Just Cruising Along.

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dfarrow
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Re: Just Cruising Along.

Post by dfarrow »

PS. Don't mention Specific Gravity ..... another layer of complexity ...
Short Haul always used 0.8 .....
Long Haul used the actual S.G. on the day ...so some days you needed more and some less in L. to get fuel wt .

And another thing .....
Jet A1 in Euro .... always . With a fuel freeze point [ FP ] of -47C .
US. Seem to remember that you could get JP-4 ? We were not allowed to use that [ more volatile ] .
BUT , US Jet A1 had a FP of only -41C .
Not so important for us as East bound from the West coast, we did not normally go to the high latitudes and it was is shorter flight time than West bound.
However Eastbound from Japan , Hong Kong , N. China it came into play . From Tokyo have been around the North tip of Novaya Zemla 550nm from NPole. With the Siberian high pressure system established in winter , and a long flight time ; problems could arise .
Once fuel temp got to within about 4degrees of FP , then action was needed . Books said descend into warmer air ... Siberian High gave Outside Air temps [ OAT ] of -61C to -65C or so . Problem was with Siberian High , if you descended it was into colder air ....... Inversion .
OK then climb into warmer air ,,,,, normally too heavy as you'd be into 'coffin corner' where low speed stall met high speed stall . Or someone else had already bagged the next level up !
Increase speed was last resort 0.01 Mach kept temp up by 1C [ I think ] , but buggered fuel reserves , and got too close to the guy in front whence you'd need to slow down [ Slow Busses normally ] .
Thus for me it was Bat out of H+++ until we got to European warmer air . Different Types/Engines had different resistance to the fuel gelling or ultimately freezing .
Witness our 777 doing an on airport , off runway landing a few years ago .

rgds dave f.

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Nigel H-J
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Re: Just Cruising Along.

Post by Nigel H-J »

Hi Dave, hope you had an enjoyable Christmas :xgrin: All that information you posted sent my brain into orbit!! :lol:
OK then climb into warmer air ,,,,, normally too heavy as you'd be into 'coffin corner' where low speed stall met high speed stall .
I had read in a book of a flight from London to Chicago on a British Airways 747 back in the 1990's and if I remember correctly there is a very fine line between a high speed and low speed stall something in the region of a few knots between the two depending on altitude so monitoring airspeed or rather Mach was extremely important.

I guess a lot of this was taken from manuals for the pilots but certainly shows the need for quick mental arithmetics something that I very much lack!! :hide:

Regards
Nigel.
I used to be an optimist but with age I am now a grumpy old pessimist.

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Chris Trott
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Re: Just Cruising Along.

Post by Chris Trott »

dfarrow wrote:
26 Dec 2019, 11:40
PS. Don't mention Specific Gravity ..... another layer of complexity ...
Short Haul always used 0.8 .....
Long Haul used the actual S.G. on the day ...so some days you needed more and some less in L. to get fuel wt .
Oh don't get me started on Specific Gravity. Beyond having to do the test on incoming loads of fuel as part of verifying what's coming off the transport truck (or pipeline) is actually what you requested and what the lab sheet says they tested, I used to fuel both Lufthansa and British Airways back from 2002-2004 at Denver International. They were the only ones on the entire airfield that not only wanted to know specific gravity (in kg/l no less), but they wanted to know what is was on THE FUEL GOING IN THE PLANE. As such, we had to run 2 sumps and 2 SG tests per flight, one when we started fueling, and another about half way through so they could do whatever loading calculations they needed. While I know they were trying to maximize payload by minimizing fuel uplift, with as much fuel as we moved through the system each day (over a million gallons) they wouldn't let us use the SG calculated at the Fuel Farm that day. It *had* to be done at the plane and their Station Engineer *had* to be present when the test was done to verify it was done correctly.

dfarrow
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Re: Just Cruising Along.

Post by dfarrow »

Nigel , Seasons greetings to you and yours . Yep I'm surprised it's still in my brain as well .
Yes , just a few knots either way depending on weight . As a matter of course we'd bug the min speed and max speed on the ASI calculated from the manual , or it would be in colour [ yellow/red bands ] on TV screen a/c. When thinking about the next level up this would be factored , and if turbulent ; a climb might be delayed .
25+ yr old Tristars -1 , -100 , -50s were never a problem , as they had a brilliant wing , but ran out of puff from RB211-22bs .
76s and 744s with RB211-524G/Hs needed more care 'specially the 76 [ not a very good wing , designed quickly to counter threat of A300 ] .
Chris, big thank you , to you for getting us home safely . Never flew a Denver [ different fleet than mine at the time ] , but hitch hiked home from there on staff travel during your years . Think then BA 'n LH were only long haul International carriers at DEN.
Denver was always a difficul;t field . United used it as a performance barometer in a/c selection [ 'specially Stapleton ] . If an a/c could get full payload , and coastal range out of Denver it was ordered ! The elevation and summer temps really hit performance badly .
It was only the new field and modern a/c enabled International non stop routes from Denver.
Your measuring SG at a/c was mandated for long haul as below.
We were paying for fuel in L. [ I guess ] So for the big volumes and erroneous SG might mean we were paying for fuel we that was not delivered ....!
And the take off performance issues , payload Vs fuel . Often cannot take full fuel and full payload ... Sometimes offload freight , or pax , or dispatch to a nearer 'Fuel' destination , and replan in flight hoping to make up fuel [ short cuts , higher level ] and get home non-stop ..... Or a gas 'n go ... [ Not popular with pax , crew , or Ops ] .
And -41C jet fuel loaded cold [winter] , might give fuel freezing probs.
Sorry for your extra work , and water testing ! [ Probable extra cause on Viscount Santander crash , water not checked at bowser , few tonne of water in the fuel uplift ] . If no Eng. at station , then flt crew supervised water check from bowser .
In aviation , assume nothing , check ; and you might live to draw pension . And remember the first people at the scene of an accident are the flight crew ! Except on 747s when seats 1A and 1K cushioned the blow.

Brgds dave f.

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Nigel H-J
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Re: Just Cruising Along.

Post by Nigel H-J »

Many thanks for the information Dave, flying was not just about take-off cruise and landings, from your post there are many factors that us flight simmers are quite unaware of and even the developers for that matter, would give many simmers a headache if all that was programmed into the aircraft and have 'em running to the help desk saying their aircraft are falling out of the skies for no apparent reason!! :lol:

Going back to what Chris wrote about checking the fuel for water when I refuelled the Vulcans the ground crews never asked whether fuel/water had been checked and if I remember correctly water was heavier than the fuel and always settled to the bottom but please correct me if I am wrong as it was some 40 years ago and my memory is a bit faded. :worried:

Regards
Nigel.
I used to be an optimist but with age I am now a grumpy old pessimist.

dfarrow
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Re: Just Cruising Along.

Post by dfarrow »

Nigel , seems like we're both of an era .
Think some developers do..... Rick's Budgie [ 748 ] / Andover ; seem to remember that if fuel heaters not switched on B4 10000 or so ....Fuel jellos and Darts wind down .
Water in fuel ... know that Avgas /petrol water sinks to the bottom . I see that regularly as little doughnuts in bottom of tester in PA28s/C150s etc.
Trying to remember Jet A1 , 'cos it's basically paraffin . Think that the water mixes with the fuel and is not visible . Thus has to be sucked through a 'Shell' [ petrol ] tablet which changes colour if H2O present .
Think from home base , procedures are sufficiently robust that the checks are done first thing in the morn and members of you own 'family' are trusted .
However , out in ' Wogga Wogga ' where standards are less rigorous , then our own based , or travelling engineer would do them , last resort at '' off line '' stations is flight crew .

Likewise , de-icing . Don't know anything about the recent Fokker in 'Stan country . But we'd saved money and taken our ground engineer away from Moscow . Week later , taxiing out ; one of the 'gurls whose other 1/2 was a 'Nigel' [ pilot ] came up ...'' Shouldn't both wings be de-iced ? Not just one ? '' She saved the whole plane .
Shades of '' Wogga Wogga '' . Our own ground engineer replaced the next day .

rgds dave f.

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Nigel H-J
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Re: Just Cruising Along.

Post by Nigel H-J »

Nigel , seems like we're both of an era .
Think some developers do..... Rick's Budgie [ 748 ] / Andover ; seem to remember that if fuel heaters not switched on B4 10000 or so ....Fuel jellos and Darts wind down .
Think we must be Dave, though I am now 68 years old but my brain is still acting like a kid when I get on to flight and train sims!! :lol:

Now that has jogged my memory, yes Ricks' 748 certainly does that as I found out when cruising along above the Scottish Highlands and nowhere to put down! I think but not exactly certain that I had managed to restart midair but only by dropping lower down.

Water in fuel ... know that Avgas /petrol water sinks to the bottom .
That is where I'm getting confused, so long ago, we did use AVGAS for the Hastings, 1066 Sqdn came to Scampton after RAF Lindholme finished training rear crew nav radar bods for the Victors and Vulcans and were trained at Scampton. Went up to the cockpit one day to have a look around, and could imagine that this aircaft would have been very heavy to handle probably more so that the Lancaster due to its' thick wing cord and large vertical stabiliser. A slow old beast in the air. Some interesting facts that I had weaned from Google: Approach speeds: Pattern - 145kts. Finals - 135Kts. Glideslope = Threshold speed + 20kts. Threshold speed 100 to 105kts at 74000lb (max land wt). 110kts max overweight landing. If max range not required cruise at 173kts. 3145 Gals usuable fuel. 10000 ft cruise 225 gph.

Apparently from reading an old post from PPrune an ex-Hastings pilot did write that on landing the aircraft was very heavy on the controls. Around ninety knots and it was a handful with heavy controls. Three point landings were preferred in the early years. The captain called the power settings and the F/E, facing backwards in the rear righthand side of a very long flight deck looked out of his window at the starboard wheel, cutting the power when he judged the time was right! If it resulted in a bad landing he blamed the pilots or claimed the credit for a greaser! :lol:

BTW Dave, be interesting to know which airline(s) you flew with, was it with BA?

Regards
Nigel.
I used to be an optimist but with age I am now a grumpy old pessimist.

dfarrow
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Re: Just Cruising Along.

Post by dfarrow »

Nigel , just behind you pushing 67. And privileged still to see the seasons change from Wessex skies . FS yes ; not sure about trains !

As Dart was first mass production turbine , I guess they learned aboout fuel heaters . Every [ later ] turbines I've been on , have had Oil powered fuel heaters , and Fuel cooled oil coolers [ Naarfick English , sorry ]. Hot oil warms cold fuel , and cold fuel cools hot oil .

1066 Sqdn flew HASTINGS ! ........Who thought that one up ? You'll be telling me next that they had BATTLES in '39 !

Last saw one in '73 low over Naarfick , whilst working on the harvest , Birds Eye Beans , Peas , and bale carting whilst looking for first flying job. Sounds like good old Brit design , Trident similar non- handling pilot set power at request of handling pilot .....10600 , 10800 , 11200 , 10800 , HP RPM etc . And pulled power off when commanded . Mainly , as Peter McC will testify ; because you could not reach the throtts whilst hand flying 'em ... Ex North East a/c T1es , had cranked over throttles thus a revelation ; easy and a joy to handle your own power on approach . Mind you 't skipper Always got the credit for a good landing !

Yep , 'fraid so , Big Bad Airways for 36 yrs . 'Tho it was BEA when we joined , BA formed in Mar '74 . IIRC.

rgds dave f.

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Nigel H-J
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Re: Just Cruising Along.

Post by Nigel H-J »

1066 Sqdn flew HASTINGS ! ........Who thought that one up ? You'll be telling me next that they had BATTLES in '39 !
:lol: :lol:

Noooo!! 1066 was used because it of the name of the aircraft. In 1972 the Bomber Command Bombing School had become Strike Command Bombing School and in 1972 moved out of RAF Lindholme and came to Scampton.
Yep , 'fraid so , Big Bad Airways for 36 yrs . 'Tho it was BEA when we joined , BA formed in Mar '74 . IIRC.
Much preferred the BEA paints than the BA ones' that came in, especially on the Tridents, never looked good after that. :hide:

Regards
Nigel.
I used to be an optimist but with age I am now a grumpy old pessimist.

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Motormouse
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Re: Just Cruising Along.

Post by Motormouse »

For even more confusion, the oil to fuel heaters use the hydraulic oil, and are installed in wing tanks.....while fuel cooled oil coolers, are at the engine...know what you mean about eastern European / China fuel Davef, few years back I had to spend hours cleaning out APPL jelly from tanks of a private jet that had picked up bad fuel in China.

Ttfn

Pete
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a government specification.

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