Never Again

This is a Blog previously published on FlightLevel.

There was a thread on COPA a few years ago where the new PiperJet is discussed. In that thread I expressed an opinion in opposition to the concept of single pilot, single engine turbojet operation above FL250. My concern actually is with the concept above FL300. I mentioned in that thread that I had a personal experience with this issue I thought I would share in detail with the group.

In 1973 I was a Captain in the US Air Force stationed at Edwards Air Force Base. It was a dream assignment. I was a flight surgeon assigned to the USAF Test Pilot School. Buss Aldrin was the Commandant of the School for part of my tour, so it was an unusual mix of aviators I had the pleasure to associate with. I was on flying status getting paid $150 flight pay per month, which required me to fly with the pilots assigned to the Test Pilot School. It was a hardship, but I managed to muddle through. Most of my flying was in T33’s, T38’s and F104’s at the school. On occasion I would fly with Test Pilot Students (all very accomplished pilots, most freshly back from tours in Viet Nam), but mostly I flew with Test Pilot School Instructors. I sought every opportunity to go out with the Test Pilot School instructors flying the F104. We flew the 2 seat F104D and the instructors made every flight with me an instructional session.

I was able to “negotiate” a weekend trip to Denver with a Test Pilot School instructor, Ken Dyson, in the summer of 1973. Ken Dyson went on to test pilot work in other test programs, including the F117, X31 & chief test pilot for the B2 bomber. Just by coincidence (as you will see later) I had flown with Ken before in the F104 practicing “lifting body” approaches into Edwards. These approaches ultimately became the “space shuttle” approach. The “lifting body” approach involved arriving at “high key” directly over the numbers at 25,000', then making a tear drop entry at 300 knots, engine idle and speed brakes deployed down to the runway. As I recall the rate of descent in the F104, speed brakes out and engine idle was around 11,000 fpm down (space shuttle glide is 10,000 fpm down). If the approach was shot right the F104 would arrive over the numbers at 300 knots at about 20 feet where the gear was lowered and the aircraft touched down. Typically it took around 12,000 feet (Edwards had a 15,000 foot runway) with the drag chute to slow down the F104 touching down at 300 knots. All this is background for my round trip cross country to Denver. Below is a picture of a lifting body approach to runway 04 at Ewdards that I took on another F104 mission. That is the threshold for runway 04 in the upper right hand corner of the picture. From this position the F104 touched down on the numbers barely visible in this image at 300 knots. I was riding in the back seat of an F104D flying formation with a lead F104 in the picture below.

On Friday afternoon that summer day, Ken and I suited up for our F104 flight to Denver. We were using one of the last F104’s in the Air Force inventory. It was an F104D, two place aircraft with tip tanks. This model F104 had upward ejection seats with a unique CAP’s like ballistic parachute worn by the crew members. The parachute had a small rocket motor packed in the chute located about over your spine in the packed parachute. During the ejection process, the ballistic charge propelled a slug out of the back pack thus deploying the parachute much quicker. The history of this ballistic deployed parachute was not good often imparting significant injury to ejecting F104 crew-members including broken ribs. The other unique feature of the F104 upward ejection system was that each crew-member wore "spurs" on their boots. These spurs were hooked to cables which retracted the feet into position on ejection - sometimes. Other times they just tethered you to the ejection seat. The entire system was designed to allow ejections close to the speed of sound with obvious survival tradeoffs.

Ken and I departed in the F104 in typical style out of Edwards in the restricted area, which was very nearly a vertical departure to cruise altitude in after burner. We leveled at FL410 with barely enough JP5 to make the eastbound trip to Denver non stop. In cruise flight the J79 engine was out of after burner and reasonably quiet even though in the back seat I was almost sitting on the engine in that airplane. The flight proceeded normally until just over head Aspen, Colorado. At that point a big red annunciator light illuminated. A quick scan of the engine instruments showed the oil pressure falling rapidly. Ken said over the intercom “Doc, we have a problem”. While we still had pressure Ken lit the after burner and got a few more thousand feet of altitude. When the oil pressure hit zero, Ken spooled the engine down to idle with hopes of using it again for landing. On the spool down turbine temperatures continued to drop so it appeared we lost the engine at that point.

Ken fired off an emergency to ATC, and then he calmly said over the intercom “Doc, as you can see in the checklist our decisions are limited”. The Emergency checklist had two lines for loss of engine oil pressure in the F104. “1. Oil pressure zero. 2. Eject”. So Ken said I had the choice of doing this one by the book, ie ejecting or staying with him for a try at recovery. The F104 ejection system allowed for either seat to eject independently or to have a sequenced ejection of each seat. So Ken left the decision to me, if I wanted to eject he was ok with it, but he was staying. It was at that point I recalled the history of using the F104 ejection system. So I asked Ken for the plan. He said “Easy Doc we will shoot a lifting body approach into Buckely AFB just outside of Denver”. I said ok, but Buckley only had an 11,000 foot runway and it was 6,000 above sea level. Ken said “Ya Doc, this will be a modified lifting body approach”. I told Ken I would stay with him for a while, but with my hands gripping the ejection ring, I was ready anytime to exercise my ejection option.

As the engine spooled down, the cockpit pressurization went away and the pressure demand regulator kicked in pushing oxygen at you through the tight fitting full face oxygen mask we always wore flying in fighter aircraft. Pressure breathing is not comfortable. If your mask seal is not just right oxygen blows by the mask which can be very distracting. We were at 44,000' when the engine spooled down and we lost pressurization. It is a very claustrophobic feeling as every time you breath pressure breathing oxygen is forced into your lungs under pressure. It is like breathing on a hospital respirator, but it is better than the alternative.

So there we were descending out of FL440 pressure breathing in an F104 glider. It was very quiet. ATC was giving us instructions that were impractical to comply with. We were descending so fast that Center lost us and did not give us a hand off to Denver Approach. Ken dialed up Buckley tower, declared an emergency and said we are landing from a lifting body approach. Buckley had no idea what that meant. We hit high key at FL300 over Buckley and began the approach at 300 knots and around 12,000 fpm descend rate. Ken did a relight on the engine but kept it at idle just in case. He never did use it except to taxi clear of the runway after landing. On short final we passed a flight of two T37 trainers who had been cleared to land. They were doing around 110 knots we were doing 300 knots. Ken touched it down on the numbers, popped the drag chute and crunched on the brakes. We used all 11,000’ and turned off the runway at the end with a small brake fire.

So that was my adventure with a single engine, single pilot emergency in the high flight levels. This was successful because of the skills of a very experienced test pilot who had practiced this type of approach many times. We had parachute recovery equipment as a backup. The lone pilot of a PiperJet at FL350 will have an entirely different view of the world. Most likely he will not be a test pilot, he will not be pressure breathing before the event and he will have no choice but to ride the PiperJet to the ground with an engine failure. That is why I think the concept offered by Cirrus in the-jet makes so muchsense for owner operated private jets flown single engine with a single pilot. The-jet will not fly into the higher flight levels where time of useful consciousness is measured in seconds and if the fire goes out there is CAPS.

Here is a 2 part video story about the history of the F104.