History of Business Jets

[Rwy in Sight]

I am wondering which was the first business jet and more important what it made it possible. For ETOPS became possible thanks to the large jet engine and because of the desire or airlines to cover long thin routes.

All responce would be most welcome...


Rwy in Sight

[treadigraph]

First past the post... Lear Jet? JetStar? DH-125? Can't research it just now, but I'll drop those into the melting pot of contenders. If I remember correctly the JetStar came first but not as a Business Jet but for the USAF.

[MReyn24050]

Treadigraph your memory is correct the JetStar came first as a Business Jet and as a VIP aircraft for the USAF.
The first civil configured JetStar was delivered in early 1961 and so the JetStar was the first business jet to enter service.

[Rwy in Sight]

JetStar

Thanks for your replies. Can I see them like JetStar was originally built as a light communication aircraft for the Air Force and then offered for civil use like the L-100 the civil version of the C-130. Or its manufacturers took a gamble and build a civilian aircraft and then they offered it to the USAF? I am falling on the chicken egg issue?

A corollary (sp?) what makes the manufacturers to build a business jet?


Sorry to bother you but I am curious about that segment that I Know so little.

Rwy in Sight

[MReyn24050]

Lockheed Jetstar

Full story here:-
http://en.wikipedia.org/wiki/Lockheed_JetStar

[old,not bold]

The late great Nat Summers, who bought and developed Southampton Airport among many achievements, designed and built a 4-seat civilian jet in the early 1950's, I think it was. I'm sure it flew successfully.

The project was defeated by the usual army of doomsayers: "It'll never catch on, you mark my words". At least that's what Nat said.

To my mind that was the first business jet, because I'm sure that's what he had in mind for it. It was just 30 years ahead of its time.

I'm hoping someone knows a lot more than I do about it, and can correct and fill in the details.

[treadigraph]

Nah, my memory that it was the first to fly was about right, but I honestly thought it became a Bizjet a bit later. One lives and learns (or perhaps re-learns faded memories)! I'll wager that it was perhaps also the first to star in a film - Goldfinger!

Per Airlife's "General Aviation" Lear Jet (Learjet was the later spelling) was '63, the 125 ("Jet Dragon" but surely more of a "Jet Dove" - no not the same ring) was '62. The Mystere 20 was '65 and Jet Commander was '63 and that other iconic aircraft, the Gulfstream II was '66? Oh and the Sabreliner won the UTX competition and entered service in 1960, and again stepped into the civil market... And the Hansa Jet, 1964... woof! Citation was a latecomer, 1969... Any others in the first ten years... How about the Paris...? 1954!

The advent of private jets over "Board Room Bombers" (converted Lodestars, Invaders and Mitchells - and even Douglas Dragons) was inevitable as jet engines developed to something more practical and reliable, which they did pretty quickly...

'Ere, remember the idea to convert Vampires to six seat bizjets in the 1960s... Didn't we have a thread on here about John Morgan (Johnny Skyrocket) a few months back?

[pigboat]

The retrofitted DH125 was a real joy to fly. We operated sn 075 a 1AR, fitted with the Garrett turbofans. It was no faster than the Viper powered counterpart because of airframe limitations, but it could climb straight to FL390 with a full load. The best I've ever done with it was takeoff from a 2000-foot elevation airport to FL310 in seven minutes flat on the Davtron clock. Mind you we were were empty, with only about 1800 lbs of fuel, and it was cold.

I seem to recall the 125 was designed originally as a piston powered aircraft to replace the Dove, but when RR developed the Viper as a drone engine, some smart engineer saw the light and hung two of them on the back of the aircraft. We used to joke that the aircraft was powered by a one-way engine. That engine also had a great appetite for oil. There was a little mini-pump on the number 5 (I think) bearing, that supplied lubrication via a fine spray. There was a minimum oil consumption rate and if the engine didn't burn the minimum it meant the bearing wasn't being properly lubricated. Later marks of the Viper did away with that restriction.

The aircraft cabin was about the most roomy of the small jets. Rumour had it that the interior design engineers had visited a gentlemen's club in London and measured the width of the posteriors of some of the members to arrive at a satisfactory seat width.

Aero Commander also had a business jet, called the Jet Commander. The manufacturing rights were later sold to Israeli Aircraft Industries and became the IAI 1121-24 series. Some were operated in the ME, where they reverted to their Jet Commander roots for flight planning purposes in order to avoid Arab restrictions on Israeli products.

[WHBM]

Originally Posted by Rwy in Sight

ETOPS became possible thanks to the large jet engine and because of the desire or airlines to cover long thin routes

Seeing as we are having a general chat I'll rise to this one in the initial post.

ETOPS became possible as it was realised that engines had become sufficiently reliable that you could take the risk over extended water that more than one engine would not fail. It had certain strange aspects of logic about it, because if a three-engined Tristar/DC-10 had a double engine failure over the ocean they couldn't keep going either. And the greatest reserve of power a twin needs is not mid-ocean when some fuel has inevitably burned off, but at engine failure at V1 at MTOW.

The main desire was not inherently to do long thin routes, which had a range of options, but to cut costs. Pioneer ETOPS was Air Canada with the B767 from Halifax/Gander to London, replacing the Tristar 500, pretty much the same capacity but one less engine and one less flight deck member. Air Canada had a large fleet of 767s by the time this was contemplated, being used across Canada on routes of comparable length. The route from Newfoundland to London was a loss-maker with the Tristar, as it still was in recent times with the B767, they have gone down to an A320 now !

Back in prop aircraft days even 4-engined aircraft suffered over water on occasion; Pan Am lost a Stratocruiser over the Pacific when two engines failed but one could not be feathered and the extra drag used up the fuel before landfall. It was put down next to a ship mid-Ocean and all on board were taken off by lifeboat. Not something the B787/A350 could probably replicate, ETOPS or not.

[Rwy in Sight]

Thanks guys,

It is a refreshing reading, far more intresting than my beer drinking activity last night!

WHBM, thanks for the analysis of the ETOPS. May I have an input on what made the construction and operation of business jet pratical? Was that developments on small engines, was it transfering of technologies from fighters?

Thanks again in advance,

Rwy in Sight

[Newforest]

The late great Nat Summers, who bought and developed Southampton Airport among many achievements, designed and built a 4-seat civilian jet in the early 1950's, I think it was. I'm sure it flew successfully.

The name is Nat Somers and I don't recall him having any connection with aircraft development. You may be thinking of the Vampire four seat project that I don't think ever flew and the project went to the States.

[larssnowpharter]

Coincidentally, over on What Cockpit we have just had the Morane Saulnier MS 760 C Paris III which was conceived as a biz jet.

[treadigraph]

Old, not Bold, are you thinking of the Somers-Kendall SK-1?



http://www.beney.org.uk/personal/miles/miles.html


Rwy in Sight, re fighters, I believe the Sabreliner used the wing of the F-86 and the Mystere/Falcon 20 sat on the Mystere fighter wing, while the Lear Jet 23 definitely used the wing developed for the Swiss P-16 fighter.

[barit1]

pigboat notes:

I seem to recall the 125 was designed originally as a piston powered aircraft to replace the Dove, but when RR developed the Viper as a drone engine, some smart engineer saw the light and hung two of them on the back of the aircraft. We used to joke that the aircraft was powered by a one-way engine.

The CJ610 (LJ23, 1121, HFB320 etc) has a similar background. GE's original application for the J85 was the Quail decoy missile, air-launched from a B-52 to divert interceptors. The CJ610 was derived from the J85.

And the CF700 (a CJ610 with added aft fan) had a NASA career as the vertical-lift engine for the Lunar Landing Research/Training Vehicle.

[con-pilot]

We used to joke that the aircraft was powered by a one-way engine.

I always watched with amusement that every time a Viper powered 125 would land the poor FO would always have to run back to the engines and pour a couple of cans oil into them.

A couple of things about the old CJ-610 was that it burned a lot of fuel and made a lot of noise, the other things about the CJ-610 was that it burned a lot of fuel and made a lot of noise.

When the aft fan was added to the CJ-610 making it the CF-700 the fuel burn remained the same, however, you got nearly an additional 1,000 pound of thrust. Let me tell you, the Sabre 80 needed every pound of it. (At least the old run-out 80s I flew.)

[old,not bold]

Treadigraph

Could well be, but I thought that the Nat Somers aircraft I saw a picture of in his office had 4 seats. But it was a long time ago!

Newforest

Absolutely right re the name, don't know what I was thinking of. But Nat was certainly involved with a small civil jet development project, and I guess it could well have been the Somers-Kendall SK1 shown above.

[chornedsnorkack]

ETOPS became possible as it was realised that engines had become sufficiently reliable that you could take the risk over extended water that more than one engine would not fail. It had certain strange aspects of logic about it, because if a three-engined Tristar/DC-10 had a double engine failure over the ocean they couldn't keep going either. And the greatest reserve of power a twin needs is not mid-ocean when some fuel has inevitably burned off, but at engine failure at V1 at MTOW.

Are high-bypass turbofans liable to chain failures because of sustained excessive thrust in the engine-out condition? I understand that one reason behind the 60 minute rule was not the probability of independent failure, but the chances of 1 remaining engine of a twin or 2 remaining engines on a trimotor failing because of prolonged high power operation...

[barit1]

Max Continuous Thrust (MCT) is a certified value, and means just that: The engine will run just fine at MCT as long as fuel and oil remain. Certainly for the remainder of an ETOPS event there will be no problem.

The only caveat is regarding the manufacturer's warranty - If you use MCT in a cavalier manner and then make a warranty claim that the engine ran out of EGT margin in 4000 hours, be prepared for some push-back!