Fire in Flight

THAT OTHER ONE---FIRE IN FLIGHT
By: Jack Serig, Sr.

    Our company commander, Captain Bob Felix, sent me to Da Nang to head our detachment of Otter* aircraft deployed to support the I Corps effort. It was May 1962.

    One day, on one of our normal resupply and passenger milk runs, we had taken off from a small MAAG (Military Assistance Advisory Group) airfield dirt strip in the boonies northwest of
Da Nang. We boarded one U.S. officer and five enlisted men to fly them to Da Nang.
After takeoff we obtained air traffic control clearance to climb to a designated altitude to make a simulated instrument approach to the Da Nang airfield, for practice. The other pilot, Lou Oliverio, flew with a hood on to restrict his vision to the instruments for the practice run. It was a beautiful VFR (Visual Flight Rules) day with umpteen miles of visibility. All unit pilots practiced simulated instrument flight whenever we could to give us an edge in the unpredictable weather patterns associated with the monsoon rains we frequently encountered.

    Just as our ADF (Automatic Direction Finder) needle indicated we were almost over the Da Nang airfield, still at the assigned altitude of 4,000 feet, our single engine began running rough---sputtering. Engine instruments were within normal ranges for the moment. Glancing behind me, our six passengers appeared calm. I instructed the pilot to begin an emergency descent after he came out from under the hood. I contacted the tower on the prescribed VHF frequency and advised the Vietnamese tower operator that we were experiencing engine problems and asked for clearance to land, requesting crash rescue trucks as a precaution.

    A “Roger, cleared to land,” was acknowledged. Still on high downwind we noted the cylinder head temperature gauge beginning to climb, the oil pressure gauge showed a drop, while the RPM needle fluctuated with the coughing engine.

    We set up our approach pattern to land north keeping close to the field to land power-off, if necessary. The engine kept coughing and sputtering but still provided power. We elected to keep it running as long as it agreed. A second call to the tower operator, on high base. Another request for crash trucks which we could see at their fire station, stationary. Another “Roger” from the tower operator but the fire trucks remained in position at the fire station.

    Unknown to us, a U.S. Air Force radar station individual, standing in his radar equipment compound, looked up upon hearing our complaining engine. He bolted to a telephone and called the local U.S. Air Force Senior Advisor, co-located on the airfield, advising him than an Army plane (US!) was in trouble, “On Fire!”

    By this time we were nearing our turn to high final, the engine still providing restrained power. Our feet began to get warm, then hotter, and streaks of fire began to appear in the slots of the paneling between our feet and our knees. We were on fire and apparently the forward and rear firewalls had not been able to retain what had to be a pretty good blaze. We were on high, short final---still no crash rescue vehicles. A third request and a third “Roger!”

    I instructed Louie to pull off the runway at the first taxiway and to shut down the engine. I had the fire bottle in my hand and was ready to use it after touchdown. Using it now would blind us inside the cockpit, even though the streaks of fire coming through the openings were brighter, longer, and hotter. I instructed the passengers to be ready to jump out of the plane as soon as we stopped.

    We landed, turned off the active runway and I reminded Louie again to shut down the engine. I failed to pull the emergency gas/oil shutoff valve. My mind was on the passengers and their safety---to get them out of the burning aircraft and as far away as possible. I opened the right cockpit compartment door, unlocked the restraint system, stepped onto the top step and jumped to the taxiway. My head jerked hard. Forgot to unplug my helmet from the headset cord. The jolt knocked off my glasses. I landed on them and felt the crunching under my boots.

    The fire bottle was still in my hand and I ran around the rear of the aircraft to reach the passenger door on the opposite side. Surprisingly, I beat them to the door, opened it, and as they bailed out they were instructed to run and keep away from the front of the plane. Still no crash rescue. Louie climbed down and he ran. I proceeded to the left side of the engine compartment and was astonished at the size of the blaze. I looked up at the big fire---and down at the little fire bottle---then I ran.

    Looking across the airfield I could see the crash rescue trucks finally responding. I later learned that one of their crew was washing his truck and just happened to see us, on fire, after we had brought the aircraft to a stop. He had alerted the emergency standby crash rescue crew and when they finally arrived they had the fire out in short order.

    Everything forward of the forward firewall was burned or damaged beyond repair. This would require that the engine and all accessories, lines, and wiring, be replaced. It was an expensive incident, even by 1962 standards, but the passengers and crew were all safe, without injuries.

HOW DID IT HAPPEN?

    A little history. All you Otter flyer-types will recall that the Otter engines had been used on the Navys' SNJs and Army Air Corps’ AT-6s. When DeHavilland of Canada bought up some of the surplus engines after WWII and put them on the front end of their Otters, they had to place metal plugs in some of the carburetor’s fuel ports to reduce the fuel and power requirements for the Otter’s engine design. A certain gauge safety wire was mandated to keep the plugs from backing out of their carburetor ports. We determined, during the investigation, through a record search, that a 3rd echelon maintenance type had, for some reason, performed unauthorized maintenance on the carburetor. When he put the plug back into its port the wrong gauge safety wire was installed. Over time, the weaker gauge safety wire broke and the plug began backing out of its port. This eventually caused a steady stream of 100-octane aviation gas, about the breadth of your little
finger, to shoot out of the now-exposed port, making direct contact with the hot, left side manifold. This raw gas ignited the fire that burned through oil and hydraulic lines, adding to the fire’s intensity. So much for the cause!

WHY HADN’T THE CRASH RESCUE UNITS RESPONDED?

    After seeing that the damaged Otter was towed to our space on the flight line at the Da Nang airfield, I paid a visit to the Senior U.S. Air Force Advisor, who was liaison with the South Vietnamese Airfield Commander. On my questioning as to what communications existed between the Da Nang tower and the U.S. Air Force crash rescue unit, he advised that all calls from the tower had to go through a Vietnamese controlled telephone switchboard. If the switchboard was busy the call placed by the tower operator, even in an emergency, would not receive a response. I couldn’t believe what I was hearing.

    Then I asked the Advisor if he had been aware that an Army Otter had landed, on fire. He said, “Yes!” That he had received a call from an alarmed crewman stationed at the local radar unit who had seen an Otter fly over with its engine on fire. When I responded that that was my ship, with eight people on board, the Advisor laughed loudly and said: “Yeah, the same thing happened to an Air Force fighter that landed on fire last week. Crash rescue couldn’t be contacted because of the telephone switchboard arrangement.” I felt my face flushing with unusual anger and said in a tone unmistakably insubordinate, that if he didn’t have a direct line between the tower and crash rescue unit by the end of the week, he’d be reported to his superiors in Saigon. I turned and left his office. The direct line was in the next day. The Advisor called me personally to let me know.Also the next day, a call from my company commander advised me to fly back to Nha Trang, our home field. He related that he had to escort me personally before our 145th Battalion Commander, a Lieutenant Colonel Richardson, in Saigon, whose armchair staff officers recommended I face an Article 15 for improper inflight emergency procedures.

    We flew from Nha Trang to Saigon the following day in our unit 0-1 Birddog. The longest flight I ever made---my career in potential jeopardy. Soon after landing at Tan Son Nhut we were admitted to the Battalion Commander’s outer office. My commanding officer was called in while I waited outside. Battalion staff officers were present with the two commanders discussing my fate. The door remained closed a seemingly long time. Finally, I was summoned, reporting as ordered. The Battalion C.O. was patient and even-handed in his questioning. I believed he was treating me fairly. I was asked to explain the sequence of events surrounding the emergency at Da Nang. I explained that we, the two pilots, were really not aware we had an engine fire until just short of turning final. Once we recognized we were on fire I believed it imperative to keep the engine running as long as it was providing power.

    “Why hadn’t I pulled the gas/oil shutoff valve, even after turning off the runway?” My response was that I had given the pilot instructions to shut down the engine. My main concern was for safe evacuation of the passengers and crew from the aircraft. It wouldn’t have made a significant difference whether or not I had pulled the lever at the same time the engine was being shut down, which would have the same effect. He thanked me and excused me. I saluted. The door closed behind me and I was again in the outer office awaiting my fate.

    It wasn’t long before my unit C.O. emerged. He was smiling. I felt some momentary relief. On the way back to our 0-1 he said: “Well Jack, we compromised! His staff wanted an Article 15, I recommended a commendation. There’ll be no Article 15 and no commendation. You’re off the
hook!”

    The Birddog flight back north to Nha Trang wasn’t as long as the flight south to Saigon.

~~~~~~~~~~~~~~~~~~~~~~~~~~~

*Otter: An 11-place single engine airplane manufactured by DeHavilland of Canada with STOL (short takeoff/landing) capability. The radial engine had 9-cylinders rated at 1350hp manufactured by Pratt & Whitney. There were eighteen in each Otter company.

This article was published in the LOGBOOK, a tri-annual publication of the Army Otter-Caribou Association, in the July, 1992 edition.