Brain fade during training

[2tonne]

This was a quote from another thread that started in relation to what must have been an interesting landing.

Well, lemme tell you this story (and it is nothing to do with me...really...). There was this student pilot who was starting to think he was getting the hang of the whole flying thing. He was at the stage of regular solo circuits and was landing consistently until the most recent lesson. Massive brain fade practicing a short field landing, pulled the throttle just before flare height with full flap. misjudged the flare and dumped the aircraft onto the strip while performing a stop and go. What happened to my, I mean, "Fred's", judgement of the flare. Severe brain fade I'd say.

 

Then to make it worse, on a subsequent glide approach things got interesting. Throttle closed at base turn to simulate engine failure. Made the turn, converted speed to height and then...started to put down a stage of flap...idiot! Instructor sets him straight and the flaps are put away ASAP (that stuff-up rectified). Then, on late final and going to make the strip, engine starts running rough at idle. Still not aligned with the runway but the instructor says they are fine to make the strip and to land (especially considering the rough running engine). Student distracted by rough running engine and still trying to align with runway once again gives the mains a thorough "test" by dropping it down on the mains. Two worst landings ever in one lesson. Aircraft (J160) was fine, but student's ego left bruised - and deservedly so.

 

Regarding the rough running engine, well being a Jabiru there are probably a few people thinking "ha, see!". But, it was interesting - the engine stopped on the "landing". After staring at the stationary prop for a few seconds, the starter was hit and she ran smoothly. And stayed running beautifully while taxiing back. No sign of rough running whatsoever.

 

In hindsight, it was 90% humidity, flying through light showers just below the cloud base. At 16-17 C, that put the flight smack in the middle of severe icing on descent power. The carb heat had been used on the glide approach, but perhaps the engine wasn't generating enough heat at idle to avoid ice? Perhaps the heavier than usual landing dislodged the ice and stopped the engine?

 

Anyhow, student is now thinking through the errors of his ways. Was a timely reminder not to get too confident with this flying thing.

[fly_tornado]

so the instructor failed to apply carb heat and maintains its good character building exercise for the student.

 

 

[2tonne]

Might not have made it clear, but carb heat was applied during the glide approach and only turned off late final as per usual procedure.

 

 

[facthunter]

CArb heat applied during a glide approach may not achieve the desired result. In bad conditions I would suggest running it with power on at least initially to clear any ice that MAY be there. Nev

 

 

[2tonne]

I think my previous post was still unclear, carb heat was actually applied during downwind checks and maintained during the glide approach. I wouldn't have thought that carb ice would be a problem in those circumstances, but found a document from the UK light aircraft association which states:

 

"In conditions of severe icing it is best to avoid making long glide approaches

 

to land, as the amount of heat available from the muff may be insufficient to prevent

 

ice developing, and the risk that the engine will not respond to the throttle should you

 

need to stretch the glide or ‘go around’. A powered approach, with full carb heat, is

 

the safer option under severe carb ice conditions."

 

 

[01rmb]

Hence why as Nev said - you should still actually apply some power for a short period of time even during a glide approach to help put some heat back into the carburettor and clear the jet of any ice. ie Don't just put carb heat on and expect that it will keep the carburettor clear of ice - especially in bad icing conditions.

 

 

[2tonne]

Ok, applying power for a short period during the glide should help clear any ice. However, it wouldn't make for the best training for an engine failure, as part of the exercise is to get a feel for for gliding distance. So, I think the lesson is to avoid practicing engine failures in the circuit when conditions are right for carb ice.

 

 

[facthunter]

Fitting a temp gauge to read carb body temp if icing conditions are common might be justified. GA aircraft have strict requirement s for carb heat effectiveness. I haven't seen much written about a lot of RAAus types. RAAus have a lot of pilots recommending glide approaches ,as standard You could easily end up with inadequate heat available. Nev

 

 

[Guest Howard Hughes]

I have been flying for 30 years now and have found there is a cycle between thinking "I've really got this flying business" and "why can't I even get the basics right". My advice is whenever you think "I've got this" be very careful because the mistress is about to bite! I gotta admit I'm at the bottom of the cycle at the moment, having made a couple of bad decisions in the last fortnight and reflecting on how at least one of those situations could have turned very nasty.

 

All you can do to get out of a slump is to concentrate on the basics, be as accurate as possible and don't forget that rudder. When I go flying today I'll be trying to fly as accurately as possible, diligently crunching the numbers on descent and making sure all my power settings are spot on. Of course in the flare I'll be chanting my mantra "RUDDER RUDDER RUDDER"!

 

 

[2tonne]

It's reassuring to hear that experienced pilots also have their moments when things don't go perfectly. Has certainly been a timely reminder not to become complacent and to keep focussed on what I am doing.

 

 

[facthunter]

When you think you have it skun, you are ready to be a menace to yourself and anyone around you. You have also stopped learning, which I have always said not to do.

 

Not a bad idea after a flight to review the way you conducted it VERY HONESTLY. That way you will improve, not deteriorate.. Nev

 

 

[ayavner]

I know that brain fade very well. Usually happens to me right at about 2 hours, and I plan stops accordingly. I try to always remind myself at my stage that I am only just now becoming aware that I don't know what I don't know!

 

My most recent planet-smiting came when just about to flare, the crosswind suddenly became a tailwind, and suddenly goodbye, 10 kts of airspeed that I really needed just then! Grabbed a bit of power and so softened it some, but still not the most graceful landing ever and I then spent the following week rereading and watching every resource I could get my hands on and so in hindsight was able to see what happened to me (at the time it was kinda like 'what tha...??').

 

As windy as it was that day, i should have gone flapless and carried in more speed. Yup, it was the BASICS that bit me!

 

 

[motzartmerv]

cant get carby ice if the engines switched off...

 

 

[Jabiru7252]

I think my previous post was still unclear, carb heat was actually applied during downwind checks and maintained during the glide approach. I wouldn't have thought that carb ice would be a problem in those circumstances, but found a document from the UK light aircraft association which states:"In conditions of severe icing it is best to avoid making long glide approaches

 

to land, as the amount of heat available from the muff may be insufficient to prevent

 

ice developing, and the risk that the engine will not respond to the throttle should you

 

need to stretch the glide or ‘go around’. A powered approach, with full carb heat, is

 

the safer option under severe carb ice conditions."

Remembering that a closed throttle doesn't need much ice to choke off the air supply where as an open throttle needs a lot more ice to cause any problems. There is a good video around that shows this in a laboratory setting but I cannot seem to find it.

 

 

[ayavner]

cant get carby ice if the engines switched off...

now that's just crazy talk Andy, how on earth would that happen??

 

 

[Jabiru7252]

Hmmm, if the engine is switched off and is wind-milling and acting an air pump, carby icing could occur, or am I being blonde?

 

 

[motzartmerv]

Jabs and rotaxes don't windmill ( generally)

 

 

[facthunter]

Rotax's are unlikely due to small blade (s) on the props and being geared. A Jab might if speed high. I wouldn't like to airstart it without a starter motor . I am unlikely to try this out, unless a good reason exists. Nev

 

 

[motzartmerv]

Ive never managed to air start a Jab. It almost gets there, but VNE comes up to quickly. I think if you were prepared to go that bit closer to the red line (which I hate) and you enough height, I think you could do it.

 

Rotax..Forget about it.. Doesnt even get close..

 

 

[Yenn]

What were you tought when doing practice forced landings? I was always tought to open the throttle every so often to keep the engine warm, even though it had carbie heat applied.

 

Motz is correct when the power stops with a Jab it will stop turning and I have never tried to restart except with the starter motor. Rotax 2 strokes stop instantly.

 

 

[Louie]

I know that brain fade very well. Usually happens to me right at about 2 hours, and I plan stops accordingly. I try to always remind myself at my stage that I am only just now becoming aware that I don't know what I don't know!My most recent planet-smiting came when just about to flare, the crosswind suddenly became a tailwind, and suddenly goodbye, 10 kts of airspeed that I really needed just then! Grabbed a bit of power and so softened it some, but still not the most graceful landing ever and I then spent the following week rereading and watching every resource I could get my hands on and so in hindsight was able to see what happened to me (at the time it was kinda like 'what tha...??').

 

As windy as it was that day, i should have gone flapless and carried in more speed. Yup, it was the BASICS that bit me!

My understanding is you would not lose airspeed with the change of wind direction but your ground speed would increase? Could be the subject for a new thread but just thought I would open it up for discussion as it is an important point to understand. Have I got it wrong? I am sure others more experienced than me may like to comment.

 

 

[motzartmerv]

Did you want some sauce with that can of worms Louie? ..lol..

 

 

[motzartmerv]

But no. You dont have it wrong. IAS shouldnt change as he turns into wind.

 

 

[Louie]

But no. You dont have it wrong. IAS shouldnt change as he turns into wind.

Yep thanks for the sauce Motz!

 

 

[ayavner]

At the risk of opening both ends of the can... i think he's right, it is important to understand so i am hoping I didn't misunderstand (or lead anyone else to) when i posted my thread. So in my mind... my understanding is this - If i am at 65 kts on short final with a crosswind, and it then becomes a tailwind (let's say 10 kts), my ground speed would indeed increase, which would lead me to perceive that I am going faster than i am, but would it not be true that my actual airspeed (ie air flowing over the wings) in fact be 10 kts lower?