I was reluctant to post on this thread - as I have copped a bit of flak about my C150M (well mostly the time it's taken - rather than the plane itself, but that too) - both directly & indirectly (behind my back).. I've done all I can to speed it up.. it's almost done now - so yea, here we are...
I will try to answer your question, and throw in some other information here - which most or all of you may already know - but could be of interest to others, as well as some inspiration or ideas if you are going to make modifications (especially if you need to do an engineering order - as ALL your custom modifications could be done in one EO for example, saving you a ton of money).. even future modifications can be on the EO - so you can modify / install the modifications when you are ready later on.
It is
Group G - 601kg - 760kg GA aircraft, this group will not apply to aircraft with light sport aircraft (LSA) and ultralight approvals.
Last I heard the 45 knot stall speed limit was to be amended / abolished, as - naturally... When the MTOW increases - so does the stall speed.
It will need to be maintained by a Part 66 licence holder, unless it is amateur-built, in which case the owner can maintain it after completing a training course. - in other words, maintenance will be the same as VH land...
So you would be looking at FACTORY BUILT TYPE ACCEPTED - CAO 95.55.
A type certified aircraft may be modified in accordance with the type certificate or a supplemental type certificate. For example, multiple propeller types may be listed as options for fitting to the installed engine. If a propeller is fitted to a type certified aircraft and it is not a listed option then it is classed as a major modification, requiring an engineering order or RAAus Modification and Repair Approval... You can also do some modifications if the option was originally an option from factory without an EO or STC if it was on the type certificate - for example, I have the overhead window frames that were installed on the aerobats (not currently fitted as they are for another project) - as it was a factory option, no EO required... However something as basic as an inertial reel seatbelt (which was NOT an option in 74-75' requires an STC / EO).
Note: Engineering orders are restricted to that serial number ONLY, and are not transferable - and just because one aircraft is approved, it does not guarantee another one will be... Whereas STC is approved for any of that type/make/model for the modification. An EO can be provided from a number of engineering places, such as five rings aerospace, or Wally Thompson at Jandakot.
Here is a list of FAA STC's (under "Design and production approvals") - you can search by aircraft type for example: https://drs.faa.gov/browse/doctypeDetails
In my experience, engineers are reluctant to do engineering orders on "experimental" avionics in type certified aircraft - this is where the FAA created "NORSEE" a sort of... pseudo-certified avionics..where if it is supplementary (not required) avionics it's ok to install - but not as primary... The Uavionix AV20 is a popular product under this scheme for example... Great replacement for that clock on the dash! ...NORSEE is not a thing in Australia however... But you could argue the same point if it's supplementary.... If the experimental avionics / autopilot in question (Garmin G3X or GFC500 autopilot for example) has a certified cousin - in my experience the engineer will be VERY reluctant to sign it off - as it could be seen as a cheeky loophole, and if something happens due to the avionics - the question will be asked why they EO'd the experimental one when the certified one was available?
It would be nice if Australia had a minor modification / field approval option like the FAA form 337... Where a LAME can sign off on some modifications (IE: Patroller door windows, headset holders, a pen holder.. etc)... This does not exist in Australia - so even for the smallest modifications - you have to go the whole hog with an engineering order, or STC.... An EO is not open slather either...
Here is the RAAus Technical Manual for further information section 6.2 page 44:
https://www.raa.asn.au/storage/raaus-technical-manual-issue-41.pdf
As you now know, it can only be modified as per it's type certificate - I don't see any 'experimental' option for type-certified group G aircraft on RAA... There's "non-compliant / experimental LSA however" (I imagine this is the majority of RAA aircraft that allow modifications - as well as the amateur built)....
Note: for aftermarket, or parts made of unobtainium from factory - there is also "PMA" which stands for parts manufacturing approval, this is where an aftermarket manufacturer can make parts for an aircraft that are as-good or better than factory... For example, all the Cessna parts from McFarlane are PMA parts.. this is recognised in Australia.. however in the land of the free - aircraft owners can also do "owner produced parts" - this is not a thing over here in Australia...
Now I definately see why you ask the question, because there is an assumption that RAA = more freedom... But it sounds like RAA made a lot of freedom trade-offs for the Group G aircraft... so for example - unless you're a LAME you already cannot maintain it yourself or modify it easily, - but when RAA you can also no longer freely navigate in CTA, Night, IFR.. or Aerobatics (A150) in your 150 ... Where you could in VH land...
I think this was almost purely aimed at getting low-acquisition cost / reliable / robust and proven training aircraft into RAA for the flying schools... IE the C150 / C152... The reality is most current RAA aircraft are not designed for the rigors of flying training... And requiring LAME maintenance - I think they also realised how many maintenance workshops would go bankrupt if even 30-50% of sub 760kg aircraft went to RAA and could do their own maintenance...
Anyway, I hope I am wrong, and it would be nice if there is an experimental / non-compliant group G option coming in RAA without needing to be amateur built - it's great to see what ideas and things people come up with when modifying these aircraft when they have the freedom to do it ! ...sounds like it would be a pain in the butt to do a MARAP (12 month wait) for something like a headset hook... Or an iPad mount...
Any changes or modifications, I would strongly suggest
EVERYTHING is very well documented - so it is reversible if anyone ever wanted to put it back on the VH register later - it sounds like it should already be, but you never know (as these are skyrocketing in price as people are now realising the value of them VS a $200,000 LSA with similar performance) - this would increase its resale value, also please make a copy of the certificate of airworthiness (electronic - e-mailed to self for backup) as it appears CASA have either LOST, or CBF finding their copies of CofA's from the 60's to the 80's.. if you don't have a paper or electronic copy of your CofA .... I wouldn't even try to convert it - because CASA will most likely not provide you with a copy... In other words ... It will need to go through a flight testing regime for certification from scratch.... And once it's bought to their attention - you will be forced to do it, at your expense - because you won't be able to get a LAME to work on an aircraft without its CofA... (Note: this is assuming the aircraft has a valid Certificate of Airworthiness - but you just don't have a copy of it... Which CASA is supposed to have a copy... But there appears to have been a big F-up in record keeping - well done CASA.. showing your competence as a regulator again... )
I don't know if you own a C150 already - or looking to buy, so I'll assume you don't to give you my 2C on the C150 - I am sure that you (as I have) did your research, and weighed up what your mission was so you could get the aircraft that fit that role perfectly... So I am sure I don't really need to "sell" you why the C150 is an excellent choice...
Bang for buck, I reckon the C150 is a ripper aircraft.. and as AVGAS heads to over $3/Litre... 22 L/PH is mighty attractive (although I estimate 23lph in mine).. Or just buy the paper STC to run the O200A on MOGAS.. (great if leaded AVGAS becomes banned in the future... Oh and by the way - it is confirmed the GAMI non-leaded fuel will be a bit more expensive than AVGAS...) ....or if you want to be like your other RAA brethren you can get the Rotax 912 S3 with a CSU in an STC... Which is far quieter due to being mounted on a longer nose for balance - and advertised benefits include 17 litres per hour, 20-25% better climb and cruise performance (CSU), 20-25kg weight saving (throw in a lithium battery for another 5kg or so saving).... For example with my LR tanks (132 litres usable) I should get 1.5 - 2 hrs more endurance (depending on how it's flown)... If you couple that with some flint internal wingtip tanks (87 litres useable) .... That should cover any single pilot missions almost anywhere.... That could then technically do Perth - Broome, or Perth - Adelaide (with a tailwind) in a single hop... But if you do that STC, the Rotax maintenance time is on running time - not airswitch (bad for places like Jandakot where the taxi can be 5-10 minutes!).... If you want more power, there is an STC for 150hp upgrade (commonly referred to as the 150/150).. if that's not enough, there's also 160hp or a 180hp upgrade (stock O200 is 100hp).. I hear the climb rate is insane..... Reportedly there's a photo of a 150/180 at 20,000 feet... Although that height is no use for RAA ! ... Sometimes these show up in salvage yards, so you can get all the hardware for those upgrades without needing the STC paperwork (if you can go experimental / MARAP....) it would be interesting as one of the 150hp upgrades also increases your MTOW... I wonder if RAA would allow it since it's been 'proven' on the STC (higher MTOW)?.... Just beware that the C150 is not 'approved' for spins when the 150hp / 160hp / 180hp mod is installed.... The A150K can have a particular tailwheel STC and still do Aerobatics.. I
think it's the only model that can... Irrelevant as aerobatics aren't a thing in RAA last time I checked.
Parts are cheap, and abundant... That spring undercarriage is designed for ham fisted students so it can handle non-sealed strips and harder landings with ease... The high wings clear fences on farms, provide shade on hot days, keeps you out of the rain a bit while you get in... And also, when your cruising around - you get a way better view! Compared to many LSA with low wings, and bubble canopies where you cook in the sun after 30 mins... some downsides to the high wings are your view is blocked when you bank (hence why the the 2 windows in the roof were an option - in future models such as the C177 cardinal, or even the C208 caravan they fixed this by having the pilot sit forward of the wings) - Just watch those sharp edges on the trailing edge of the flaps / ailerons while walking around.. unless you want a zigzag scare on your forehead (harry potter?) - it sounds obvious - but people STILL do it !!
As it was designed for training - its easy to fly for everyone (and to insure), as most purpose-built LSA have very light control loading - making control inputs very snappy (more difficult in crosswinds etc)... couple that with weak undercarriage.... Yep..
Try to find one with long range tanks, but beware as filling them right up can make it a single person aircraft... I developed some aftermarket tabs which can be modified to suit whatever litres you want for 2 X whatever weight pax.... (See picture) For example, with mine, when someone is done with the aircraft it can be "filled to the tabs"... So the next person using it is not restricted to single-pilot ops.. more for a flight school / rental environment.
If you are doing an avionics upgrade, I highly recommend an avionics switch, and replace the fuses with circuit breakers... Swap the 12V plug for a GSB15 or similar USB charger for your iPad.... Also consider moving as many instruments from the co-pilot side (or one of the sides behind the yoke on the Pilot side) as an iPad can fit behind the pilot / co-pilot yoke very nicely (and doesn't block any external view)... There isn't many good places to suction cup an iPad in a C150 without blocking a huge amount of external vision..
If you are getting one with 40 degree flaps (I think all C150's had this?) Just beware that 40 degrees isn't great for a go-around, which is why I will be recommending 30 degrees for landing when mine is up and running (soon hopefully .. it's been a long wait... ) - this is why Cessna went to 30 degrees flaps on the Cessna 152.
Here is my panel if you want some inspiration (done with Engineering orders and STC's)... Modifications are only really limited by your imagination.. money... And the engineer signing it off.... For example some simple mods I did like headphone jacks & headphone hooks in the roof behind the pilots, patroller doors and wingtip landing lights (with wig wag function)... You will notice it also has an autopilot, if you are wondering what options there are for the C150, the options are STEC 40/50, and soon the Trio Pro-Pilot from "The STC Group" .... experimental autopilots would be a lot cheaper.. but I doubt you will find any engineer in Australia willing to do an EO for an experimental autopilot (or the ones I spoke to were reluctant)... This is where a MARAP in RAA could come in handy ! - price-wise for autopilots - for example the STEC-40 in mine retails for about 15k+ (quoted installed)..... bought it for about 3.5k second hand, brand new never-installed, and Genesys were kind enough to provide the STC paperwork for free... Which shows how good the second hand market is for these aircraft...
It will be available mid-october (99% certainty) for 24/7 self-hire at Jandakot, if you want to try a glass panel in a 150 before installing your own, or want to check out the Garmin line of products compared to the Dynon...
I am sure I am going to get a smart arse comment here about how long it's taken to get it's upgrades from people that know of my aircraft - these things were beyond my control, the excuses fed to me have been a combination of supply, COVID and staffing issues..
I will also attach some other 'mods' that some have done to their "One-Thrifties" ...everything from 3-4 blade warp-drive props (Canadian friend) to tail-wheels with Alaskan bush wheels! ... If you ever want to put a CSU prop on your C150 (if it can be experimental / MARAP route)... I'd love to get some real-world performance data on this..
https://www.propellor.com/ap523ctf-wwr72a
My next C150 project I haven't decided wether it will be polished aluminium, or a bird dog replica.. I'd love an experimental C150 where I could go 'all-out' on it... But unfortunately I'm restricted to things the engineer is happy to sign-off on in an EO (so I guess JATO / RATO's on an Aerobat for airshows would be out of the question... I still think that would be hilarious.... Unrelated but - they did fit JATO / RATO rockets to an ercoupe - google if you don't believe it !) ... I also considered an ALE-47 countermeasure dispenser on an aerobat for "night displays" ...but I think unless I was some well-known figure my chances of getting approval from CASA for dispensing flares from an aircraft at night / twilight for displays / airshow would be slim to none... It's already used on many civilian aircraft that fly in and out of contested areas (such as contractor aircraft flying into Iraq / Afghanistan until recently)... I got that idea from watching the guy in the glider launching his fireworks at Avalon doing his amazing twilight display !
One of the benefits of the Cessna 150 / 152, is it has a great following. I recommend checking out the Facebook groups such as Cessna 150/152 lounge.
there is also this place (where I got my autopilot):
https://www.cessna150-152club.com/
If you want something more modern but love the C150 / C152 design, check out Texas Aircraft Manufacturing "Colt" aircraft LSA - basically I think it's what a C150/152 would look like if the engineers went to the drawing board today.. it's like a C177 Cardinal and a C150 had a baby... They took into consideration control loading, heavy duty undercarriage, visibility in turns etc... There will also be an electric version, and a Part 23 (higher MTOW, NVFR / IFR / Commercial ops etc) soon... Otherwise there is also the "Aeropilot Legend 600" which is a pretty cool LSA.. basically an 80% C182 copy...
