Xtreme prototypes GLJ25

[Ray Proudfoot 8,944]

Thanks Bob. I had a read of the manual and found the reason I was running out of fuel was because I hadn’t switched the fuselage tank pumps on. Silly me.

This aircraft seems to climb faster than Concorde. That’s come as quite a surprise.

[Dean33 69]

1 minute ago, Ray Proudfoot said:

Thanks Bob. I had a read of the manual and found the reason I was running out of fuel was because I hadn’t switched the fuselage tank pumps on. Silly me.

This aircraft seems to climb faster than Concorde. That’s come as quite a surprise.

Ha!  I thought it might ‘float your boat’ Ray. Think of it as the feeder aircraft for ferrying the Concorde crew around!

[onebob 125]

I can't get the hang of it on take off yet. I think the manual says 100% thrust and 15deg pitch but gets to 400"/m and overspeed to quick.

 

bob

[Ray Proudfoot 8,944]

Dean, what’s the pitch up angle after rotation? I find I’m hitting 300kts far too quickly and the climb rate is around 5000fpm. That seems way too much.

Does it really need full power for takeoff? I know Concorde did but it had no flaps so speed was essential for rotation before running out of runway.

i’m taking it on a test flight tomorrow from EGCC to LEPA. Manchester to Palma, Mallorca to tweak fuel figures for PFPX but also to get a good feel for all the systems.

[Ted Striker 338]

Ray, Your comments have got me laughing and entertained so I must respond. I learned to fly the Citation X and Lear before struggling with the Concorde. Frankly, I expected the Concorde to climb a lot faster than it does. I think the Lear has the highest thrust to weight ratio of all three so yes you can takeoff with full power but you should reduce thrust shortly after to maintain a manageable climb rate. Definitely not 123 Now, slam the throttles forward and keep them there . If you keep them at full throttle you really need to pitch up but you’ll be so busy trying to control the plane you won’t have time to navigate.

Ted

[Dean33 69]

Don’t forget the 250k limit upto 10,000. That takes a lot of throttling back. To be honest I usually use the autopilot/speed/throttle control at 250 and then later climb speed. 

This aircraft does NOT like to exceed 359k I’ve had the systems go wild several times  

Here’s my ‘cribsheet’ as a starter for you:

LEARJET LJ25

Climb at 300 Kias 13000 LBS
35000 71 Miles 11mins
41000 104 Miles 16min
45000 218 Miles 33 mins

Cruise speed max 359KIAS MACH.82

Fuel
1000Take off climb to cruise
1300 first hour and cruise (after 30 mins climb)
1200 second hour
350 descent and land (30 mins)
1000 Reserve 

GEAR DOWN below 250
FLAPS 8 

VREF 40 122, 20 135, 8 144

Ive spent best part of 5 months mainly flying the Lear.  I’m learning the Maddog presently but I’ll be back when I need some speed and altitude!

 

 

[ryanbatc 12,833]

Yes, you MUST reduce power on takeoff in this jet, especially if flying in the USA as we have a 250 kias rule under 10000 (there are exceptions).

With a light load this thing will easily do 4000+ fpm at 250kias

[Greggy_D 935]

"We're going ballistic, Mav !!!!"

[Nyxx 6,993]

Ray, I did tell you......Speed lol.

After takeoff,gear up....reduce thrust. Watch speed climb at around 1000 fpm auto pilot. Increase thrust climb at 2000 fpm.Above 10000, increase thrust climb at 4000 fpm.

 

[Ray Proudfoot 8,944]

Hi Ted. Yes, it came as something of a surprise it climbs that quickly. But it's still behind Concorde with a light load.

I will reduce thrust once airborne to keep the speed and climb rate at sensible levels. But I feel I need to ask if there's so much power available why is it necessary to apply full power for take-off? 85% would seem more logical.

Dean, thanks for those tips.

David, see above. Why so much power for take-off? I suppose when you have an executive jet saving a few bob with fuel isn't a factor.

[Nyxx 6,993]

8 minutes ago, Ray Proudfoot said:

David, see above. Why so much power for take-off? I suppose when you have an executive jet saving a few bob with fuel isn't a factor.

They just want to get there asap if the pilot had a CI it would be max out. Money for them pax is not a concern 

[Ray Proudfoot 8,944]

20 minutes ago, Nyxx said:

They just want to get there asap if the pilot had a CI it would be max out. Money for them pax is not a concern 

But doesn't passenger comfort come into the equation? 6000fpm climb can't be particularly pleasant.

[Nyxx 6,993]

I only use 3000-4000. to 1000ft to 30000+ 

1000 PFM <10000ft

You can use 1000 like  I said watching the speed of this aircraft is key. It's a constant task. Its a pocket rocket 

Edited March 5, 2018 by Nyxx

[Ray Proudfoot 8,944]

2 hours ago, Nyxx said:

I only use 3000-4000. to 1000ft to 30000+ 

1000 PFM <10000ft

You can use 1000 like  I said watching the speed of this aircraft is key. It's a constant task. Its a pocket rocket 

Currently enroute to Palma and I engaged the a/p at 500ft. The LISTO SID from 05L at EGCC requires a sharp right turn 1nm out so I felt it best to leave it to the a/p until I become more familiar with the aircraft. Climb rate around 3000-4000fpm is reasonable.

Descent isn’t a problem. I have a moving map that displays the ToD point and descent rates taking into account altitude restrictions.

[onebob 125]

1 hour ago, Ray Proudfoot said:

Currently enroute to Palma and I engaged the a/p at 500ft. The LISTO SID from 05L at EGCC requires a sharp right turn 1nm out so I felt it best to leave it to the a/p until I become more familiar with the aircraft. Climb rate around 3000-4000fpm is reasonable.

Descent isn’t a problem. I have a moving map that displays the ToD point and descent rates taking into account altitude restrictions.

Throttles:

 During descent, maintain 75% RPM minimum until 12,000 ft.

Use spoilers .

Edited March 5, 2018 by onebob