100hrs! - The perfect circuit
Classic Spin Recipe
- Tail wind on base
- Illusion of higher airspeed than actual
- Pilot anxious to get lined up with final
- Shallow turn
- "Help" turn with rudder
Join Date: Jan 2001
Location: In the boot of my car!
Posts: 5,982
Likes: 0
Received 0 Likes
on
0 Posts
So it's full flaps immediately, chop the power, carb heat on, continue perpendicular to the runway for five seconds, make a continuous descending 270 degree turn at flap limiting speed and, oh, 45 degree bank or so, join final somewhere over the threshold at 100' or so, milk out the excess speed you have above the runway and touch down.
There are a number of reasons for that. Firstly you are in a high drag situation with little extra lift with full flaps. ie you are carrying drag you dont want in the event of a go around. Secondly a good approach and landing is all about speed and profile control. Speed control is about reducing speed in various portions of the circuit till you come back to the VREF for your aircraft on short finals.
In gusty windy conditions you may not want full flap.
On a Seneca I never take full flap unless the strip is very short.
This doesnt matter whether its a 152 or business jet. Application of drag, gear and flaps is part of a managed speed approach and varying degrees of flap should be added to assist with that speed control.
I believe certain aircraft will not go around with full flap so why take on a potentail problem when you dont need it?
I would also not recommend the use of 45 degrees bank for the following reason. Your margin to a stall spin accident is smaller which may be fine when you are well in control but not so fine when the visibility goes down or you get distracted. It is also not a comfortable practice for any passengers.
Yes there maybe occasions when you grab full flap and bank over sharply but that is an exception rather than good flying practice.
The satisfaction you will get from a well managed and controlled approach profile will not only serve you well but set you up for handling faster and larger aircraft in the future.
Pace
Join Date: May 2006
Location: Londonish
Posts: 779
Likes: 0
Received 0 Likes
on
0 Posts
Pace, all good points (bar a couple 
) I hope both backpacker and I have made it clear that IF we're taking the bigger bank angles, it is done with extra knots in the bank - thereby covering the reduced margin. It's not a recommendation that everyone should do it. Unfortunately I was more reacting to someone's implication that banking >15degrees in the circuit made one a bad pilot. Silly of me.
As for speed and profile control every approach needs it, however, horses for courses - The average jet requires a stabilised approach, particularly because of the response of jet engines. Your average bugsmasher is not so constrained. If I ever fly jets I'm sure I'll use a stabilised approach as per SOP. That's no reason to fly one in a warrior.
Having done most of my flying with old school instructors - my circuits are close, so I can turn in at any point if it goes quiet, and I rarely take much, if any flap until I'm sure I can make it without the noise up the front (aka the glide approach, and very much out of fashion). By modern standards I'm too high. Flying at an urban airfield I'll take that any day over the off field landing alternatives, and before anyone screams 'shock cooling', I'll have cooled the engine quite adequately on descent.
None of that is to say I'm not giving thought to margins (e.g. having an extra few knots in the tighter turns), or planning where/when I'm going to hit my 'profile'. But at a fairly busy mixed airfield it's a fluid environment - a rigid numbers circuit holds everyone up, and serves little purpose. You'll quite likely get a request to maintain speed, cos there's a twin about to chew your tail off, or similar.
All of which is a very long winded way of trying to make the point there is no 'perfect' circuit (even if there are an awful lot of imperfect ones!)
And yes, I score every one of mine, critically and aim to improve. The good ones are very satisfying. For some bizarre reason my more unconventional approaches usually work out better than the more conventional ones - who knows why!
) I hope both backpacker and I have made it clear that IF we're taking the bigger bank angles, it is done with extra knots in the bank - thereby covering the reduced margin. It's not a recommendation that everyone should do it. Unfortunately I was more reacting to someone's implication that banking >15degrees in the circuit made one a bad pilot. Silly of me.As for speed and profile control every approach needs it, however, horses for courses - The average jet requires a stabilised approach, particularly because of the response of jet engines. Your average bugsmasher is not so constrained. If I ever fly jets I'm sure I'll use a stabilised approach as per SOP. That's no reason to fly one in a warrior.
Having done most of my flying with old school instructors - my circuits are close, so I can turn in at any point if it goes quiet, and I rarely take much, if any flap until I'm sure I can make it without the noise up the front (aka the glide approach, and very much out of fashion). By modern standards I'm too high. Flying at an urban airfield I'll take that any day over the off field landing alternatives, and before anyone screams 'shock cooling', I'll have cooled the engine quite adequately on descent.
None of that is to say I'm not giving thought to margins (e.g. having an extra few knots in the tighter turns), or planning where/when I'm going to hit my 'profile'. But at a fairly busy mixed airfield it's a fluid environment - a rigid numbers circuit holds everyone up, and serves little purpose. You'll quite likely get a request to maintain speed, cos there's a twin about to chew your tail off, or similar.
All of which is a very long winded way of trying to make the point there is no 'perfect' circuit (even if there are an awful lot of imperfect ones!)
And yes, I score every one of mine, critically and aim to improve. The good ones are very satisfying. For some bizarre reason my more unconventional approaches usually work out better than the more conventional ones - who knows why!
Join Date: Jan 2001
Location: In the boot of my car!
Posts: 5,982
Likes: 0
Received 0 Likes
on
0 Posts
And yes, I score every one of mine, critically and aim to improve. The good ones are very satisfying. For some bizarre reason my more unconventional approaches usually work out better than the more conventional ones - who knows why!
The problem with a standard is just that and there are times where high banks and full flaps could be a problem usually at the worst times.
Your question concerned the perfect circuit? I have no idea of your experience level but for me any perfect circuit or approach is one that is governed by speed and profile control as well as configuring the aircraft for the worst scenario.
That has to be minimum drag with max lift and keeping tools back to control speed and descent profile.
In the Citation approach flap is the norm. Taking full flap in one go causes a pitch up on the glideslope and a fair amount of drag. I will bleed from app flap to full in small amounts allowing the flaps to act as airbrakes and to help the autopilot on the glideslope. Drag taken that way brings the speed smoothly back to VREF with the aircraft stabilised.
The last thing you want is everything hanging out with your VREF achieved too early. Its not friendly to ATC or other aircraft to plod in at slow speed or to make power your only speed control.
Get on the back of the drag curve and you will soon know about it especially with light low powered aircraft.
Yes there are times to dump the lot and in a jet that might be full flap gear and speed brakes, but that is one trick up your sleeve not a standard.
There is littel difference with a light single. You may find it easier with full flap as you only have the power or pitch left to worry about but for the perfect circuit consider different speeds and drag at different phases of the circuit.
Ultimately more challenging but more satisfying. when you master that the full flap bit if needed is a piece of cake.
Consider a circuit climb out speed is low you only require 15 deg bank in the climb where will that put you with full flap and 45 deg bank at simular speeds on the approach? It cannot be a perfect circuit?
In nil wind a 15 deg banked climb at 80 kts with an 80 kts down wind and 80 kts down the approach would require a 15 deg bank to bring you onto the centreline of the approach?
Vary your speed or bank and your circuit would not be square.
Pace
