Why does the Falcons have 3 engines?

[E1453]

With the exception of the Falcon 2000, all new Falcons (as long as I know) have 3 engines. Why?

Is it for the passengers / owners feel safer?

It doesn't make sense, at least in the costs aspect.

[pigboat]

I've had a P&W rep tell me it's so's you can finish a flight on two, but I suspect he was biased.;)

[skyhawk1]

It's so that they can do long range flights without having to worry about ETOPS certification

[Torquelink]

I had a Challenger rep tell me it's because Dassault fit "Garrett Grenades" but I think he was being a little unfair!

[747FOCAL]

It gives the fat cat that owns it a little piece of mind when out over the pond. And.....mostly because if you can afford a new Falcon, engine maintenance is not one of your worries. :E

[Zoom]

And why does (did?) the Lockheed Jetstar have 4?

[GlueBall]

And the B-52: Eight (8)!

[Onan the Clumsy]

...and the Dornier Do X had TEN!

[Zoom]

I suppose that's why those last 2, and others like them, had all those engineers on board - just to work the throttles!

[pigboat]

Gentlemen, please. Enough with the terrible jokes already. Time for a serious answer. :D :p

The Jetstar prototype was originally built for a military application with two 4800 lb thrust Bristol Orpheus engines - that were to be built under license by Curtiss-Wright - and no slipper tanks. The deal to build the Orpheus in the US fell through, and the American military were reluctant to acquire an aircraft with a foreign built engine. Lockheed went back to drawing board and added two pairs of 3000 lb thrust P&W JT12's in place of the single powerplant, added two 560 gallon slipper tanks to counter the increased fuel requirement and as they say in French "Viola!"

Trivia tidbit: The four rear mounted engines configuration Lockheed used was first proposed by Vickers in 1956, for the project that became the VC10.:cool:

[Specnut727]

What's wrong with terrible jokes ?

I thought I saw a VC10 once, but it was only an Ilyushin !!!!

[Boss Raptor]

Educated guess - at the time of the inception of the first of the Falcon trijets, the Falcon 50, the only proven light fan engine was the TFE 731 series which had a track record on the LR35/36 and 125-700 (the later 731-5 series was fitted to the Falcon 900 and 125-800).

The only other suitable contender in the power bracket for a 2 engined alternative being the ALF502 from Avco Lycoming which at the time has all sorts of teething problems which were being experienced by operators of the 146 and Challenger 600.

[Dufwer]

Specnut727, that has to be the worst aviation joke I have ever read.

Made me smile :D

D

[DA50driver]

I don't know, but it feels really good to have 3 throttles in my hand. I have flown a Falcon 50 for a couple of years, and it is a wonderful airplane.

Also, if you lose one engine on a twin, you loose a lot of your excess power(which makes you climb). If you lose one of three, you lose a lot less of your excess power on a percentage basis.

The airplane has an amazing performance envelope. We operate out of a 4300 foot strip, and can legally carry 3.5 hours of fuel on a wet runway, ISA day. Off longer runways we can non-stop it to Western Europe.

[DanAir1-11]

specnut727!! LOL - :D

VC10 was a thing of beauty! Sad to see her retire from airline ops as indeed I was with Tridents and my beloved 1-11's!

[The Ripper]

So then the answer must be it has three engines because it has three throttles.:cool:

[Mad (Flt) Scientist]

DA50driver
Also, if you lose one engine on a twin, you loose a lot of your excess power(which makes you climb). If you lose one of three, you lose a lot less of your excess power on a percentage basis.

But since both the twin and the trijet must meet cert requirements, the worst you can ever be for FAR25 is:

takeoff first segment (gear down):
on a twin:
"positive" climb (25.121(a))
On a trijet:
0.3% climb (25.121 (a))
takeoff second segment (gear up):
on a twin:
2.4% climb (25.121 (b))
On a trijet:
2.7% climb (25.121 (b))
above 400ft:
on a twin:
1.2% climb (25.111(c)(3)(i))
On a trijet:
1.5% climb (25.111(c)(3)(ii))

So following engine failure the climb gradients are not dissimilar - which means that all other things being equal a twin will have better performance (in terms of excess thrust) when all engines are operating, which is the most common case (you hope :)). So unless that 0.3% difference is make-or-break - in which case the twin won't be taking off without unloading - the twin is usually a better climber.

[Dale Harris]

There is a bit more than just the certification to it mad scientist. What you quote is the certification requirements. I can't think of any of the aircraft quoted above that wouldn't exceed those requirements, some by a large margin. So the difference lies in the figures actually achieved by the individual aircraft.

[Intruder]

Ripper:

No, the real answer is that it doesn't fly very well on 2 engines.

[pigboat]

...and the thrust reverser on the center engine is to make noise so you think it's slowing you down. ;)

[master slug]

VC10 in Manchester the other night.

The style and looks of the old bird put others to shame.

Long may she fly on.

[Mad (Flt) Scientist]

I agree, under normal conditions aircraft will exceed the cert requirements.

But unless grossly over engined, all aircraft end up WAT climb limited at some point. And that's when the cert minima come into play.

That min performance case is also likely to be when you care most about your performance - "plenty" and "more than plenty" are both fine, "just enough" and "not quite enough" is another matter

[tired]

Mad Scientist - no great secret there, squire, twins will certainly climb better than tri-s with all engines turning.

But with 2-engines out, the tri flies better ;)

DA50pilot - agreed! The 50 and the 900 are magic machines. And on a dark stormy night over the Atlantic or Pacific that 3rd go-lever used to give me such a warm fuzzy feeling. :) :)

[used2flyboeing]

As my piston twin instructor put it - the Falcon has three engines - because it can't fly with two ..

This aircraft is not in a FAR category where ETOPS is an issue.

It is a beautifully designed aircraft - DASSAULT should be making commercial jet liners rather than Le brand- X.

The PRATT comment is typical from a company that has been resting on their laurels - recall these were the same guys who said GE should stick to lightbulbs - Pratt will have to exit this business if they dont quit making "buggy whips"

[ICT_SLB]

used2flyboeing,

"DASSAULT should be making commercial jet liners rather than Le brand- X"

They tried it once - can you say <<Mercure>>? and they were NOT a success.

[used2flyboeing]

When DASSAULT rolls out a product it is spot on - AIRBUS - it is redesigned while it is in production ..

[whynerh8ter]

Because for numerous reasons in the corporate market segment these jets are designed for...3-small is better than 2-bigger...so be happy you have the choice...;) ;) :ok:

[natedog74]

looks like adapted from caravelle, number of windows at least...

[used2flyboeing]

you mean 727 ??

[natedog74]

nope, 27 has the standard 2-pane windshield, falcons seemed to have stuck with the 3-pane design of yore reminiscent of caravelles and comets...it's flat of course so it's probalby also noisier on top of restricted visibility

[wondering]

Two stories which circulate at FSI:

The Fed's made a stop at Aspen the other day and checked all departing IFR traffic. And guess what, the only aircraft to fly legally out of Aspen IFR are tree-engine Falcons. All other twin jets departing IFR got busted for vioaling the FARs. Cuz there´s no way they could have managed the required engine out climb gradient. Maybe under certain condition they might be able. But I reckon they checked on a hot summer day.

Oh, and the Falcon 900 is the only airplane which can legally fly between St Moritz and NY non-stop. Now that must be quite convenient for some individuals with deep pockets.

I am sure there are a lot more examples which prove the flexibility of three-engine Falcons.