Ibra

I met a retired airport staff who told me about this Mooney accident: https://asn.flightsafety.org/wikibase/326152 Looking at the picture from archives, I am surprised how Mooney and pilot survived? The interesting part of the story: the pilot walked 2km for 30min in the fog all the way to the terminal (the pilot was Wubbo Ockels, a Dutch astronaut who flew US Space Shuttle, I understood it was a case of mis-communication between pilot and tower)

On the topic, how does one go about getting these approved? something looks fishy !

There is no equivalent for EASA CS-STAN ("standard change") in US rules, however, the FAA has two routes for "minor change" and "major change", these are done with logbook signature and 337 forms (with an IA) You can argue that FAA "minor change" route is equivalent to EASA "standard change" route (CS-STAN), however, these things gets highly mixed up and there is no one-to-one (in EASA, you can use some ASTM UL fuels with CS-STAN as long as they are approved for engine, all you need is logbook signature while in FAA rules this require an airframe STC) For major changes, if you see them in a given N registration, you can request all 337s in CD-ROM from FAA for that registration (these should include all 337s major mods that are done via field approvals as well as STCs, even those associated with serial numbers) In EASA land, you can look at similar "well trodden" paths... https://www.easa.europa.eu/download/stc/MajCh-Digital-Certificate-Publication-Report.pdf

Does that apply to components you are allowed to remove and put back according to some POH procedure? It's not just M20J wheel doors, same for wheel pants in C172 or PA28 (I think they are beyond one pound or less for an aircraft under 5,000 pounds) I have not gone as far as checking WnB (it's easy to notice 3kts-5kts loss in cruise and one may need to update fuel burn tables)

Damn easy in this case: YES Otherwise, welcome to MooneySpace we got plenty of pilots, mechanics...with different AFMs, SOPs and interpretations once you have gone over all of it: you are now well informed and able to make your own mind (Joke) once the lawyers joins this conversation: it seems that POH allows it when flying in ice, mud and tall grass, I doubt about legality on paved runway (unless your intention is to refuel before going on grass runway)

Yes ok to remove everytime you take M20J to eat the turf and the mud? I am less keen on cleaning the gear wells now but 4 years ago the M20J had load of fun joining cows and pigs (one need a long strip, takeoff distance does go to infinity)

Yes it's only factory that produce TEL and handle transport licences when it's used as fuel additive (my understanding anyone can produce it as the process is "simple" but not many outfits have paperwork to export and transport. Apparently, the TEL factory in India can't export for say 100LL in America or Europe) https://innospec.com/ In Europe, Shell Netherlands is the main 100LL producer: they managed to secure an extension of approval to handle TEL in refineries until 2032 (Warter are expecting approval this month) https://echa.europa.eu/en/applications-for-authorisation-previous-consultations?diss=false&search_criteria_ecnumber=201-075-4&search_criteria_casnumber=78-00-2&search_criteria_name=Tetraethyllead

Is it that difficult to survey highest obstacle in say +/-1nm or +/-5nm and decend down to 500ft (or 1000ft) above it then "join" VFR pattern? I know in US one has to comply with General Echo airspace, radar MIA, airway MEA or VMC minima...if we put "ground in sight" aside, I am wondering how much "M/DH advantage" (or "dispatch rate advantage") some Part91 operators would get from say designing FAA approved procedure for let down on private air park? * For takeoff: nada (you are not designing SID, ODP, Omni?) * For landing: would you go for M/DH < 400ft (1sm vis) without proper infrastructure (HIALS+ATC)? for M/DH > 800ft well that's enough to fly VFR pattern I can see how 135/121 operators need to justify design or cost to gain approval for CAT-I LPV down to 200ft on every threshold. Again, most of their internal IFR procedures are proprietary: they are not in public AIP and not coded in Jeppesen database (aka, not available to visitors or non trained pilots). I assume FAA take different views if it's "operator approval" versus "airport approval"?

Maybe H- (Haiti) and HA- (Hungary) were already taken? CH would have been more intuitive Someone was unhappy with CH, a referendum was held, HB comes out of it, all aircraft were repainted and everyone is happy

Those are wise words, it's hard to cater for all variations in fleet when designing new fuel specs: one has to assume that a Mooney (or any other aircraft) that is taking G100UL (or any other fuel) has an approved sealant with tanks being resealed to a high standards. For these, I would expect, 100LL and G100UL will have the same results, then life carry as before For Mooneys that falls out of specs, it's hit and miss with learning curve while we are "in-transition." Anyone with a background in risk engineering will have to accept that testing involves different sensitivities, thresholds, and confidence levels. The point about toluene (%) variations (in 100LL and G100UL or whatever fuel) is something one should watch for, especially, if they are differing tank reseals or using non specialised shop It's hard to make binary YES or NO statements, let's leave this to general public or politicians who love binary stuff: "no 100LL in California next year", "drop-in replacement as is", "let's ban TEL",...So far, one need more data on both Mooneys that showed problems and those that don't and figure out why? GAMI offer to look on a case by case seems reasonable on how one should approach the problem, then it's wait and see I suspect Mooneys and other wet wing designs (especially +30 years vintages like mine) could have higher sensitivity to toluene (%) than other airframes

I am definetly surprised, I would pay cash if I see 175kts at 10gph (seems like Risen rather than Cardinal) 160kts at 10gph seems plausible (some Mooneys, Comanches)

I copied George post here which was very informative at least for me on the history and chemistry sides. Especially for subject that is still under discussion while Avgas is “in transition” (I can understand why OP post on a specific aircraft gets removed, maybe request? or AvWeb story?) “Very much appreciate the discussion and the feedback, here. Please allow me to provide a response to some of the messages. 1) I am a big Mooney fan. Flew a 67 Mooney Super 21 for nearly 2,000 hours. Commuted to and from law school in Norman, Ok. to the family Ranch (100miles each way) on a daily basis for 3 years. 2) Part I - - Some aviation fuel chemistry history: A- During WWII fuels with very large amounts of aromatics were adopted. Arguably, the Air War would have been much more costly in terms of losses for the fighter aircraft without the introduction of aromatics to aviation gasoline. The fuel approved for D-Day was "100/150" - - and used a lot of different aromatic components; B- In the ranking of the levels of "aggressiveness" as solvents, the ranking starts (most severe) with benzene. Then add a single CH3 group and you get toluene. Yes. Paint stripper you buy at the paint store. C- Add a second Ch3 group and you get xylenes (three isomers - ortho, meta, & para) Xylenes are significantly less aggressive as a "paint stripper" than is toluene. <== THAT is important. Keep that in mind. D- Many fuel bladders were developed during WWII and are labeled "approved for aromatics" or something similar. If you look closely at some of the P-51s and other planes at Oshkosh, you will see a placard that states "approved for aromatic fuels." Part II - - Post WWII. A- We had "Green" 100/130 with LOTS and lots of lead. And even purple 115/145 (with lots of aromatics) At the end of the piston airline and going into the late 1970s and 1980s, the ASTM folks decided to drop the lead content and created BLUE 100Low Lead. Still lots of lead. But much less than GREEN 100/130. B- Some of the refiners had very good "aviation alkylate" (~ 70% of some 100LL fuel formulations) with relatively high MON values for that aviation alkylate (a less than pure form of isoctane). Those refineries could make 100LL with relatively low levels of aromatics (almost always "toluene" from the paint store). Maybe 10-20%. C- Other refineries (P66 at Borger, Tx, for example) had lower MON quality "aviation alkylate" and the had to use a LOT of toluene. I can show you detailed hydrocarbon analysis (GC-FID) test results for local (Ada, Ok. FBO) P66 Borger, Tx 100LL that has 29% toluene and another 4% of other aromatics for a total of about 33% aromatic content. 3) Fleet Experience during the transition to 100LL - - A-Starting shortly after the introduction of 100LL, with high levels of aggressive toluene, A LOT of Mooney, Piper, and other airplane owners that had aluminum integral fuel tanks (no bladders) began to leak fuel out of lots of rivet holes. That started a whole new business for G.A. with companies initially specializing in re-sealing those tanks. Later, companies developed retrofit fuel bladders for those problematic "integral fuel tanks". B- A big part of the problem was the aircraft manufacturers did an "inconsistent" (careful choice of words) job of applying the polysulfide sealant to the interior (rivets and seams) of the aluminum integral wing tanks as they were manufactured. [As we have learned during material compatibility testing, the devil is in the details when it comes to the proper application of sealants to fuel tanks. ] C) Over the decades, the level of toluene from most refiners has decreased due to better quality aviation alkylate, but some refiners - - for at least some production runs - - still (from looking at their data sheets) still have a lot of toluene. 4) G100UL Avgas - - A- Uses a very high quality aviation alkylate (2-4 MON numbers higher than the alkylate used for 100LL) and then uses xylenes rather than toluene in order to achieve the 100/150+ octane/supercharge rating for G100UL avgas. The right choice of xylene isomers will have higher octane blending value than does toluene. Using "xylenes" also has the advantage of being less chemically "aggressive" than is toluene. But the high quality alkylate and the premium xylene isomers also "cost more" than the related components in 100LL. BUT - - there ends up being no lead. B- We did extensive material compatibility testing, including a whole variety of older bladders and a whole range of tests for sealants applied to aluminum. All of that supervised (in person) by multiple FAA engineers and managers and then later approved by the FAA. 5) The 100LL we have at the airport in Ada (typically Phillips from Borger, Tx) still tends to have a lot of toluene in that fuel. A- Late October of 2023, AOPA brought their 1965 demonstration Baron to Ada. Two freshly overhauled IO-520s. One fuel bladder was 46 years old and the other ~50 years old. They were supposed to have been replaced with new, prior to the start of testing, but the bladders were on "back-order". B- G100UL avgas was exclusively kept in the LH bladder and 100LL was exclusively in the RH bladder. C-Within 30 days, we noticed fuel "spots" on the hangar floor. Investigation - - we found fuel leakage and staining on the bottom of the RH wing - - which had ONLY ever had 100LL. See photographs. 6- Oshkosh, the leakage from the LH wing tank (G100UL Avgas) was ( based on Eagle Fuel evaluation) caused by pre-existing damage to the tanks and the gaskets associated with the access panels. (In addition, there were pin-hole leaks in both fuel bladders). 7)-G100UL Avgas is NOT a threat to normal aircraft paint. A- Embry Riddle did extensive certification testing of G100UL avgas. They used G100UL in their C-172s for over a year, at Daytona Beach. They had no evidence of any fuel leaks and they had zero staining on the wings. B- As part of our due diligence, wee have deliberately spilled a LOT of G100UL Avgas onto various painted components from the many Bonanza aircraft that come through the TAT shop for turbo systems. That includes LOTs of wing tips and the lower cowling access panels, both of which are removed and replaced (with tip tanks and newly louvered lower access panels.) C- Some of that has been allowed to dry on those painted surfaces and then the process was repeated. NO SIGN OF ANY LOSS TO THE INTEGRITY OF THE ADHESION OF THE PAINT. D- We have even soaked a couple of those side panels in G100UL for a week or more. The paint was fine at the end of that. E- What does and will happen - - is if you do not properly clean up the spilled fuel, and allow it to dry, it can and will leave a light tan stain on the paint. If you do properly clean it up, it will not stain the paint - - even after repeated spills in the same location. But, to date, we have never seen any evidence of any type of "paint striping" activity to any of the dozen or more aircraft parts that were removed from our customers Bonanzas and used as "test articles." See https://g100ul.com/dl/Refueling Hygiene G100UL Avgas.pdf F- An aside - - some of the recent crystal and graphene coatings improve the resistance of aircraft paint to any damage from any variety of 100LL or G100UL - - but that is not a cure all. See the link Refueling Hygiene! 8. So "what happened" on the bottom of the Mooney wings ? A- In one case, the sump drain appears to be leaking. Likely the fittings inside the wing are also leaking. B- In the other case, there appears to be some kind of leakage from inside the wing. Not sure from the photographs. C- Almost certain that old drain valve has a "nitrile" set of O-rings. D- The paint on the bottom of the wings has likely had many months of exposure to steady drips of 100LL. In California, probably with only ~ 15% toluene in the 100LL . . . maybe. E- No information about the age of the paint on the bottom of the wings, but from its overall appearance and the multiple rivet holes that are bare and which have lost their paint - - it is likely a they are rather old paint jobs. The paint on my personal Bonanza, N11RT is about 35 years old and it is in much better condition than the appearance of the paint (away from the damaged paint). F- It would be good to know the age of the paint for each of those two aircraft. 9. What to do ? A-There is a long standing FAA / maintenance bulletin (20 + years old ???) that tells mechanics that when they find fuel leaks or deteriorated fuel lines or gaskets or O-rings, they should replace those components with parts that are made from chemically resistant materials (viton, fluorosilicones, etc.) Those types of materials are specifically stated to be for use with a wide variety of fuels, including aromatic based fluids. A lot of mechanics have ignored that recommendation over the years. Last . . . 10. I would like to have the chance to borescope an older Mooney fuel tank that has not been converted over to a bladder. A- If anyone on this forum would like to bring their plane to Ada we can do that here. You might find it interesting. If you have the STC you can probably leave with some G100UL in your tank, if you want. I hope this information helps to bring some clarity and understanding to these issues that will be the subject of conversations during the transition away from leaded avgas.”

I have done winter trips with Clean, TKS, FIKI, Boot…there is so much grey in these capabilities depending if you are climbing, descending, cruising and how much VFR above/under “Known ice” is somewhere between actual clear ice splashes (10kts speed loss every 1min) and forecast of moisture bellow freezing level getting (where you can fly 10h), so at the end of the day, it matter of how much time you have versus how much time you need Pilots wants simple answers, * Known ice = IMC < 0C * FIKI: go flying vs Non-FIKI: no flying * Jets: go flying vs Piston: no flying The reality is much more complex of course To add more more grey: “your equipment is proportional to airspace and airport complexity”: in busy ATC system and airspace, you should not fly if you can’t take some heat (wrong choice) and be fully equipped for that, otherwise, you are getting into the way of those who are equipped From FIKI certification, one can see it’s more about redundancy than effectiveness, however, empirical evidences shows that they cope more than +10min, even some clean wings can last +10min Look at Appendix C to Part 25 (Part 23 as reference as well), to see just how limited FIKI certification is, you will see that the maximum droplet size contemplated is 40 microns...smaller than a human hair...so if you can see the droplets you are in conditions beyond which FIKI applies; if I recall the distance correctly, if the cloud you are in is stratus and extends more than 17 miles, you are once again outside of FIKI standards. All FIKI certification buys you is time to escape (10min at best), not permission to continue.

Damn, I got scammed: I would 1/ sell the beloved Mooney and 2/ get Cardinal that go 175kts at 10gph I would then fly that Cardinal at 130kts at 4gph on it's Carson speeds ! I now have to stop thinking about that 252/Encore, I am on the market for the Cardinals You have less problems as you only have to do 2/

I am not sure why you are looking at J/Missile? I would personally bite the bullet and go for Ovation (Eagle) if I am looking for +30kts deltas then it's 310hp Ovation, that is what qualifies as "normally aspirated perfection". The same applies to J/Rjay turbos, I don't think they are worth it? if one is looking for turbos they should "ditch J" and get 252/Encore which are "turbo perfection". Under 20kts delta, I don't think it matters that much? +/-20kts is barely changes from winds, time of the day and routings...I don't think pilots notices it, I would look at avionics or leather as they come with perceived comfort For Avionics: a coupled digital auto-pilot with WAAS/LPV is a must. The rest is mostly nice to have, they fall under personal projects...

If my landing is challenging (busy procedures, instruments, night, winds, icing...), I put takeoff flaps or no flaps. For some reason, I like the feel of more speed and another extra advantage is less things to worry about on visual segments, go-around, balked landing: I throttle up and pitch for my speed. It's mostly personal preferences, I can do full flaps but it's not my cup of tea: on full approach it feel too mushy/slow on 3deg glide (no flaps feels stable/fast, especially in gusty winds), on short final, I hate when it balloon and I hate large trim change from idle power to full power during go-around I use full flaps when doing landing in tight strips in nice days or when doing tight pattern work with steep glide (6deg) The go-around with full flaps require orderly execution

One barely need more than 50ml to pre-wash a filthy belly (exposures are tiny and are ok while wearing gloves, after all it's not injecting straight in the blood) I may pick cleaning solvants but then one gets into all sort of compounds, dosage, chemicals, additives, allergies... avgas is cheap and available, for now

They are not saying a lot but I recall George mentioning that one should wipe G100UL stains right away (while 100LL stains can wait months or years or until next flight in rain). For Mooney with leaking tanks this could be problematic, especially, if it's left outside (with UV exposure) For Mooneys without leaks, there should be no concerns on paint. For impact on sealants, let's "wait and see", I don't think there are any issues? or at least not the kind we will see after one week? maybe decade or 5 years? (at least the fuel inside our tanks does not get lot of UV exposure) I wonder if one should have some sort of "UV protection" around fuel caps and fuel drains? also ceramic coating (and hangar) helps

There are lot of evidences that G100UL is not good for aircraft paint From the horse mouth, "very small portion of the fuel composition includes a molecule that reacts with ultraviolet (UV) from sunlight and creates the potential for staining" https://www.g100ul.com/dl/Refueling Hygiene G100UL Avgas.pdf I would not clean grease/oil on aircraft belly using G100UL and leave to dry under the sun (I am happy to do it with water and 100UL, even for fibreglass or plastic aircraft)

That's my take of it, no leaks: then no problems, if leaking: the paint will take the hit, even with small leaks !

That's my understanding as well, it's part of certification, however, it's rather a weak requirement for all practical purposes, one need to see 3% climb out of ground effect, likely at sea level with standard weather (say balked landing with failed full flaps and gear) FAA FAR23.2120 (and EASA CS23.2120) Climb requirements For a balked landing, a climb gradient of 3 percent without creating undue pilot workload with the landing gear extended and flaps in the landing configuration(s). The 3% climb on good days (3×70kts ~ 210fpm), is ahem, very shallow, it's no different than level flight

It does, it depends what speeds one tries? but VY(fullflap) is way down compared to VY(clean) and the performance deteriorates a lot on backside of drag curve As awlays, one has to accelerate from VS0(fullflaps) to VY(fullflap) at level flight or in ground affect before climbing The aircraft will not climb on full flap when the speeds are near or bellow stall speed, this effect is more prounounced with full flaps: at slow speeds, the whole wing is acting as flaps or airbreak and require infinite amount of power the controls are also reversed, to climb one need to pitch down ! I tried go-around and takeoff with full flaps near MTOW in M20J, it's a suboptimal profile in terms of performance but very safe on say long runway (as long as one can control their speeds and pitch while allowing enough time for acceleration). The main challenge is that the aircraft is atrociously out of trim at slow speeds: require flying by attitude and airspeed dials rather than the usual feel of controls, one has prevent nose from going +20deg in order to go faster and to climb...

Sorry, I was exagerating a bit and also sorry to see this happening to your aircraft, however, here are probably dozens (10 or 100) who already got STC and took gallons of G100UL in the last two months from the few airports delivering it in CA, maybe someone who already did can share their feedback on MooneySpace? As always, we have one data point is not enough to do stats, so one need to look at the "other set" (survivorship bias)

I wouldn't worry about AD as there are already thousands of Mooneys already flying on G100UL for the last 2 months or so with no problems, we will see in 5 years or so? The issue is that if a Mooney already has big leak that was acceptable with 100LL, it's likely to be aggravated, especially, the paint will take a hit with G100UL ! On effect on paint, we already know that the paint will take a hit with G100UL (part of it's specs shall we say) and many owners are happy to have this kind of trade-off while making precautions Where I am puzzled is that all of this happens after one week, even the occasional spills after reful would be problematic ! Long term, I am sure we will have new sealants and paints compounds that work better with G100UL Also, there is something weired about chemicals after first use , we should expect things to stablise at some point? reminds me of oil consumption after changing oil brands (or even new oil from same brand)

Thanks @Hank, I am hoping to make it next year !