LeSving wrote:
Why use AOPA training program instead of FAI?
I dont think there is much between them?
LeSving wrote:
But, if the instructor gets incapacitated in a tandem, what can you do anyway, how would you know in a spin? Something to think about.
As I said earlier, I think only by having clearly briefed instructions as to the point at which either pilot will apply spin recovery. If the instructor is incapicated and the student is unable to recover for various possible reasons from the spin there it is, but if either passes out then the other must surely be clear when to attempt a recovery and because things happen relatively quickly the point at which this occurs does need to be briefed, along the lines that if you see and feel no spin recovery being applied as we pass x feet, then you must apply spin recovery.
I fully appreciate that fore the ab initio student things are so disorientating and so much is going on they may struggle to react to the situation and to apply the correct technique, but even then it is better than nothing.
LeSving wrote:
But, if the instructor gets incapacitated in a tandem, what can you do anyway, how would you know in a spin?
Also there is the possibility that the incapacitated instructor’s feet is applying pressure to the rudder pedals (especially when the plane is in a nose down attitude) and it might take a couple of extra seconds for the student to put the anti-spin rudder input in once they realise the instructor is unresponsive (which in turn, has taken extra time, because with the instructor behind the student, the student won’t know as quickly that the instructor is incapacitated). Or worse still, perhaps the instructor is in severe pain and has ‘locked up’ somewhat. e.g. there is a hypothesis that the captain in the Staines Trident disaster was in severe pain from his cardiac condition, which may have led him to do the wrong thing, being able to think straight due to severe pain.
In my work operation, we use:
Minimum Abandonment Height = 3000’ AGL
Minimum Height to Commence Recovery = MAH + 2000’
Minimum Entry Height = MHCR + (400 x each turn of spin intended)
For a 4 turn spin this would give us a MEH of 6600’ AGL which could be about 7100’ QNH in our local area
If the intended pilot handling was not taking / applying effective recovery action at MHCR the other pilot or student should take over and apply recovery action
skydriller wrote:
Have you ever tried doing W&B for a C152 with 2×90Kg adults?
90kg is simply too heavy for an FI – sorry for that. It’s even worse in the UL-scene – you can tell easily that there is a fundamental issue with sticking to safety relevant rules by realizing that there is no trend towards jockey like body shape for UL-instructors.
skydriller wrote:
Our aeroclub Robin DR400s use “2×78Kg front & 2×70Kg rear” in its example W&B…
Average weight of a French male is 82kg, that of a French woman 68kg. If you consider that private pilots are often above average active and therefore below average weight, the example is not far off…
skydriller wrote:
Is [C152] an unsuitable primary training aeroplane?
No, but it is a borderline case. Also, there is no reason to use parachutes for the kind of training you do in a 152.
Difficult thread as I knew the instructor and have flown this aircraft. Very professional and competent lady (UK Advanced champion) and difficult to come to terms with the accident.
The flight was an early sortie in teaching aerobatics at the Sports level. This will have an extensive brief, with the instructor teaching a walk through and planning a sequence in a competition box. At Sports, the floor of the 1 km cube box is 1,000 feet AGL, and spin entry in a sequence is toward the upper limit of the box.
The spin at sports level is upright, and limited to one, or one and a quarter, or one and a half turns, exceptionally one and three quarter turns. Depending on where the judges are, and how many turns, you might spin right or left. Power on entry is reduced to idle, but re applied on the recovery dive. The Pitts recovers in half a turn, and spin recovery is very straightforward. The spin is not in stable auto rotation and is an aerobatic precision spin – quite different to old style UPRT where you aim to achieve stable auto rotation, and where typically recovery floor is 3000’ The new advanced UPRT no longer covers full, stable auto rotation phase. The basic AOPA course does not necessarily spend that much time on precision spinning, so the student may have had very limited training on spinning. At Sports level, recovery is planned around 1500’ agl. This was the second spin on a second sortie, so I surmise, based on experience as a student and instructor, that the student was conducting the manoeuvre, the instructor having demonstrated the first spin. This is just speculation.
There is no ambushing type manoeuvre in this training where the instructor would enter an un briefed manoeuvre and then announce to the student, ‘recover’. Or a scenario of the instructor carrying out the spin entry and the student recovering. A UPRT scenario would be later in training to demonstrate either a change over spin (upright to inverted) or an accelerated/flat spin with demonstration of aileron/elevator/power on spin characteristics. It would be briefed.
On station mass limits, this is not unusual. Some military spec trainers have station mass limits, typically around 90kg, but net of parachute.
One odd conclusion is around the M&B. The aircraft had a new MT propeller fitted which increased the empty weight by around 27 lbs, but moved the empty CG back by a significant margin. At first reading this doesn’t make sense, unless the new propeller weighed considerably less (moving CG aft) and the increase in empty weight was due to the usual weight gain (new paint or avionics which sit in the rear, but it only had Trig com from memory), with age. Ideally the AAIB might have been more careful before saying it was being operated out of envelope. The revised M&B just doesn’t look right.
This seems very sad and hard to understand. It’s not as though the student was new to acro – if he had an acro rating (whatever that is – doesn’t exist in FAA land) then presumably he had done spin recoveries ad nauseum (literally). When I flew acro regularly I would do at least one spin at the end of each flight, just as a way to get down to the altitude I wanted for the return flight.
I just once got into a spin I couldn’t get out of. Somehow I entered this odd thing called a “knife edge spin”. It isn’t really a spin in the normal sense, but it is gyroscopic. I had got so blasé about spin recoveries that I would do them without the P (power reduction). In this case that was essential. My instructor cut the power and we popped out within a fraction of a second. Then he said, “I think I just earned every dollar you’ve ever given me.” A bit later I got into one again, instantly recovered, and he said, “Well done, but I was hoping you would hold it for a while to see where it went.”
As far as W&B goes – I don’t believe a Decathlon has ever taken off here in the US with two adult males, under gross. 180 lbs (82kg) is about the lowest weight for a normal American male (e.g. my acro instructor, who is 6’ and pretty slim). With two of those you can take enough fuel for about 15 mins of flight. Make it 200 lbs – typical weight of an adult US male – and you can’t even fly round the pattern twice. Much the same for the 152.
RobertL18C wrote:
The flight was an early sortie in teaching aerobatics at the Sports level. This will have an extensive brief, with the instructor teaching a walk through and planning a sequence in a competition box. At Sports, the floor of the 1 km cube box is 1,000 feet AGL, and spin entry in a sequence is toward the upper limit of the box.
This is exactly as I would have expected, and i am sure there would have been a thorough brief.
Ultimately it maybe as simple as surmised earlier – unfortuantely the instructor had a medical event, the student did not realise, and did not initiate a spin recovery. Unfortunately sometimes it is this simple, and a chance in a million.
The student may simply have not had the experience to realise the spin should have been recovered, or maybe it was his recovery but he was disconcerted by the added pressure on the controls caused by the instructor’s medical event.
Sometimes we can only speculate, and with these incredibly rare events even the ebst brief may not provide the solution.
The floor was 1500ft agl and you do max 1.5 spin from 3000ft which is way more than enough but in congested airspace not ideal for an-initio training or instructor incapacitated, if aircraft is out of balance, the height at which the spin starts may not matter much…
I agree with Rob, the revised W&B is just odd (a bit like saying an aircraft losing a heavy prop will pitch up stall too early and go into unrecoverable spin?)
If an MT three blade replaced a metal two blade (I don’t know, just speculating), there will be a W&B change, and possible effect on the power off glide characteristics. we often choose an MT prop to reduce a nose heavy effect (particularly Cessna floatplanes). A tail heavy airplane will usually seem nicer to fly and be a little faster, because less tailplane downforce is required. However, a C of G behind the aft limit might make a spin much more difficult to recover, and startlingly so. When you push the stick full forward, and the nose does not come down as expected, and perhaps increased drag from an idling prop changed the airflow over the tail. This was certainly a factor in one of my planes, when I changed from a Hartzell two blade to an MT three blade, the airplane have much less favourable glide characteristics.
I trust that the AAIB considered this in their report, and their remarks about behind the aft limit seem clear to me. Pilots need to consider aft C of G errors with great seriousness, particularly for spin recovery.
