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Death of Flying Officer John Jack in Sabre Mk.4 XB647 at RAF Jever on 8Jul54
From Report by Accidents Investigation Branch (Civil Aviation)

JohnJack.jpg, 6125 bytes


1px-trans.gif, 43 bytesAccident to Sabre 4. XB.647 on 8.7.54

1.   Circumstances

1px-trans.gif, 43 bytesWhilst overshooting the airfield at R.A.F. Jever, Germany, the undercarriage
1px-trans.gif, 43 byteswas seen to retract but the dive brakes remained "OUT".   A climbing turn to port
1px-trans.gif, 43 byteswas then carried out at a low airspeed with the dive brakes still "OUT".   The
1px-trans.gif, 43 bytesaircraft climbed to about 1500ft. at the same time turning through 90°.   It was
1px-trans.gif, 43 bytesthen seen to flick rapidly, after which it continued to roll and lose height until
1px-trans.gif, 43 bytesit hit the ground.   The aircraft was destroyed and the pilot was killed.

2.   The Aircraft

1px-trans.gif, 43 bytesThe aircraft was built by Canadair Ltd. in September, 1953.   It had. flown
1px-trans.gif, 43 bytes46 hours since new.   The General electric J.47 turbo jet engine was installed
1px-trans.gif, 43 bytesduring construction and had run 46 hours since installation.   The maintenance
1px-trans.gif, 43 bytesrecords showed that the aircraft was serviceable when it took off.   The estimated
1px-trans.gif, 43 bytesall up weight at the time of the accident was about 13,000 lb. and the C. of G.
1px-trans.gif, 43 bytes24.9% m.a.c. (aft 1imit is 26.57% m.a.c.).

3.   The Pilot

1px-trans.gif, 43 bytesThe pilot, age 24, held an 'Average' flying assessment and his total flying
1px-trans.gif, 43 bytesexperience as first pilot in all types amounted to 277 hours.

1px-trans.gif, 43 bytesHis experience in the Sabre 4, was 64 hours.

4. The Weather

1px-trans.gif, 43 bytesThe weather at the time was fine, with excellent visibility and is not
1px-trans.gif, 43 bytesconsidered to have any bearing upon this accident.

5.   Investigation

1px-trans.gif, 43 bytesThe general disposition of the wreckage indicated a fairly slow speed impact.
1px-trans.gif, 43 bytesThe first point of impact was a large tree with the starboard wing tip, whilst the
1px-trans.gif, 43 bytesaircraft was ins nose down attitude.   The wreckage was slightly burnt by the
1px-trans.gif, 43 bytesimpact fire. The condition of the compressor and turbine was consistent with the
1px-trans.gif, 43 bytesengine rotating at high speed when impact with the ground occurred.   [See below]   The tailplane,
1px-trans.gif, 43 bytesrudder and aileron trim was approximately neutral.   There was no evidence of any
1px-trans.gif, 43 bytespre-impact structural failure of the airframe or malfunctioning of the flying
1px-trans.gif, 43 bytescontrols.   The undercarriage, flaps and air brakes were in the retracted position
1px-trans.gif, 43 byteswhen the aircraft struck the ground (witnesses state that the airbrakes were in
1px-trans.gif, 43 bytesthe "OUT" position in the early stages of the overshoot).   No useful evidence was
1px-trans.gif, 43 bytesgained from the damaged cockpit owing to the severe damage sustained to all
1px-trans.gif, 43 bytescontrols and switches.

6.   Observations

1px-trans.gif, 43 bytesThis accident happened, after a climb away from a practice overshoot in fine
1px-trans.gif, 43 bytesweather.   Several witnesses saw the aircraft with undercarriage and flaps
1px-trans.gif, 43 bytesretracted but with air brakes OUT.

1px-trans.gif, 43 bytesAccording to AP4503D (Pilot's Notes) para. 62 the aircraft is extremely
1px-trans.gif, 43 bytessensitive to "G", fractional amounts will produce a noticeable increase in the
1px-trans.gif, 43 bytesnormal stalling speed of approximately 110 knots.

1px-trans.gif, 43 bytesPower controls with artificial feel do not transmit air loads to the control
1px-trans.gif, 43 bytescolumn and in consequence the only warning of a stall being slight buffeting of
1px-trans.gif, 43 bytesthe airframe which occurs some 5 to 10 knots above the critical speed.   An aircraft
1px-trans.gif, 43 bytesin a turn with too low a power setting if not handled carefully could quickly drop
1px-trans.gif, 43 bytesa wing and roll either into or out of the turn, the rate of descent would be high
1px-trans.gif, 43 bytesand considerable height would be lost during recovery from the stall.

1px-trans.gif, 43 bytesWith the three position air brake control, pilots report that it is quite
1px-trans.gif, 43 bytespossible to place the switch in "NEUTRAL" when selecting air brakes "IN" and it
1px-trans.gif, 43 bytesis only when the aircraft fails to accelerate away at the recommended, power
1px-trans.gif, 43 bytessetting of 85/90% RPM for a light and clean aircraft that a check shows the switch
1px-trans.gif, 43 bytesset to NEUTRAL.   At this stage of events the drag caused by the extended air brakes
1px-trans.gif, 43 bytesat low power settings could reduce the aircraft's speed to a dangerously low figure,
1px-trans.gif, 43 bytesthe power controls would give no indication of an impending stall and the nose
1px-trans.gif, 43 bytestrim caused by too late an retraction of the airbrakes could have brought about
1px-trans.gif, 43 bytesa state of affairs from which recovery could not be effected in the height available.

1px-trans.gif, 43 bytesAt the time of this accident the Sabre Mk.4 (without leading edge slats)) was the
1px-trans.gif, 43 byteslatest version to go into squadron service and it is interesting to note that since
1px-trans.gif, 43 bytesthis accident took place there has been at least one other accident to a Mk.4 Sabre
1px-trans.gif, 43 bytesin Germany which was attributed to loss of control following a stall at low
1px-trans.gif, 43 bytesaltitude.   Signal AB.36EA dated 6/8/54. refers.

7. Conclusions

1px-trans.gif, 43 bytesIt is probable that the pilot lost control during a low speed turn with
1px-trans.gif, 43 bytesinsufficient height in which to effect a recovery.   Failure to select air brakes
1px-trans.gif, 43 bytes"IN" during the early stages of the overshoot may have been a contributory factor.

Accidents Investigation Branch
1px-trans.gif, 43 bytes(Civil Aviation)
Ministry of Transport and Civil Aviation1px-trans.gif, 43 bytesChief Investigating Officer
20th January, 1955.1px-trans.gif, 43 bytesfor Chief Inspector of accidents.

Circulation: -

1px-trans.gif, 43 bytesA.D.P.A.
1px-trans.gif, 43 bytesR.D.  Structures)
1px-trans.gif, 43 bytesR.D.A. (Defects)

1px-trans.gif, 43 bytesCONFIDENTIAL1px-trans.gif, 43 bytesR.A.F.   FORM   412
1px-trans.gif, 43 bytes(Pages 7 and 8)
1px-trans.gif, 43 bytes(Revised January, 1950)

25.   Conclusions of the Court (Note 10)

A.     On the 8th. July, 1954 Flying Officer Jack took off at 0806Z
1px-trans.gif, 43 bytesto carry out, as authorised and briefed, three Radio Compass
1px-trans.gif, 43 bytesletdowns followed by a V.H.F./D.F. controlled descent.
1px-trans.gif, 43 bytesDuring these exercises nothing unusual was noticed.   He
1px-trans.gif, 43 bytesovershot from the controlled descent apparently normally, the
1px-trans.gif, 43 bytesundercarriage was seen to retract and the dive brakes to
1px-trans.gif, 43 bytesremain "OUT".   About three quarters of the way down the
1px-trans.gif, 43 bytesrunway the aircraft was seen to exercise a climbing turn to
1px-trans.gif, 43 bytesport at low speed with the dive brakes "OUT ".   The aircraft
1px-trans.gif, 43 bytesclimbed from seven hundred feet to an estimated fifteen
1px-trans.gif, 43 byteshundred to two thousand feet, at the same time turning
1px-trans.gif, 43 bytesthrough approximately ninety degrees.   It was then seen to
1px-trans.gif, 43 bytesflick rapidly, after which it continued to roll and lose
1px-trans.gif, 43 bytesheight until it hit the ground, killing the pilot and
1px-trans.gif, 43 bytesand completely destroying the aircraft.

B.     The Court finds that there is no conclusive evidence as to
1px-trans.gif, 43 bytesthe precise reason for the accident, but considers that the
1px-trans.gif, 43 bytesmost probable cause was the pilot losing control of his
1px-trans.gif, 43 bytesaircraft in a low speed turn.   It is characteristic of a non
1px-trans.gif, 43 bytesslotted Sabre to flick and then go into a spiral dive under
1px-trans.gif, 43 bytesthese conditions.   Attention is drawn to the evidence of
1px-trans.gif, 43 bytesthe 9th. witness whom the court considered to be the most
1px-trans.gif, 43 bytesreliable witness produced.   He was the only witness who saw
1px-trans.gif, 43 bytesthe whole sequence of events from the start of the overshoot
1px-trans.gif, 43 bytesto the actual crash.   It is pointed out that although this
1px-trans.gif, 43 bytesofficer is a member of the Royal Air Force Regiment he is
1px-trans.gif, 43 bytesextremely interested in flying and is about to commence
1px-trans.gif, 43 bytespilot training himself.   The evidence of the 2nd. witness,
1px-trans.gif, 43 bytesis not considered so conclusive, as, although he is a Sabre
1px-trans.gif, 43 bytespilot he did not see the aircraft during the overshoot or
1px-trans.gif, 43 bytesthe ensuing turn, and due to his distance from the aircraft
1px-trans.gif, 43 bytesthe court do not consider his evidence as to the direction
1px-trans.gif, 43 bytesof the roll conclusive.

1px-trans.gif, 43 bytesThe court also considers that the failure to *select dive
1px-trans.gif, 43 bytesbrakes "IN" during the early stages of the overshoot was a
1px-trans.gif, 43 bytescontributing factor.   The evidence of the 8th. witness and
1px-trans.gif, 43 bytesthe A.I.B. inspector's estimate as to the speed on impact
1px-trans.gif, 43 bytesboth point to the aircraft being at a very low speed in the
1px-trans.gif, 43 bytesturn.

C.     There is no evidence of any technical failure.

D.     Flying Officer Jack was killed on impact.

E.     Sabre Mk.4 XB.647 is category 5 (scrap) and Safety Equipment
1px-trans.gif, 43 bytesand Flying Equipment worn by Flying Officer Jack was
1px-trans.gif, 43 bytestotally destroyed.

F.     There were no injuries to civilian personnel.

G.     There was considerable damage to standing crops and several
1px-trans.gif, 43 bytestrees.   The exact extent of the damage cannot be ascertained
1px-trans.gif, 43 bytesuntil the wreckage and widely scattered live ammunition has
1px-trans.gif, 43 bytesbeen cleared.   [See below].

H.     No other service personnel received injuries.

J.     It is unable to allocate responsibility or apportion blame
1px-trans.gif, 43 bytesother than a possible error of judgement on the part of the pilot.

K.     There are no relevant recommendations that it can make.

1px-trans.gif, 43 bytesSignature of
1px-trans.gif, 43 bytesPresident
     B.G. MEHARG   Wg.Cdr.................

1px-trans.gif, 43 bytes(...  L.  BYRAM Flt.Lt......................
1px-trans.gif, 43 bytesSignatures(...  G.C.  WILKINSON   Fg.Off..........
1px-trans.gif, 43 bytesof      (............................................................
Date...16th. July, 1954...1px-trans.gif, 43 bytesMembers

   (*687)   Wt. 11241--149   4,200   6/51   T.S.   8391px-trans.gif, 43 bytesCONFIDENTIAL

4sqnpic344.jpg, 145626 bytes

1px-trans.gif, 43 bytesThe crash site south of the airfield.


1px-trans.gif, 43 bytesOn the web site there has been considerable speculation about the cause and investigation of this accident.   Comments have been put forward by Ron Gray, 4 Sqn Sabre pilot, who, with Snowy Ewens another 4 Sqn Sabre pilot, witnessed the accident from the top of the 4 Sqn Hangar tower; Eric Pigdon, 93 Sqn Sabre pilot who happened to be talking to Flt Lt Lind about station basket ball in the entrance to the runway and Homer caravan, who saw some of the accident and, by co-incidence, George Englefield-Bishop who was a corporal in the same Homer vehicle who witnessed the crash from the same rear doors of the caravan, but did not know Eric Pigdon at the time.   Finally, Ken Senar, 93 Sqn Sabre pilot who was Flying Wing Adjutant, who did not see the accident from his office but heard the crash.

1px-trans.gif, 43 bytesOne person thought he heard the engine stop before the aircraft nose-dived into the ground.   This appears not to be true as the AIB Inspector found that the engine was rotating at a high speed when it hit the ground.   Two others thought he forgot to retract his airbrakes in a low speed turn and flicked in.

1px-trans.gif, 43 bytesI hope the publication of this report has cleared up these discrepancies although it still does not explain why none of the above witnesses were ever called by the Board of Enquiry.

[Click to see 4 Sqn F540 Report.]

1px-trans.gif, 43 bytesThe report in Colin Cummings book on RAF Accidents "Category Five" says: " 08-Jul-54 XB647 Sabre F4 4 Sqn 3 miles south south west of Jever 1 killed.   After overshooting from a controlled descent, the aircraft executed a climbing turn to port at low speed, with the undercarriage retracted and the dive brakes out to a height of about 2000 feet, whilst turning through 90 degrees.   It then seemed to flick rapidly and to roll and lose height until it struck the ground.   The most probable cause was the loss of control at low speed and the failure to retract the dive brakes.   Flying Officer John JACK aged 24."

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