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Post by Herman on Mar 24, 2015 0:39:34 GMT
I recently came across an article which referred to an aircraft accident report involving a South African Airways Boeing 707-344C in January 1968.
The article mentioned that the cause of the crash was....the crew used a flap retraction sequence on takeoff from a 707-344 series, which removed the flaps in larger increments than desireable for that stage of flight leading to a loss of lift at about 600ft. above ground level leading to the aircraft crashing.
I have had a look at our HJG 707-320 and 707-320C aircraft.... and yes there is a difference in flap setting increments between the two aircraft.
The flap increments for the 707-320 are 0- 10-20-30 etc. The flap increments for the 707-320C are 0- 15-25-30 etc.
I am assuming that the TO setting for the 707-320 is 20 or 30deg. and the 707-320C is 15 or 25 deg. but I have never been able to find any charts\graphs\procedure detailing what the settings should be.... so I am not quite understanding the error made by this particular crew.
The article did mention that it was the Captain's first flight on the 707-344C but had many hous on the 707-344.
Does any one have any information regarding these flap retraction sequences???
Herman
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Post by aerofoto - HJG Admin on Mar 24, 2015 2:35:18 GMT
I'm only "GUESSING" (and could be wrong) .... but .... the SAA B707-320C crew error could simply be that they might have "pulled the flaps" too soon, whilst still too low and slow, after T/O .... and which could, possibly, have resulted in a stall. The B707-320C wing (and power too) is "quite different" from that of the earlier -320 (I thought SAA operated -420's prior to -320B's/C's) .... so .... their flap settings are different too .... to the extent that pilots would probably need to be (I don't say they actually needed to be because I don't know for sure) trained/retrained and "type rated" in order to fly the B707-320B/C SERIES .... due to the differences between both aircraft versions. I "suppose" (guess) that because B707-120/138/320/420 SERIES could, and often did, T/O with a FLAP 30 setting .... if one was new to a later/heavier model and different version of the same aircraft type, but, inadvertantly used a procedure typical of the earlier/lighter model .... THEN .... it could, possibly, result in "a problem". The like of that has resulted in a number of nasty accidents in the past .... and among all sorts of aircraft types. FS-WISE .... There'e not much available, but, Matt ZAGORAN (I think his name is) did produce a basic flying guide for FS which contains extracts from "a B707 manual", but, if I remember correctly, it relates to the B707-120/B SERIES (only) .... and which had a different wing again from that of the -320/420 and -320B/C. STILL .... it could be used, in FS, as "a guide". Differences are compiled into the various HJG B707/720 FDE's, but, they are minor .... although minor enough to still make "a difference" .... for sure. Depending on virtual weight, field length, and airport altitude (first and foremost) .... flying the HJG B707-120 to 320/420 SERIES simulations (as well as those for each of the B720's too) I routinely use FLAP 30 anytime I perform a T/O at, or near, MGW .... and then 2-knotches of flap (roughly FLAP 20 or 25) for each of the later models .... along with a bit of Elevator Trim setting also. I think the ZAGORAN file is available at both FS.COM and AVSIM.COm under the following file name .... 707PERF.ZIP .... or simply search "ZAGORAN" and then sift through the displayed results .... and you'll be sure "WILL" find it  I've also emailed a document to you  Mark C AKL/NZ |
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Post by Herman on Mar 24, 2015 14:54:32 GMT
Thank you Mark for your response.
I do have a copy of Matt Zagoran's Boeing 707 Performance Manual which deals with various 707 types, however, it goes into a lot of detail about the actual operation of the aircraft from start up to shut down and everything in between, but no where is there any mention about the actual flap settings or sequence\schedule for take off or landing.
I do have a set of takeoff and landing charts, which I think were compiled by George Carty, which give detailed information on all the 707 series aircraft.
In these descriptions it also has the following information about takeoff flap selection.
For all 707's series up to and including the 707-320B....use 30 degrees.
For the 707-320B ADV. and 707-320C's there are two settings...14 deg. and 17.deg depending on the engine cowl flap configuration.
These flap selections are properly depicted and simulated in our HJG 707 models.
Now, getting back to the accident, I am still trying to figure out how all this co-relates to improper flap retraction with respect to the two different types of 707's.
I will do some homework and report back.
Herman
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Post by walterleo on Mar 24, 2015 19:28:57 GMT
Hi: One of the basic facts for safe flying is the Angle of Attac (AoA). Its important to know, that even with nose down the Angle of Attac can be in dangerous regions. The writer, test pilot (Cessna and Vought) William Langwische in his book "Stick and Rudder" eleborated extensivly about that concept. Strange thing, that US aviation did not follow his advices. So US airliners have all the sensors to meassure AoA, but dont display it. Russian and French aiplanes (not all not the A320, A330, 340)) have it. The US built airliners give speedbooklets to their pilots and show the attitude but not AoA. When Aeroflot bought 737 NGs Boing had to integrate an AoA indicator into the Primary Flight Display. So while flying at low speeds a pilot with an AoA indicator knows where he is and if its safe to retract some notch of flaps without turning pages of the speedbooklet.
The unhappy pilots of the MD-82 of Spanair would have acted differently if they had seen their actual unsafe AoA while trying to take off without slats and flaps. Another crew saved the day in a similar situation by not forcing the nose upwards.
Kind regards
Walter
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Post by aerofoto - HJG Admin on Mar 24, 2015 21:46:36 GMT
In the absence of such material that's where one .... the End User .... becomes the "TEST PILOT". George's information is always "VERY ACCURATE" .... so .... I'd recommend "relying upon it" I "always fly the B707/720 simulations at, or near, MGW .... meaning .... a long RWY, max permissable power (different for each engine type), and FLAP 30 for each of the early aircraft models .... OR .... 2 knotches of flap for the later aircraft models .... is desirable. Clicking the ASI opens a V-REF chart which displays the pre-calculated V-REF T/O speeds .... and clicking this chart then sets the ASI speed bugs in accordance with the pre-calculated V-REF. Precisely the same should be done prior to landing also. The recommended V-REF airspeeds are always calculated in accordance with the weight of these simulations .... and somewhere above and within the displayed V-REF range are the best flap retract/extend airspeeds. The best/recommended after T/O ROC differs in accordance with aircraft type (weight and power) and is presented within my "Basic Flying Guide" for each of the B707/720 SERIES on the ABOUT HJG AIRCRAFT forum page .... see "SECTION 3:' of my following posting .... tonymadgehjg.proboards.com/thread/1567/b707-panels-installation-handling-notesJust remember though .... although my above recommendations work fine in FS it's not based on actual realworld data It's been a while since I last flew any of the B707/720 SERIES simulations (just busy with other project developments) .... BUT .... maintaining an after-T/O ROC of around 1500-1800 FPM for most of the early turbojet powered B707/720 simulations .... and between 2000-2500 FPM for most of the later fanjet/turbofan powered simulations is desirable. I like to pull the first knotch of flap at/around 200 KIAS .... then the 2nd/final increment of flap at/around 215 KIAS, and which usually equates to an altitude of roughly 1200 FT - 2000 FT respectively .... depending upon the established ROC. "IF" using the HJG supplied B707 panel series then an audible warning indication will activate, auromatically, any time the simulation senses that airspeed exceeding the pre-set flap increment .... OR AGAIN .... if the simulation senses that airspeed getting too slow for a pre-set flap increment. These indications are, or should be, "slightly" different between most (not all though) of the B707/720 aircraft versions. On the basis of a fair bit of testing .... one will/should then be able to deternmine the best flap extend/retract airspeeds for each of these simulations. Getting back to the SAA accident .... and what you've presented of it (since 've not read the report) .... I suspect "some" of the key facts surrounding it that (may/possibly) need being born-in-mind are .... 1. The later B707-320B ADV and -320C are considerably "higher MGW" aircraft that the earlier B707-320 and -420 versions. 2. The "wing" of the earlier B707-320/-420 is quite different from that of the later B707-320B/-320B ADV and -320C versions .... and so are the associated "flap settings" too .... and those (flap settings) for the standard/early B707-320B differ from the -320B ADV and -320C also despite it having essentially the same/later wing design .... - B707-320/-420 312,000 LBS MGW (different wing .... from earlier models) - B707-320B 327,000 LBS MGW (modified/later wing design .... with half span LE flaps and revised trailing edge flap system and FLAP 17 increment) - B707-320B ADVANCED 335,000 LBS MGW (modified/later wing design .... same as -320B .... with full span LE edge flaps and further revised trailing edge flap system with FLAP 14 increment) - B707-320C 335,000 LBS MGW (modified/later wing design .... same as -320B ADV) I "SUSPECT" (and I could be completely wrong .... because I'm not B707 certified or a pilot either) that "IF" a crew member, whom was familiar with the earlier and "lighter" -320/-420 version, after transitioning to the later/"heavier" -320B ADV or -320C. might (inadvertantly) have begun flap retrction in accordance with a B707-320/420 schedule .... THEN .... that, could, possibly, result in a stall, and subsequent loss of the aircraft if altitude and airspeed weren't in their favour, I "suspect" the key to understanding this particular accident "might" be dependent upon understanding the differences between B707 wings, flap systems (and the associated aerodynamics), and aircraft weights, and how each of these factors inter-relate. Really needs one of our community based pilots to provide "a better/more technical aoppraisal (if they're willing) than I can offer Mark C AKL/NZ |
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Post by Herman on Mar 25, 2015 0:51:03 GMT
Thank you Mark for your continued interest and your contributions to this issue.
I have been able to find the official report of this accident on the internet and your observations are basically correct.
Below is a sort of condensed and shortened version of the reports finding as to the probable cause of this accident and it also explains the flap retraction issue that I was trying to understand. Because at the time this aircraft was not equipped with a flight data recorder nor was it required, there are a few speculative assumptions.
The aircraft involved was a newly acquired Boeing 707-320C. It was both the Captain's and First Officer's first flight on this type, but had plenty of experience on the 707-320 and 707-320B.
The aircraft was fairly light (below Max landing Weight) as the next leg of the flight was short.
Flaps Up was probably selected at 400ft. AGL .The minimum height for this model is 700ft AGL.... but in the 707-320\320B flaps are reduced from 30 to 20 deg. at 400ft AGL whereas on the 707-320C flaps are raised from 14 deg. to 0 deg. at 700ft AGL.
Premature selection of flaps up at V2 + 10 knts with a reduction of power to climb power would cause the nose of the aircraft to lower with a resulting loss of altitude.
It can be assumed that there would be some difference in speed of the aircraft between 400ft AGL and 700ft. AGL.
Other possible contributing factors are mentioned in the Accident Report but I won't bring them up because there are many.
If anyone is interested, here is the link for the Report....www.caa.co.za
Herman
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Post by quintinc on May 16, 2024 16:46:16 GMT
Hello Herman and All,
Did you ever get more information on the flap retraction on the various 707 320, 320B and 320C variants.
Specifically:
707 320/320B Flaps retracted from 30deg to 20 deg at 400 feet
1. At what speed in relation to V2 would this be done?
2. When/at what speed are they retracted from 20deg to zero?
707 320C Flaps are retracted from 14deg to 0 deg at 700 feet
1. At what speed in relation to V2 would this be done?
Background:
I am an aviation safety writer and have been asked to write a story on the South African Airways B707-320C take-off accident at Windhoek.
Any information would be most helpful.
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Post by aerofoto - HJG Admin on May 16, 2024 22:29:52 GMT
I'd assume flap retractions speeds would be based on aircraft weight and altitude after TO .... just as TO V-speeds are similarly dictated by weight and Flap settings too (plus airport altitude, ambient air temperature, and available RWY length as well(. Without knowing the SAA accident aircraft's actual weight ("fairly light" could be anything over a very wide margin) .... and environmental parameters associated with the day, and locality, of that accident too then it's probably hard to answer the question  .... at least reliably Just one comment though .... A "FLAP 30" TO setting is only relevant to the early "B707-120/-120B/-120BF/-138/-138B/-220/-320/-320F/-420 and B720-A/-AF/-B/and BF ONLY" (at least 3 different wing design changes were applied during development and among just this B707 group alone) but not to any of the other later B707 versions. For the later "B707-320B (early)/-320B SCD/-320B ADV/-320C/and -700 ONLY" (to which different wing design were again applied) no more than a "FLAP 23" setting is normal for TO even .... "when operating at/near MGW". Mark C AKL/NZ |
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Post by joscyriacv2 on May 18, 2024 3:50:13 GMT
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Post by aerofoto - HJG Admin on May 18, 2024 8:43:51 GMT
I couldn't view/open your link "CYRIAC" but found the following couple of references in regard to this same .... SOUTH AFRICAN AIRWAYS B707-320C ZS-EUW, WINDHOEK, NAMIBIA, APRIL 20TH 1968aviation-safety.net/asndb/331864WIKIPEDIA relates to this same accident as follows .... en.wikipedia.org/wiki/South_African_Airways_Flight_228.... and stating the following in particular .... Captain had (apparently) accumulated some 4,600 HRS total flying time on the B707 (presumably the B707-320 which preceded the -320B and -320C), but, only 1 hour on the B707-320C. Cited possible causal factors are stated as follows .... Using the HJG B707-320C simulations: Retracting FLAP 23 at too low an altitude, and too low an airspeed too, following TO might absolutely ensure one goes "DOWN" (big time) rather than "UP" too as a result of the ballooning effect common to some early aircraft types during flap retraction/extension Mark C AKL/NZ |
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Post by joscyriacv2 on May 18, 2024 10:49:38 GMT
Hi Mark. Please check the 3rd link in the references section. Cyriac |
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Post by aerofoto - HJG Admin on May 19, 2024 3:51:33 GMT
Gonna digress a bit once again (I don't do it often) .... in relation to the following 2 PAN AM B707 accidents of 1973 and 1974. As "seems to" have occurred with the SAA -320C: The first of these accidents relates to a B707-320B which also plummeted back to earth, and from a few hundred FT, immediately following TO .... although the "actual cause" of this particular accident remains "UNKNOWN/UNPROVEN" to this day. It's an accident I've never forgotten since its occurrence for whatever reason .... and despite being young at the time .... other than to suggest certain events/incidents are probably sufficiently impacting as to become indelibly impressed into one's memory On the evening of July 22nd 1973, B707-321B N417PA "Clipper Winged Racer", was operating FLT PA 816 from Auckland/NZ to San Francisco/USA .... via Pape'ete/Tahiti. Upon arrival at their Pape'ete transit the crew reported a "windshield crack" (not described in any further detail per any available historic media referencing), however, upon being authorized by PAN AM HQ, in New York, the flight was cleared to proceed on to San Francisco .... though operating at a lower altitude than normal .... and for which additional fuel was loaded aboard the aircraft. At around 22:04 (Tahiti time) the aircraft was cleared for TO and departed Pape'ete. Shortly after becoming airborne, and from an altitude of approximately 300 FT only, eye witnesses reported "it banked steeply left and then plummeted into the sea" .... within 1.6 KM of the Pape'ete shoreline (very deep water over that reef and from my own vast experience/knowledge of Tahiti). Aboard the aircraft were 76 POB .... of which there were initially 2 survivors only .... one of whom (a Cabin Attendant) passed away shortly after being rescued. There's no shortage of convincing theories as to why/how this accident possibly occurred, but, none have yet been proven .... and whatever now remains of this aircraft continues to rest on the sea bed today, undisturbed, and within hundreds of yards of the reef at Pape'ete/Tahiti .... despite deep water retrieval equipment having being sent to Tahiti, during 2007, in order to recover wreckage of the AIR MO'OREA TWIN OTTER which crashed into the sea (equally deep water over that reef too) immediately upon departing Mo'orea (Tahiti Nui's sister island) less than 19 KM across the channel between both islands. The following are the best references I can locate in relation to this particular accident .... PAN AMERICAN WORLD AIRWAYS, B707-321B, N417PA, PAPE'ETE, TAHITI, JULLY 22ND 1973aviation-safety.net/asndb/330135en.wikipedia.org/wiki/Pan_Am_Flight_816www.baaa-acro.com/crash/crash-boeing-707-321b-papeete-78-killedlostmediawiki.com/Pan_Am_Flight_816_(lost_flight_recorders_of_fatal_passenger_aircraft_crash;_1973)Another major PAN AM B707 accident also occurred in the Pacific during 1974 .... although this particular calamity occurred through "entirely different" circumstances than the above referenced SAA and PAA accidents and its causal factors were quickly proven following investigations. On the evening of January 30th 1974, B707-321B N454PA "Clipper Radiant", was operating FLT PA 806 from Auckland/NZ to Los Angeles/USA .... via both Pago Pago/American Samoa and Honolulu/Hawaii .... and with "a very highly experienced crew". The aircraft departed Auckland at 20:14 with 101 POB .... one of whom was a student of my then teacher (a Catholic Christian Brother). The flight proceeded uneventfully across the Pacific to Pago Pago (actually pronounced "PANGO PANGO"). Weather conditions upon arrival there were "moderate" .... with heavy rain showers and occasional strong wind gusts. These conditions not only had a destabilizing influence upon the aircraft's approach to landing .... but .... the approach was also conducted within what seasoned professional crew (later) described being a "Black Hole" type scenario. Adversely impacted by wind gusts resulting in corresponding altitude and airspeed fluctuations throughout the final approach to landing .... and with RWY visibility also being obscured by the intensity of intermittent rain showers at the time too, it was, according to the evidence of 1 of 4 surviving PAX, "a fairly bumpy ride in" and right up to the moment of this accident occurring. At a critical moment during final stages of the approach to landing a combination of weather influences caused the aircraft to suddenly shear before the crew became situationally aware .... then basically pan cake into terrain some 3,000 FT short of the RWY threshold. Although damage sustained by the aircraft was significant the impact was actually described as being no more severe than that resulting from a "HARD LANDING". PAN AMERICAN WORLD AIRWAYS, B707-321B, N454PA, PAGO PAGO, AMERICAN SAMO, JANUARY 30TH 1974en.wikipedia.org/wiki/Pan_Am_Flight_806aviation-safety.net/asndb/329962VIDEO ANALYSIS/APPROACH TO LANDING/PA 806/30/01/74youtu.be/zVQQUWUTzE4?t=34MArk C AKL/NZ |
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.... at least reliably 
