A learning thread starter

[Sempai-mj]

What do think happened?
What would you have done to save the plane? (see the post with the youtube link)

[Sempai-mj]

Skip to the end
What do think happened?
https://www.youtube.com/watch?v=PHBw5sQzr7E

[Mezri]

Good approach, ...

Loss of altitude loss due to turbulence of the relief ...

Nice recovery and continuation of the approach ... this is very good except that it is not exactly on the runway ...

Instead of trying to flair hard to land, the pilot added a bit of gas to improve the touch down ...

Error. With twin gas engines, never do sudden gas at low speed ... one of the engines doesn’t respond ... twisted stoll ...

He had the chance to land hard but wanted to do better ...:(

[Dwight Macdonald]

His final approach was to slow and it was tip stalling.

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[Sempai-mj]

His final approach was to slow and it was tip stalling.

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I agree, I would have pushed the throttle first sign of the problem and go around. Nothing wrong with going around!

[Ricardo]

A good approach starts at the base curve. It seems he did not finish base curve at a proper speed, altitude and runway alignment (he was way left of the runway)
Combined with turbulence, he became destabilized. After that he was fighting the plane, but dangerously low.
In my view he was afraid of engine failure on go around, thats why he insisted on landing.
But seems the best course of action would have been to gradually apply power, regain control, and go around.

[raymondb]

I also agree with previous diagnostics:

The approach is done too slow (with high angle of attack).
They have wind bursts and/or the model seems a bit tail heavy.
A quick RPM ramp up on a twin engine will rarely be even on both sides.
All of this caused a wing tip stall 6 feet above ground (practical impossible to recover...).

This is a clear situation where a go around should have been done.
(For is defense, keep in mind that this is always easier to say when we are just watching from the the back seat ...)

Lets learn from this as an example of what not to do.

Regards,

[Hector]

My two cents on the diagnostic. To add to the approach speed, evident turbulence and to all others valid explanations, there are two key points to take in consideration:

1) The drag originated by a propeller spinning at very low RPM (This is way bigger than the drag of a propeller completely stopped).

2) The "shadow" over the wings that a propeller spinning a very low RPM can cause, blocking the air flow which will translate directly to lost of lift/sustentation and faster stall.

[Michael O'Bree]

Good question, Michael J. and thanks for all the expert responses.
It will be a while before I’m ready for a twin, but plenty of tips even for landing an electric trainer!

[Mezri]

My two cents on the diagnostic. To add to the approach speed, evident turbulence and to all others valid explanations, there are two key points to take in consideration:

1) The drag originated by a propeller spinning at very low RPM (This is way bigger than the drag of a propeller completely stopped).

2) The "shadow" over the wings that a propeller spinning a very low RPM can cause, blocking the air flow which will translate directly to lost of lift/sustentation and faster stall.

Hi Hector, I always beleave that the idle is less drag then stopped prop...
See the following video ...my be you will change your idea...
https://www.youtube.com/watch?v=24BU15dGdJE

In the B-25 Video, You can hear the sound of the engines at the last secound : the pilot quick the gaz to inproove the touch down. One engine get bettre acceleration then the other...crash.

[Kevin Rochon]

Ricardo you're right bad approach not lined up with runway and Mezri I was going to say that also contrary to what we thought spinning blade or not it's the same drag.

On landing we need to try to remember elevator is speed, throttle is hight and Never correct with ailerons but(you see me coming Michael) with the RUDDER and gently. This way the plane doesn't roll and lose lift.

One last thing keep the nose down until the beginning of the runway......nose down = can't stall.


My 2 cents

[Dwight Macdonald]

Very interesting video! I find my electric planes always sink faster with the prop stopped than with it running very slow ... Which agrees with the video.


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[Hector]

Hi Hector, I always beleave that the idle is less drag then stopped prop...
See the following video ...my be you will change your idea...
https://www.youtube.com/watch?v=24BU15dGdJE

Hi Mezri, I watched the video and read the comments. Really interesting, thanks for sharing.

I have to agree with you, iddle motor is not the equal than windmilling :)

In the B-25 Video, You can hear the sound of the engines at the last secound : the pilot quick the gaz to inproove the touch down. One engine get bettre acceleration then the other...crash.

The pilot applied some power last minute, but too late. Should have approached with some more power/speed.

When the plane drifted away from runway, and it is very noticeable when it sink the first time, marked the moment to abort.

The video is edited but I didn't see any slow speed behavior test, which should be mandatory for a maiden. I guess they did it.
:confused:

[Sempai-mj]

Quote
(you see me coming Michael) with the RUDDER

Yes Kevin, every landing your instructions resonates in my brain, "use the Rudder and don't lift your fingers off the sticks":) :D

[Florin]

At 7:16 we can see the left propeller damaged, but right propeller ok. Possible lost thrust on RHS and an unsuccessful go around attempt.

[Kevin Rochon]

I've look at it again(and I had seen this a few years ago) same conclusion. From looking at the bushes it didn't seem windy at all I think he realized he wasn't lined up perfectly so he used the Ailerons to correct to the right (of the plane) and overcompensated again with Ailerons to the left.

He was still high enough to just let it come down, he was clearing the bushes, their runway is much wider than at WIMAC.;)

[Sempai-mj]

Post mortem,

Trying to steer with the ailerons at low speed and low altitude = Crash!

Use the rudder:)

[Jdonald]

Have been practicing on flight simulator. Takes a bit of repetition. Left hand needs to remember it is in charge of the throttle too. In time I hope it is as good as the right at controlling elevator and ailerons.

[Jdonald]

Back again from the flight simulator. This is scale aircraft and should be landed scale. The best approach is a good approach. Line the plane up with the runway keep the wings level and steer gently with the rudder. Even rudder couldn't save this one. Pilot should realized this was a poor approach much further back and aborted. Too slow and off course.

[Jdonald]

About one third into the video, is that a cigar the pilot has in his right hand? Not sure.

[Jdonald]

A quick note to let all who replied to this thread your replies has been very helpful to improving and understanding how to safely land an aircraft. I have been working on a balsa plane over winter and I realize how fragile they are. Watching the video and using a flight simulator so hopefully this new plane has more than one flight. This thread has been a great learning tool. I have added a few comments even if I look like a novice but working on improving and landing is key.

[Sempai-mj]

A quick note to let all who replied to this thread your replies has been very helpful to improving and understanding how to safely land an aircraft. I have been working on a balsa plane over winter and I realize how fragile they are. Watching the video and using a flight simulator so hopefully this new plane has more than one flight. This thread has been a great learning tool. I have added a few comments even if I look like a novice but working on improving and landing is key.

Right on!
Never rush a landing, go around if not looking good way out there.:)

[Ricardo]

I agree with Mike that a go around is a good resource. But the best is to master the approach and landing.
Remember that electric airplanes tend to spoil the pilots, since the risk of dead sticks can be drastically reduced.
Gas/Glow can be more temperamental, dead sticks can happen, specially when throttling up on a go around.
In summary, go arounds can fix bad approaches, but one should not be negligent with approaches simply relying on a go around as a last resource.
Cheers,
Ricardo

[Dwight Macdonald]

Good points Ricardo. It is suggested good to work on improving your flying in a consistent way.

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[Sempai-mj]

Jump to 1:29
It looked good, aggressive flare and engine failure.:confused:

https://www.youtube.com/watch?v=1YcgSYXXXco

[Michael O'Bree]

How NOT to land by a (FPV) flyer more experienced than any of us...:D

https://www.facebook.com/embryriddlememes/videos/1525651524212515/

[David Janashvili]

How NOT to land by a (FPV) flyer more experienced than any of us...:D

https://www.facebook.com/embryriddlememes/videos/1525651524212515/

Very Funny:):):)

[Dwight Macdonald]

Ouch! I wonder how often that happens ... Birds often hit house windows, but the ground? Perhaps he was catching a flying insect too close to the ground ...

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[Jdonald]

Should have used rudder on approach. Landing gear was lowered too late. Any one have some CA glue handy?

[MichaelLevy]

A lot has been said on this thread about the pilot skills but one important thing has been left out...the airplane,and the pilot's knowledge of this particular model. That scale B-25 has a long narrow wing which, especially when combined with a high wing loading is very prone to stalling. Just before the final stall, the wings wobbled a couple of times announcing that he was very close to the edge of stalling, the speed decreased as he raised the nose and it was all over. The lack of performance indicates the wing loading was high. I fly EDF jets with stubby or delta wings and this rarely if ever happens, even if I come in with a high AOA of 30-45 degrees. Also, I avoid the traditional square "pattern" approach, preferring to slide in on a curve with power and straightening out a short distance before touchdown. I find it make my planes less likely to get into the "danger zone".
As a matter of public interest, the U-2 which has a very long, extended wing is extremely prone to stalling. At 70,000 feet, the difference between the stall speed and maximum speed never to exceed is a mere...7 mph.