...to Have an Ungrateful Child
The troublesome flight characteristics of the turboprop Yarara prototypes proved a puzzle for the FMA engineers to solve. Many sleepless nights were spent on pinpointing the problems and developing solutions that would result in a revised prototype in the most expedient manner.
The troubles experienced by the pilots on the first flight had, thus far, been kept low key and known only to a few; the intent was to keep it that way. In the interim, Jochen Marseille confered extensively with the test pilots and fimiliarised himself with the plane's controls and operations in preparation for a test flight of his own.
“It wasn't an easy task to convince the powers that be at FMA to allow me to take one of the turboprop prototypes up for a test flight, but I felt the need to see for myself what the pilots had experienced and make a report of my own.
Persuading them that an extra opinion couldn't hurt was easy enough. However, they didn't want the prototype to be too visible to the public until revisions had been made lest an accident occur and expose the problems to a wider audience.
They finally relented to me flying the aircraft, though it came on the condition that I had to fly the aircraft in gear down configuration at moderate speed to the La Pampa facilities and do the test flying there.
La Pampa was in a rural setting with very few people near it. The isolated nature of it meant that prying eyes were at a minimum. It was an understandable compromise that I accepted.”
Preceded to La Pampa by transport aircraft carrying the two test pilots plus testing personnel and their equipment; Marseille settled into the cockpit of one of the Yararas and took off from Cordoba on a totally uneventful flight to La Pampa.
“As I made my way south, I took my time to examine the cockpit layout and accessibility of the various knobs, levers and switches. I could certainly see what the test pilots meant when they said the cockpit felt dated. As I thought about some of the more modern jet cockpits I had experienced in America, I made some notes on my knee board for changes that could be made.
Upon arriving at La Pampa, I met again with the pilots and discussed the observations I'd made about cockpit layout. Generally, all three of us were thinking in a similar way about how to make the cockpit a more modern place.
Keeping in mind the Yarara's mission of low level ground attack, my mind returned to the cockpit of the Republic F-84 Thunderjet that I had spent time flying in America.
While I didn't really enjoy flying the Thunderjet, I felt that it had a cockpit layout that could serve as a good model for revisions to the Yarara's. Both test pilots had seen the F-84 cockpit and agreed that my idea had merit and should be looked into.
We also unanimously agreed that an ejection seat should seriously be considered for the new variant.”
One of the FMA test pilots also recalls:
“There were lots of notes being compared between ourselves and Jochen during our time in La Pampa and lots of new ideas coming up just from his flight to La Pampa. In a way, we had already begun writing a report before he took his test flight.
I didn't like the idea of anyone flying the prototype until modifications had been made on it, but I couldn't deny the usefulness of extra input from another experienced pilot could provide.
Two days after arriving in La Pampa, everything was ready for Jochen's test flight. We were all very nervous as he taxied out and opened the throttle. It might have been better had we not known what to expect.
He went through all of the moves that we had in Cordoba, plus a few others before taking the speed up towards the maximum end. The aircraft was definitely looking shaky as he took it into a shallow dive. Fortunately, he had given himself a good amount of space between himself and the ground as it seemed to take forever for him to fully recover from the dive.
He was clearly experiencing the same sluggishness on the controls that I had. Much to everyone's relief, he landed the plane shortly after that last manouver.”
Getting the Ghost out of the Machine
After a thorough post flight inspection showed the aircraft to be unharmed from the most recent of test flights; pilots, crew and aircraft returned to Cordoba.
The consensus of many meetings between pilots, engineers and executives confined what most had already suspected; the airframe and engine were not the problem. It was the cockpit and flight control system that needed a complete reworking.
A former FMA engineer:
“The teams tasked with designing the cockpit and flight control systems clearly had been struggling. During the most recent meetings, there had been a clear undercurrent of friction within them resulting from relatively young people being supervised by decidedly old school thinkers who had a propensity for forcing things to be done the old way and intimidating their younger charges into keeping quiet.
It became clear that before we removed a single component from the inside of the aircraft, there were certain components that had to be removed from those teams.
What was also clear was that we would need outside advisors to help us design a cockpit and flight controls appropriate to a modern, jet powered aircraft. Representatives from both American and British aviation companies were very helpful to us in these regards.”
After much frenzied work and many overtime hours, a revised single seat prototype was cleared for flight testing. Wisely, the revised aircraft was taken to La Pampa for testing.
Jochen Marseille relates his experience flying the revised version:
“The new cockpit was an entirely different place and we all felt a lot safer sitting on a Martin Baker Mk.2 ejection seat!
All of the flight instruments were easily visible and in sensible arrangement; the sight was no longer a war relic, but a very modern one.
Once in the air, feedback on the controls was much improved. The new flight control system had assisting mechanisms built in that made responsivemess much quicker and eliminated any need for the pilot to expend energy wrestling the aircraft into or out of position.
The aircraft still got shaky at higher speeds, but these speeds were also around the 550 km/h mark. It was a very respectable speed and we decided to use it as reference for setting the aircraft's “never exceed” speed.
We were all very happy with the revised prototype, as were the air force. Production was approved shortly after.”