Search found 130 matches

by Airgypsy
Thu Jul 11, 2013 3:30 pm
Forum: Technical/Operations
Topic: Thrust Reversers - How Do They Work?
Replies: 38
Views: 33890

RE: Thrust Reversers - How Do They Work?

Reverser types are: Target type - The clam shells block the path of the exhaust and deflect it slightly forwards. Cascade type: - A clamshell in side the exhast "plugs" the tail pipe and the exhaust is forced out of cascade vanes in front of the "plug" or as the aft fan cowl moves aft (most common) ...

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by Airgypsy
Sat Aug 06, 2011 3:41 am
Forum: Technical/Operations
Topic: 737 Classic Take Off Spool
Replies: 2
Views: 5582

RE: 737 Classic Take Off Spool

The CFM-56B and C series engines on the -300 and -400 737 had no published (and therefore very unpredictable) acceleration times from Idle to 40% N1 (fan speed). So, the SOP is to get both engines to 40% N1 and then accelerate them together to T/O RPM. Any pause was the choice of the driver. B and C...

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by Airgypsy
Tue Apr 01, 2008 2:21 am
Forum: Technical/Operations
Topic: BAE-146 And Avro Without Leading Edge Slats
Replies: 13
Views: 7140

RE: BAE-146 And Avro Without Leading Edge Slats

The constant radius leading edges made their appearance on LearJets and were very effective and efficient. I'm supprised more aircraft aren't sporting them. The secret of lift on the BAe-146 is the aft translation of the flaps prior to lowering. Large wing area increase. Its part of that race car so...

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by Airgypsy
Fri Feb 01, 2008 3:56 am
Forum: Technical/Operations
Topic: Using The Air Truck To Start My 737 Flight Today
Replies: 64
Views: 19331

RE: Using The Air Truck To Start My 737 Flight Today

The 727 was designed without an APU. (Initially it was design with only two engines. This is why the APU is in the <acronym title="Meridiana Air (Spain) and Régionnair (Canada)">RH</acronym> wheel well. No CG margin left for a tail installation after the third engine #2 was installed.) USAir (now US...

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by Airgypsy
Tue Jan 01, 2008 1:02 am
Forum: Technical/Operations
Topic: J-52 / JT8D / Swedish RM-8 Turbofan: Spool-up Time
Replies: 15
Views: 6075

RE: J-52 / JT8D / Swedish RM-8 Turbofan: Spool-up Time

Straight 8s are "low" bypass engines. -200s are "medium" bypass engines. JT9s are "high" bypass. A J-75 turbojet is a no bypass.
Otherwise referred to as LRT = Little Round Things and BRT = Big Round Things.

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by Airgypsy
Tue Jan 01, 2008 12:56 am
Forum: Technical/Operations
Topic: How Does An Engine "Surge"
Replies: 12
Views: 28607

RE: How Does An Engine "Surge"

Flameout vs Compressor flow reversal. If the engine is mismanaged (older types) you can cause it to lean the mixture out and have more air than fuel and litterally cause combustion to cease. This is the reason why ignition is turned on before landing as the throttles are constantly adjusted during l...

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by Airgypsy
Mon Dec 31, 2007 3:09 am
Forum: Technical/Operations
Topic: IA Seminar Presentation Ideas
Replies: 3
Views: 2143

RE: IA Seminar Presentation Ideas

Hi,
I moved from Iowa last year. I probably saw your presentation.
Iowa has a lot of one man shops and small FBOs. From my own experience, I am interested in dealings with the FAA as they relate to violations as a shop owner.
I won't be there in 08 but say Hey, to Phil for me.

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by Airgypsy
Mon Dec 31, 2007 12:11 am
Forum: Technical/Operations
Topic: Official Story Of Northwest BAC-146 N528Xj
Replies: 33
Views: 14609

RE: Official Story Of Northwest BAC-146 N528Xj

I was pushed back from the gate in a BAe-146 and had the opportunity to experience the ease in which hydraulics can be left "off". Dropped the tow bar and released the brakes to find the nose wheel steering inoperative. Logic prevented me from letting my feet off the brakes the second time. We sat t...

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by Airgypsy
Sun Dec 30, 2007 11:44 pm
Forum: Technical/Operations
Topic: Compression Ratio Vs Turbine Temp
Replies: 17
Views: 20760

RE: Compression Ratio Vs Turbine Temp

Checkout the website for the ATF-3 engine for a look at an engine designed as close to the "ideal" engine as you can get. <a href="http://www.pocketprotectors.com/atf3/Engine.htm" target=_blank>http://www.pocketprotectors.com/atf3/Engine.htm</a> Cooling in the right places improves mass flow. Heatin...

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by Airgypsy
Sun Dec 30, 2007 11:20 pm
Forum: Technical/Operations
Topic: J-52 / JT8D / Swedish RM-8 Turbofan: Spool-up Time
Replies: 15
Views: 6075

RE: J-52 / JT8D / Swedish RM-8 Turbofan: Spool-up Time

ACU = Compressor Bleed Control for JT8s. The range of JT8s makes any general statement impossible. Straight 8s (1-17R) and the -200 series. The -17s bore almost no resemblance to the very popular early -7s. -200s came with a real fan and very advanced compressor control. Acceleration times are very ...

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by Airgypsy
Sun Dec 09, 2007 3:09 am
Forum: Technical/Operations
Topic: Influence Of Reduced Thrust T/O On MX Cost
Replies: 11
Views: 8932

RE: Influence Of Reduced Thrust T/O On MX Cost

Discounting other factors such as cycle time or abnormal number of starts per flight hour -

Gas turbine life is EGT/Seconds
Piston engine life is ring inches of travel.

Less of either makes the on-wing calendar time increase.
Airgypsy

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by Airgypsy
Sun Dec 09, 2007 2:58 am
Forum: Technical/Operations
Topic: MD-83 Start Up Sound.
Replies: 8
Views: 3746

RE: MD-83 Start Up Sound.

The sound is the exciters charging repeatedly as they fire the igniters. The exciters work much like a flash unit for a camera except the firing is determined by the gap in the outbound igniter connection. When the voltage in the capacitor gets high enough to jump the gap, the igniter provides the p...

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by Airgypsy
Thu May 31, 2007 9:47 am
Forum: Technical/Operations
Topic: B787 Vertical Gust Supression
Replies: 12
Views: 7654

RE: B787 Vertical Gust Supression

The A320 has active gust dampening that uses the spoilers to dampen motion in the wings. A very fast system that can almost out run the hydraulic system.
B-2 has one to reduce airframe stress.
Airgypsy

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by Airgypsy
Mon Apr 09, 2007 7:15 am
Forum: Technical/Operations
Topic: Kias Vs Mach Number @ Altitude
Replies: 17
Views: 13559

RE: Kias Vs Mach Number @ Altitude

This is an excellent demostration of the "Coffin Corner" where the Mach limit and the stall speed meet. For subsonic aircraft like the U-2, the place is where you are a few knots from going supersonic or falling out of the sky in a stall.
Thanks,
Airgypsy

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by Airgypsy
Sun Mar 04, 2007 12:00 pm
Forum: Technical/Operations
Topic: Cockpit Windscreens Getting Damaged By Winds?
Replies: 26
Views: 3948

RE: Cockpit Windscreens Getting Damaged By Winds?

Years of maintenance control experience alerts me that this is a procedural problem. The outter Anti-ice pane is very thin and is usually very hot. It is something that is very time restricted for ground operations. The inner (thick) panes are heated for defog and can be operated continuously. I hav...

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by Airgypsy
Mon Jan 08, 2007 3:05 am
Forum: Technical/Operations
Topic: Signing Off Job Cards Electronically?
Replies: 25
Views: 4551

RE: Signing Off Job Cards Electronically?

I design and implement databases to perform Maintenance Control functions at an airline. It is mostly getting the will of management in line to implement these new paperless systems. The computer systems now in place do a fine job of tracking and securing data. The problem is the older people in man...

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by Airgypsy
Thu Dec 28, 2006 10:12 am
Forum: Technical/Operations
Topic: "High Pressure Bleed Valve" Problem
Replies: 25
Views: 32210

RE: "High Pressure Bleed Valve" Problem

With every departure, another tree falls.

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by Airgypsy
Thu Dec 28, 2006 10:08 am
Forum: Technical/Operations
Topic: Removal Of Connexion Antennae/Radomes?
Replies: 10
Views: 3411

RE: Removal Of Connexion Antennae/Radomes?

Removal of any installed antennas is a quick and easy job. Replaced the doubler with a solid doulber and put a flush patch in the skin hole. Use too much <acronym title="Prescott - Ernest A. Love Field (PRC / KPRC), USA - Arizona">PRC</acronym>-1422 for a real seal and have a happy. Look at installa...

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by Airgypsy
Sun Dec 10, 2006 7:58 am
Forum: Technical/Operations
Topic: Turbine Engines Are Ruining Aviation
Replies: 39
Views: 5933

RE: Turbine Engines Are Ruining Aviation

Anyone that yearns for the "Good Old Days" doesn't own a tool box. I've maintained working aircraft radials and they will suck up your time and blood quick engough for you to miss the sound of a satifying thump of a turbine enigne starting up. Change plugs every 25 hours? Change 25 gallons of oil ev...

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by Airgypsy
Sun Dec 10, 2006 7:51 am
Forum: Technical/Operations
Topic: What Is The Difference Between A PCU & A PCA?
Replies: 11
Views: 9122

RE: What Is The Difference Between A PCU & A PCA?

Names are "invented" by bright young people with no field experience or history. Naming convention failures by engineering are the nightmare of mechanics and material control people.
So, what is a THS?

Airgypsy

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by Airgypsy
Sat Nov 25, 2006 12:43 pm
Forum: Technical/Operations
Topic: A380 Electrical Harnesses
Replies: 86
Views: 17965

RE: A380 Electrical Harnesses

The problem may be more than just wires. The cabin systems, as previously mentioned, have computer networks to run the InFlight Entertainment. The small problems with wiring multiply when several systems or compoinents are using the same piece of clad steel to communicate. ARINC buses are a way of r...

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by Airgypsy
Sat Nov 25, 2006 12:35 pm
Forum: Technical/Operations
Topic: Funny Or F&*(@$# Up Write Ups.....
Replies: 62
Views: 45059

RE: Funny Or F&*(@$# Up Write Ups.....

My all time military favorite was: I-F-F inoperative in O-F-F mode.

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by Airgypsy
Thu Nov 16, 2006 1:32 pm
Forum: Technical/Operations
Topic: Two DC9 Questions
Replies: 15
Views: 5214

RE: Two DC9 Questions

You can hear this sound replicated in any old style camera flash unit. The recharge ciruit charging up the capacitors. The ignitor units operate in the exact fashion as the flash units. A step up circuit increases the voltage to charge the capacitors through a pulse excitation (DC lacks the pulse of...

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by Airgypsy
Thu Nov 16, 2006 1:13 pm
Forum: Technical/Operations
Topic: 747 SP A Waste?
Replies: 56
Views: 6548

RE: 747 SP A Waste?

BAe-146 was the four engine short range market champ. Became the Avro <acronym title="Royal Jordanian">RJ</acronym>-85/100. It NEVER got stuck out on some remote place. Four with one bad gets you three that will bring you home. In the bad days PSA changed every engine every 30 days. It still made sc...

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by Airgypsy
Wed Aug 02, 2006 7:14 am
Forum: Technical/Operations
Topic: ATA 100 Codes For Business/Corporate Aircraft
Replies: 1
Views: 20839

RE: ATA 100 Codes For Business/Corporate Aircraft

ATA codes are universal except they are being replaced by the more refined JASC codes which are basicly ATA NG. Some manufacturers just aren't on the ball with their pubs.

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by Airgypsy
Thu Jun 08, 2006 7:53 am
Forum: Technical/Operations
Topic: How Do You Change A Wheel On An Airliner?
Replies: 97
Views: 24584

RE: How Do You Change A Wheel On An Airliner?

The gate race. Get those tires changed. The C-5 can jack it own gear. Onboard compressor for inflation and axel mounted valves for deflation. The mantra of tire change is: Worn to the cord, low on pressure, no pressure, blown, other tire on same axel low/blown, excessive heat from brake that causes ...

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by Airgypsy
Tue Mar 28, 2006 12:20 pm
Forum: Technical/Operations
Topic: 727 Cockpit Question
Replies: 22
Views: 4586

RE: 727 Cockpit Question

Those three little lights? Those innocuous little handles? When they illuminate and the warning sounds - they are the biggest objects in the cockpit. Time slows down, your palms sweat and you get the feeling (instantly) that you want to be SOMEWHERE ELSE! Try standing in the wheel well when the APU ...

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by Airgypsy
Tue Mar 07, 2006 12:48 pm
Forum: Technical/Operations
Topic: What Is The Correct Way To Land A Tail Dragger?
Replies: 14
Views: 12166

RE: What Is The Correct Way To Land A Tail Dragger?

Tail draggers are from the era of grass runways. The high traction afforded by touching down on pavement makes even the slightest mistake get magnified. I always recommended my tail dragger customers to maintain the highest recommended tire pressure when landing on pavement because it keeps the cont...

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by Airgypsy
Sun Feb 26, 2006 1:16 pm
Forum: Technical/Operations
Topic: MD-80 Engines
Replies: 6
Views: 3844

RE: MD-80 Engines

The <acronym title="Air Madagascar">MD</acronym>-80 grew from the DC-9 in several ways. It got longer, so they put a longer landing gear on the <acronym title="Air Madagascar">MD</acronym>-80 to keep the tail from dragging on takeoff (kept the same nose gear). The wing is bigger so, they added a Zer...

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by Airgypsy
Sun Dec 18, 2005 10:15 am
Forum: Technical/Operations
Topic: Tricks Played On Apprentices
Replies: 53
Views: 9829

RE: Tricks Played On Apprentices

The CFM-56 on the 737-300 and -400 has a flat bottomed cowl. I heard a mechanic deadpan an explanation to a ramper that the fan blades were on a cam so they could "pull up" and get by the "flat spot". We had a great time confirming that story! Yep, that is the way it is! They eventually figure it out.

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by Airgypsy
Fri Dec 16, 2005 12:39 pm
Forum: Technical/Operations
Topic: Can An Airliner Stop By Only Using Reverse Thrust?
Replies: 35
Views: 19056

RE: Can An Airliner Stop By Only Using Reverse Thrust?

Aircraft are certified with stopping distance by brakes alone. Thrust reversers are "auxilary deceleration devices". I have witness a DC-9 stop in less than 2k feet only reversers on an iced runway. FOD is the reason that most aircraft cancel T/R at around 60-80kts and brake from there. Brake and ti...

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by Airgypsy
Fri Dec 16, 2005 12:31 pm
Forum: Technical/Operations
Topic: Hole In The Side Of A 330
Replies: 5
Views: 4832

RE: Hole In The Side Of A 330

You can build an airplane around a dataplate if you have enough ink in your pen, a big stack of paper and an FAA Form 337. A real good SRM helps with damage but the assembly of "new" parts isn't damage. Odd but true.

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by Airgypsy
Fri Dec 16, 2005 12:26 pm
Forum: Technical/Operations
Topic: Tricks Played On Apprentices
Replies: 53
Views: 9829

RE: Tricks Played On Apprentices

I once had a senior mechanic ask me to look up the timing procedure for a jet engine, about a second later I realized I was being had. Doesn't help when you've spent a lot of time timing magnetos. I liked the military flight line. No shortage of "new" mechanics. There was a block in the forms titled...

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by Airgypsy
Sun Dec 11, 2005 9:40 am
Forum: Technical/Operations
Topic: Question About Mi-8/-17 Propeller
Replies: 4
Views: 2430

RE: Question About Mi-8/-17 Propeller

Those weights seem to be part of the rotor pitch change mechanism. Loss of a connection could be catastrophic but a flyweight could provide a very good safety by commanding the blade to a safe pitch. (Dassault Falcons have springs that neutralize control surfaces if they get disconnected from the co...

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by Airgypsy
Sun Dec 11, 2005 9:30 am
Forum: Technical/Operations
Topic: Belly Cameras Essential Equipment?
Replies: 29
Views: 3451

RE: Belly Cameras Essential Equipment?

The camera issue has been bouncing around the FAA and they are well on their way to putting video in the cockpit with the voice recorder (the Egypt Air crash left too many questions). They also want a cabin camera to view the cockpit door area and external cameras to monitor aircraft configuration. ...

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by Airgypsy
Sun Dec 11, 2005 9:20 am
Forum: Technical/Operations
Topic: Lifting Lugs On A320 Wings
Replies: 40
Views: 10769

RE: Lifting Lugs On A320 Wings

Wing mate and demate are a maintenance procedures that few mechanics in the airlines ever see. Quite common in business aviation. They put it together, it comes apart. USAir had a 737-300 wing replaced back in the late 80s. Got hit by a Cessna 310. Boeing did the work. As maintainers it is a good id...

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by Airgypsy
Sun Dec 11, 2005 8:46 am
Forum: Technical/Operations
Topic: Hypergolic Fuels
Replies: 8
Views: 3671

RE: Hypergolic Fuels

Wasn't some of that leathal stuff the German rocket plane used, was it? TPE/TPC?

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by Airgypsy
Sat Dec 10, 2005 12:21 pm
Forum: Technical/Operations
Topic: Innovations That Could Alter The Aviation Industry
Replies: 58
Views: 5852

RE: Innovations That Could Alter The Aviation Industry

NOW THAT was a great idea. Self loading cargo. I suppose we've all experienced the remote gate transport that carries the plane load of people from the terminal to a "remote" gate. Now just stretch a little further to a 747 with a full width loading system where the passengers are preloaded into a "...

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by Airgypsy
Mon Dec 05, 2005 3:01 am
Forum: Technical/Operations
Topic: C-40A Main Deck Cargo Door Operating Sequence
Replies: 7
Views: 5340

RE: C-40A Main Deck Cargo Door Operating Sequence

Another 737 Combi! Real cool, thanks for the picture.

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by Airgypsy
Mon Dec 05, 2005 2:58 am
Forum: Technical/Operations
Topic: Reverse Thrust As Opposed To Tug
Replies: 22
Views: 4365

RE: Reverse Thrust As Opposed To Tug

Powerbacks were first approved at Atlanta for eastern airlines. It is an airport thing. Tail mounted engines work best. <acronym title="Air Madagascar">MD</acronym>-80, DC-9, RJs, etc. Cautions are exhaust ingestion and compressor stagnation due to elevated temps. The Feds view it there must be room...

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by Airgypsy
Mon Dec 05, 2005 2:46 am
Forum: Technical/Operations
Topic: Rattling CFM56's?
Replies: 30
Views: 8620

RE: Rattling CFM56's?

I must have missed something in the past few years away from the airlines. Last I knew, <acronym title="Trans Asia Airways (Taiwan)">GE</acronym> did a mod that eliminated (or reduced) mid-span shroud contact (clacking) because of wear to the hard coat where they meet. Something like some rubber blo...

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by Airgypsy
Wed Nov 30, 2005 12:42 pm
Forum: Technical/Operations
Topic: WHOOP-WHOOP Sound On Engine Start UP
Replies: 12
Views: 15686

RE: WHOOP-WHOOP Sound On Engine Start UP

The igniters firing. Worked <acronym title="Air Madagascar">MD</acronym>-80s for years. The flash units on cameras work just the same and as you listen closely they will produce an very good imitation of an exciter box charging. Unlike the camera flash, the exciter box has an air gap trigger. When t...

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by Airgypsy
Mon Nov 28, 2005 12:26 pm
Forum: Technical/Operations
Topic: Compressor Surge
Replies: 19
Views: 4308

RE: Compressor Surge

"Passengers reported seeing flames from the engine exhaust when moving away from the gate." I told them to have the people up front turn around and see the flames coming out of the inlet. When the EPA mandated reduction of "smoke" from aircraft exhaust the Pratts got an instant reputation for belchi...

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by Airgypsy
Mon Nov 28, 2005 11:57 am
Forum: Technical/Operations
Topic: JT-8D For Supersonic Business Jet!
Replies: 29
Views: 5200

RE: JT-8D For Supersonic Business Jet!

Sports fans! The JT8d would make a wonderful supersonic engine after the afore mentioned mods about inlet temperatures. The venerable J-75 (same engine family) is still driving supersonic and subsonic aircraft around the skies. The J-75 (15.5K/lbs no burner) could get to 1.1 before the compressor st...

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by Airgypsy
Fri Nov 25, 2005 10:35 am
Forum: Technical/Operations
Topic: Stick It - Anyone Use This Product
Replies: 5
Views: 2804

RE: Stick It - Anyone Use This Product

And here I though that semi-dried red hydraulic fluid was the best. Off in search of "Stick It". The question is: will it hold against rotation as well as duct taping the nut to your finger? I'll look for it but a tip from a guy with BIG fingers, I use all manner of short, long, and curved hemostats...

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by Airgypsy
Thu Nov 17, 2005 11:02 am
Forum: Technical/Operations
Topic: Personal Equipment On Line/Major Mx
Replies: 34
Views: 4880

RE: Personal Equipment On Line/Major Mx

I carried an electricians line belt and pouch with dykes, duck bills, safety wire pliers, safety wire, 1/4 ratchet, set of small snap on 1/4 drives on a rail, Apex driver with a film can of tips, some open/box end wrenches 3/8 to 9/16, a 6in cresent wrench, 3 cell mag light with halogen bulb (very s...

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by Airgypsy
Thu Nov 17, 2005 10:52 am
Forum: Technical/Operations
Topic: 28 VDC Ground Power & Soft Start
Replies: 7
Views: 7013

RE: 28 VDC Ground Power & Soft Start

The BAe-146 (RJ-85, etc...) has soft start to prevent the starter from breaking the starter pad off the gearbox (which they did). When I first worked on them, starting an engine sounded like a car crash immediately followed by a very fast crank up. Soft start saved the engines and the starters. The ...

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by Airgypsy
Wed Nov 09, 2005 11:43 am
Forum: Technical/Operations
Topic: Bleedless Engines... What Are They?
Replies: 25
Views: 12799

RE: Bleedless Engines... What Are They?

Gentlemen, Go back, way back to pistons. Aircraft were pressurized with very efficient compressors driven by shaft power of several varieties. Big advantage is they could be disengaged for operation when engine power was needed elsewhere. A combination of ram air and compressor would do nicely. Leak...

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by Airgypsy
Mon Oct 24, 2005 3:36 am
Forum: Technical/Operations
Topic: Replacement Of H-11 Bolts By Inconel 718 Bolts
Replies: 11
Views: 7948

RE: Replacement Of H-11 Bolts By Inconel 718 Bolts

There is a factor to consider in "weaker bolts". They lack the strength to hold their form under stress above their rating, but they will first, deform under overload rather than fracture and fail. The <acronym title="Carpatian Air Transport (Hungary)">KC</acronym>-135 had cracking problems with it ...

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by Airgypsy
Mon Oct 24, 2005 3:28 am
Forum: Technical/Operations
Topic: Relations Between Pilots And Mechanics.
Replies: 56
Views: 8039

RE: Relations Between Pilots And Mechanics.

There are no good answers and it is an ever changing environment. In the beginning, mechanics built and flew airplanes (Orville, Wilbur, and Glenn). Pilots that didn't wrench came into the system slowly. It was painfully apparant to crews how much work it was to maintain piston aircraft by the const...

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