Another Twin Down

[Piloto]

Just after take off the pilot reported having problems. Likely left engine failure.

When loosing an engine after takeoff is better to kill both engines and land straight ahead. On a prop twin it is almost impossible to gain any speed/altitude on asymmetrical thrust on takeoff.

 

José 

 

[AndyFromCB]

Just after take off the pilot reported having problems. Likely left engine failure.

When loosing an engine after takeoff is better to kill both engines and land straight ahead. On a prop twin it is almost impossible to gain any speed/altitude on asymmetrical thrust on takeoff.

 

José 

 

 

V1 cuts in commuter turboprops are very doable and you will gain speed and altitude just fine. What you will find is a very reduced climb gradient. In this video, it appears he slowed down way too much in order to clear the apartment building and performed a Vmc roll. Probably saved a bunch of lives not hitting the apartment building.

 

From my personal experience, I will tell you that a KA350 will fly away just peachy on one from the runway and still climb better than any short or medium body Mooney even at gross, even at 5000 feet, even on a +20 day.

 

My bet is the ATR was overloaded and was not flown according to op specs for that particular departure. 

[jetdriven]

Commuter category twins such as the ATR series are guaranteed to have a safe takeoff and climb following an engine failure on the runway after V1. If you use the speeds and the takeoff data such as weigh restrictions, turns, etc it is guaranteed. What I didn't see is the left prop feathered, which is also required for a safe outcome.

[aviatoreb]

Looking at the video several times - from the time you see the airplane in view it is rolled slightly to the left and seems a little nose high - should he have pushed the stick?  Besides feathered the prop.

 

But wow its a miracle it didn't hit the buildings.  That is one big airplane so I won't second guess the pilot who successfully did not hit the buildings.

[frcabot]

Looking at the video several times - from the time you see the airplane in view it is rolled slightly to the left and seems a little nose high - should he have pushed the stick?  Besides feathered the prop.

 

But wow its a miracle it didn't hit the buildings.  That is one big airplane so I won't second guess the pilot who successfully did not hit the buildings.

I think the pilot not hitting the buildings had more to do with the Vmc rollover than any controlled plane behavior. Once the plane rolled over (what is known as a minimum controllable airspeed rollover, something twin-engine pilots are very familiar with), the plane was no longer controllable. 

[frcabot]

Here's another example of a VMC rollover in real life: 

[ryoder]

The aviation guys on cnn said the left prop was feathered. Not sure how they see that.

I wish airports had miles of crash landing areas ahead of departure paths. One reason I am glad to be at Zephyrhills is the amount of fields available right around the airport.

[frcabot]

The aviation guys on cnn said the left prop was feathered. Not sure how they see that.

I wish airports had miles of crash landing areas ahead of departure paths. One reason I am glad to be at Zephyrhills is the amount of fields available right around the airport.

Not sure it would add much. A run-of-the-mill engine failure is fairly common and recoverable in a turboprop if the pilots are trained properly. 

[Piloto]

AndyFromCB, here is a King Air

http://www.kansas.com/news/local/article3596912.html

that lost the left engine on take off and crashed into the Flight Safety school.

 

I found that planes glide better in level flight than on a 90 deg bank angle.

What would you have done on the above cases?

 

José

[frcabot]

AndyFromCB, here is a King Air

http://www.kansas.com/news/local/article3596912.html

that lost the left engine on take off and crashed into the Flight Safety school.

 

I found that planes glide better in level flight than on a 90 deg bank angle.

What would you have done on the above cases?

 

José

I can't imagine any pilot executing a left turn intentionally at less than 150 feet. Again, sounds like a VMC rollover situation where the left engine failed and the pilot did not maintain minimum controllable airspeed by pitching down and landing straight ahead.

 

It's always easy to second-guess but oftentimes in emergency situations one panics and responds inappropriately. That's why it's so important for emergency maneuvers -- especially of the engine failure variety -- to be so drilled in that the response is nearly automatic.

[jetdriven]

AndyFromCB, here is a King Air

http://www.kansas.com/news/local/article3596912.html

that lost the left engine on take off and crashed into the Flight Safety school.

 

I found that planes glide better in level flight than on a 90 deg bank angle.

What would you have done on the above cases?

 

José

I would use my professional training and if the auto feather failed to operate, I'd verify by N1 and fuel flow, shut down and feather the failed engine and carry on. We did it a hundred times in the sim. It will fly. You can crash these things but if flown properly they are guaranteed to fly and climb. Mishandled they are not.

[Piloto]

Not sure it would add much. A run-of-the-mill engine failure is fairly common and recoverable in a turboprop if the pilots are trained properly. 

 

I better stick to my Mooney, no roll overs and half the probability of an engine failure.

 

On a twin you get rid of the Vmc roll over issue by shutting down the running engine.

 

José  

[jetdriven]

They roll over really well when an engine fails and the pilot attempts to return to the runway. But the other part is absolutely correct.

[frcabot]

I better stick to my Mooney, no roll overs and half the probability of an engine failure.

thats the age old question about whether twins are safer. Statistics have shown consistently that your weekend warrior is safer in a single prop plane than a twin, because of improper recovery to engine failure in twins and other such reasons. But for professional pilots who fly daily and are trained frequently and consistently, commercial twins are much safer, hence why all commercial jets and nearly every bizjet have two or more engines.

I mean the gold standard for me is a cirrus or single prop with a chute. 0% fatality where the chute was deployed in the envelope. Seriously, 0%. Can't beat that. The relatively high fatality rate in cirri is from people who win the Darwin award by thinking they can do better than a 0% fatality rate and try to needlessly dead stick land instead.

[frcabot]

I better stick to my Mooney, no roll overs and half the probability of an engine failure.

 

On a twin you get rid of the Vmc roll over issue by shutting down the running engine.

 

José

Ya but shutting down the remaining engine sort of defeats the purpose of having a twin :-P. I think there was a study a few years back that Vmc rollover was only the cause of 2.5% of twin GA crashes but almost everything was pilot error in some way or another. Which is also true of single engine props. Weekend warriors just tend to make more mistakes in twins.

[Piloto]

Here's another example of a VMC rollover in real life: 

 

That is a very good video. If the pilot would had shutdown the running engine he could had glided to a safer crash landing.

 

José

[frcabot]

That is a very good video. If the pilot would had shutdown the running engine he could had glided to a safer crash landing.

 

José

or he would have stalled. In either case it would have been failure to maintain appropriate airspeed. The same pilots who are at risk for the Vmc rollover are the ones who stall a single engine plane after engine failure. In either case you pitch for a certain airspeed.

[Johnnybgoode]

I better stick to my Mooney, no roll overs and half the probability of an engine failure.

On a twin you get rid of the Vmc roll over issue by shutting down the running engine.

José

Yes, you can. But by judicious use of remaining engine, aileron ("raise the dead") and rudder you can fly the aurcraft much more cleanly than was exhibited here. My twin experience is limited to KA200's. Nothing says you have to leave the remaining engine firewalled. In fact, depending upon airspeed, you may not be able to use full power. Second vote for emergency procedures training!

Patrick

[Piloto]

FAR 23 

 

Climb Performance Requirements

 

The current 14 CFR Part 23 single engine climb performance requirements for reciprocating engine twins are as follows: More than 6,000 pounds maximum certificated takeoff weight and/or Vs0 more than 61 knots: The single engine rate of climb in feet per minute at 5,000 MSL must be equal to at least .027 Vso squared. For twins type-certificated on February 4, 1991 or thereafter, the single engine climb requirement is expressed in terms of a climb gradient, 1.5 percent. 6,000 pounds or less maximum certificated takeoff weight and Vso 61 knots or less: The single engine rate of climb or climb gradient at 5,000 MSL must simply be determined. The rate of climb could be a negative number. There is no requirement for a positive single engine rate of climb at 5,000 feet or any other altitude. Rate of climb is the altitude gain per unit of time, while climb gradient is the actual measure of altitude gained per 100 feet of horizontal travel, expressed as a percentage. An altitude gain of 1.5 feet per 100 feet of horizontal travel is a climb gradient of 1.5 percent. With regard to climb performance, the light twin with one engine inoperative will perform marginally at best, and may not be capable of climbing at all under existing conditions. There is no requirement that a light twin in the takeoff or landing configuration be able to maintain altitude, even at sea level, with one engine inoperative.

[frcabot]

FAR 23 

 

Climb Performance Requirements

 

The current 14 CFR Part 23 single engine climb performance requirements for reciprocating engine twins are as follows: More than 6,000 pounds maximum certificated takeoff weight and/or Vs0 more than 61 knots: The single engine rate of climb in feet per minute at 5,000 MSL must be equal to at least .027 Vso squared. For twins type-certificated on February 4, 1991 or thereafter, the single engine climb requirement is expressed in terms of a climb gradient, 1.5 percent. 6,000 pounds or less maximum certificated takeoff weight and Vso 61 knots or less: The single engine rate of climb or climb gradient at 5,000 MSL must simply be determined. The rate of climb could be a negative number. There is no requirement for a positive single engine rate of climb at 5,000 feet or any other altitude. Rate of climb is the altitude gain per unit of time, while climb gradient is the actual measure of altitude gained per 100 feet of horizontal travel, expressed as a percentage. An altitude gain of 1.5 feet per 100 feet of horizontal travel is a climb gradient of 1.5 percent. With regard to climb performance, the light twin with one engine inoperative will perform marginally at best, and may not be capable of climbing at all under existing conditions. There is no requirement that a light twin in the takeoff or landing configuration be able to maintain altitude, even at sea level, with one engine inoperative.

Right, which is why single-engine go arounds in light twins are both stupid and deadly. And yet that doesn't stop people from doing it, even with a CFI sitting next to them.

[AndyFromCB]

FAR 23 

 

Climb Performance Requirements

 

The current 14 CFR Part 23 single engine climb performance requirements for reciprocating engine twins are as follows: More than 6,000 pounds maximum certificated takeoff weight and/or Vs0 more than 61 knots: The single engine rate of climb in feet per minute at 5,000 MSL must be equal to at least .027 Vso squared. For twins type-certificated on February 4, 1991 or thereafter, the single engine climb requirement is expressed in terms of a climb gradient, 1.5 percent. 6,000 pounds or less maximum certificated takeoff weight and Vso 61 knots or less: The single engine rate of climb or climb gradient at 5,000 MSL must simply be determined. The rate of climb could be a negative number. There is no requirement for a positive single engine rate of climb at 5,000 feet or any other altitude. Rate of climb is the altitude gain per unit of time, while climb gradient is the actual measure of altitude gained per 100 feet of horizontal travel, expressed as a percentage. An altitude gain of 1.5 feet per 100 feet of horizontal travel is a climb gradient of 1.5 percent. With regard to climb performance, the light twin with one engine inoperative will perform marginally at best, and may not be capable of climbing at all under existing conditions. There is no requirement that a light twin in the takeoff or landing configuration be able to maintain altitude, even at sea level, with one engine inoperative.

commuter category, different certification requirements

[AndyFromCB]

I better stick to my Mooney, no roll overs and half the probability of an engine failure.

 

On a twin you get rid of the Vmc roll over issue by shutting down the running engine.

 

José  

not really true when it comes to comparing piston vs turbine. Turbine engines are exponentially more reliable.

 

Or you simply fly the blue line speed? Whether it takes you up a few hundred FPM, or down a few hundred FPM, it's still better and more controllable than a single. Pilots who do Vmc rollovers are usually the same kind of folks who would fuck up a forced landing. There is nothing magical about flying a twin.

[ArtVandelay]

thats the age old question about whether twins are safer. Statistics have shown consistently that your weekend warrior is safer in a single prop plane than a twin, because of improper recovery to engine failure in twins and other such reasons. But for professional pilots who fly daily and are trained frequently and consistently, commercial twins are much safer, hence why all commercial jets and nearly every bizjet have two or more engines.

I mean the gold standard for me is a cirrus or single prop with a chute. 0% fatality where the chute was deployed in the envelope. Seriously, 0%. Can't beat that. The relatively high fatality rate in cirri is from people who win the Darwin award by thinking they can do better than a 0% fatality rate and try to needlessly dead stick land instead.

Nope, not 0%, there is a vid of a cirrus with chute deployed and its descending slowly but engulfed in flames, a couple died IIRC

[frcabot]

Ok, they burned, thats a little different and chute or no chute the outcome would have been the same. Short of that, though, it is 0.

[AndyFromCB]

Commuter category twins such as the ATR series are guaranteed to have a safe takeoff and climb following an engine failure on the runway after V1. If you use the speeds and the takeoff data such as weigh restrictions, turns, etc it is guaranteed. What I didn't see is the left prop feathered, which is also required for a safe outcome.

 

Looked feather to me, Byron. You are the pro here, but I've seen them spin very slowly on KA even when feathered.