Exadios

All aircraft have a higher angle of attack as they approach their service or absolute ceiling. At the absolute ceiling if you slow up you stall and lose height, if you speed up you lose height, but don't stall. A stall is always an angle of attack.Powerin, at the highest possible cruise height (which would not be safe in turbulence, or for manoeuvering) and sensible pilots keep away from, the airliner IS flying at a high angle of attack.

Exadios , it's a balancing act. Adding power can cause a pitch up which is just what you don't want, but the more power you have on the less height you will ultimately lose to effect a safe recovery, because all things being equal and making sure that good control is maintained, the less nose down pitch required and the lower the maximum rate of descent achieved. Once you establish a steep nose down attitude and high ROD the more chance of structural failure due overspeed or entering another dynamic stall if level off is too rapid Nev

Assuming that the plane has not been flown to the altitude where the two velocities intersect (and I certainly hope that would not happen) there is a nose attitude, not too much different to the attitude at which incipient stall occurs, at which the plane will fly. My point is that it is not necessary to go into a dive in order to recover from an incipient stall.

Exadios, I am not discussing Af447. Where did I say pull back on the stick? I said that adding power in an aircraft where the engines are underslung will cause a pitch up that may not be resisted by the elevators. There are new training techniques used by Boeing currently that have reviewed the use of power, of which there is generally not much extra available at height. The amount of height lost is considerable in doing the new procedures safely. Of course reducing the AoA is a critical factor, because it is what is causing the stall. You also get a reduction of induced drag immediately because you are momentarily reducing the requirement for lift, One negative of lowering the nose is that the thrustline does not have an upward component. Nev

The thrust vector may help by reducing the wing loading but that's a (advsrse) square law relationship where as airspeed is a linear realtionship.

Talking to ex Airline pilots at Old Station, the quality of new airline pilots was discussed and the general concensus is that they are afraid to fly by hand, and leave it all to the autopilot. If the autopilot plays up they have little ability to look after the plane.Reading the accident reports and news info confirms that opinion. For the moment stick with Qantas or an airline using "round eyes" as pilots.

What height do you have to be to run into the area with stall and overspeed very close together. I have been told that 42000' is perfectly manageable.

The squeeze between stall and Vne depends on wind loading and the Vne for a particular plane. For instance, gliders up to 100,000' have no problem. On the other hand the US U-2 aircraft has about 10 knots between the two at 75,000'.

For interest, here is what the BEA have released so far. Down near the bottom is:

"the inputs made by the PF were mainly nose-up".

This stuff relates totally to airliners operating at high altitudes. The margin above stall is only about 9 knots., depending on how close you are to "coffin corner". With airplanes that have underwing engines, ( the majority) applying extra thrust will cause a pitch up which may not be able to be controlled by the elevators, so the plane, if it isn't already, will become well and truly stalled. In this instance. It's not a question of proficiency at anything like normal stall recovery, but analysis and recognition of a situation that has only recently been assessed and understood. In search for efficiency, the limits are visited more and more. The air is very thin up there. At 18,000 feet half of the molecules of the atmosphere are below you. at about 40, 000 feet it would be around 80%.. You're talking of true airspeeds of 480 knots and a stall speed about 6% or less, below your cruise speed. You are in an environment where the plane could not do a 5 degree banked turn without getting a stall burble. You get a bit fast and you get high speed buffet. (Separation because of the airflow over part of the wing becoming supersonic). Nev

A stall is a stall at any altitude.

Surely they wouldve been taught it in their basic training when they first learnt to fly... If all else was failing, they couldve atleast given it a shot.... I dunno...

So basically they are now using the recovery technique that we have been using in the light aircraft for a while now, reduce angle of attack, that is?

How not to land out.

An accident report arrising from a fatal glider crash in the UK.

I dunno mate, when I worked in Saudi Arabia, I got the impression that there is alot more Oil around than what we are told. Eg- Iran =at the time found a oil reserve that will keep us going for years maybe 50 plus from memory that was one find at the time. Australia has alot off oil, but cap it waiting for either the price to go up or for the middle east countries to run out.PS- dont listen to the shirt lifter Bob Brown. He is full od BS.IMO

PPS- The Horn of Africa has alot of Oil also found recently over the last couple of years.Thats why the Oil companies are try to buy out the local governments.Just heresay though.

PS. Do you have any coordinates for all these capped fields?

(Some language removed - Moderator)

http://au.news.yahoo.com/thewest/business/a/-/wa/9322747/woodside-makes-oil-discovery-off-wa-coast/Pud

A better source is something like the OGJ exploration page. You will see lots of discoveries around the world there. With those in mind we still ran out in 1967.

I suspect once the market segment for plastic fantastics is saturated the aviation manufacturing industry will stagnate like how the string bag manufacturers are now. Just need oil to hit $150 a barrell again.Next big thing will be electric planes and I suspect 600kgs will be too much for the current battery technology.

I think with current battery technology, 600kgs will be too little. Unfortunately there are presently no batteries that match liquid fuels for Joules / Kg or Joules / M^2.

Thanks. Excelent work.

Hi all, just wanted to clarify that yes Gladiators was the first and Sailplane Grand Prix is the second production, but this time in full high definition! I am working on the blu ray and DVD that I hope will be available in 3 or 4 weeks, incorporating this movie as well as some other programs.Quite happy to answer any questions you may have!

Ken

That was great thanks Exadios,I was surprised to see how much the wings flexed in high lift situations.

 

Very nice glide ration too, especially when compared to the Thruster I fly!!

 

Pud

I think that the Boeing 787 has ASH 25 like wings - for a jet airliner. High aspect flexible wings may be the future for power aviation.

One way to get glider aspect ratio without the span. Of course, it suggests ideas for gliders as well - like a 27M span box wing. :)

The article includes a link to the NASA/CAFE competition.

Can't remember the EXACT details or date, but this has already happened at YSSY.I think it was a Jab flying down Victor One in deteriorating weather (100 feet in rain) and called to come in and land.

Pretty sure they declared an emergency, which 'made things happen', but afterwards had to dismantle and truck out.

 

Anyone out there remember?

Wave flying at Minden sets record.

I've spoken to the technical manager about this. You CAN tow GFA Gliders on an RA-Aus certificate, in an RA-Aus aircraft. RA-Aus and GFA have an agreement to let this take place. You must hold the RA-Aus glider towing endorsement on your recreational certificate in order to tow in an RA-Aus plane (this is just a case of sending your paperwork through for it to be issued onto your certificate).The GFA documentation is out of date and doesn't depict this.

 

-Andrew

FWIW not all a/c can be sustained into a slid slip or more to the point loading up the vertical Stabiliser With side loads.Classic eg is that I know of is a 737 that lost its verticle stabiliser due to the pilot being taught/maybe to use full deflection of the rudder (each way) when in wake turbulence.The full deflection caused the Vertical Stabilizer to depart company with the A/c.Also A B52 lost a Vertical Stabilizer during low level Tact flying .(Why a B52 was doing low level work has got me F*^^%) Anyway they lived to fly another day.737 crew and passengers didnt.I know there is a difference between holding a side load (side slip) and kicking peddals each way and loading up each side of the vert stabilizer depending of the rudder deflection.But they are not as strong as people thing they are.IMO

My guess as to why the B52 was at low level is because flying at 500' AGL is one of their tactics.

It depends. I would not start turning anywhere (and loose height and thus options) without knowing if the options would get any better. That does leave the possibility of missing out on the option behind you, which may be gone by the time you work out it would have been best. Damned if you do, damned if you don't. I would not hold his decision making against him.Again, the guys trying in the sim had nothing to loose. What if Sully did immediately try to turn back and didn't make it? He'd have killed hundreds of people in the aircraft and on the ground!

Why do you think he would he not make the runway?

As I understand the incident the crew did not start selecting landing options until after the engines failed. The time to make that decision is before the engine failure.

Funnily, they put some pilots through the sim for what Sully and Skiles went through and they all made it back to the runway! Easy having prior knowledge that you are not going to get your engines back and turning around immediately...

I have seen that a while ago, amazing he managed to side-slip that thing and land...