Originally Posted by Sunfish
What is to stop you retracting flap to extend your glide?
I think most pilots would be better served by going straight for the carby heat if on short finals at YMMB if the engine splutters and dies, historically carby icing is the real issue, not how much flap one has selected or the size/shape of circuit flown. Off field, what should have been taught is that first, if you are looking short, is to reduce the distance to touchdown by turning towards the aim point earlier, i.e. making crosswind, downwind, base shorter. Flap selection should be restricted to leave as much variation of control as possible over the angle and rate of descent.
Originally Posted by Sunfish
I've never seen this discussed, let alone demonstrated or taught.
Originally Posted by The Green Goblin
First of all, you should not have 'full flap' in a C172 at 500 feet.
The CASA standard that is expected to be taught is "turn onto final at about 500FT and select landing flap when rolled out on final", that is straight from their instructor manual. In reality if you turn onto final at 500 ft, and select full flap when rolled out, you will be just below 500 feet, but not by much.
Originally Posted by The Green Goblin
It may be okay at a GAAP (class D) aerodrome where everyone is doing the same thing, if you fly in the real world and do this with an RPT aeroplane up your behind, you could become an accident waiting to happen - especially if you were not making the required radio calls (which has happened to me on occasion).
Airmanship and situational awareness is a two way street.
Originally Posted by The Green Goblin
Energy management is a crucial aspect of airmanship which is not taught.
Originally Posted by The Green Goblin
A well known ex Kununurra CP used to demonstrate a turn back after take-off and expect his boys to be competent at the maneuver ( manoeuvre ).
A turn back in a C172 would require a 45 degree AoB turn, which places the aircraft at the stall speed at low altitude in an emergency. The altitude loss for a 180 degree turn in "test pilot" conditions is 200-300 ft. A PPL holder being hit with an engine failure, and then a subsequent stall warning would not fair so well. In a paper presented to the AIAA, 28 pilots with experience levels from 40 hrs to 5000 hrs were put in a simulator and told to expect and emergency at some stage. They were given a takeoff clearance to climb straight ahead to 3000'. At 500 ft they were given an engine failure, 85% of pilots landed straight ahead, no crashes, of the 15% that attempted a turn back, 2/3 crashed from steep bank/stall. Then they were repositioned for takeoff, pilots were told to expect engine failure at 500’, and they could handle it any way they wish. 90% of the pilots landed straight ahead, no crashes. Of the 10% that turned back, 50% crashed. They were then repositioned again for takeoff. Pilots were told to attempt 180 turn upon engine failure, only 43% of them were successful. 85% of failures involved bank exceeding 55 degrees which is a low level stall/spin entry. It is far safer to land in area that would require smaller angles of bank to maximise the stall buffer. This become even more pronounced in low visibility and at night, and with low experience. Turn backs in GA aircraft at low altitude in my view are right up there with going past a perfectly good airport if you have a problem to save your boss a few bills, or not closing the second throttle on a light twin when not achieving some climb performance.
Originally Posted by The Green Goblin
Something like a PC12, a turnback after takeoff is a QRH maneuver ( manoeuvre ).
Originally Posted by RadioSaigon
WHY oh why are you even discussing a "stabilised" approach??? It's an inappropriate notion when discussing the average GA airframe -up to & including most twins!!!
The majority of people I have taught went on to fly other aircraft apart from GA singles. Even in a GA single, conducting an instrument approach requires the aircraft to be stabilised from the FAF/FAP. The earlier this concept is taught, the easier it is to move from the known (VFR) to the unknown (NVFR/IMC) training. Night training should also involve stable consistent approaches.
Originally Posted by ForkTailedDrKiller
What is the problem with overshooting with 40o flap?
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I have to fess up, it's a while since I've flown one in any configuration... but from memory, with 40 degrees out in the breeze and even a moderate load (say 2 POB, 1/2 tanks) full throttle in that configuration resulted in a negative ROC. If a missed approach was necessary from that configuration, I started getting the flaps up (very carefully) from the instant the throttle was in.
American courts of the day (70's, 80's) took pretty much the same view, which very nearly sounded the death knell of the GA manufacturing industry around that time -and certainly resulted in Cessna reducing the available flap from 40 degrees to 30. The old crash reports were replete at the time with details of Yanks flying their 40 degree equipped 172's into oblivion on a missed approach from a 6,000' concrete runway!!! No editorialising necessary from me there... So I guess really the problem with overshooting from that configuration (something I have done -apparently successfully :E) is, or should I say was apparently a lack of training and inept mishandling. |
My question is as follows. Suppose you are on final, configured with full flaps for a landing, say just at 500ft. The engine coughs splutters and dies. You are doing 65 knots. You judge you aren't going to make the field. Yes, I know I should be able to make the field, but that's moot just now. In addition at places like YMMB, some pretty flat approaches get taught in my opinion. What is to stop you retracting flap to extend your glide? Simple question and a pretty simple lesson being tought here. |
Here is another worthy video to watch.
This is NOT a suits all demonstration, but it does make you think carefully about how you would deal with a turnback scenario and how best to train for and execute. If you know you can....its better than a controlled crash. If you only think you can..........you can't. Best to know what you can and can't do. Aerobatics in California J:ok: |
Or consider this
Accident description
Status Date:27 DEC 1986Time:13:48 Type:de Havilland DH-114 Riley Heron 2B Operator:Sunflower Airlines Registration Q-FEFC/n / msn:14056First flight:1955 Crew:Fatalities: 2 / Occupants: 2Passengers:Fatalities: 9 / Occupants: 12Total:Fatalities: 11 / Occupants: 14 Airplane damage:Written offAirplane Location:near Nadi (Fiji) Phase:Approach (APR) Nature domestic Scheduled Passenger Departure Savusavu- Nadi, Fiji At 500 feet the right flap jammed at 35° while the left one continued to 60°. The aircraft rolled to 90° bank, struck the ground and cart wheeled short of runway 21. PROBABLE CAUSE: Unsecured non-standard flap attachment pin migrated upward and lodged in a lightening hole. |
As Im at work, I cant watch the above vids but I can say that I have been shown the turn back once and it was followed by pretty strict instructions on its use.
In a 152 we set out to perform this maneuver, where just short of 700ft(xwind turn for us) the instructor pulled the power and performed the move. Back on the strip he asked me to perform this as per his prompts, which I did and we landed again safely (quite day at the field). His instructions were that it was possible, BUT only if you can check these 3 things off can you attempt it. Good head wind on takeoff, giving a good tailwind to help get back. Never below 500ft, and even then it shouldnt be below at least 600ft. No one following you on the runway. Before anyone says anything, he drove home that landing ahead option 1 and 1a. The only time you should consider this was if in your pre take-off brief you know there is no a safe field off the end of the runway to land in. Never exceed 30deg AoB. Ive never attempted it again or been asked to perform it. Just giving a newbie’s point of view on whats being taught :ok: |
Never exceed 30deg AoB. I think when you get to see the video's you will change your mind on that. Seems that more is good. I am going to do some tests myself some time soon to see what results can be achieved safely. |
Originally Posted by SWH
Stabilised approaches need to be taught...
Jabawocky's 1st video is one of the examples I was going to quote myself... their stabilised approach went all to hell in a hand-basket when the power faded. Had a stabilised approach been the only trick in their arsenal, how do you think that would have wound up? They were able to see and do what was necessary to achieve a bloody good result because they were trained to see and respond to what was necessary rather than slavishly follow a formalised procedure. Likewise, Captain Sullenburger of Hudson River fame -how "stabilised" do you reckon his approach was? The Politically Correct stance of "train 'em for the majors" is bull**** IMO. Many will never make it, some don't want to. They still have years of active GA flying in front of them and need to be trained to fly what they are in. |
Firstly in reply to Sunfish I would say that retracting flap would be OK if overshooting as long as the IAS is adjusted appropriately and the aircraft trimmed, as previously stated. Certainly worth a try if all else has failed, anyway! For information, the ADF teaches CT4 students to initially pick an aiming point 1/3 into the selected landing field, then when on final full flap is selected to bring the aim point back in order to take full advantage of the landing distance available.
Secondly – my 2c on glide slope management for powered approaches. The ADF teaches CT4 students to roll out final at 500FT AGL then select full flap. The resulting glide slope is significantly steeper than those flown by other GA types I have observed that also are using full flap. I estimate that the full flap glide slope some GA drivers are using are shallower than the glide slope we teach CT4 students for flapless approaches. As others have stated, a case of trying to fly 747 circuits in lighties in my opinion. Why? Thirdly – turn backs. Reciprocal turnbacks are possible in the PC9. However these manoeuvres are not to be briefed, demonstrated or taught to students. And with good reason. Remember the PC9 has an ejection seat that works quite well. Why risk stalling the aircraft at high AoB trying to make it back when the Martin Baker roadside assist plan is available? As a first tourist QFI on the PC9 I recall practicing reciprocal turnbacks with other QFIs. The “manly” thing to do was to hack the throttle at 500FT AGL and try to get it back on the runway from there. Frequently this required pulling to the light buffet in order to haul the nose around. The lunacy of this eventually dawned on me after practicing these manoeuvres at night, scaring the sh!t out of myself. A couple of thousand more hours on the beast later, I wouldn’t consider a reciprocal turnback in the PC9 below 1,000FT AGL. Remember the ADF has spent a motza installing ejection seats. They’re not there for looks. Reciprocal turnbacks are only practiced (sans students!) in the CT4 to demonstrate the absolute futility of attempting such a manoeuvre in that aircraft. |
I've practiced and pulled off the odd turn back successfully, no dramas, but that was ideal conditions. As we should all know it wouldn't take much for things to go pear-shaped; one thing leads to another when the proverbial hits the fan.
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My question is as follows. Suppose you are on final, configured with full flaps for a landing, say just at 500ft. The engine coughs splutters and dies. You are doing 65 knots. You judge you aren't going to make the field. Yes, I know I should be able to make the field, but that's moot just now. In addition at places like YMMB, some pretty flat approaches get taught in my opinion. What is to stop you retracting flap to extend your glide? |
Jaba, your correct saying my tune would change after watching the aero vid. From memory Im sure he said I should try to nail 30deg and best glide speed during the turn, but we were also at around 650-700ft, and again he said it would depend on good conditions, like XXX described.
Anyway, when I go for a nav this week Ill still be prepping for the fields off the end of the strip:ok: My circuits are a 300ft decent on base and a 700ft final with flap 30 at around 500ft. 1/3 strut spacing downwind, 45deg to threshold base turn. It seems like a pretty standard pattern to me, I hardly think this is airline stuff? We have RPT at our CTAF, and when ever the PAPI is on we pretty much ignore it as our profile is more like 4 or 5 degree profile due to being much smaller and having a steeper profile. Its all good to train students to act in a professional way "gettin em ready for the majors" but part of that should be teaching people to fly their current type correctly? Back to the flaps though, a small change of one stage just extend the glide a little shouldnt be a problem I think. But if you find yourself wanting to pull back more than that, chances are you've made a meal of it and probably shouldnt be up there flying in the first place. They drummed it into me pretty hard about getting it right, you only getting one shot in a real failure. |
Originally Posted by RadioSaigon
I'm of the opinion that trainees need to be taught appropriately to fly what they are flying now, not what they may or may not fly several years and thousands of hours down some future track -when they can be properly and appropriately trained in what they need to know, in what they need to know it in.
Originally Posted by RadioSaigon
The "consistent picture they need to hang their hat on" when training and in the early stages of their career does not come from attempting to fly an inappropriate "stabilised" approach. They need to be getting trained to see and accurately perceive the sight-picture in front of them and manage their approach path and appropriately respond to managing their profile to achieve the desired result.
It does not mean a 3 degree ILS approach from 3000'/10nm.
Originally Posted by RadioSaigon
Had a stabilised approach been the only trick in their arsenal, how do you think that would have wound up?
Originally Posted by RadioSaigon
Likewise, Captain Sullenburger of Hudson River fame -how "stabilised" do you reckon his approach was?
Originally Posted by eocvictim
It is important to recognise that its not just airlines that use stabilised approaches.
Originally Posted by eocvictim
If you fly most bugsmashers the way the book says I'm sure you'll find yourself very close to the glide profile anyway. Personally I would argue that this is stabilised; I haven't seen a broad definition that states a requirement to be on a 3degree profile in order for it to be called stabilised.
In larger aircraft, manufacturers get more specific with their published procedures, and hence their operations are less variable.
Originally Posted by SpyderPig
I hardly think this is airline stuff?
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What I was taught way back was:
1) Don't select full flap until a landing (on the runway) is assured, 2) Don't select flap, when the result will be the requirement to add power to overcome the associated drag. I suggest that if the above is followed, then the circumstances outlined in the question at the start of this thread is minimised. These days I believe there is far too much emphasis on following strict procedures and not in teaching students that there are other options on the menu that may be suitable. The student must be able to think outside the box! |
As for the 'keeping the circuit tight so that you can glide to the runway if you have an engine failure' , that would mean a glide approach for every circuit you do, would it not? Either that, or you land long with a normal power approach.
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The majority of pilots issued with a new CPL in Australia transition to a multi-crew aircraft with less than 250 hrs total time, and normally do so within 6-12 months of being issued with the CPL (some are asked to sit and wait for a bit longer like during the last downturn). A lot of those CPL holders are trained for overseas airlines (be around 30-40%) did you know that 75% of all statistics are made up.............:hmm: |
SWH, what you're describing pretty much mirrors what I've been taught since I started flying charter. That is, every approach is required to be stabilised (yes, even in a 210) - the only thing that changes with type/weight/size of aircraft is how far out this must occur. And that "stabilised" doesn't have to mean a perfect 3 deg slope - it just means being able to continue the approach to the runway without any gross changes in configuration or attitude, and with airspeed continually reducing to reach threshold speed on short final.
What I was taught way back was: 1) Don't select full flap until a landing (on the runway) is assured, 2) Don't select flap, when the result will be the requirement to add power to overcome the associated drag. I experienced what I see as the "opposite" view a few months ago - riding in the back of a 210 with a pilot I'd never met - he kept around 20" on with an aiming point a few hundred metres past the threshold, then on very short final, cut the power to near-idle, dumped full flap and shifted his aim point to the threshold, resulting in a very steep approach for the last half-mile or so. Nothing really out of whack, airspeed pretty much where it should be and a good landing not too far past the threshold - but it hit me as a completely opposing theory on how to fly a piston single approach. Not what I'd call stabilised. If he'd had an engine failure on short final though, he may well have been in a better position than I'd got used to flying a C206/210. But I wouldn't like to jump out of the 210 into a PA31 and use the same technique. I'm not saying this is "wrong" though - some here will probably say this is how they do it and any other way is crazy. Don't know. The concept of always flying a stabilised approach has always been completely logical to me though, and make the transition to heavy piston twins (and I assume turbines and beyond, not there yet) a lot more straightforward and logical. |
Look guys, it would appear you all do not know the definition of a stabilised approach.
I'll post it here for you: 1. The aeroplane is on the correct flight path 2. Only small changes in heading and pitch are required to maintain the correct flight path 3. The aeroplane is not more than Vref +20 and not less than Vref 4. The aeroplane is in the correct landing configuration 5. Sink rate is not greater than 1000 feet 6. Power setting is appropriate for the aeroplane configuration 7. All briefings and checklists have been completed 8. Stabilised by 500ft in VMC or 1000ft in IMC This is in regards to an above 5700kg aeroplane. Whenever we are talking stabilised approach criteria, this is what is being referred to. In regards to a light piston single or twin, there is no reason why you can't use this as a reference, however you should fly the aeroplane as is required to do so in the interests of safety. In regards to the ongoing debate about the 3 degree glideslope, the requirement is to be on the correct flight path for the approach that is being flown. Some require more, others less. A piston single feels mighty awkward when you are trying to fly a PAPI! |
If you need to ask
Go back to flying school. Who was it Wilbur or Charlie ??.
Certainly not the mad fool Orville. FFS. |
Forget the theory, reconfiguring flaps close to the ground should be done with great care regardless of type .... and only when absolutely necessary.
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