https://rotorwayforums.com/ Thu, 20 Aug 2026 05:58:56 +0000 MyBB https://rotorwayforums.com/thread-205.html Wed, 19 Aug 2026 11:22:10 -0500 Geno Mancini]]> https://rotorwayforums.com/thread-205.html So I designed and built an aluminum block V6 4.3L chevy driving my custom built planetary transmission.
It had to run backwards, meaning a custom crank and a custom cam shaft.
It made over 300 hp and I had over 50k in the engine alone.
And that was when 50k actually ment something.
There was no internet back then, you gained knowledge by reading and talking to people.
I actually had one of the first IBM floppy disk computers.
It had a huge 10 megabite hard drive with 2 floppy disk drives.
Fast forward 40 years, I now fly an Allison turbine, more reliable with less moving parts.

I've always been a designer/builder as far back as I can remember.
I was at my grandpa's side, as a little boy, helping him with his projects.
Then I built a dune buggy when I was 15 years old and have been building ever since.
I've had quite a few adventures in the past, including dune buggys, dirt bikes, street bikes, snowmobiles, race cars.
I have no desire to do those things anymore.
Once you've built/fly your own helicopter, nothing else compares.

Here's a few pictures of my past. 















]]> So I designed and built an aluminum block V6 4.3L chevy driving my custom built planetary transmission.
It had to run backwards, meaning a custom crank and a custom cam shaft.
It made over 300 hp and I had over 50k in the engine alone.
And that was when 50k actually ment something.
There was no internet back then, you gained knowledge by reading and talking to people.
I actually had one of the first IBM floppy disk computers.
It had a huge 10 megabite hard drive with 2 floppy disk drives.
Fast forward 40 years, I now fly an Allison turbine, more reliable with less moving parts.

I've always been a designer/builder as far back as I can remember.
I was at my grandpa's side, as a little boy, helping him with his projects.
Then I built a dune buggy when I was 15 years old and have been building ever since.
I've had quite a few adventures in the past, including dune buggys, dirt bikes, street bikes, snowmobiles, race cars.
I have no desire to do those things anymore.
Once you've built/fly your own helicopter, nothing else compares.

Here's a few pictures of my past. 















]]> https://rotorwayforums.com/thread-204.html Tue, 18 Aug 2026 21:08:48 -0500 Fredy Irizarry]]> https://rotorwayforums.com/thread-204.html Disclaimer: This is what *I did*.  You do your EXPERIMENTAL aircraft as you see fit,  and assume the responsibility of what you do and how you do it.

I decided to use Sikaflex (Sika Aktivator 100, Sika Primer 209-D Black and Sikaflex-295 UV) for the doors rather than rivets.

I made a jig to hold the shape of the fiberglass stiffener out of wood. So far no rivets.
I'll use 6-32 screws and t nuts for the stall strip to avoid pull rivet action.

Here are some pictures of the process and the door installed.

Others indicated they have used Panel Bonding Adhesive MB-835









]]> Disclaimer: This is what *I did*.  You do your EXPERIMENTAL aircraft as you see fit,  and assume the responsibility of what you do and how you do it.

I decided to use Sikaflex (Sika Aktivator 100, Sika Primer 209-D Black and Sikaflex-295 UV) for the doors rather than rivets.

I made a jig to hold the shape of the fiberglass stiffener out of wood. So far no rivets.
I'll use 6-32 screws and t nuts for the stall strip to avoid pull rivet action.

Here are some pictures of the process and the door installed.

Others indicated they have used Panel Bonding Adhesive MB-835









]]> https://rotorwayforums.com/thread-197.html Sun, 16 Aug 2026 13:53:41 -0500 Orv Neisingh]]> https://rotorwayforums.com/thread-197.html
Once the fuel stopped leaking we inspected the fuel system and found that the pilot side fuel tank fitting had completely fallen out of the fuel tank and was laying against the frame member below the fuel tank. As we looked at the fuel tank outlet fitting we marveled that Rotorway did not have a positive mechanical stop on the inside of the fuel tank to prevent the fuel outlet fitting from falling out. The fitting was depending on the friction of the fuel seal only to keep the fitting in the tank outlet hole. Below you can read the post that I made years ago detailing how we came up with a fix for this dangerous design error. It took the Rotorway factory over 10 years to adopt this modification of installing a washer on the inside of the fuel tank to secure the outlet fitting in place preventing it from falling out. If you have a 162F you should check to insure that this modification has been done or you may experience the same issue that we did at some point. 

To install Orv's fuel tank outlet fitting mod, you will first need to drain all of the fuel out of your fuel tanks in a well ventilated area away from any flame, gas vapors hug the ground so be careful. You do this by removing enough screws on the side of the tub to allow the rear side of the tub to be pulled away from the fuel tank to allow you to get your wrenches on the fuel tank fitting and nut.\
Disconnect the fuel line from the fuel tank fitting. Remove the fittng nut and washer. Pull the fuel tank outlet fitting out of the bottom of the fuel tank. Inspect the rubber grommet to insure that it is in good condition. If not order a new set from the Robin or Kris.

Once you have the fitting removed, drill a 3/16" (or close to that) hole in the top of the aluminum fitting as seen in the photo below.

Next take a 10' piece of string and tie a nut to the end for a weight. The nut on the string is then dropped into the top of the tank and jiggled until it comes out the outlet hole in the bottom of the tank.

The photo below shows the string with the nut weight coming out the bottom of the fuel tank. The Tootsie Pop is optional. You will notice a lot of rust and chipped paint on this ship. This is what happens when a frame is not primed before painting and when the ship is parked outside in the rain. It took me a week to get this ship airworthy before we could begin the builders flight training.

Tie the nut end of the string around the landing gear step to prevent it from accidentally being pulled back into the fuel tank.

You will need to purchase or make a washer that will fit over the fuel tank fitting threads and bevel but not pass the small shelf at the upper portion of the bevel. This washer is what keeps the fitting from being able to exit the bottom of the fuel tank. You can usually find a washer that is close in size and then file or dremmel out the ID to fit the fitting. You don't want the washer to contact the bevel to the point that it does not fit snugly up against the flat shelf above the bevel.
The OD of the washer should be at least 1/4" larger than the OD of the outlet fitting top. If the washer OD is too large, it may not fit the space at the bottom of the tank.
Place the washer and fitting onto the string as shown below.


Next you will drop the washer into the fuel tank (with the beveled side facing up to mate with the fuel fitting bevel) and allow it to slide down the string to the bottom of the fuel tank. You can reach your finger up into the tank outlet and insure that the washer has room to fit flat against the bottom of the inside of the tank. Too large of a washer OD may not fit.

You do the same for the fuel outlet fitting.

In the photo below the fuel tank fitting end has been slid down the string, through the washer, and out of the bottom of the fuel tank.

Now you should tie off the upper end of the string to prevent it from falling into the fuel tank as you are working on the bottom end. The string will keep the fitting and washer captive until you have them secured in place.
Slide the rubber grommet up the string and into place around the fuel fitting threads and inside of the tank hole. You will need to hold onto the outlet fitting threads to keep the fitting from going back into the tank. The grommet will hit the new washer inside of the tank.

Next slide the bottom washer and nut up the string and into place on the threads of the fuel tank outlet fitting. Tighten the nut and then reattach the fuel lines on each tank when you are finished installing the fittings.
Your fuel tank outlet fittings will not be able to fall out of the fuel tanks now while you are flying so you now have a much safer helicopter.
]]>
Once the fuel stopped leaking we inspected the fuel system and found that the pilot side fuel tank fitting had completely fallen out of the fuel tank and was laying against the frame member below the fuel tank. As we looked at the fuel tank outlet fitting we marveled that Rotorway did not have a positive mechanical stop on the inside of the fuel tank to prevent the fuel outlet fitting from falling out. The fitting was depending on the friction of the fuel seal only to keep the fitting in the tank outlet hole. Below you can read the post that I made years ago detailing how we came up with a fix for this dangerous design error. It took the Rotorway factory over 10 years to adopt this modification of installing a washer on the inside of the fuel tank to secure the outlet fitting in place preventing it from falling out. If you have a 162F you should check to insure that this modification has been done or you may experience the same issue that we did at some point. 

To install Orv's fuel tank outlet fitting mod, you will first need to drain all of the fuel out of your fuel tanks in a well ventilated area away from any flame, gas vapors hug the ground so be careful. You do this by removing enough screws on the side of the tub to allow the rear side of the tub to be pulled away from the fuel tank to allow you to get your wrenches on the fuel tank fitting and nut.\
Disconnect the fuel line from the fuel tank fitting. Remove the fittng nut and washer. Pull the fuel tank outlet fitting out of the bottom of the fuel tank. Inspect the rubber grommet to insure that it is in good condition. If not order a new set from the Robin or Kris.

Once you have the fitting removed, drill a 3/16" (or close to that) hole in the top of the aluminum fitting as seen in the photo below.

Next take a 10' piece of string and tie a nut to the end for a weight. The nut on the string is then dropped into the top of the tank and jiggled until it comes out the outlet hole in the bottom of the tank.

The photo below shows the string with the nut weight coming out the bottom of the fuel tank. The Tootsie Pop is optional. You will notice a lot of rust and chipped paint on this ship. This is what happens when a frame is not primed before painting and when the ship is parked outside in the rain. It took me a week to get this ship airworthy before we could begin the builders flight training.

Tie the nut end of the string around the landing gear step to prevent it from accidentally being pulled back into the fuel tank.

You will need to purchase or make a washer that will fit over the fuel tank fitting threads and bevel but not pass the small shelf at the upper portion of the bevel. This washer is what keeps the fitting from being able to exit the bottom of the fuel tank. You can usually find a washer that is close in size and then file or dremmel out the ID to fit the fitting. You don't want the washer to contact the bevel to the point that it does not fit snugly up against the flat shelf above the bevel.
The OD of the washer should be at least 1/4" larger than the OD of the outlet fitting top. If the washer OD is too large, it may not fit the space at the bottom of the tank.
Place the washer and fitting onto the string as shown below.


Next you will drop the washer into the fuel tank (with the beveled side facing up to mate with the fuel fitting bevel) and allow it to slide down the string to the bottom of the fuel tank. You can reach your finger up into the tank outlet and insure that the washer has room to fit flat against the bottom of the inside of the tank. Too large of a washer OD may not fit.

You do the same for the fuel outlet fitting.

In the photo below the fuel tank fitting end has been slid down the string, through the washer, and out of the bottom of the fuel tank.

Now you should tie off the upper end of the string to prevent it from falling into the fuel tank as you are working on the bottom end. The string will keep the fitting and washer captive until you have them secured in place.
Slide the rubber grommet up the string and into place around the fuel fitting threads and inside of the tank hole. You will need to hold onto the outlet fitting threads to keep the fitting from going back into the tank. The grommet will hit the new washer inside of the tank.

Next slide the bottom washer and nut up the string and into place on the threads of the fuel tank outlet fitting. Tighten the nut and then reattach the fuel lines on each tank when you are finished installing the fittings.
Your fuel tank outlet fittings will not be able to fall out of the fuel tanks now while you are flying so you now have a much safer helicopter.
]]> https://rotorwayforums.com/thread-196.html Sun, 16 Aug 2026 13:33:28 -0500 Orv Neisingh]]> https://rotorwayforums.com/thread-196.html Fuel level sender

• The photo below is what we found when we tilted a clients helicopter back during our pre-flight inspection. You can see the puddle of fuel on the ground that leaked out of the gasket where the fuel level sensor attaches to the fuel tank. The build instructions have the builder use 5 screws placed into the soft plastic tank and often they can loose their grip and not hold the sender in place.
  
• If the fuel level sender is not leaking then it was installed correctly and should not be a problem. If the sender does leak then I am offering a fix that I have used several times to insure a good seal and return us to flight within a relatively short period of time.
  

 
The fuel sender attache point can sometimes leak fuel when we do autos and quick stops due to the fuel sender screws not holding the sender securely to the top of the fuel tank. They could strip out and leak when we progress in the training to the point of performing flares during autos and quick stops.
If the fuel sender gasket begins to leak we will need nut plates and machine screws to solidly attach the sender unit to the tank. Shown below are aluminum riv-nuts installed, we used fuel resistant gasket seal and another cork gasket and then machine screws with fuel resistant sealant on the threads to attach the sender. 

Installing the nut plates on the inside of the fuel tank requires drilling holes for the rivets and catching all of the drilled debris to keep it out of the tank. The other caution is to not drop the nut plates into the tank when positioning them in place on the underside of the tank top. I have done this several times with success but it is a bit nerve wracking. Caution, if the fuel tank has fuel or fuel vapors remaining it is best to remove that fuel tank and do the work on the work bench where there is less likely of igniting any fuel residue left in the tank. 
The photo below shows where the fuel sender is attached to the fuel tank.

Here the riv-nuts are ready for installing into the tank, They mush out on the inside of the tank preventing them from rotating (sometimes) or pulling through and the threads allowing the sender attachment screws enough bite to allow you to pull the plastic lip snugly up against the sender base to make a complete seal. I have had better results with nut plates installed on the underside of the tank lip with rivets.
If this area is not leaking, it is not a problem.

Some cork gasket seal applied between the riv-nuts to take up the gap


 

Fuel resistant sealant was used to seal the new cork gasket to the tank. Be sure to put some fuel resistant sealant under the head of each screw so that fuel does not wick up to the top of the sender and leak.
 
]]> Fuel level sender

• The photo below is what we found when we tilted a clients helicopter back during our pre-flight inspection. You can see the puddle of fuel on the ground that leaked out of the gasket where the fuel level sensor attaches to the fuel tank. The build instructions have the builder use 5 screws placed into the soft plastic tank and often they can loose their grip and not hold the sender in place.
  
• If the fuel level sender is not leaking then it was installed correctly and should not be a problem. If the sender does leak then I am offering a fix that I have used several times to insure a good seal and return us to flight within a relatively short period of time.
  

 
The fuel sender attache point can sometimes leak fuel when we do autos and quick stops due to the fuel sender screws not holding the sender securely to the top of the fuel tank. They could strip out and leak when we progress in the training to the point of performing flares during autos and quick stops.
If the fuel sender gasket begins to leak we will need nut plates and machine screws to solidly attach the sender unit to the tank. Shown below are aluminum riv-nuts installed, we used fuel resistant gasket seal and another cork gasket and then machine screws with fuel resistant sealant on the threads to attach the sender. 

Installing the nut plates on the inside of the fuel tank requires drilling holes for the rivets and catching all of the drilled debris to keep it out of the tank. The other caution is to not drop the nut plates into the tank when positioning them in place on the underside of the tank top. I have done this several times with success but it is a bit nerve wracking. Caution, if the fuel tank has fuel or fuel vapors remaining it is best to remove that fuel tank and do the work on the work bench where there is less likely of igniting any fuel residue left in the tank. 
The photo below shows where the fuel sender is attached to the fuel tank.

Here the riv-nuts are ready for installing into the tank, They mush out on the inside of the tank preventing them from rotating (sometimes) or pulling through and the threads allowing the sender attachment screws enough bite to allow you to pull the plastic lip snugly up against the sender base to make a complete seal. I have had better results with nut plates installed on the underside of the tank lip with rivets.
If this area is not leaking, it is not a problem.

Some cork gasket seal applied between the riv-nuts to take up the gap


 

Fuel resistant sealant was used to seal the new cork gasket to the tank. Be sure to put some fuel resistant sealant under the head of each screw so that fuel does not wick up to the top of the sender and leak.
 
]]> https://rotorwayforums.com/thread-191.html Sat, 15 Aug 2026 11:42:22 -0500 Orv Neisingh]]> https://rotorwayforums.com/thread-191.html
How many of you actually remove the rubber cap and inspect those fuses on every pre-flight? I know that I did not. If one of the fuses has blown then we are flying with only half of the electrical system powering the overhead. If the other fuse should then blow it will shut off all alternator power to the overhead panel. 

A simple solution is to install reset able breakers to replace the fuses. If the breaker trips a red flag drops down and is easily seen during your preflight inspection. With a standard battery installed it would require two 30 amp breakers to replace the fuses. If Lithium batteries are installed then it may require a 30 amp breaker to feed the overhead and a 60 amp breaker and heavier wiring to feed the battery. Along with that a special voltage regulator for lithium batteries must also be installed. In the photo below you can see the installation of the breakers and also the wires from the alternator run through an amp sensor to give me an amperage reading on my instrument panel so that I can verify that current is flowing from the alternator during flight verifying that my electrical system is in proper order.




]]>
How many of you actually remove the rubber cap and inspect those fuses on every pre-flight? I know that I did not. If one of the fuses has blown then we are flying with only half of the electrical system powering the overhead. If the other fuse should then blow it will shut off all alternator power to the overhead panel. 

A simple solution is to install reset able breakers to replace the fuses. If the breaker trips a red flag drops down and is easily seen during your preflight inspection. With a standard battery installed it would require two 30 amp breakers to replace the fuses. If Lithium batteries are installed then it may require a 30 amp breaker to feed the overhead and a 60 amp breaker and heavier wiring to feed the battery. Along with that a special voltage regulator for lithium batteries must also be installed. In the photo below you can see the installation of the breakers and also the wires from the alternator run through an amp sensor to give me an amperage reading on my instrument panel so that I can verify that current is flowing from the alternator during flight verifying that my electrical system is in proper order.




]]> https://rotorwayforums.com/thread-189.html Sat, 15 Aug 2026 09:09:04 -0500 Orv Neisingh]]> https://rotorwayforums.com/thread-189.html
I was able to perform a safe auto to a grass field below us and upon inspection found that both of the 30 amp fuses at the Alternator were blown. Looking further I found that the 30 amp fuses in the overhead panel had also blown cutting off all power from the battery. How could this happen? We have redundant systems to prevent just such a dangerous condition from occurring. 

I got the wiring diagram out and traced out the power feeds from the alternator to the overhead pane, the feed from the battery to the overhead panel, and the feed from the alternator to the battery. What I noticed was that both of the "REDUNDANT" systems shared the same power feeds from the alternator and the battery, they were not separated but jumpers went from one 30 amp fuse to the next to the next in the overhead panel. The designers idea was that if one supply failed the jumpers would carry the power from the other supply over to the other system and the pilot would not ever know that there was a failure of one power feed. 

This worked but... what if one of the power feed wires should short out to ground...Power would surge to the short blowing every fuse in the path between the short and the power source. Now that made sense so we began inspecting the power feed wire originating at the alternator and traveling up along the frame to the overhead. At one point the wire was rubbing on the sharp metal edge of a frame bracket and when the insulation rubbed through, the wire shorted directly to the frame taking out every fuse in the power feed system to critical components needed to run the engine. 

The fix for this flaw in the wiring was to isolate one FADEC, fuel pump, and ignition system completely from the other, not by just switches but by separating the power feeds themselves. After replacing the alternator feed wire that had shorted out, and the blown fuses, we change the wiring overhead. We ran the alternator power through one 30 amp fuse in the overhead then to the individual fuses that protected one FADEC, one fuel pump and one ignition system. We then ran the power feed from the battery through a 30 amp fuse to the other fuses that protect the other FADEC, fuel pump and ignition system. With this new wiring routing if one power feed would short out, one system would shut off and the pilot would immediately know that there was an issue as they would get a FADEC warning light, but the other system would continue to keep the engine running and the occupants safe.]]>
I was able to perform a safe auto to a grass field below us and upon inspection found that both of the 30 amp fuses at the Alternator were blown. Looking further I found that the 30 amp fuses in the overhead panel had also blown cutting off all power from the battery. How could this happen? We have redundant systems to prevent just such a dangerous condition from occurring. 

I got the wiring diagram out and traced out the power feeds from the alternator to the overhead pane, the feed from the battery to the overhead panel, and the feed from the alternator to the battery. What I noticed was that both of the "REDUNDANT" systems shared the same power feeds from the alternator and the battery, they were not separated but jumpers went from one 30 amp fuse to the next to the next in the overhead panel. The designers idea was that if one supply failed the jumpers would carry the power from the other supply over to the other system and the pilot would not ever know that there was a failure of one power feed. 

This worked but... what if one of the power feed wires should short out to ground...Power would surge to the short blowing every fuse in the path between the short and the power source. Now that made sense so we began inspecting the power feed wire originating at the alternator and traveling up along the frame to the overhead. At one point the wire was rubbing on the sharp metal edge of a frame bracket and when the insulation rubbed through, the wire shorted directly to the frame taking out every fuse in the power feed system to critical components needed to run the engine. 

The fix for this flaw in the wiring was to isolate one FADEC, fuel pump, and ignition system completely from the other, not by just switches but by separating the power feeds themselves. After replacing the alternator feed wire that had shorted out, and the blown fuses, we change the wiring overhead. We ran the alternator power through one 30 amp fuse in the overhead then to the individual fuses that protected one FADEC, one fuel pump and one ignition system. We then ran the power feed from the battery through a 30 amp fuse to the other fuses that protect the other FADEC, fuel pump and ignition system. With this new wiring routing if one power feed would short out, one system would shut off and the pilot would immediately know that there was an issue as they would get a FADEC warning light, but the other system would continue to keep the engine running and the occupants safe.]]> https://rotorwayforums.com/thread-177.html Sun, 09 Aug 2026 13:10:34 -0500 Orv Neisingh]]> https://rotorwayforums.com/thread-177.html
Nathan did not like the idea if the engine oil return hose to the tank being just a standard coolant hose. He decided that he would replace the rubber coolant hoses with Teflon stainless braided hoses. These worked out well except on the engine to tank hose. He was able to adapt a large diameter braided hoses to the engine and tank and was doing some hover testing when suddenly the cabin filled with smoke and the helicopter was on fire.

Nathan had a fire extinguisher on board so he landed and extinguished the flames but the heat wrap on the exhaust pipes was soaked with oil and the hot exhaust kept igniting the oil. He had landed right in front of his hangar so he was able to grab a large fire extinguisher and totally emptied it as well but the wrapped exhaust continued to ignite the oil.

At that point all Nathan could do was watch the fire spread to his plastic fuel tanks and consume his helicopter. When the fire had burned itself out Nathan found that the female threaded casting at the bottom of the engine had broken allowing the modified hose and fitting to separate from the engine pouring the engine oil all over the exhaust system. He surmised that his replacement hose was too ridged to safely absorb the engine vibrations thus cracking the engine casting.

Nathan’s experience is precisely why we began wrapping heavy aluminum tape or foil around the heat wrapped exhaust system to prevent any fluids from being soaked up by the heat wrapped exhaust system. The photo below shows the heavy foil covering the exhaust heat wrap.
]]>
Nathan did not like the idea if the engine oil return hose to the tank being just a standard coolant hose. He decided that he would replace the rubber coolant hoses with Teflon stainless braided hoses. These worked out well except on the engine to tank hose. He was able to adapt a large diameter braided hoses to the engine and tank and was doing some hover testing when suddenly the cabin filled with smoke and the helicopter was on fire.

Nathan had a fire extinguisher on board so he landed and extinguished the flames but the heat wrap on the exhaust pipes was soaked with oil and the hot exhaust kept igniting the oil. He had landed right in front of his hangar so he was able to grab a large fire extinguisher and totally emptied it as well but the wrapped exhaust continued to ignite the oil.

At that point all Nathan could do was watch the fire spread to his plastic fuel tanks and consume his helicopter. When the fire had burned itself out Nathan found that the female threaded casting at the bottom of the engine had broken allowing the modified hose and fitting to separate from the engine pouring the engine oil all over the exhaust system. He surmised that his replacement hose was too ridged to safely absorb the engine vibrations thus cracking the engine casting.

Nathan’s experience is precisely why we began wrapping heavy aluminum tape or foil around the heat wrapped exhaust system to prevent any fluids from being soaked up by the heat wrapped exhaust system. The photo below shows the heavy foil covering the exhaust heat wrap.
]]> https://rotorwayforums.com/thread-176.html Sun, 09 Aug 2026 00:18:27 -0500 Graeme Smith]]> https://rotorwayforums.com/thread-176.html

]]>

]]> https://rotorwayforums.com/thread-173.html Fri, 07 Aug 2026 06:05:52 -0500 Graeme Smith]]> https://rotorwayforums.com/thread-173.html ]]> ]]> https://rotorwayforums.com/thread-171.html Thu, 06 Aug 2026 07:37:37 -0500 Orv Neisingh]]> https://rotorwayforums.com/thread-171.html




I wanted to modify my doghouse to make it look like the new Exec 90, who needs a hole in the front of the doghouse anyway? With a couple of late evenings worth of work I covered the hole with fiberglass and painted it to match the rest of the doghouse and I was really proud of my handiwork. I hovered the helicopter and monitored the temps and all appeared normal after the modification. 

Some friends invited us to join them for lunch in Lower Lake on the shore of Clear Lake in northern California and I was excited to show off my dog house modification to them. We set a time for Sheila and I to meet them and called just prior to lifting off. It was about a 60 mile flight which we could easily accomplish in about an hour. We left our home around 11am and began transitioning our route from the Sacramento valley over the coastal range mountains. Our route had us climb several thousand feet and as we climbed over the highest mountain on our route Sheila told be to land because she was getting burned on her thigh. 

The Execs did not have an enclosed collective slot for the middle collective, the slot was open to the tub and engine compartment. My modification of closing off the hole in the front of the doghouse had dramatically changed the air flow in the engine compartment and now hot air off the exhaust pipes was entering the cabin through the center slot, right below the passengers thigh. As we climbed over the mountain at full power and slower airspeed, the intense exhaust heat was literally blistering my wife"s thigh. She told me "Land now or I will land it!".

Near the top of the mountain there was a small grass covered meadow so I entered an auto, flared and landed on the flat grassy "meadow". As I lowered the collective the surface gave way and the skids began to sink as grey mud oozed up over both skids. This was not a meadow but a grass covered mud bog with about an inch of dry cracked soil covering the mud. As I lifted the collective to keep from sinking the pilot side skid broke free of the
mud's suction but the passenger side skid held firm and as I added collective input the helicopter tilted dangerously to the passenger side...what to do??

Sheila was hurting and our helicopter was trapped in a mud bog on top of a isolated mountain at a serious right tilt. I did not dare to lower the collective because we would just sink more into the bog. I then recalled a previous flight instructor telling me about getting a skid stuck on the ice of a frozen lake. He had told me that he was able to break free by using the anti-torque pedals to wiggle the helicopter back and forth with upward collective and it broke free of the ice so that is what I did. As I wiggled the helicopter back and forth with just enough collective to keep from sinking the right skid came up out of the mud and I was then able to skid the helicopter lightly across the dry surface to the shore line where there were some rocks so I assumed it was solid there, it was. At that altitude above sea level the little Exec did not have the power to totally break the ground and hover so skidding it was all I could do.

I shut the helicopter down once we were resting on solid ground and sheila jumped out and checked her burns, sure enough she had several large burn blisters on the side of her left thigh. I realized that my dog house hole covering modification had drastically changed the airflow through the engine bay and was the reason for the burns to my wife's leg. I always fly with my Leatherman multi-tool and I used it to cut out the fiberglass cover over the hole in the doghouse, it wasn't pretty but it would do. Our present altitude on top of the mountain was well above our near sea level hover performance and I had to get airborne to depart this desolate bog. 

With the low-powered Execs it was not uncommon to run the main rotor RPM up to the red line then increase collective to jump the helicopter off the ground so that is what I did. As we jumped off the surface I made a left turn letting the torque turn the nose of the helicopter as a right turn would require anti-torque and rob the engine power to the main rotor and I needed every bit of that power to accelerate through ETL. Once through ETL we continued our flight and as we approached the Lower Lake gang anxiously waiting for us we could see that they were relieved that we had made it although we were over due. 

When we landed we were told that they knew there was a story to tell by the long clumps of grass and mud still hanging from the helicopter skids. We had a great visit, a good lunch, and shared lessons learned. One of the guys there to meet us was Nathan Fronsman with his wife Elaine. The other was Len Chriysler. I have an interesting story of one of Nathan's modifications that did not fare well either, for another time. 
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I wanted to modify my doghouse to make it look like the new Exec 90, who needs a hole in the front of the doghouse anyway? With a couple of late evenings worth of work I covered the hole with fiberglass and painted it to match the rest of the doghouse and I was really proud of my handiwork. I hovered the helicopter and monitored the temps and all appeared normal after the modification. 

Some friends invited us to join them for lunch in Lower Lake on the shore of Clear Lake in northern California and I was excited to show off my dog house modification to them. We set a time for Sheila and I to meet them and called just prior to lifting off. It was about a 60 mile flight which we could easily accomplish in about an hour. We left our home around 11am and began transitioning our route from the Sacramento valley over the coastal range mountains. Our route had us climb several thousand feet and as we climbed over the highest mountain on our route Sheila told be to land because she was getting burned on her thigh. 

The Execs did not have an enclosed collective slot for the middle collective, the slot was open to the tub and engine compartment. My modification of closing off the hole in the front of the doghouse had dramatically changed the air flow in the engine compartment and now hot air off the exhaust pipes was entering the cabin through the center slot, right below the passengers thigh. As we climbed over the mountain at full power and slower airspeed, the intense exhaust heat was literally blistering my wife"s thigh. She told me "Land now or I will land it!".

Near the top of the mountain there was a small grass covered meadow so I entered an auto, flared and landed on the flat grassy "meadow". As I lowered the collective the surface gave way and the skids began to sink as grey mud oozed up over both skids. This was not a meadow but a grass covered mud bog with about an inch of dry cracked soil covering the mud. As I lifted the collective to keep from sinking the pilot side skid broke free of the
mud's suction but the passenger side skid held firm and as I added collective input the helicopter tilted dangerously to the passenger side...what to do??

Sheila was hurting and our helicopter was trapped in a mud bog on top of a isolated mountain at a serious right tilt. I did not dare to lower the collective because we would just sink more into the bog. I then recalled a previous flight instructor telling me about getting a skid stuck on the ice of a frozen lake. He had told me that he was able to break free by using the anti-torque pedals to wiggle the helicopter back and forth with upward collective and it broke free of the ice so that is what I did. As I wiggled the helicopter back and forth with just enough collective to keep from sinking the right skid came up out of the mud and I was then able to skid the helicopter lightly across the dry surface to the shore line where there were some rocks so I assumed it was solid there, it was. At that altitude above sea level the little Exec did not have the power to totally break the ground and hover so skidding it was all I could do.

I shut the helicopter down once we were resting on solid ground and sheila jumped out and checked her burns, sure enough she had several large burn blisters on the side of her left thigh. I realized that my dog house hole covering modification had drastically changed the airflow through the engine bay and was the reason for the burns to my wife's leg. I always fly with my Leatherman multi-tool and I used it to cut out the fiberglass cover over the hole in the doghouse, it wasn't pretty but it would do. Our present altitude on top of the mountain was well above our near sea level hover performance and I had to get airborne to depart this desolate bog. 

With the low-powered Execs it was not uncommon to run the main rotor RPM up to the red line then increase collective to jump the helicopter off the ground so that is what I did. As we jumped off the surface I made a left turn letting the torque turn the nose of the helicopter as a right turn would require anti-torque and rob the engine power to the main rotor and I needed every bit of that power to accelerate through ETL. Once through ETL we continued our flight and as we approached the Lower Lake gang anxiously waiting for us we could see that they were relieved that we had made it although we were over due. 

When we landed we were told that they knew there was a story to tell by the long clumps of grass and mud still hanging from the helicopter skids. We had a great visit, a good lunch, and shared lessons learned. One of the guys there to meet us was Nathan Fronsman with his wife Elaine. The other was Len Chriysler. I have an interesting story of one of Nathan's modifications that did not fare well either, for another time. 
]]> https://rotorwayforums.com/thread-163.html Fri, 31 Jul 2026 22:36:29 -0500 Graeme Smith]]> https://rotorwayforums.com/thread-163.html The top of the fan is inline with the top of the flap opening. 


]]> The top of the fan is inline with the top of the flap opening. 


]]> https://rotorwayforums.com/thread-155.html Fri, 17 Jul 2026 22:53:13 -0500 Orv Neisingh]]> https://rotorwayforums.com/thread-155.html




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]]> https://rotorwayforums.com/thread-149.html Tue, 14 Jul 2026 10:26:41 -0500 Orv Neisingh]]> https://rotorwayforums.com/thread-149.html
I measured the distance between the bottom slider rails to be just over 4” so I used a 4” hole saw and installed an access hole between the slider rails on the bottom of the tail boom. This mod has worked out great for me and I have trailered my ship to many meets over thousands of miles of bumpy roads with absolutely no issues. I am not recommending this for you, I am just telling you what I did and would do again.
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I measured the distance between the bottom slider rails to be just over 4” so I used a 4” hole saw and installed an access hole between the slider rails on the bottom of the tail boom. This mod has worked out great for me and I have trailered my ship to many meets over thousands of miles of bumpy roads with absolutely no issues. I am not recommending this for you, I am just telling you what I did and would do again.
]]> https://rotorwayforums.com/thread-148.html Tue, 14 Jul 2026 10:15:37 -0500 Orv Neisingh]]> https://rotorwayforums.com/thread-148.html


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]]> https://rotorwayforums.com/thread-147.html Mon, 13 Jul 2026 22:13:20 -0500 Homer Bell]]> https://rotorwayforums.com/thread-147.html Another suggestion is to recess all the switches in the over head switch panel. Get them up where they can’t cut your head. First Scorpion I crashed had the screws in the top windows come across the top of my helmet. Some nice deep scratches there . Glad I was wearing a helmet that day. That’s been over 50 years ago. How time flies.]]> Another suggestion is to recess all the switches in the over head switch panel. Get them up where they can’t cut your head. First Scorpion I crashed had the screws in the top windows come across the top of my helmet. Some nice deep scratches there . Glad I was wearing a helmet that day. That’s been over 50 years ago. How time flies.]]>