djpacro

only helicopter that is cleared to do full on inverted aerobatics it pulls +3.1g and -1g doing rolls and loops.

I didn't see it do anything that I've not seen a helicopter do before by company demo pilots at Marignane years ago.

(Sorry, I'm airshowed out, I only go to see friends now.)

 

 

Yes, KidVenture was marvellous - I worked as a volunteer there for two mornings (via the International Aerobatic Club with the Christen Eagle) and other days worked with the IAC. The IAC had a Christen Eagle at KidVenture for the kids to try on for size (some big kids too).

 

We did something similar at Avalon last year although on a much smaller scale - a number of companies provided activities for schoolkids. I expect that we'll be doing it again next year.

 

 

If anyone is doing a driving tour I'd recommend the Automobile Association's website to plan it - free registration. Seems that Oz auto clubs have reciprocal rights with them too but I've not yet had to try that.

 

http://www.aaa.com/

 

Currently we're in western Wyoming and at Oshkosh I'll mostly be at the International Aerobatic Club building.

 

 

Pretty much all the rules of thumb that I'm familiar with are on Whitts Flying website eg:

 

http://www.whittsflying.com/web/page4.71Landing_in_Winds.htm#Landing%20in%20Turbulence

 

Airworthiness requirements normally specify a minimum approach speed of 1.3 Vso.

 

 

Sorry, can't make it otherwise I'd be there. I enjoyed my last visit to an LAA meeting.

 

 

The designer gets to choose Vb to some extent. It doesn't have to be more than Vc. It must not be less than the intersection of the Vb gust line and the stall line.

 

That sample chart shows Vb to be about halfway between Va and Vc obviously chosen where it is as the gust load factor at Vb gets to be the same as it is for Vc. Choosing a higher Vb puts a higher load on the structure. Choosing a lower Vb is maybe not rational but something a designer may want to do just to simplify life.

 

That sample flight envelope coincidentally shows the intersection at Va so the designer may choose to take Vb = Va. (That intersection would not normally be at Va).

 

Depending on the aircraft characteristics (and especially if the limit manoeuvre load factor is 4.4 for utility rather than 3.8 for normal category) the gust load factors may turn out to fall entirely within the manoeuvre load factors. In such a situation the designer may choose to take Vb = Vc as there is no structural penalty.

 

PS I started to do some quick sums using approx data for a Cessna 150 but time is running short.

 

 

The insurance question has halted my RAA flying until I get my own separate policy. The RAA 3rd part policy is excellent. Some aeroplanes around that are for rent have no insurance so I need to think about the paper the owner wants me to sign about paying for the first $XXXX etc etc.

 

The big consideration for me is that I want to take a friend or a family member and I won't do that without adequate cover.

 

 

I'd been working with earlier amdts of Far 23. Yes, Vb is there for those with a recent certification basis - I haven't done any sums but I'd guess that the gust envelope would be within the maneuver envelope for many small aeroplanes. That'd put Vb=Vc per that reg.

 

 

The 8KCAB Airplane Flight Manual states:

 

"GREEN ARC extends from power-off stall speed (Vs1) to maximum structural cruising speed (Vno).

 

YELLOW ARC extends from maximum structural cruising speed to never-exceed apeed (Vne). Operate in this range with caution and only in smooth air."

 

The POH (I.e. not approved by the FAA) goes further:

 

“In severe turbulence do not exceed 121 mph. Maintain a constant nose attitude rather than flying by reference to the altimeter and airspeed indicator.â€

 

Maneuvering speed (Va) at gross weight in normal category is 121 mph.

 

The above approach and similar text is what I have seen in other FAR 23 certified airplanes.

 

Just had a quick look at the Airtourer T-6 AFM – similar notes wrt max structural cruise speed but I didn't see anything about severe turbulence and Va.

 

The old British airworthiness regulations had a specific turbulence penetration speed, Vb. They used a different set of design gust loads. Seems that “everyone†uses stuff similar to FAR 23 now.

 

May be worth noting that load factor arising from a gust is a function of the gust velocity, speed of the aircraft and inversely proportional to the aircraft wing loading.

 

 

I'll be at Oshkosh until the Thursday. Before that will be visiting the Pitts factory in Wyoming then to the East coast.

 

I was also at Watts bridge last Sunday.

 

 

- Apparently, CASA's intent is to provide a choice of going to CASA for admin of LSA-style a/c and ops in future without having to suffer anything fundamentally different from the new Part 103

 

- All hypothetical as I don't expect CASA to get any significant regulatory changes thru the Attorney General's Dept in my lifetime

 

- The intent of the draft Part 103 is to provide simple rules for simple aircraft engaged in simple operations. CASA has drawn the line (for landplanes) at 600 kg and a stall speed of 45 KCAS. They have included aerobatics. (I admit to being out of date by quoting the old draft rather than recent proposals)

 

- I guess that the RAA needs to draw its own lines which may be different from where my own personal ones are, as follows.

 

- Aerobatics in something like a Clipped-Wing Cub or RANS S-10 is simple. Aerobatics in an RV is not so simple.

 

- Operation and support of aircraft where flutter and fatigue life (or damage tolerance) substantiation becomes significant - that is not simple. The type of structure employed on a Cub and application of FAA Rept 45 to flutter (where applicable) is simple enough.

 

- In another thread I mentioned that I liked the Ultrabat but I didn't want to buy one or operate one. I didn't know about how its flutter was substantiated. I didn't see any fatigue life on parts where I may have expected it.

 

Some-one mentioned the Cessna 150/152. I'm quite comfortable flying it - it is not pushing the frontiers of science but I know its history of safe operation.

 

 

Sounds good - see you next weekend.

 

 

"When fuel indicator reads ZERO, fuel remaining in tank cannot be safely used in flight"

is commonly found in American Flight Manuals. The origin is in FAR 23:

Each fuel quantity indicator must be calibrated to read "zero" during level flight when the quantity of fuel remaining in the tank is equal to the unusable fuel supply ...

 

"Fill her up mate!"

With my weight, I like to consider other limitations that may be in the Flight Manual. eg with the aeroplane that I normally fly: myself plus wife and a toothbrush plus half fuel is max gross weight.

Flygirl, was that you departing for Ballarat in the Alpha this afternoon? Looking forward to your next chapter.

 

 

I was reminded that the late Alan Hannah competed at the national aerobatic championships at Bendigo in 1987 flying the Ultrabat which was when I flew it. As I stated I would've been happy to compete in Advanced in it, wasn't sure about it at Unlimited level but one of my colleagues (flying a Pitts in Unlimited) said he'd do it. The only adverse comment that I heard was about the shape as presented to the judges - would take a bit of education. George was very pleased with the response he got from "serious" aerobatic pilots. Some notes I found from some-one else (complete with original typos):

 

rod f. says "it snap rolls and lomcavaks better than any aeroplane Ihave ever flown, loops well, stall turns on a dime, rolls ok and

flies inverted well. The machine actually spins inverted better than

 

it does upright because of the aerodynamics assciated with the

 

engine fairing etc. And flat spins inverted are a real buzz with

 

full throttle, and when you need to recover it is instantanous as

 

there is not much inetia at 200kg. For an areoplane with 50hp it is

 

pretty hard to beat"

Last I heard, only a few years ago, it was alive and well in Mt Gambier. I see that the website is still there.

http://groups.msn.com/ultrabat

 

Perhaps I should've started a new thread but as I'm still here, another comment related to the Stratos. I got involved a little with a technical assessment after the accident. It is not easy developing a new aircraft, let alone one with a unique configuration. Ron should update his online CV, he's moved on since then.

 

 

I did some flying in an Ultrabat and was very impressed with it. Straining the memory to offer much comment off the cuff except to state that it was competitive at Advanced category competition level back then.

 

As this thread is about Stratos I should add - Ron is very keen on succeeding with his project and I wish him well with it.

 

 

Good Times Remembered

 

An article about Bryscen in the latest AAC magazine.

 

http://www.aerobaticsaustralia.com.au/dloads/National%20Newsletter/may8good.pdf

 

 

I don't think that is quite right, Yenn. My recollection is that flight time starts when the aircraft first moves under its own power and if you don't get to fly at all then there is nil flight time.

 

 

Agreed. Saw the meter there but not the pressure switch.

 

 

http://www.aircraftspruce.com/catalog/inpages/hobbsswitch.php

we looked at incipent spin entry and recovery .... somewhat underwhelmed

I guess that you didn't aggravate it to make it go flat?There was a good reason why spinning was restricted - have you seen the civil Flight Manual for that type (I assume that you use the old RAAF manual)?

 

 

J430, I believe there's one misunderstanding and one incorrect assumption there.

 

By alignment with the runway, I meant the important alignment of the fuselage axis with the runway centreline for touchdown. Further back, at higher altitude on the approach we're crabbing into wind so therefore the fuselage axis and the runway centre-line are not aligned. Perhaps I should've written more words and used the word parallel somewhere.

 

You assume that

 

this is to be done close to the ground

Nope, assuming that we have the same understanding of what is "close to the ground".Enough words from me, I'll renew the invite for discussion - perhaps when I visit Brisbane in June.

 

Maybe this helps

 

https://www.youtube.com/watch?v=hXaM2pGnVXg

 

 

djpacroPart B sounds fine, Part A is something you should reconsider.

I have reconsidered J430. Happy to discuss over a coffee at the airport or over a glass of red wine sometime. I'll never be able to write enough words here to be equivalent to that chat but here's a few more words anyway.

If there is no need to sideslip to lose height then Part A is simply crabbing into wind and I'd transition to Part B when appropriate. Given that we're doing a deadstick landing in a xwind and I feel the need to sideslip to lose height at some stage then I'd continue to leave the nose into wind and simply apply rudder in that direction and drop the downwind wing - maintains the crab into wind and loses height - lost the height I chose then back to the straight crab.

 

Was riding along with a grey-haired instructor yesterday who did exactly this. Later, I was with another experienced instructor and I flew the same method. In both cases we'd reduced previously reduced power to idle (no flaps) and still high.

 

 

As someone stated previously, I break the question into two separate parts:

 

Part A - losing height - nose crabbing into wind then drop the downwind wing for the reason of better visibility of the landing area. Reason, not concerned with aligning the fuselage with runway direction at this stage so, in my opinion, more comfortable. Deadstick so need to set sideslip angle to determine approach angle rather than to counteract xwind.

 

Once in the right place and right height then transition to:

 

Part B - the normal xwind landing technique with the wing down into wind.

 

 

Some light reading material which may answer you question:

 

- near the top of http://www.zenithair.com/kit-data/ht-90-5.html - see Fig 8

 

- near the bottom of http://www.pilotfriend.com/training/flight_training/wt_bal.htm

 

- Mechanics of Flight by Kermode. Page 160 and subsequent

 

Enough of theory - flight tests of the Bell XS-1, Fig 6 of http://www.nasa.gov/centers/dryden/pdf/87529main_RM-L8A23A.pdf