Typed in the B-727
- Thread starter Bandit_Driver
- Start date
Maximilian_Jenius
Super User
Is this why newer planes like the 757,767,777,787 only have 30 degree of flaps?
Though the NG 737's do have 40 degree flap settings.
Stage I and II turbojets still rule.
Maximilian_Jenius
Super User
Turbojets. Are those the LOUD engines that used water injection, and had the large black plooms of smoke escaping out the rear?
Maximilian_Jenius
Super User
Maximilian_Jenius
Super User
Okay, then why did some use water injection and others didn't. What're the pros and cons if any?
Okay, then why did some use water injection and others didn't. What're the pros and cons if any?
To increase thrust on hot days, some mil aircraft used water injected into the compressor inlet for non-afterburning engines. Pros, increased thrust by about 20-30%, since the water allows the inlet air to be cooled and thus increases its density, allowing for more fuel to be burned. Cons, weight of lugging the water, desalinization plants needed for it, and logisitcs of using it. The B-52 went from something like 11,000 lbs thrust without it, to 13,500+ with water injection. Normally only used for takeoff.
Turbojet engines have no bypass such that turbofans do (no fan in front), and their compressor/turbine share the same shaft using the velocity of the exhaust gas directly to produce. Noisy and fairly fuel inefficient, but cool.....essentially what goes in, goes through the combustion chamber and goes out back, versus some being bypasses around the engine core, such as low/high bypass turbofans do. GE CJ-610 (Lear 23), P&W JT12 (Lockheed Jetstar), and J60 (NAA Saberliner) are good examples of these.
Corporate Pilot
Well-Known Member
The 60 Saberliner was fun to fly but hard to make it go very far. In the GE Falcon 20 we could push about 85K of wind from LGA to DAL. Pushed 150K of wind one day out of DCA back to DAL but the weather was good in DAL. 60 Saber never would have made it.
That sucks, because I love the Saberliner series.......cool looking design.
Corporate Pilot
Well-Known Member
I only flew the 60. From what I had heard the 65 has a much greater range but does not fly as well. Again from what I have heard the 80 is the best overall. The 80 has the same engines as the Falcon 20 but it is much lighter.
Only one I've been aboard inflight is the 40, and even it was a cool bird. I would like to see a 75/80 sometime firsthand. Between the Saberliner and the Jetstar, two of my favorite corporate jets.
Corporate Pilot
Well-Known Member
I was told some of the 40’s had the same engines as the 60, which would have made them a real hot rod.
Departed DAL for LIT one day and we ran all over a 757. Going to LIT we would climb out at 350K until .80 at about 35000 we would pull the power back to idle and glide to LIT
Departed DAL for LIT one day and we ran all over a 757. Going to LIT we would climb out at 350K until .80 at about 35000 we would pull the power back to idle and glide to LIT
Bandit_Driver
Gold Member
The 727's PW JT8D engines aren't pure turbojets they are actually turbofans with a 1:1 bypass ratio. Some of the RJ's have medium bypass TF's at about 5:1 and obvously the newer planes 777, 767, etc have hi bypass engines. The medium and high bypass engines reduce the exhaust noise that you hear. On the higher bypass engines a lot of the fan air goes around the core and mixes with the exhaust air.
I think the loudest civilian jet I have ever heard has to be the Lear 23 on a cold winter morning.
Out of the military the F-15, F-4 and F-14 were the loudest I expereienced. They were so loud it hurt. I remember a pair of F-15's ran up their engines prior to take off on a wet runway and after they departed the runway had a lot of steam coming off of it for a minute or two.
Orange Anchor
New Member
we didn't use 40 that often and many guys didn't use them at all. I tried to use them as often as possible just to keep current with them. With 40 the plane seemed to sit down a lot quicker in the flare and stop better although the Vref speed was not that much slower. Lots of additional drag however. Don't remember the growl. Do remember the YS-11A moaning when it was loading up with ice just before it began throwing it against the fuselage.
One of the last times I landed 40 was going into DCA on an ugly day. We were on the ILS36 and tower asked us if we could use 33 which we sometimes did. I agreed, went 40 and we maneuvered. We touched down and the controller told us he expected us to clear 33 faster and made some remark about us taking too long. I just told him, "Don't worry.. it WON'T happen again." I think he caught the meaning.
In the tanker, on a non-precision we would drive to the MAP with gear down and flaps 50. You would have all four engines above 4000lb/hr easy.
As for the -23 being loud, remember that is the same engine as in the T-38, the T-2 and the Hansa. LOUD but what a fun little engine that is real responsive.
Just remembered.. in the late 90s Raisbeck came out with a mod that changed the flap/slat deployment and angles to reduce noise on t/o and landing. Not a lot of 727s were modified but some where. This was a small group like the Valsan 727s with the JT8D200 series engines on the pods.
ppragman
FLIPY FLAPS!
DC6 has water injection. They use the hell out of that on takeoff I hear. Back in the old days when guys were flying fish off of the beach in the thing, and were paid by the lbs of freight, you can guess what one of the practically mandatory callouts by the captain on takeoff: a frantic "ADD MORE WATER!!!" A good buddy of mine's dad flew em' at NAC until they got rid of them. Those things are amazing.
Bandit_Driver
Gold Member
All our birds have a mod for Stage III. The majority fleet only uses Flaps 25 with the two odd balls using 30 or 28.
I wish we had some Super 72's as it would be nice to have the -217's or 200's on the pods. However, we are fourtnate that the smallest engine we have are -9A's. I have heard the war stories of guys flying the -7Bs out of Vegas and what a PITA those planes where.
Wow, a YS-11, that looks like it is an interesting plane to fly. There are a few of them sitting down in Laredo, TX.
I wish we had some Super 72's as it would be nice to have the -217's or 200's on the pods. However, we are fourtnate that the smallest engine we have are -9A's. I have heard the war stories of guys flying the -7Bs out of Vegas and what a PITA those planes where.
Wow, a YS-11, that looks like it is an interesting plane to fly. There are a few of them sitting down in Laredo, TX.
Orange Anchor
New Member
we had -7, -9 and -15 engines with an intermix approved. The USAir birds, which I never flew, had the -17 engines.
I did get to fly the 727 in the FEDEX mod which I think had 2 -217s and a -17 in the center and a 727-100 with 2 -217s on the pod and a -7 in the center. It was as if they added a 4th engine and you could climb above the wing's ability.. or so it seemed.
The YS-11 was one odd duck. Water injection, 2 16ft props and a wicked flare required for a good landing. But it would haul 48 pax out of ROA, BLU, and Huntington with no problem.
When I got hired at PI I went to some of my USAF buddies still on active or reserve and pulled a big set of the mil charts and put them in my flt kit. We seldom got above 10,000 and so I would pull out those charts and follow the flight via ground ref. One of the old grumpy SOBs asked one day what the hell I was doing. I said I was just following the flight via landmarks and he asked why. I said I had never flown anything that far and that low routinely.. that most of my time was above a reset of 29.92. That remark came back to bite me. This was all prior to the big onset of CRM and some capts were textbook.
Bandit_Driver
Gold Member
Sounds like fun....I think every airline has at least one SOB...