PDA

View Full Version : Short field Landings and stalling


Tee Emm
5th Aug 2014, 13:41
AOPA magazine called Australian Pilot (August-September 2014) has an article called Short Field Landings. The author is Bill Grieve of Aeroskill Ultralight Flight Training Centre, Caboolture. He recommends pilots should first learn to fly slow at an altitude where "mistakes don't hurt." He then writes:
"If a wing starts to drop, pick it up with opposite rudder using secondary effect of roll. If the aircraft starts to yaw, correct it with sharp punches on the rudder to yaw the aircraft without inducing roll. Remember you are flying near the stall - if a wing drops and you try to pick it up with aileron, the down-going aileron on the dropped wing causes that wing to exceed critical angle of attack and the wing will drop further sometimes violently."

He continues: "For a short field landing you are now dragging the aircraft in with power- remember that once you are set up on final, with wings level and at the correct speed, the stick is not moved sideways. Use rudder to pick up a dropped wing. To overcome the angle of descent/rate of descent problems associated with slow flight in short-field landings, use power to drag the aircraft in much flatter. I'm sure there are many other techniques used to achieve the same result but this is the one I use and teach."

Presumably as Bill Grieve is an experienced instructor at an Ultralight flying school, he article is aimed at Ultralight pilots. It may go some way to explain why pilots flying ultralights have a higher accident rate than standard general aviation pilots flying Cessnas, Warriors and similar everyday flying school aeroplanes.

It seems extraordinary that Bill Grieve would continue to perpetuate the hoary old myth of picking a wing up with rudder when close to the stall. More alarming is his advice to students to "correct yaw with sharp punches on the rudder without inducing roll.::eek:

Is the short field technique he advocates common to only ultralight types? My understanding of Light Sports Aircraft is they are designed to stall benignly and part of the design includes the ailerons are effective below stall speed. As for "dragging" in to land with power to make the approach flatter, the situation becomes fraught with danger if for some reason the engine falters (according to some reports, happens in ultralights more often than standard aeroplanes)

It is good that that AOPA encourages people to send articles for publication, but maybe there is a need to vet these articles for technical integrity before publication.

sapperkenno
5th Aug 2014, 17:21
Do these ultralight tacky plastic things have a wing with an equal angle of incidence, or do they have washout?
That's still my argument in relation to teaching the SSR here in the UK, with it's "don't use aileron to pick up a dropped wing" method. Why the hell would you set yourself up to enter a spin, when coordinated use of aileron and rudder would be the better option?! Even better, reduce the AoA with elevator, then level the wings, then increase AoA again if you're trying to achieve minimum controllable airspeed.

spinex
5th Aug 2014, 21:44
Bill's a braver man than me, sticking his head above the parapet on that subject. He does have some pedigree in the topic though, one of the aircraft in the following video belonged to him at the time and I'm reliably informed he was poling it.

https://www.youtube.com/watch?v=bzizD3N0PBY

Snakecharma
5th Aug 2014, 22:47
Christ! I wouldn't fly a model aeroplane out of there, let alone one with my backside strapped to it!

Flying Binghi
5th Aug 2014, 23:15
via TeeEmm:
...may go some way to explain why pilots flying ultralights have a higher accident rate than standard general aviation pilots flying Cessnas, Warriors and similar everyday flying school aeroplanes...

The ultralight pilot certificate (ultralight pilot license) came in during the mid 1980's. Before the pilot certificates ultralight owners could teach themselves to fly. Anybody who were flying ultralights when the certificate requirements came in just sent a copy of their log book away and back came a pilot 'license'. From then on training were required to get the cert.

My recollection of the time were most of the ultralight fatals were of VH licensed pilots, and many high time, whilst those who trained themselves to fly had minimal problems. I do not know the then proportion of GA to self trained ultralight pilots.

Obviously the difference then to now is the equipment. Though, why were the majority of the early ultralight fatals of GA trained pilots ?








.

ForkTailedDrKiller
6th Aug 2014, 01:25
If people are being taught to fly short-field approaches so close to the stall that they need to pick up the wing with rudder - then its no wonder they smack in with such regularity!

Dr :8

Mach E Avelli
6th Aug 2014, 01:29
It is probable that pilots brought up on heavier and more benign GA aircraft were not adequately prepared for the lack of inertia and low operating speed range that is typical of ultra lights, particularly the early rag and tube variety. Whereas those who taught themselves often graduated from hang gliders where inertia is low and the margin between stall and VNO/VNE narrow.

Highly experienced airline pilots have also come to grief when returning to grass roots flying.

Also, if people take the advice to use 'sharp punches' of rudder at low speed to keep wings level, then more will come to grief! As for the advice to drag it in flat for a short field, fine and beaut if there are no fences, trees or powerlines in the way, but that's not the reality of most short strips in the bush. Struth, what next? Some stuff should never be published by organisations claiming to be responsible.

If you want some blood sport around the weekend warrior flying club fraternity, try asking the resident guru what controls speed on approach - stick or throttle? Most of them preach it arse about so that if their students move on to more advanced equipment instructors have to beat out bad habits. Unfortunately what is first learned is usually best remembered.

Ultralights
6th Aug 2014, 03:01
yes, i now own the savannah in that video, but that was filmed long before i owned it.

i tend to fly it more like these guys, steep approaches, nose high, low power, using gravity, and a short flare with burst of power, and keeping BALANCED at all times. but also with lots of practice with spot landings at normal fields
real interesting stuff starts at around 2;15

CrPJac80W9Y