Quoting Mastropiero (Reply 41): I am sure there is a very logical explanation for this, and once you tell me what it is I know I´ll feel really stupid but right now I can´t figure it out....

Just ask,no need to feel stupid,We all are learning every day  

As explained above,Applying brakes while the Aircraft is rolling back can cause a tilt backwards hence its reccommended that Fwd thrust be used to slow & stop the aft mvmt.

regds
MEL

Quoting HAWK21M (Reply 50): Applying brakes while the Aircraft is rolling back can cause a tilt backwards hence its reccommended that Fwd thrust be used to slow & stop the aft mvmt. regds MEL

Yes and why would the 27 tip and sit on its tail during refueling if the aft stairs were not down? Then if they were down and did not tip after you put them up? Would it not still be tail heavy even after the bags and cargo was loaded on to the A/C?

Quoting TWAL1011727 (Reply 29): Continental did a powerback with a B737-200 at MLB one time, so most A/C with reversers can do it.

The Air Florida 737 that crashed into the Potomac River in Washington, D.C. used reverse thrust to push back as well. Also as a child I was on an Eastern L-1011 from MCO to PIA used reverse thrust to pushback as well.

I'd say that some of the tridents having a fourth engine would probably be one of the quirkier design features.


Blackbird

Quoting HaveBlue (Reply 52): The Air Florida 737 that crashed into the Potomac River in Washington, D.C. used reverse thrust to push back as well. Also as a child I was on an Eastern L-1011 from MCO to PIA used reverse thrust to pushback as well.

That was supposed to be MCO to PIT.

Quoting Tdscanuck (Reply 46): I was under the impression that none of the CRJ's or tail-mounted E-jets were certified for powerbacks. Can somebody confirm?

That is what I figured you were talking about, I got as close as I was going to get with the F-28, and only because they made the F-100 out of it.
I was thinking about "major airline" airliners here, not the little regional ones, but they are kinda cute. Like the BAE146/RJ-85 we always call those the "Smurf Jet".            

Quoting JoseKMLB (Reply 51): Yes and why would the 27 tip and sit on its tail during refueling if the aft stairs were not down? Then if they were down and did not tip after you put them up? Would it not still be tail heavy even after the bags and cargo was loaded on to the A/C?

Fill #1&3 fuel tanks up and not #2 with the air-stair up, and it will sit right on it's tail. Everyone from fueler's, bag handlers, and mechanics that dealt with that airplane knew it was tail heavy. But as insurance the air-stair is left down during fueling, loading, and boarding. The forward bag bin was larger, and held more, more pax forward of the wing than aft, things like that.

Quoting HaveBlue (Reply 52): The Air Florida 737 that crashed into the Potomac River in Washington, D.C. used reverse thrust to push back as well.

This was actually one of the contributing factors ... the powerback sucked a lot of ice/snow into the engine; this was one of the reasons for the incorrect engine instrument readings.

- litz

Quoting JoseKMLB (Reply 51): Yes and why would the 27 tip and sit on its tail during refueling if the aft stairs were not down

I was talking about B732.

Quoting Litz (Reply 56): This was actually one of the contributing factors ... the powerback sucked a lot of ice/snow into the engine; this was one of the reasons for the incorrect engine instrument readings.

The P1 EPR ports in the nose dome if Iced will give a much higher false EPR [p7/p1].

regds
MEL

Quoting FLY2HMO (Reply 47): I thought the Beta setting was just for putting the props on discing, and reverse thrust was moving beyond the Beta point. Or is Beta=reverse thrust?

Beta control is used for reverse. Early turboprops had ground fine pitch settings without beta control.

Quoting Cpd (Reply 38): Not so unique - it was to go on Concorde 002 as well (Decca Omnitrack moving map display). It never did get used as far as I knew.

Interesting. INS development scuppered the idea presumably. So I believe the Trident was the only production airliner to have mechanical moving map installed.

The DC-3 never seized to amaze me.
It first flew on Dec.22 1935, more than 73 yers ago, and is still going on:

There were a few conversions that I bet the original design-team never thought of:

A modern turbine-conversion
View Large View Medium

Photo © Thai Spotters


-also a float-plane that was never commercially used
View Large View Medium

Photo © Chris Markerson

-a glider:


-and probably a few others that I can't even think of right now...


Scooter01   

Quoting HAWK21M (Reply 57): I was talking about B732.

Yeah Mel I know you were I was just asking a question about the 27 and why would it tip if the stairs were not down during loading and fueling but after all is said and done when putting the stairs up the plane would be still tail heavy and not tip. Just a question I wanted to know when people would tell you to make sure the stairs were down but after you put them up it would not tip. Do you get what I mean lol?

Quoting Max Q (Reply 18): On the MD80 they were not able to mount the compass above the glareshield due to excessive deviation error. Solution, mount it behind the First Officers head ! then mount two mirrors above the glareshield and tell Pilots to swivel them so by looking into one then reflecting that image into the other you could 'at a glance' tell your compass heading. Not that we look at the mag compass very much but still !

It was evidently the same on the DC-8, and was certainly the same on the DC-9. I understand it was perpetuated into the DC-10 program, but I can't verify that personally. I actually got to fly an MD-80 using the standby compass for heading reference once, and am pleased it was day and VMC.

Quoting HAWK21M (Reply 19): Amazing.what caused it.

The Douglas guys I spoke with back in the DC-9 era said it was due to issues with the proximity to the annunciator panel and its impact on accuracy of the standby compass. I don't have documentation to this effect, but had quite a bit of contact with their engineers and systems gurus and they always seemed to have good information. That's the best I can offer.

Quoting HAWK21M (Reply 39): The Pilot needs to remember to stop a powerback on a B732 with Fwd thrust & not the Brakes.

That's the same on other aircraft I have powered back as well.

Quoting PGNCS (Reply 62): I understand it was perpetuated into the DC-10 program, but I can't verify that personally.

I'm not sure if you mean the problems followed along into the DC-10 program, but it's mag compass was mounted right out in front, plain sight. Well you could flip it up out of your way if you wanted to. Swung quite a few compasses on DC-10s, I don't recall hearing about any accuracy problems from structural or electronic interference.

Quoting JoseKMLB (Reply 61): Just a question I wanted to know when people would tell you to make sure the stairs were down but after you put them up it would not tip

I've not worked the B727,but I'm surprised if thats the case.In fact noticed a B727 being refuelled last week & the Aft stair was retracted.

Quoting PGNCS (Reply 62): The Douglas guys I spoke with back in the DC-9 era said it was due to issues with the proximity to the annunciator panel and its impact on accuracy of the standby compass.

Whats in the annunciator panel thats contributing to the magnetic drift?

regds
MEL...

Quoting Ex52tech (Reply 63): Quoting PGNCS (Reply 62): I understand it was perpetuated into the DC-10 program, but I can't verify that personally. I'm not sure if you mean the problems followed along into the DC-10 program, but it's mag compass was mounted right out in front, plain sight. Well you could flip it up out of your way if you wanted to. Swung quite a few compasses on DC-10s, I don't recall hearing about any accuracy problems from structural or electronic interference.

Thanks, Ex52tech, I stand corrected. I had been told that the DC-10 compass was mounted similarly, but that is obviously bad information. That's why I made the disclaimer that I couldn't personally verify that information. Thanks for the info!  

I am not, by the way, claiming there is any significant interference with the compass on the DC-9/MD-80 fleet there; I am claiming that that is what the guys I talked to at Douglas when I was heavily involved with the DC-9 program claimed. For further third party information that I can't verify (if anyone can clarify, please join in) there was evidently a difference between power on and off in the annuniciator panel that amounted to a slight (but practically negligible) difference in compass readings. Evidently the FAA down in Long Beach interpreted certification regulations differently than everyone else and wouldn't allow the compass there which is where I'm told it was originally conceived to be, and where it is on pretty much every other airliner brand of I have ever flown. Like I said, this seems remotely plausible to me, but I don't have specifics as this story was related by Douglas staff to me several times either in person or over the phone. The Douglas guys totally blamed the FAA for an implausible interpretation of regs forcing them do something seemingly ridiculous. If in fact that is a true story, I would personally like to meet the FAA genius who thought this was a better idea, as I have actually had to fly the airplane with the thing, and it is far more difficult than you can imagine if you haven't done it yourself. It's my single least favorite piece of engineering in the aircraft.

Quoting HAWK21M (Reply 64): Quoting PGNCS (Reply 62): The Douglas guys I spoke with back in the DC-9 era said it was due to issues with the proximity to the annunciator panel and its impact on accuracy of the standby compass. Whats in the annunciator panel thats contributing to the magnetic drift?

According to the people at Douglas I spoke with it was an issue of slightly variable compass readings depending on whether power was on or off to the annunciator panel, and because it was felt that depending on what combination of annunciator lights were on or off that the compass accuracy could be degraded. I honestly have no idea if that is true or not (see above), but I relate the story from the most authoritative source I know of. If any engineers from Douglas know the real story, please let us know, because this is a very odd piece of engineering and those of us with an interest in the aircraft would love to know the whole truth.

Quoting Jetlagged (Reply 58): Beta control is used for reverse. Early turboprops had ground fine pitch settings without beta control.

Ah, gotcha.

[Edited 2009-02-02 10:56:59]

Quoting Vasu (Reply 24): Is the DC-9 the only airliner that can reverse from the gate without needing pushback?

Was on an EA 757 from ATL to EWR and we reversed out of the gate as well...Very Loud!

Quoting JohnClipper (Reply 67): Was on an EA 757 from ATL to EWR and we reversed out of the gate as well...Very Loud!

I heard that Eastern used Powerbacks frequently on their B757s.Although its not permitted as per our SOPs for our B757s.
regds
MEL

Quoting HAWK21M (Reply 68): heard that Eastern used Powerbacks frequently on their B757s

I heard that too, and something says the L1011 too, although I think I am wrong about that.

Another quirk, the Fokker F100 and F70 don't require flaps for take off.

Quoting Starlionblue (Reply 21): IIRC the A310 only has inboard ailerons, using spoilers for extra control at low speeds. A little bit quirky at least.

The A300-600 doesn't have outboard ailerons either.

I wouldn't call it a quirk but I think its pretty unique how when Airbus planes (Modern non A300 and A310) are first turned on (IE not engine start up but from a cold-dead power up), the cabin doesn't receive any air for about two minutes as the air is diverted for avionics cooling. And the avionics cooling vent after landing pushes out a lot of air too.

Quoting AC320tech (Reply 69): Another quirk, the Fokker F100 and F70 don't require flaps for take off.

I think I heard somewhere that the A300/310 can do the same.

While on the subject of quirky flaps, how about McDonnell Douglas' dial-a-flap system?

Quoting Scooter01 (Reply 30): You mean like this one? http://www.youtube.com/watch?v=tUdVR...jHqvA

I'm suprised that in the 1940s-1950s they would be that risque
having a woman remove her blouse like that in this video.
She looked like she was wearing a sheer nightie and she looked fine at it too.

KD

Quoting BMI727 (Reply 70): Quoting AC320tech (Reply 69): Another quirk, the Fokker F100 and F70 don't require flaps for take off. I think I heard somewhere that the A300/310 can do the same.

IIRC at certain weights they don't need slats.

Quoting TWAL1011727 (Reply 71): I'm suprised that in the 1940s-1950s they would be that risque having a woman remove her blouse like that in this video.

Not that I'm an expert but the mores of the 40s and 50s were far less strict than, say, the 1900s.

Quoting TWAL1011727 (Reply 71): I'm suprised that in the 1940s-1950s they would be that risque having a woman remove her blouse like that in this video. She looked like she was wearing a sheer nightie and she looked fine at it too.

Not sure she was taking her blouse off, more like a nightgown. Still, I'll watch it a few more times to make sure.  

Actually Hollywood films of the era showed equally "racy" scenes on occasion.

Interesting to see how the cabin was converted to sleeper configuration.

Quoting BMI727 (Reply 70): While on the subject of quirky flaps, how about McDonnell Douglas' dial-a-flap system?

Pardon my ignorance, but what exactly is this and how is it different from other flap systems?

Tom

Quoting Scooter01 (Reply 60): The DC-3 never seized to amaze me. It first flew on Dec.22 1935, more than 73 yers ago, and is still going on: There were a few conversions that I bet the original design-team never thought of: A modern turbine-conversion View Large View Medium Photo © Thai Spotters

Now that you mention it, there was a *three* engine turboprop conversion of a DC-3 in 1977:


View Large View Medium

Photo © Eggert Norðdahl

Quoting Phatty3374 (Reply 74): Quoting BMI727 (Reply 70): While on the subject of quirky flaps, how about McDonnell Douglas' dial-a-flap system? Pardon my ignorance, but what exactly is this and how is it different from other flap systems?

https://www.airliners.net/aviation-forums/tech_ops/read.main/180051/

It basically allows you to pick any flap position over a fairly large range, rather than just a few predefined detents.

Tom.

My favourite quirk is on the 767: during gear transit there apparently isn't quite enough room within the wing volume above the trunnion area for the folding struts to pass, which requires a small door in the top of the wing to pop open slightly (couple of inches?) spoiler like for a few seconds to allow the struts/joints to transit. When the gear is fully extended or retracted presumably this door is sprung closed ?

Quoting DH106 (Reply 77): When the gear is fully extended or retracted presumably this door is sprung closed ?

Quite. It is closed when the gear is retraced or fully extended. It only opens in a certain range of travel. I have always found this to be a very elegant solution.

Quoting DH106 (Reply 77): which requires a small door in the top of the wing to pop open

It would be interesting to hear the story that prompted this mod.
regds
MEL

Quoting HAWK21M (Reply 79): Quoting DH106 (Reply 77): which requires a small door in the top of the wing to pop open It would be interesting to hear the story that prompted this mod.

"Dude, the gear has to be yay long or the butt will slam the ground when she rotate."
"Well duuuude, if it's that long it won't fit in the wing while retracting."
"Dude, we could make the wing thicker."
"Dude, that seems like a lot of work. How about a little door instead?"
"Totally rad dude. All this thinking is stressing me out, like. Let's go grind some railings."
"Totally."

[Edited 2009-02-05 05:21:36]

[Edited 2009-02-05 05:22:13]

Quoting Starlionblue (Reply 80):

Tell me the truth.....You left out the discussion in the Pub part deliberitly   

On a serious note.....Was wondering if a damage during production prompted this mod.

regds
MEL.

Quoting DH106 (Reply 77): My favourite quirk is on the 767: during gear transit there apparently isn't quite enough room within the wing volume above the trunnion area for the folding struts to pass, which requires a small door in the top of the wing to pop open slightly (couple of inches?) spoiler like for a few seconds to allow the struts/joints to transit. When the gear is fully extended or retracted presumably this door is sprung closed ?

The C-17 has a similar "quirk". When the gear is down small doors open in the MLG fairing to allow gear extension. These doors close when the gear is retracted.


View Large View Medium

Photo © André Inácio

Quoting 474218 (Reply 82): The C-17 has a similar "quirk".

Educational.
Any pic of the B767 with that panel.
regds
MEL

Quoting HAWK21M (Reply 83): Any pic of the B767 with that panel.

I think I found it. I think it's the rectangular panel in the lower-left corner of this shot:


View Large View Medium

Photo © York Schreiber


And if I'm not mistaken, I think it's visible in these two shots:

View Large View Medium Photo © Ivan Coninx - Brussels Aviation Photography

View Large View Medium Photo © Stefan Sjogren - Stockholm Arlanda Photography

2H4

Quoting 2H4 (Reply 84): I think I found it. I think it's the rectangular panel in the lower-left corner of this shot

Quoting 2H4 (Reply 84): And if I'm not mistaken, I think it's visible in these two shots:

Yep - good pictures, well caught !
It's very difficult to see the panel open as you have to catch the 767 "from behind" (   !) with the gear legs mid transit.

Quoting 2H4 (Reply 84):

Interestingly the wing walk area goes over that panel.
regds
MEL.

Quoting HAWK21M (Reply 83): Any pic of the B767 with that panel.

So is that on all 767 versions? I've only flown on the 764 and, I may be mistaken, but I don't remember seeing something like that. The 764 has a totally different MLG than the other versions after all AFAIK.   

Don't SAHA Air's 707s have a double window toward the back of the fuselage? That's another weird feature of their planes.

Quoting UltimateDelta (Reply 88): Don't SAHA Air's 707s have a double window toward the back of the fuselage? That's another weird feature of their planes.

Yes. It was to facilitate observation of aerial refuelling activities when the aircraft were used by the Iranian Air Force as tankers. Second photo below shows one still in the tanker role. The double window is visible in both, 5th window from the rear.

View Large View Medium Photo © Iman - Iranian Spotters

View Large View Medium Photo © Iman - Iranian Spotters

Nobody mentioned the IL-62,

It has a tail-strut/wheel to prevent the plane from ending up on it's tail during loading. The tail strut has to be retracted before takeoff otherwise the plane couldn't get into the air.


Blackbird

Quoting HAWK21M (Reply 83): Any pic of the B767 with that panel.

Here is another good picture from a previous thread on the topic.


View Large View Medium

Photo © Quinn Savit



https://www.airliners.net/aviation-forums/tech_ops/read.main/424/

Quoting Tdscanuck (Reply 76): t basically allows you to pick any flap position over a fairly large range, rather than just a few predefined detents.

Somebody is going to prove me wrong here, but here goes.........I am about 99% sure that Dial-a-flap was an option on the DC-10. I believe we had some that didn't have it, but it's been a while, so if anyone knows for sure pipe up.

Another thing that came to mind was the split slat/flap function. We in maintenance could operate the flaps and slats separately on the ground on the DC-10, but I am not sure if the crews were allowed to operate the slats or flaps separately in flight or not.

So let me know guys.

I think that is a Douglas 'thing'

Certainly on the MD 80 we operated the Slats and Flaps separately, although with the same handle, sounds confusing but you deployed slats only by moving the flap / slat handle to the first position then flaps were deployed as you selected more movement.

On retraction to raise the slats required moving a lever in a different direction as a safeguard from inadvertent retraction.

Quoting Max Q (Reply 93): On retraction to raise the slats required moving a lever in a different direction as a safeguard from inadvertent retraction.

Yeah, that is the same way the handle functons on a DC-10. You have to raise the slat handle while pushing down on the flap handle in order to retract the slats. What I was talking about is that you could actually seperate the two handles, and operate them seperately, by removing tab between the two levers that brought the slat lever along as you lowered the flaps beyond the first detent.

As I stated, I think that this was a function for maintenance only. I can not imagine the crew wanting to move the slats seperately beyond the first detent/takeoff slat only position, but it was just a question to see if you guys even had it in your flight manuals. I can not remember if you can even seperate the two levers on a DC-9 or not.

Quoting Mastropiero (Reply 45): Today, though, virtually no airliner has them.

Ok not today but "yesterday"   , the concorde had brakes in the nosewheel.

Quoting B777Neuss (Reply 95): Ok not today but "yesterday" , the concorde had brakes in the nosewheel.

Where?

http://www.concordesst.com/gear.html

I also know this source, but trust me, the concorde had.
In the documentary of ITVV the flight ingenieur talks about the front gear. I don't remember which buildup, brake either in the right wheel and antiskid in the left or vice versa.

I also heard of a 727 with CFM engines. Do somebody have pictures or more information about it?

The Lockheed L188 Electra and Navy P-3 based on the L188 seem to have a wider than usual cockpit with separate sets of throttles for the captain and first officer. Do any other aircraft have that type of design?

View Large View Medium Photo © Europix - AirTeamImages

View Large View Medium Photo © Mario Serrano

Quoting Viscount724 (Reply 98): The Lockheed L188 Electra and Navy P-3 based on the L188 seem to have a wider than usual cockpit with separate sets of throttles for the captain and first officer. Do any other aircraft have that type of design?

The Fokker F28 had this, and I have no clue why.