Testing engines

[john e. holliday]

Courtesy of Plane-A-Day a picture of a Convair F-106 that looks like it has Ram Jets under the wings.  Just wonder have that little baby will go with all three burning.

[Steve Scott]

I don't think the airframe could take all 3 engines at full bore.  The '106 was an Eisenhower-era design and was basically an F-102 with the big J-75 engine.

[Bill Johnson]

I was searching on "engine testing" and came across this thread. That's a NASA bird conducting testing "To investigate airframe installation effects on exhaust nozzle systems mounted on underwing engine nacelles, a combined flight and wind tunnel test program is being conducted utilizing a modified F-106 aircraft. Flight tests were conducted in the transonic speed regime to determine nozzle performance and boattail drag for variable flap ejector, conical plug, and auxiliary inlet ejector nozzle concepts."

You can see the two underwing engines have different tail cone configurations. If you're interested, here's more on this experiment:
http://www.f-106deltadart.com/nasa_airbreathing_propulsion_research.htm

[Elwyn Aud]

The F-106 had several aerodynamic tweaks that made it much cleaner than the F-102. Has everybody heard the F-106 story where the pilot got in to a flat spin where he ejected as per the flight manual instructions after which the plane recovered and made a perfect belly landing in an open field? If I remember right it was still idling when the policeman showed up to investigate. It was repaired and put back in service and is now in the Air Force Museum.

[Tim Wescott]

The F-106 had several aerodynamic tweaks that made it much cleaner than the F-102.

The reference I have says that the F-102 prototype couldn't go supersonic, and that it was redesigned using the area rule (https://en.wikipedia.org/wiki/Area_rule).  Such a significant redesign at that late stage in the project would have been a total kludge job -- there were almost certainly parts on the wrong side of the jet from their hook-ups, parts that had to be specially built to be long and skinny or round or whatever instead of nice and square, etc.  The F-106 was designed from the ground up with its final shape, and as such would have had a much cleaner detail design.

[Randy Ryan]

I was an F-106 Crew Chief and can assure you all it was NOT a tweaked up F-102, it is an entirely different airframe. It was however originally to be designated the F-102B however the redesign was so complete that it was redesignated. It was originally designed as a 10,000 hour airframe and was recertified 10 times, several of the A models and both of the B models (2 place) in the 87th FIS were over 100,000 hours and going strong. It was an incredibly well built and service freindly bird and everyone I knew was very proud to be assigned to squadrons with "6'es". Our squadron flew the first combat evaluations against the then new F-15s and those pilots very quickly gained a very heathy respsect for the aging Delta Dart. I remember the story of the one that landed in the field pilotless, pulled back to idle and correcting itself it landed at a pretty steep glide ratio yet was sound enough to be returned to service, others may have self destructed. Power was a J-79-P17, with full AB and variable nozzle, max climb takeoffs were VERY IMPRESSIVE to say the least, even fully loaded with external tanks and armament. We lost one B model, 57055, which was lost in Lake Superior after the pilots punched out, finding them was another story with it's own humor for another time. I crewed the Commander's aircraft 57231, an A model and was extremely proud of it. If you haven't noticed, I have very fond memories of my time on the "6'es"

[Dan McEntee]

  I'm hoping Bruce Shipp sees this and checks in here. He was on the acceptance team for the Air force when they were using up the F-106 as target drones. I know Bruce's Dad (Alden) from my sailplane days. I ran into Bruce somewhere along the line, and asked him what he was flying for a living and he told me "F-106s". I just looked at him and asked, "Before or after they started shootin' at them?" There was/is a company at the airport in Alton, Illinois that was doing the conversion on F-4 Phantoms and the F-106s and I live just a few miles from there on the west side of the river, and every once in a while we would get treated to an accidental sonic boom when they were test flown. Bruce could tell us what they were like sittin' in the drivers seat. I prefer pistons and props on my airplanes, but do like the century series jets and the 106 is one of my favorites.
  Type at you later,
  Dan McEntee

[Steve Thornton]

If I'm not mistaken, the 106 had a "Coke Bottle" fuselage as opposed to the straight fuse of the 102 and that's was one of the reasons for the speed difference between the 2 jets.  The bottle design resulted in less drag...some of you aerodynamisistss may 'splain a little more precisely.
Steve

[Steve Thomas]

This photo gives a pretty good idea of how the Area Rule was applied to the F-102. Original (subsonic) YF-102 on the right, improved M1.3 F-102A on the left.  The 106 was obviously much better again (having a J75 instead of a J57 wouldn't hurt either).