THE EVENT
U.S. Air Force Plant 42 (KPMD) in Palmdale, California. A small DoD facility in the Mojave Desert that was the home to such famed projects as the Space Shuttle Orbiter, the F-117A, and right now, my Vans RV-8. I was in no mood to appreciate the rich aviation history of the location as I pondered how I found myself on the wide expanse of Plant 42?s ramp in my little homebuilt.
The flight had originated at Inyokern Airport (IYK) in California, just North of Edwards Air Force Base, and West of Naval Air Weapons Station China Lake where I was stationed as an Operational Evaluation (OpEval) F/A-18 pilot. I grew up in General Aviation, having taken my first flying lesson at age 11, but had stepped away when I joined the military, and the RV-8 was my return to the joys of GA flying. I purchased the airplane from the builder a few years previous and had flown it to Oshkosh twice, accumulating about 300 hours in the aircraft. I was beginning to feel fairly confident in the machine, as well as the owner-assisted maintenance program that I was learning under the tutelage of a local A&P mechanic.
Leading up to the flight there had been some fairly extensive maintenance. I recently had the aircraft re-wired with a full Garmin glass cockpit setup and engine monitor, and had all the hoses firewall forward replaced with Teflon-steel braid hoses for longer service life. I?d flown the airplane for 50 hours since the work had been completed, so I changed the oil, and took advantage of the downtime to rework the engine baffle seals for better cooling. The higher fidelity of the Garmin engine monitor had revealed some inadequacies in my cooling setup in the high desert heat with CHT?s reaching 400F+ during takeoff, so I took on the project of improving the airflow under the cowl. I also rebuilt the tailwheel assembly. After a quick leak check, a successful post-maintenance check flight put the airplane back in service.
The next day I came out to fly, and found that the battery was dead. The battery was new, only 6 months old, but I checked and cleaned all the connections, ordered a new battery and installed it on the afternoon of the incident flight.
Once I had the fresh battery installed and ready to go I pulled the airplane out, and started it up. The engine start was noticeably rough. The Lycoming O-360 coughed to life one cylinder at a time more like a radial than the quick snarling starts typical of the horizontal motors. I chalked it up to over-priming and taxied to the runway. The idle was a little rough with something of a lope, as it had been recently (if not slightly worse today), but I justified this as the common issue seen with fuel injection systems of fuel boiling in the low pressure injector lines. I found it annoying, but minimized the problem to the max extent I could by leaning aggressively while taxing out.
After an uneventful runup, I lined up on Runway 33, smoothly pushed the throttle forward and felt that glorious acceleration as the Hartzell prop dragged the 1100lb airplane and me into the late afternoon sky. On climbout I noted with satisfaction that the baffle work seemed to have worked; cylinder head temperatures were now about 370 vice the 405 I had been seeing previously during climb, and I patted myself on the back as I climbed overhead the airfield. The airplane was running well, and I wanted to fly for at least an hour to get a good charge on the battery, so I turned South and started leaning the mixture for Lean of Peak (LOP) cruise.
I had installed custom tuned injector nozzles to allow all the cylinders to peak simultaneously as fuel flow settled down, and I found myself 50 degrees LOP flowing 8.5 GPH. This seemed moderately higher than the 7.5-8.0 GPH that other RV-8 owners were claiming, but they probably weren?t running the same power settings that I was. Plus, pilots are known for exaggerating their performance numbers. Other than an occasional light stumble LOP, I took comfort in the fact that I was running cooler cylinder head temps and saving a little bit of gas as I cruised around the Mojave area.
Looking for something to do instead of just burning gas, I figured some practice approaches would help me get more familiar with the new autopilot and glass displays during ILS and RNAV LPV approaches. I initially set a course for Victorville Airport (VCV) and contacted Joshua Approach for Flight Following services. Joshua advised me that Victorville was not currently accepting practice approaches, and asked what my intentions were. Still desiring to try an ILS Approach, I asked if Palmdale was accepting VFR practice approaches. After a short pause, ATC issued vectors for the ILS and I shot the first approach with the autopilot coupled to the approach all the way to minimums for a published missed approach. Being a USAF base, civilian aircraft are not permitted to touchdown, so I planned on low approaches to Runway 25. The GPS flawlessly sequenced the missed approach, and I accepted further vectors while I programmed the RNAV LPV Runway 25 approach into the panel.
Joshua Approach handed me off to Tower and the RNAV went smoothly until 100? above Decision Height. As I watched the minimums bug march down the EFIS tape, I reduced power to idle and a flashing yellow box in the bottom right corner of the display caught my eye. The EGT?s on all cylinders were climbing above 1500 degrees. Now, I know that the exact numbers are less important than the Delta when it comes to EGT, but this engine has never had an absolute EGT above 1500?even when descending well LOP. I reached over, and pushed the mixture up. The lever didn?t move; it was already fully forward. I snapped on the electric boost pump, and the EGT?s continued to rise to 1575. During my early Private Pilot training, I had an instructor tell me; if the airplane does something you don?t like; undo what you last did. In this case, pulling the throttle to idle. I advanced the throttle and was met with sounds of backfiring and no reassuring press of the seat against my backside. The radio exchange with Palmdale Tower at 200? AGL took maybe 10 seconds.
?Tower, RV has an engine issue and needs to full stop.?
?RV, are you declaring an emergency??
?Affirmative.?
?Cleared to land, Runway 25.?
The landing and touchdown were uneventful, but the engine condition deteriorated noticeably as the RV decelerated on the runway. The prop began to stop, and I advanced the throttle in an attempt to keep it running to clear the duty runway. The engine wouldn?t run with the throttle anywhere below 1400 RPM, and it ran awful at that power setting. I managed to snap, crackle and pop my way onto a taxiway where I notified tower I was going to shut down and egress. Fire crews were on station immediately, and security personnel shortly thereafter. Now that I was safely on deck, the administrative nightmare of landing a civilian airplane on a military installation began.
Upon landing at a military facility expect to be asked for a Photo ID, Pilot Certificate, Medical, and Proof of Insurance. A Department of Defense ID would help the process along if you happen to have one. Second, security personnel are going to want to inspect the aircraft to ensure there are no explosives or other contraband onboard. These tasks complete, the first challenge was a total lack of chocks or tiedowns available. All the ground support equipment at military installations is centered around large fighter or transport category aircraft. Chocks and tiedowns for General Aviation aircraft typically aren?t available unless the field you find yourself at has a Flying Club. At Palmdale, our solution was to use bungee cords provided by Airfield Management to tie the airplane down to grounding points in the concrete, and I had chocks that I carry with me in the airplane. Don?t bank on hangar space; the potential liability is too great. I called the Airfield Manager, and exchanged information, as well as inquiring as to any shelter from the wind. Unfortunately, none was available, but as it turned out, the wind forecast proved inaccurate and the air was calm for the duration of the stay at the base.
All said and done, the paperwork took about 3 hours. This included a Hold Harmless Agreement for the departure the next day, a Proof of Insurance document, and an official statement of the events that had transpired. All in all, relatively simple. In addition, the base required a mechanic to authorize the departure, and that mechanic had to be someone other than the Pilot in Command. The only other administrative requirement was a phone call the next day from the local Flight Standards District Office (FSDO) confirming the events that had occurred, and they called the case closed. Very painless by all accounts.
So, what actually happened to cause my predicament? The cause became immediately clear as soon as the mechanic and I uncowled the engine. The first thing that caught my eye was a large blue stain on the #1 cylinder intake tube that hadn?t been there previously. There was also blue staining on the alternator, as well as the #1 cylinder itself (both top and bottom) and the inside of the cowling. There was obviously a world-class fuel leak under the cowl. I powered up the battery and engaged the boost pump. At once the culprit exposed itself. The B-nut on the main fuel line that runs between Cylinder #1 and #3 from the servo to the fuel spider was not torqued. In fact, it wasn?t even finger tight. The sudden leak had caused all 4 cylinders to immediately run lean, which I noted in the cockpit as very high EGT?s. The line and B-nut were inspected, deemed airworthy, tightened, and the airplane flew home without issue.
U.S. Air Force Plant 42 (KPMD) in Palmdale, California. A small DoD facility in the Mojave Desert that was the home to such famed projects as the Space Shuttle Orbiter, the F-117A, and right now, my Vans RV-8. I was in no mood to appreciate the rich aviation history of the location as I pondered how I found myself on the wide expanse of Plant 42?s ramp in my little homebuilt.
The flight had originated at Inyokern Airport (IYK) in California, just North of Edwards Air Force Base, and West of Naval Air Weapons Station China Lake where I was stationed as an Operational Evaluation (OpEval) F/A-18 pilot. I grew up in General Aviation, having taken my first flying lesson at age 11, but had stepped away when I joined the military, and the RV-8 was my return to the joys of GA flying. I purchased the airplane from the builder a few years previous and had flown it to Oshkosh twice, accumulating about 300 hours in the aircraft. I was beginning to feel fairly confident in the machine, as well as the owner-assisted maintenance program that I was learning under the tutelage of a local A&P mechanic.
Leading up to the flight there had been some fairly extensive maintenance. I recently had the aircraft re-wired with a full Garmin glass cockpit setup and engine monitor, and had all the hoses firewall forward replaced with Teflon-steel braid hoses for longer service life. I?d flown the airplane for 50 hours since the work had been completed, so I changed the oil, and took advantage of the downtime to rework the engine baffle seals for better cooling. The higher fidelity of the Garmin engine monitor had revealed some inadequacies in my cooling setup in the high desert heat with CHT?s reaching 400F+ during takeoff, so I took on the project of improving the airflow under the cowl. I also rebuilt the tailwheel assembly. After a quick leak check, a successful post-maintenance check flight put the airplane back in service.
The next day I came out to fly, and found that the battery was dead. The battery was new, only 6 months old, but I checked and cleaned all the connections, ordered a new battery and installed it on the afternoon of the incident flight.
Once I had the fresh battery installed and ready to go I pulled the airplane out, and started it up. The engine start was noticeably rough. The Lycoming O-360 coughed to life one cylinder at a time more like a radial than the quick snarling starts typical of the horizontal motors. I chalked it up to over-priming and taxied to the runway. The idle was a little rough with something of a lope, as it had been recently (if not slightly worse today), but I justified this as the common issue seen with fuel injection systems of fuel boiling in the low pressure injector lines. I found it annoying, but minimized the problem to the max extent I could by leaning aggressively while taxing out.
After an uneventful runup, I lined up on Runway 33, smoothly pushed the throttle forward and felt that glorious acceleration as the Hartzell prop dragged the 1100lb airplane and me into the late afternoon sky. On climbout I noted with satisfaction that the baffle work seemed to have worked; cylinder head temperatures were now about 370 vice the 405 I had been seeing previously during climb, and I patted myself on the back as I climbed overhead the airfield. The airplane was running well, and I wanted to fly for at least an hour to get a good charge on the battery, so I turned South and started leaning the mixture for Lean of Peak (LOP) cruise.
I had installed custom tuned injector nozzles to allow all the cylinders to peak simultaneously as fuel flow settled down, and I found myself 50 degrees LOP flowing 8.5 GPH. This seemed moderately higher than the 7.5-8.0 GPH that other RV-8 owners were claiming, but they probably weren?t running the same power settings that I was. Plus, pilots are known for exaggerating their performance numbers. Other than an occasional light stumble LOP, I took comfort in the fact that I was running cooler cylinder head temps and saving a little bit of gas as I cruised around the Mojave area.
Looking for something to do instead of just burning gas, I figured some practice approaches would help me get more familiar with the new autopilot and glass displays during ILS and RNAV LPV approaches. I initially set a course for Victorville Airport (VCV) and contacted Joshua Approach for Flight Following services. Joshua advised me that Victorville was not currently accepting practice approaches, and asked what my intentions were. Still desiring to try an ILS Approach, I asked if Palmdale was accepting VFR practice approaches. After a short pause, ATC issued vectors for the ILS and I shot the first approach with the autopilot coupled to the approach all the way to minimums for a published missed approach. Being a USAF base, civilian aircraft are not permitted to touchdown, so I planned on low approaches to Runway 25. The GPS flawlessly sequenced the missed approach, and I accepted further vectors while I programmed the RNAV LPV Runway 25 approach into the panel.
Joshua Approach handed me off to Tower and the RNAV went smoothly until 100? above Decision Height. As I watched the minimums bug march down the EFIS tape, I reduced power to idle and a flashing yellow box in the bottom right corner of the display caught my eye. The EGT?s on all cylinders were climbing above 1500 degrees. Now, I know that the exact numbers are less important than the Delta when it comes to EGT, but this engine has never had an absolute EGT above 1500?even when descending well LOP. I reached over, and pushed the mixture up. The lever didn?t move; it was already fully forward. I snapped on the electric boost pump, and the EGT?s continued to rise to 1575. During my early Private Pilot training, I had an instructor tell me; if the airplane does something you don?t like; undo what you last did. In this case, pulling the throttle to idle. I advanced the throttle and was met with sounds of backfiring and no reassuring press of the seat against my backside. The radio exchange with Palmdale Tower at 200? AGL took maybe 10 seconds.
?Tower, RV has an engine issue and needs to full stop.?
?RV, are you declaring an emergency??
?Affirmative.?
?Cleared to land, Runway 25.?
The landing and touchdown were uneventful, but the engine condition deteriorated noticeably as the RV decelerated on the runway. The prop began to stop, and I advanced the throttle in an attempt to keep it running to clear the duty runway. The engine wouldn?t run with the throttle anywhere below 1400 RPM, and it ran awful at that power setting. I managed to snap, crackle and pop my way onto a taxiway where I notified tower I was going to shut down and egress. Fire crews were on station immediately, and security personnel shortly thereafter. Now that I was safely on deck, the administrative nightmare of landing a civilian airplane on a military installation began.
Upon landing at a military facility expect to be asked for a Photo ID, Pilot Certificate, Medical, and Proof of Insurance. A Department of Defense ID would help the process along if you happen to have one. Second, security personnel are going to want to inspect the aircraft to ensure there are no explosives or other contraband onboard. These tasks complete, the first challenge was a total lack of chocks or tiedowns available. All the ground support equipment at military installations is centered around large fighter or transport category aircraft. Chocks and tiedowns for General Aviation aircraft typically aren?t available unless the field you find yourself at has a Flying Club. At Palmdale, our solution was to use bungee cords provided by Airfield Management to tie the airplane down to grounding points in the concrete, and I had chocks that I carry with me in the airplane. Don?t bank on hangar space; the potential liability is too great. I called the Airfield Manager, and exchanged information, as well as inquiring as to any shelter from the wind. Unfortunately, none was available, but as it turned out, the wind forecast proved inaccurate and the air was calm for the duration of the stay at the base.
All said and done, the paperwork took about 3 hours. This included a Hold Harmless Agreement for the departure the next day, a Proof of Insurance document, and an official statement of the events that had transpired. All in all, relatively simple. In addition, the base required a mechanic to authorize the departure, and that mechanic had to be someone other than the Pilot in Command. The only other administrative requirement was a phone call the next day from the local Flight Standards District Office (FSDO) confirming the events that had occurred, and they called the case closed. Very painless by all accounts.
So, what actually happened to cause my predicament? The cause became immediately clear as soon as the mechanic and I uncowled the engine. The first thing that caught my eye was a large blue stain on the #1 cylinder intake tube that hadn?t been there previously. There was also blue staining on the alternator, as well as the #1 cylinder itself (both top and bottom) and the inside of the cowling. There was obviously a world-class fuel leak under the cowl. I powered up the battery and engaged the boost pump. At once the culprit exposed itself. The B-nut on the main fuel line that runs between Cylinder #1 and #3 from the servo to the fuel spider was not torqued. In fact, it wasn?t even finger tight. The sudden leak had caused all 4 cylinders to immediately run lean, which I noted in the cockpit as very high EGT?s. The line and B-nut were inspected, deemed airworthy, tightened, and the airplane flew home without issue.