SL-00078 and Updates to RV-12 POH and RV-12iS POH/FTS Published

[greghughespdx]

Last night we published SL-00078, which covers the operation of the RV-12 and RV-12iS in high-temperature environments and with non-aviation fuels, specifically related to the prevention and recognition of fuel system vapor lock.

We also published updates to the RV-12 POH and the RV-12iS POH and FTS documents to add information about risks related to vapor lock and the need to carry an emergency egress hammer, among other changes.

After a number of vapor-lock-related incidents in a variety of airplanes, industry-wide ASTM requirements were changed to require fuel testing of Light Sport Aircraft. The results of that testing on the RV-12 and RV-12iS, as well as other aircraft and experience, resulted in the necessary changes/additions to the above documents.

Be sure to read the POH and FTS documents as applicable to your aircraft model. The information contained therein is critical safety information that you need to be familiar with. In addition, please read SL-00078, which contains a detailed discussion about vapor lock and the use of different fuels in the RV-12 and RV-12iS aircraft.

Emergency egress hammers are commonly carried in aircraft in case of the need to break the canopy to exit the aircraft in an emergency. Van's has always recommended the use of such devices, and these have been formally added to the POH for both aircraft models.

In the next few weeks, we will publish a video update that covers this topic as well. We will update this thread when that video is posted.

Thank you.

greg

[BryanStearns]

Ron Singh posted a great presentation on YouTube about this; it includes a clip from a slightly earlier EAA 252 presentation he gave, with Rian Johnson talking about Vans' vapor-lock testing:

https://youtu.be/aKVyA7ROQ6A

Lotta good info about mogas in any plane, not just the -12.

[Piper J3]

I agree with all items and logic listed in this new Service Letter 00087. In my opinion this formal discussion as related to RV-12 is long overdue. This is a topic that is near and dear to my heart. Perhaps the folks who wrote this Service Letter have never experienced vapor lock in flight first hand…. I did. I started a thread to discuss vapor lock with RV-12 / 912ULS two years ago after having a bad day… https://vansairforce.net/community/s...ght=vapor+lock

In addition to the above thread, I have a few other comments…

• Everyone who flies RV-12, without exception, needs to be completely aware of risks of vapor lock and mitigation techniques especially with RV-12 ULS Legacy that is very tightly cowled and has very small air inlets. If there is something you don’t understand…. ask for help.
• Extended taxing downwind will nullify air flow through the cowling. Therefore, avoid as much as possible takeoff / landing to full stop with long taxi back. This will be tough for flight instruction, but a necessary caution.
• If engine is heat-soaked, run electric pump for several (5) minutes to bring cooler fuel into fuel distribution above hot engine.
• Leave oil access door open when not flying.
• Use a cooling fan on oil access door opening when airplane is parked to draw hot air out of cowling.
• Install higher pressure auxiliary (electric) fuel pump Notification N 18-07-12 and run it 100% of time.
• Several RV-12 accidents, including one very recently, have earmark of vapor lock. I don’t think NTSB has ever stated vapor lock as probable cause. Hard to prove vapor lock after the fact. Best to avoid at all costs…

[EchoJuliet]

Originally Posted by greghughespdx

Last night we published SL-00078, which covers the operation of the RV-12 and RV-12iS in high-temperature environments and with non-aviation fuels, specifically related to the prevention and recognition of fuel system vapor lock.

We also published updates to the RV-12 POH and the RV-12iS POH and FTS documents to add information about risks related to vapor lock and the need to carry an emergency egress hammer, among other changes.

After a number of vapor-lock-related incidents in a variety of airplanes, industry-wide ASTM requirements were changed to require fuel testing of Light Sport Aircraft. The results of that testing on the RV-12 and RV-12iS, as well as other aircraft and experience, resulted in the necessary changes/additions to the above documents.

Be sure to read the POH and FTS documents as applicable to your aircraft model. The information contained therein is critical safety information that you need to be familiar with. In addition, please read SL-00078, which contains a detailed discussion about vapor lock and the use of different fuels in the RV-12 and RV-12iS aircraft.

Emergency egress hammers are commonly carried in aircraft in case of the need to break the canopy to exit the aircraft in an emergency. Van's has always recommended the use of such devices, and these have been formally added to the POH for both aircraft models.

In the next few weeks, we will publish a video update that covers this topic as well. We will update this thread when that video is posted.

Thank you.

greg

The RV-12iS POH still has an incorrect spark gap callout (pg. 8.4). It should be .023-.027 for the NGK plug and .031-.035 for the Rotax 297656 plug. I contacted the support team last September regarding this.

[Bob Y]

Greg, inquiring minds are interested to know why Van’s decided to move away from the A6 paper size to 8.5”x11” for the POH, which is definitely NOT user friendly for storage in the aircraft?

[greghughespdx]

Originally Posted by Bob Y

Greg, inquiring minds are interested to know why Van’s decided to move away from the A6 paper size to 8.5”x11” for the POH, which is definitely NOT user friendly for storage in the aircraft?

Going forward, the POH we provide is actually printed in spiral-bound, fold-flat book form. They are 8.5" tall, 5.5" wide, and (now) full-color booklets. No more binder. It's compact and quite usable. You can also print it from the PDF to that size or another percentage if you like, of course. The old/original binder style is no longer available.

I'll post a couple of photos of the new style book soon.

[rcarsey]

Paper.. if anyone wants to print...

24lb bond:
https://www.amazon.com/Bright-White-...a-810947736446

32lb bond:
https://www.amazon.com/Premium-Weigh...ts%2C79&sr=1-6

[pstraub]

I just bought 50 gallons of mogas two days ago(93UL, ethanol-free) but I have no idea if the blend is summer or winter. I am in East TN and obviously not quite May 1st yet. It would be great to measure the RVP per SL-00078. Does anyone know of a reasonably priced RVP tester? (if there even is such a thing!) Thanks!!

[Bob Y]

It’s the fuel distribution terminals that are required to start distributing summer-blend gas by May 1st. It takes time for the gas stations to sell off their winter blend and have 100% summer blend in their tanks. That’s why the June 1st requirement for gas stations to be 100% summer blend. But I’ll bet if you ask a clerk at your local gas station if they’re distributing summer vs. winter blend they’ll look at you with a blank stare. That being said, your gas is almost assured to be winter blend. I made my own crude RVP tester with some 3/4” copper pipe, fittings and a plumbing pressure tester, like this one:

CARBO Instruments Gas Test Pressure Gauge 15 Pound, 15 PSI / 100 kPa, 3/4” FNPT Connection, Brass Valve, Chrome Plated Steel Body Assembly. https://a.co/d/fpcB112

A pipe that holds 50 ml, filled with 10 ml of gasoline gives you the correct ratio. Go to YouTube and you’ll find several videos showing the test process. Since we’re just trying to determine winter vs. summer blend, exact values aren’t important - relatively high vs. low pressures will tell us which blend we’ve got. My tester gives me pretty reasonable results.

[pstraub]

Originally Posted by Bob Y

A pipe that holds 50 ml, filled with 10 ml of gasoline gives you the correct ratio. Go to YouTube and you’ll find several videos showing the test process. Since we’re just trying to determine winter vs. summer blend, exact values aren’t important - relatively high vs. low pressures will tell us which blend we’ve got. My tester gives me pretty reasonable results.

Thanks very much Bob, appreciate the info! Paul