djpacro

13 hours ago, F10 said:

.... your aircraft flight manual instructions on spin recovery actions, should always be followed.

Indeed. A flight manual will have the recovery procedure from a spin.

Even types not approved for intentional spins.

The certification test pilots define a spin as "a sustained autorotation at angles-of-attack above stall" per FAA AC 23-8C. That's all. 

Types not approved for intentional spinning are only tested "to assure that the airplane will not become uncontrollable within one turn (or three seconds, whichever takes longer) if a spin should be encountered inadvertently". No need to discuss whether it is an incipient spin or not. If it is autorotating then it is spinning so use the spin recovery method. Only done one turn - may be an incipient spin - doesn't matter, that's all that has been tested and the test pilot tells you in the flight manual how to recover.

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there is a difference between the incipient recovery and a fully developed spin recovery.

The people who write the spin recovery method in the flight manual use the above definition of a spin, nowhere in AC 23-8A does it even mention an incipient spin. An incipient spin is a spin so use the spin recovery method in the flight manual.

Cessna's Spin Document notes:

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The subject of airplane spinning is a complex one, which is often over-simplified during hangar-flying sessions. .... During this incipient phase, spin recoveries in those airplanes approved for intentional spins are usually rapid, and, in some airplanes, may occur merely by relaxing the pro-spin rudder and elevator deflections.
However, positive spin recovery control inputs should be used regardless of the phase of the spin during which recovery is initiated. Briefly, these control inputs should be 1) neutral ailerons and power off, 2) full rudder opposite to the direction of rotaiion, 3) just after the rudder reaches the stop, elevator briskly forward to break the stall, and 4) as rotation stops, neutralize the controls and recwer from the resulting dive.

Note the use of the word "may"!

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there is a difference between the incipient recovery and a fully developed spin recovery.  In the incipient phase .. if you immediately centralise the controls, ....  Most aircraft will be considered to be in a fully developed spin after 2-3 turns.

So you recommend simply centralising the controls if in an incipient spin? Before 2-3 turns? AC 23-8A states "Most airplanes will not attain a fully developed spin in one turn." When I demonstrate an aggressive unintentional spin entry with power and aileron it will be fully developed well before 2-3 turns.

By all means, if in an aerobatic aircraft and unintentionally enter a spin while conducting aerobatics and take immediate action (so very early in the incipient spin phase), centralise the controls to prevent the spin from developing - it is appropriate then.

In other circumstances, this acccident is a good example of what goes wrong when transitioning from a stall recovery method to a different stall recovery method with a wing drop to a different recovery method from an incipient spin then to a different fully developed spin recovery method https://www.atsb.gov.au/publications/investigation_reports/2014/aair/ao-2014-083/

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So this is when you need to pull the stick back, to prevent rudder blanking and go check power off, then full opposite rudder, ease stick forward, to install wings.

Depends on the aircraft.

A type I flew recently stated that these 4 actions "must be carried out immediately and simultaneously. Power lever - idle. Ailerons neutral. Rudder - full deflection against direction of spin. Elevator - fully forward." That type is not approved for intentional spins so that is the required action when it is autorotating ... in the incipient spin phase. I wonder if the flight instructor in the fatal accident of that type knew of that when he was doing stall practice with a student as it is quite different from the method he was taught when he got his spin endorsement?

1 hour ago, skippydiesel said:

Me thinks you not only exaggerate horribl (the number),  you also oversimplify the reasoning - all any of us (I suspect you included) want is to be treated consistently fairly

1. There has indeed been a large number of such posts over the years.

2. Ask the airport management for their reason and compare with what I stated.

3. “consistently fairly” is not what airport managements have experienced over the years trying to invoice RAA registered aircraft cf VH aircraft.

Moorabbin simply had enough of RAA pilots avoiding payments and I can understand that having read a large number of online posts from pilots who avoid paying any landing fee whatsoever. 

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Unless otherwise agreed in advance by MAC, the Airport Access Charges will apply ..... Itinerant (visiting) aircraft. MAC may (at its sole discretion) waive certain Airport Access Charges and Reserved Parking Charge for some categories of itinerant aircraft in order to encourage airport visitation and use of commercial facilities.

11 hours ago, djpacro said:

Depends on the certification. These days I only fly small FAR 23 certified airplanes where

The POH for a FAR 23 airplane simply states the maximum weight i.e. cannot have more than that when one starts the engine.

and how it was done, I should've added. I see that PA-28 and Cessna 172, even the 152 have a MTOW and max ramp weight defined in the POH. The Decathlon AFM simply has maximum weight. Pitts POH has both maximum gross weight and maximum takeoff weight - the same number.

The ASTM for LSA has slightly different terminology again "maximum takeoff or maximum design weight". My copy of a Jabiru POH specifies maximum takeoff weight in one section, gross weight in another section (same number 600 kg)

7 hours ago, red750 said:

I noticed when completing the Aircraft profiles, some listings quote Gross Weight, and some MTOW. A few quote both.

 

It appears that with GA aircraft, the Gross slightly exceeds MTOW, which I have assumed allows for fuel consumed in runup and taxying - I could be wrong, please correct me if that is so.

 

Depends on the certification. These days I only fly small FAR 23 certified airplanes where

Sec. 23.25 — Weight limits.

(a) Maximum weight. The maximum weight is the highest weight at which compliance with each applicable requirement of this part (other than those complied with at the design landing weight) is shown. 
 

The POH for a FAR 23 airplane simply states the maximum weight i.e. cannot have more than that when one starts the engine.

More complex types may specify a MTOW and an associated max ramp weight.

Australian pilot theory seems to me is a hangover from when Australia had its own certification requirements and unique flight manuals which generally used the term MTOW. (There were also MTOW limits depending on the density altitude for even simple types like a Cessna 150.) Pilots naturally assumed they could make a very generous allowance for additional taxi fuel in the absence of a specified max ramp weight.

The term “maximum weight” is simply that.

4 hours ago, Bruce Tuncks said:

Please tell us more djpacro. I have been looking on google for the upgust which determines rough air, alas to no avail. I sure got the 40 knot figure from somewhere ..

This may explain https://airfactsjournal.com/2020/12/understanding-vb-turbulence-penetration-speed/

That is for transport category aircraft and does not apply to small aircraft.

6 hours ago, APenNameAndThatA said:

If Va increases with increased weight, then so will Vno, I expect. Both are counter intuitive. I suppose that the reason is that the engine mounts are designed to break before the wing spar.

Design cruise speed Vc, from which Vno is derived, does increase with weight because whoever wrote the regulations decided that. The ASTM for LSA is quite similar to FAR 23 in this respect. This Advisory Circular explains considerations of design airspeeds (see page 26 etc) https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC_23-19A.pdf

I know of one airplane where the engine mount is definitely not stronger than the wing. At lighter weights the load factor due to a gust increases (aeroplane flying at the same airspeed, Vno does not vary with weight) so there is more load on the engine mount than at the higher weight where the wing stresses are higher.

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The "rough airspeed" figure is a regulation ...

Not a regulation applicable to small aeroplanes.

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The rough airspeed is where  the wing stalls when hitting an upgust. The stresses caused by this are in proportion to V^2 ....

Nope. Nope - gust loads are a function of V not V^2.

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As I said earlier, the upgust is 40 knots by regulation

Nope.

On 06/03/2022 at 12:27 AM, Roundsounds said:

What would you consider pro-spin inputs to be?

A very good question. The link to a chapter of the FAA's Airplane Flying Handbook that I provided earlier provides the typical explanations that pilots are taught. But it only touches on the answer to the question.

Page 5-20 describes the "Cross-Control Stall" - a good scenario to have demonstrated however there are many other scenarios with cross controls with different outcomes.

Page 5-22 discusses spin awareness with some generic comments and useful advice.

It then goes on to explain the normal practice spins.

The FAA's document does not directly answer that question and I wouldn't try to answer that question directly myself either.

On 02/03/2022 at 11:21 PM, APenNameAndThatA said:

Thanks! Power on stalls were a total anticlimax in the Decathlon. ..... I’ll test the idea you can’t spin an aircraft without pro-spin inputs! 

The Decathlon is very docile but it sometimes bites. Simply applying full throttle can result in "pro-spin inputs" if the pilot doesn't "Advance the throttle promptly, but smoothly, as needed while using rudder and elevator controls to stop any yawing motion and prevent any undesirable pitching motion." per https://www.faa.gov/regulations_policies/handbooks_manuals/aviation/airplane_handbook/media/06_afh_ch5.pdf

I should’ve added: if you use the Vixen method in the Super Decathlon and it will not recover but instead transition to an inverted spin.

7 hours ago, Garfly said:

Would you elaborate on that djp?

Compare the guidance from the FAA when certifying new aircraft per FAR 23, the Super Decathlon in which I teach spins and the Vixen. An inadvertent spin in a Vixen requires correct actions per its manual promptly rather than attempting a different method as one may have learnt in a Super Decathlon. If the manual states full forward yoke then don't expect halfway to be effective.

2 minutes ago, facthunter said:

 Recovery techniques vary also.  IF the plane is spin certified the recovery should be in the POH.

All certified types must have the spin recovery method in the AFM and/or placarded.

For those types not approved for intentional spinning then that correct recovery method must be initiated within one turn to ensure recovery.

Interesting that most I encounter have a different spin recovery technique than types commonly used for spin training.

19 hours ago, rgmwa said:

Having learned to fly in one, I can vouch for their toughness too, although the door had a tendency to pop open, and you were literally rubbing shoulders with the instructor. 

 

Pilots were narrower back when the 150 was designed. Standard pilot weight for design was 77 kg for many years. They conceded a little with the bowed doors in 1967 to give extra elbow room.

The 150/152 is a great trainer, including spinning and aerobatics (the last in the Aerobat of course).

1 minute ago, APenNameAndThatA said:

Was in a Decathlon with my instructor. I could spin easily from a side slip: the high wing dropped and just kept going.

A sideslip is inherently spin resistant so I guess that you did something other than keep the sideslip straight just prior to the stall?

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In a skidding turn it just kept kind of mushing even with rudder into the turn and the stick back and out of the turn. 🤷‍♂️I probably wasn’t positive enough with my inputs. After what I had heard, I expected to invert with only slightly crossed controls. Maybe I would have in a Cessna.

The Decathlon is very docile, there is a sweet spot of airspeed, power, rate of turn and pitch etc where it will aggressively enter a spin with little warning. The Cessna 150 does it much better, trainee instructors would typically go around a couple of turns in a spin if they weren't expecting it.

I hadn't landed a Pitts in over a year so my brain was a bit rusty.

12 hours ago, walrus said:

Yes, I get the message they are sending. They don't want RAA aircraft at all.

That is the consequence of some people using airports without paying. If you can talk to the General Manager Aviation my guess is that he'd be OK and nil fees.

3 hours ago, Flying_higher said:

Check the YMMB website for charges. Last time I looked there was a $560 (i think) parking charge for non-VH registered aircraft. 

Per 1000 kg pro-rata

I witnessed an accident where an unlicensed pilot was trying to take off in an unregistered aeroplane. He destroyed one aircraft and damaged another. Got his aeroplane trucked away within a few hours. I spoke to the guy who's aeroplane was destroyed. CASA took no interest because he did not break any of their rules, if it had lifted off the ground then it would've been a different matter. Neither did the police. Just one vehicle crashing into another on private property.

31 minutes ago, Garfly said:

A UNICOM service is a basic aerodrome information service: it is not an Air Traffic Service.

 

The next level up at a non-controlled aerodrome is a certified air/ground radio service (CA/GRS) per https://www.casa.gov.au/sites/default/files/2021-08/advisory-circular-139-d-02-guidelines-certified-air-ground-radio-services.pdf

13 hours ago, ClintonB said:

Long as you know the right speeds it is fine. cessnas hand book is all in MPH and dial in Knts, it is a pain reading pencil scribbles next to all figures.

 

Courtesy of CASA and the great flight manual debacle. Many years ago all aircraft here required Australian-specific flight manuals and ASI's to be in kts so all American airplanes had to be converted. Around 2001 CASA reversed and required all aircraft to use the original flight manual. So, now people end up with ASIs in kts and the flight manual using mph. Airplanes which had been operating for 30 years now had to get their original flight manual - at least one aircraft manufacturer refused to respond to such requests for airplanes that old.

2 hours ago, Thexder said:

I've seen guys take-off 20kg over weight because "I've got a big engine and she'll lift anything" when they haven't considered the forces on the plane during turbulence, or guys think the yellow arc on the ASI is the turbulence penetration speed. 

I always consider the forces on the airplane ..... https://www.avweb.com/flight-safety/technique/turbulence-v-speeds/  Do the sums on gust loads.

Manoeuvring loads and structural fatigue are adversely affected by overweight operation. So is performance but, as you say, a big engine is good. 20 kg .... 3% maybe .... almost trivial compared to those aeroplanes found to have incorrect empty weights a while back along with a gross error in crew moment arms so their CG was way further aft. Fixed by adding mass on the engine - a much bigger % increase - what effect does that have on the engine mount and forward fuselage structure?

I would and I do.

Class D towers wouldn't specify a speed as they don't know what my airplane is capable of.

https://www.aircraftspruce.com/catalog/appages/gapseal.php

Effectiveness depends on the design of the ailerons you have and the size of the gap. Some designs are not intended to have the gap sealed.