it's better than the silly 'accelerate-go' distances published in the AFM.

Gotta go. ;)

dtuuri
 
I had a rather long exchange of emails with Richard Aarons on the subject of the extended gear having a "keel effect" in an engine-out situation. He told me that a lot of the information included in that article was based on conversation with factory pilots and not on any kind of performance testing. He did not seem happy that the FAA had latched onto his article as the gospel truth.

Bob Gardner
I think highly of the article even if a few details are technically suspect. I understand you've published some good words on the subject too. :thumbsup:

dtuuri
 
I can see a young man full of p_ss and vinegar doing what Douglas relates. But as a more mature airman, I think there was misconduct on both sides.

Let me tell you a story, from my district.
About 10-12 years ago a young man was on a part 135 ride, FSDO ops examiner, in an Aerostar 600. When they were basically done (after the OEI miss, and were on downwind with two operating, the young pilot says to the examiner (there's an observer in the back seat....)"would you like the landing". The examiner says, "my aircraft". Whereupon the young pilot pulls the fuel from the left engine.

After a great bit of confusion, the examiner cobbs the good engine, cleans up the frame, identifies, feathers, and brings the AStar around for a long final. Trouble is, neither pilot remembered to put down the gear.

The Examiner retired. The 135 Candidate was busted down to PVT ASEL and enjoined from reapplying for a year. The insurance company scrapped the bird.

Good decisionmaking, huh............not.

Then there's the matter of posting it.....sigh.
"Senior Airmen are senior because they know where the bones lie and refuse to disturb them".

Nice.
 
An overpowered twin isn't guaranteed to save you either....

Report on the Va Beach Hornet crash just released.....turns out it was a dual engine failure:

http://www.cnn.com/2012/07/02/us/virginia-f-18-crash/index.html?hpt=hp_t2

That one is more of a "sometimes it's just not your day" compared to flying something that simply can't maintain altitude at your home base above ground level.

Light twins with one caged around here are just gliders with a better glide ratio over a single with an engine out. Maybe not even better depending on load.
 
Light twins with one caged around here are just gliders with a better glide ratio over a single with an engine out. Maybe not even better depending on load.

They are single-engine airplanes with distributed power.
 
That one is more of a "sometimes it's just not your day" compared to flying something that simply can't maintain altitude at your home base above ground level.

Light twins with one caged around here are just gliders with a better glide ratio over a single with an engine out. Maybe not even better depending on load.
Right. That's why I have the attitude I do about light twins. I flew one for a long time but it was my job. Ok, it was also a cool airplane and I wanted twin time. However, I knew that at this altitude it was no more than a glorified single, maybe even worse because it would have more energy in a crash. We always took off with heavy because the job was mapping and most of the time the objective was to get as much work done as possible without stopping for fuel.
 
Right. That's why I have the attitude I do about light twins. I flew one for a long time but it was my job. Ok, it was also a cool airplane and I wanted twin time. However, I knew that at this altitude it was no more than a glorified single, maybe even worse because it would have more energy in a crash. We always took off with heavy because the job was mapping and most of the time the objective was to get as much work done as possible without stopping for fuel.

It's why in any situation you need to take a look at the actual aircraft performance and what your risk tolerance is.

In your case doing mapping, the risk of potentially not being able to fly on one engine if you had an engine failure was part of the job. If it's not a risk you were willing to take for the money offered, then you could have taken a different job.
 
They are single-engine airplanes with distributed power.
Wally's got it. The reason planes like the 310 and Baron have two engines is because they need two engines to have enough power to produce the desired speed and payload. Back in the day, they just put more cylinders on the engine, until you ended up with something like the An-2. However, the other issues with radial engines made them undesirable for these purposes, and there's just no way to build an air-cooled horizontally-opposed engine that produces more than about 350 HP reliably -- just ask anyone who owned a 400 Commanche or a P-Navajo, with those eight-cylinder IO/TIO-720 engines, or anyone pushing that limit with a six-cylinder engine, like those on a Duke or Cessna 421.

So, when you start needing more than 400 HP to get the desired capability, the only way to get it is to put two engines on the plane. Sure, you can go turbine, and have plenty of reserve power, but then the cost factor goes up enormously -- check the price of a TBM-700 versus a piston twin of the same capability, and that's only one turbine engine. That means if you want the capability and the economy, you need two piston engines, and both of them running, or things get ugly fast.
 
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