Astra 1125 Info


#1

Any Astra 1125 pilots out there willing to answer some questions regarding runway performance? Company I work for is looking at a straight 1125 and I’d like to compare numbers to our current aircraft.

I’m interested in hearing from SP operators as well.

Here is our typical mission:

4 Pax
1200 NMs (Block/Air Miles)
8,000’ Runway @ SL

We occasionally do the following:

4 Pax
2400 NMs (Block/Air Miles)
8,000’ Runway @ SL

I’m looking at the most limiting factor, which is gonna be temperature and associated BFL.

So, during the summer hottest temps would reach 35C. Winter would be about 28C.

If possible I’d like to see Dry and Wet numbers given the following conditions:

0’ MSL
A29.92
35 degrees C (and 30 degrees C)
No Wind
8,000’ Runway
0% runway slope
Pressurization Off
Dry Rwy (And Wet Rwy)

As an example, our current a/c is climb limited at 35C to 22,600 Lbs, Dry or Wet, with a dry BFL of 7,400’ and a wet BFL of 7,800’ (Flaps 0)

At 30 degrees, dry, we are MGTOW limited to 23,500 Lbs and 7,600’ Flaps 0. Flaps 12 performance becomes 2nd segment limiting @ 22,500 Lbs and 5,800’ Rwy.

30 degrees, wet, we are limited to 23,200 Lbs. and 7,800’ Flaps 0, and 22,500 Lbs. and 6,200’ Flaps 12.

Will the Astra beat these numbers with a Slats/Flaps 12 config?

What about the Astra SP with a flaps 0 takeoff?

Thanks to anyone who can provide the requested info.


#2

It sounds like you are comparing it to an 1124.
As I remember the only performance difference between the 1125 and 1125SP is because of the gear doors closing fully on the SP when the gear is down. There is a service bulletin available to retrofit the earlier 1125’s.
Without having the book here I would venture the 1125 runway numbers will beat the 1124A which beats the 1124 pretty much across the board although not by a whole lot (the 1124 wing does get anemic during the summer). Cruise is a different story. The best trip I ever did in an 1125SP was FLL-LAX with 3 or 4 pax. 120 Knot headwind climbing out across Florida which slowly dropped to 100 by DFW and 40 at ABQ. Landed in LAX with 1200#. TAS was not very impressive that day!!
As I said it has been a while since I’ve been in either one.
Hopefully somebody here will have the books and can give you some real numbers.


#3

I fly a GALX and I doubt our little brother the Astra could get 2400nm with zero pax without a fuel stop.
I flew from PDK to VNY 2 days ago with 6pax and landed with min IFR reserve, and took off at max allowable.
Wiki says that the 1125 can do 3100nm and the G200 can do 3400 with 4 pax so I think the page needs to be edited. I doubt (I’ve been wrong before) that the Astra is a coast to coast .80 airplane, plus you don’t hear about an 1125 making Atlantic crossings…


#4

2400 is no problem if you slow down, I think the book is 29xx with the aux tank installed. That is a long ways for that cabin.
It will do .80 no problem, but LRC is closer to .74 slowing to .68. Constant .74 is not much of a penalty though. The FLL-LAX trip was 2035 direct with no wind, I don’t remember what the ESAD was but probably pushed 2400-2500. I think we were around 6+05 or something like that.
The 1125 will definitely beat the Lear 60 in all out range and I’ve flown the 60 from Gander to London. In fact I think the 1125, with the aux tank, will go roughly about as far as our tip tanked G2. Full fuel payload is obviously different but I don’t get knee burn on the way to the toilet in the 2 either.


#5

go to show you what I know. I see our little brother on the ramp and I think short range.


#6

LB won’t do what the Galaxy will do but that didn’t live up to it’s original billing either.
The SPX/G100 doesn’t have any more range but is a rocket ship when it comes to runway needs.


#7

Thanks guys for the info. Yes we currently operate a Westwind I. During the summer we are usually 2nd segment limited, but then again who isn’t, although in order to get the best TOW we usually do flaps 0 and thus are BFL limited, more so with a wet runway of course.

I have heard, as porterjet said, if you slow the Astra down to WW speeds you get better SFC. We flew a trip yesterday that was 6+47 in two stages. 4+0 on leg one and 2+47 on leg two. Winds on the nose were around 110. At one point we were at FL380 doing 280 GS. Ended up at FL400 in the 3rd hour of leg one and got out of the wind a bit with the GS picking up to 320. Had 5 pax and about 4000# of fuel. Good thing it was cold otherwise FL400 would have been impossible. Ended up burning 6200# of fuel on leg one, making for an average of 1550/Hr.

I understand the Astra holds approximately the same amount of fuel as a WW1, no aux tanks installed. We would not be operating with the aux tank as it would predicate the need to leave behind the kitchen sink lol.

Do any one of you know approximate cost for the SP mods, and does the SB for the straight 1125 SP mods allow a 0 flap takeoff? The straight 1125 we’re looking at is a possible bargain given the condition, pedigree, mx status and times/cycles. Last we were told an offer of 600k may just be accepted. However, if there is no real gain to the Astra we may just wait for something better to come along.

Thanks again and any further info you can provide sure is appreciated.


#8

I remember a couple of takeoffs in the I that ummm…let us see the entire runway length up close and personal. Always in the summer when we were sweating anyway. The II was better and the Astra is another step up.
Without the aux tank the baggage compartment is pretty nice. Carrying that 100 gallons cost you about 40 of it in higher fuel flows on a long trip so it wasn’t really worth much.

Just found an early article, the doors hung out up to S/N 30 and was not a problem if flaps were used for takeoff. In fact the linkage was pretty simple and allowed for easier pre-flights. But with 0 flaps they were out in the airstream a bit more and really killed performance. The door mod originally was called something like the zero flap takeoff solution so, yes it looks like if the mod is done you get zero flap takeoffs. Please verify this on your own. You local friendly Gulfstream center will gladly give you the most expensive solution… :smiley:
I would be interested to see if the early Astra did better or worse with flaps 12 than a WWI with zero flaps, both loaded for the same long trip on a warm day.

The early 1125’s had the -3A engine, it is upgradeable to the -3C which has a bit more oomph high and hot. If I remember right MSP was offering to upgrade engines fairly cheaply as they came in for CZI inspections. There is an S/B to install -3C’s on early airplanes.

Your average FF numbers will be a couple of hundred pounds better in the 1125 as well as still going 10 to 15 knots faster compared to the WWI. Or you can pump up the fuel flow and get .80 instead of .72 and typically be 2 to 4000 ft. higher. (again that’s off the top of my head) LRC’s are about the same but the Astra does not have much range penalty up to about .75M. On range critical trips you have the choice of starting at .75 and slowing down as you get light or start at .70 and let the airplane accelerate, the choice comes down to do you have a headwind or a tailwind and in which part of the trip do you need to go fast/slow. That FLL-LAX trip we started at .75 and slowed to .70 as the headwind died off. We were almost making fuel the last hour.

Compared to a WWI you will be impressed. We used to joke that the Astra had more range than cabin. Although the cabin is something like 6 inches longer and 9 inches taller. It is definitely a nice upgrade to the 1124.

A couple of things I remember maintenance wise on the flaps/slats:
Rigging is critical so you don’t get an asymmetric condition in the slats. Also don’t extend the flaps at max allowable speed (250 I think). Wait at least 20 and preferably 30 knots for flaps 12. You don’t need flaps that fast anyway. There is no penalty if the slats don’t come out, you can bypass a slat asymmetry and still get full flaps. don’t dick with it, there is nothing you can do about it inflight.
IAI would never say who designed the wing, but I had a demo pilot tell me to stand behind a Falcon 50 and compare that wing to the Astra. Surprisingly similar.
The weirdest thing about an Astra: learning to taxi without duck-walking. Hopefully you will get to see what I mean. Brakes are the key, I can’t explain it any better here, you just have to practice it a bit.


#9

more quick thoughts.
The 1125 is enough better than the WWI I would go for it if you can get a good one at a good price. I can’t think of anything that isn’t better in the Astra.
An Astra salesman once told me their biggest competition was the used Falcon 50 market. That might be a bit of a stretch today, but in the mid 1990’s it was true. Not that you can claim an 1125 and a 50 are the same airplane but in those days there was nothing in between them.
If you can possibly swing an SP do it. It is not that much better but it is newer and will have all of the nice to have S/B’s that likely were not done on the earlier S?N’s.
This covers the entire 1125/G100 series:
gulfstream.com/product_suppo … 0Index.pdf