Cruise Mach for various Business Jets

[WeekendFlyer]

All,

I was wondering if you could provide me with the cruise mach number and Mmo for the various business jet types that you fly? I understand that some of them are quite a lot faster than typical commercial jets and I want to get an idea of the speed difference. It is for a project I am working on, to correlate high cruise speed with specific design features (e.g. wing sweep, thickness to chord ratio, aerofoil section, etc).

Grateful for any help you can provide.

Regards,

WF

[marianoberna]

My Cessna 150 cruises at mach 0.12 at 8000 feet :}:}:}:}:}:}:}

[Gulfstreamaviator]

it does make a difference, of 0.00001, and speed is important.

glf

tin hat at the ready

[falconeasydriver]

The falcon I used to fly told you it was doing .82, but was really only doing .81
The G550 I flew was happy at .83
The 777 I now fly is happy at .83-85.

[Dash8driver1312]

We're straining our PeeDubs trying to drag our wings up to M0.6 on the Mighty Q400!

[dirk85]

Citation Excel/XLS as close as possible to the MMO without triggering the overspeed warning, ie about .73/.74.

[Globally Challenged]

Cruise 0.82 (unless you are trying to eek out 7 hours across the atlantic with a jet stream in the face - in which case it was 0.80 today)
MMO 0.83

[Astra SPx]

Cruise Mach usually between 0.82 - 0.83, have seen 0.85.
Mmo 0.875

[His dudeness]

C680 MMO .8 max speed varies a lot with altitude and weight. Usually doing HSC at .74 to .8

The ones much faster are few, the G650 and Citation 10/X spring to mind.

[fleigle]

Citation X could do .92 but normally .88-.89 for "economy"
f

[Pratt X 3]

CL604/605
Mmo 0.85
Normal cruise 0.80 (large decrease in fuel efficiency above that speed)
Most efficient speed 0.77-0.78
LRC 0.74

G200
Mmo 0.85
Normal cruise 0.81-0.82
LRC 0.74-0.75

[Deep and fast]

Embraer legacy M0.78

No the fastest but has a huge cargo hold for a biz jet

D and F

[Jet Jockey A4]

For the Global 5000 and XRS the speeds are as follows...

Keep in mind that maximum TAS and Mach vary with altitude/temperature and the higher you go the lower the MMO will be.

VMO (SL - 8000') = 300 KIAS

VMO (8000' - 30,267') = 340 KIAS

MMO (30,267' - 35,000') = 0.89M

MMO (41,400') = 0.88M

MMO (47,000') = 0.858M

MMO (51,000') = 0.842M

Normal cruise speed is 0.85M and we use for long range cruise speed when heavy 0.82M.

If you really want to go fast and fly as close to the VMO/MMO you would fly the Global between 30,000' and 41,000'.

[Trim Stab]

VMO (SL - 8000') = 300 KIAS

VMO (8000' - 30,267') = 340 KIAS


Is that a step-change at 8000'? Must be a right PITA in the descent! The CJ2 has a similar step-change at about 6000' IIRC and it was always a challenge to remember to slow down enough to stop the overspeed klaxon sounding.

[His dudeness]

That change is also at 8000ft (something to do with windshield certification) - I think every Citation has it....

For the Sovereign that is 270/305

[south coast]

DA7X

High speed 0.85
LRC 0.8
MMO 0.9

[Jet Jockey A4]

Quote...

"Is that a step-change at 8000'? Must be a right PITA in the descent! The CJ2 has a similar step-change at about 6000' IIRC and it was always a challenge to remember to slow down enough to stop the overspeed klaxon sounding."

I don't see how it is a problem seeing that you have to be at 250 kts below 10,000' in most if not all airspaces in the world.

[First.officer]

I don't see how it is a problem seeing that you have to be at 250 kts below 10,000' in most if not all airspaces in the world.

Not in the London TMA if they give you free speed....:eek:

Quite happily get 270kts in the CJ2+ - as said, you get to 8000ft, and then VMO drops to around 263kts IAS, and if you forget that (as previously mentioned), you do get a nice alarm in your earholes hehe - you only forget once or twice after that ;-)

Oh, CJ2+ MMO I think is M0.737, usually with a good ISA and FL450 Cruise, you can expect say M0.71...

F/o

[Jet Jockey A4]

Quote...

"Not in the London TMA if they give you free speed...."


I did say "most" airspaces in the world... Too bad Canada changed their speed restrictions to align themselves with "the rest of the world" some years back.

It used to be that on departure in Canada if you were cleared above 10,000' one could accelerate to any speed above 250 knots while in the climb. )-:

[ksjc]

@AstraSPx

Are you sure about your cruise speed and MMO?

I spent 13 years in the IAI 1125 ASTRA and it was a 0.78 cruiser with 0.835 MMO. Is the SPx different?

Also, regarding GLEX speeds...

A quiet flight deck to be sure but anything above 320 KIAS gets unbearably loud up front. Don't know why one would want to fly faster. You are only in this realm in the teens during descent anyway.

[WeekendFlyer]

All, thanks for replies so far, very useful. Just wondered if there are any G650 pilots who would be willing to add to the discussion?

[A Pandy]

I fly the G650.
The MMO is .925. Normal cruise is .90 with long range cruise between .85 and .87.
For flights under 5000nm we will normally plan .89 as this seems to be far more fuel efficient than pushing up the power to .90.
For legs over 5000nm we will normally plan at .85 or .87 mach. Speeds below .85 do not benefit much due to the drag curve.

[SCSflIer]

DA2000

MMO-.865
Intermediate- .75
LRC- dependent on temp/ ALT. In the ball park of .72
Normal cruise .80, seems to be the best of both worlds. (Speed/Efficiency)

[SCSflIer]

HS-125 (800XP)

MMO- .80
Normal cruise- .74-76
LRC- .72

And for 700 series, you are lucky for .70 on a good day!

[WTON]

HS 125 Hawker XP series:

MMO .80

Long range .70
Normal cruise speed .76

@ FL410

[Astra SPx]

I spent 13 years in the IAI 1125 ASTRA and it was a 0.78 cruiser with 0.835 MMO. Is the SPx different?

Absolutely. It's a completely different bird.

From the QRH, max cruise:

FL450, ISA, 17000 lbs, 0.81, ISA - 10 gives 0.835, ISA + 10 gives 0.717
FL370, ISA, 24000 lbs, 0.825
FL390, ISA, 16000 lbs, 0.839
FL410, ISA, 18000 lbs, 0.83, ISA - 10 gives 0.847

Mmo 0.875
Vmo 353 KTS
High speed climb is 0.72

[epsum]

Lear 60,
MMo M.81 (up to F380-390)

Normal cruise .77-.78 (@F400/410)
Long range .72

[Booglebox]

Here's one: Cessna C525 CitationJet ("CJ0" as we like to call it) - M0.62 :}

[stilton]

The G650 is pretty impressive.


Just wondered why Gulfstream didn't give it slats and / or more range ?

[Welle]

GLEX - normally cruising 0,83- 0,85
LR cruise - 0,80-0,83

welle

[formulaben]

That change is also at 8000ft (something to do with windshield certification) - I think every Citation has it....Bird strike protection.

§25.631 Bird strike damage.

FAA
The empennage structure must be designed to assure capability of continued safe flight and landing of the airplane after impact with an 8-pound bird when the velocity of the airplane (relative to the bird along the airplane's flight path) is equal to VC at sea level, selected under §25.335(a). Compliance with this section by provision of redundant structure and protected location of control system elements or protective devices such as splitter plates or energy absorbing material is acceptable. Where compliance is shown by analysis, tests, or both, use of data on airplanes having similar structural design is acceptable.

EASA
The aeroplane (all structure, including windshield) must be designed to assure capability of continued safe flight and landing of the aeroplane after impact with a 4 lb bird when the velocity of the aeroplane (relative to the bird along the aeroplane’s flightpath) is equal to VC at sea-level or 0.85 VC at 2438 m (8000 ft), whichever is the more critical. Compliance may be shown by analysis only when based on tests carried out on sufficiently representative structures of similar design. (See AMC 25.631.)