Hawk XX204 Service Inquiry
The incoming airflow has to drive the engine to rotate which creates a lot of drag, whereas at idle, some of the turning force is taken up by the engine's idle thrust. In a seized engine, there are no moving parts for the airflow to turn so it passes through with drag only from the stationary parts.
Beardy
When I opened the link I didn’t get all that information.
I will take your word for it and hope I never have to find out for real.
What I would add is that, having practiced gliding in a variety of aircraft fits, the maintenance of a constant sight line angle and careful energy management will let you know how you’re getting on. Therefore I believe that even a more draggy engine would be no worse than gliding in a heavy fit and sensible decisions can be made in any case.
BV
I will take your word for it and hope I never have to find out for real.
What I would add is that, having practiced gliding in a variety of aircraft fits, the maintenance of a constant sight line angle and careful energy management will let you know how you’re getting on. Therefore I believe that even a more draggy engine would be no worse than gliding in a heavy fit and sensible decisions can be made in any case.
BV
When I opened the link I didn’t get all that information.
I will take your word for it and hope I never have to find out for real.
What I would add is that, having practiced gliding in a variety of aircraft fits, the maintenance of a constant sight line angle and careful energy management will let you know how you’re getting on. Therefore I believe that even a more draggy engine would be no worse than gliding in a heavy fit and sensible decisions can be made in any case.
BV
I will take your word for it and hope I never have to find out for real.
What I would add is that, having practiced gliding in a variety of aircraft fits, the maintenance of a constant sight line angle and careful energy management will let you know how you’re getting on. Therefore I believe that even a more draggy engine would be no worse than gliding in a heavy fit and sensible decisions can be made in any case.
BV
It became apparent from a friend who landed a propeller driven aircraft that a stopped prop gave a much longer glide after round out than he had anticipated. He was lucky he had a runway, not a field. The Hawk is not as heavily laden a wing as a true swept wing aircraft and would glide very well with a seized engine. At what speed would it cease to windmill?
It's good to have time, without secondary duties, to think about these things.
I’m fairly sure that my memory is correct in that on the JP5, during PFLs, some QFIs used the airbrakes to simulate the drag of a failed engine..... one assumes (dangerous I know) that this was based on experience?
One other factor that influences energy management and sightline angle and which has not yet been mentioned is wind. When we cleared the Tucano to fly in a 40 kt surface wind one of the most interesting points was that when using the normal 1500 ft Low Key abeam the Initial Aim Point it was not possible to make a touchdown at the IAP; a 2000 ft Low Key was required, almost independent of the wind direction.
When the Hawk T1 entered service the bad weather engine failure profile taught was the '1 in 1' profile of the Hunter whereby you were vectored towards the runway centreline and when established on it and the range to touchdown in nms equaled the height in thousands of feet then you lowered the landing gear . Airspeed was then varied around the nominal glide speed (165 KIAS) to stay on the '1 in 1' slope and when visual with the runway the flaps were lowered when required to make the desired touchdown point. However, although this worked satisfactorily with idle thrust, at some stage it was realised/identified/confirmed that with a windmilling engine the drag was too high and it could not maintain the '1 in 1' profile. The result was that the radar Forced Landing pattern was developed. I am not sure precisely when but the radar FL/PFL was not taught when I was a student at Valley on the Hawk in early 1978.
Most engine problems for real do not require an engine shutdown nor involve a total loss of thrust which often makes diagnosis difficult and choosing the optimum course of action difficult. In some cases, what is needed from the engine is to drive the electrical and/or hydraulic system more than to generate thrust. Typically, a low power setting will load an engine less than a high one such that the engine may be kept running for longer at idle, or a little above it, and favouring a precautionary forced landing pattern to a fixed power approach if feasible (although this is very type specific). This becomes a critical decision following an EFATO; do you turn back to the reciprocal of the take-off runway, climb to/decelerate towards low key or fly a fixed power approach? The best decision will be on a case-by-case basis but practising all options will give you the best chance of success. However, if you lose more aircraft practising some of the more marginal profiles such as turnbacks than you will save if you get it right for real then the practise is, perhaps, not justified. The pros and cons of practising EFATOs, turnbacks, low energy PFLs etc is not black and white.
When the Hawk T1 entered service the bad weather engine failure profile taught was the '1 in 1' profile of the Hunter whereby you were vectored towards the runway centreline and when established on it and the range to touchdown in nms equaled the height in thousands of feet then you lowered the landing gear . Airspeed was then varied around the nominal glide speed (165 KIAS) to stay on the '1 in 1' slope and when visual with the runway the flaps were lowered when required to make the desired touchdown point. However, although this worked satisfactorily with idle thrust, at some stage it was realised/identified/confirmed that with a windmilling engine the drag was too high and it could not maintain the '1 in 1' profile. The result was that the radar Forced Landing pattern was developed. I am not sure precisely when but the radar FL/PFL was not taught when I was a student at Valley on the Hawk in early 1978.
Most engine problems for real do not require an engine shutdown nor involve a total loss of thrust which often makes diagnosis difficult and choosing the optimum course of action difficult. In some cases, what is needed from the engine is to drive the electrical and/or hydraulic system more than to generate thrust. Typically, a low power setting will load an engine less than a high one such that the engine may be kept running for longer at idle, or a little above it, and favouring a precautionary forced landing pattern to a fixed power approach if feasible (although this is very type specific). This becomes a critical decision following an EFATO; do you turn back to the reciprocal of the take-off runway, climb to/decelerate towards low key or fly a fixed power approach? The best decision will be on a case-by-case basis but practising all options will give you the best chance of success. However, if you lose more aircraft practising some of the more marginal profiles such as turnbacks than you will save if you get it right for real then the practise is, perhaps, not justified. The pros and cons of practising EFATOs, turnbacks, low energy PFLs etc is not black and white.
This was supplied on the tech log forum :
Windmilling drag
So when practicing a turnback be aware that in the real case a windmilling engine is high drag, higher than idle thrust or a seized engine.
Windmilling drag
So when practicing a turnback be aware that in the real case a windmilling engine is high drag, higher than idle thrust or a seized engine.
DCT,T/O flap was used on JPs to simulate drag; airbrakes destroy the lift and you resemble a slightly streamlined brick..
Even NACA cant do the maths ..3.5 sq ft gives 56 lib drag /sq.ft ,not 5.6....engine would be about similar to Strikey or Dominie Viper....
LOM,from memory of the Hunter ,210 clean to 3nm on a 1:1,gear,to 175/180, flap about 1.5, then start heaving...as it would be all in manual of course......
Even NACA cant do the maths ..3.5 sq ft gives 56 lib drag /sq.ft ,not 5.6....engine would be about similar to Strikey or Dominie Viper....
LOM,from memory of the Hunter ,210 clean to 3nm on a 1:1,gear,to 175/180, flap about 1.5, then start heaving...as it would be all in manual of course......
The study considers internal drag of the engine only and acknowledges that overspill of air from the intake can affect airframe drag. As airflow through the windmilling engine is reported as 3x greater than the seized engine, that’s potentially a lot of air to redirect. In a podded engine with aerodynamically shaped lips I can quite imagine that a ‘blob’ of slower air in the intake would act as quite an effective fairing to divert surplus airflow around the nacelle in streamlined fashion. What I know from experience is that the angular, aerodynamically-complex maw of the Tornado didn’t like having a seized engine inside it... probably not helped by most of the spilled air immediately colliding with the external stores and landing gear (admittedly not as much of a problem for the Hawk, but probably still more than for a podded type).
At least in the Tornado there wouldn't have been excessive asymmetry.
High or Low approach ?
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High Approach or Low Approach ? It would seem from the narrative in 1.3.6 onwards, that this expression refers to whether the practice is terminated early or late on the approach, as opposed to completing the exercise with perhaps a runway touchdown.
Explanatory footnote 11 at the bottom of page 1.3 -2 quotes Valley Flying Orders as "....if a PFL is not planned to touch-and-go, a high approach should be initiated by 300 ft QFE. .."
Question -
Is 'initiated' a typo for 'terminated' ? Or are there some other words missing from Note 11 ?
For instance '... if a PFL is not planned to touch-and-go, a go-around from a high approach should be initiated by 300 ft QFE ...'
Or is the FOB quote actually correct ?
LFH
...
High Approach or Low Approach ? It would seem from the narrative in 1.3.6 onwards, that this expression refers to whether the practice is terminated early or late on the approach, as opposed to completing the exercise with perhaps a runway touchdown.
Explanatory footnote 11 at the bottom of page 1.3 -2 quotes Valley Flying Orders as "....if a PFL is not planned to touch-and-go, a high approach should be initiated by 300 ft QFE. .."
Question -
Is 'initiated' a typo for 'terminated' ? Or are there some other words missing from Note 11 ?
For instance '... if a PFL is not planned to touch-and-go, a go-around from a high approach should be initiated by 300 ft QFE ...'
Or is the FOB quote actually correct ?
LFH
...
Ground track diagrams ?
...
Ground track diagrams -
I can't find any reference to, or mention of the information sources used to determine the quite precise ground track diagrams exhibited in the SI.
Nothing seemingly relevant (such as a recorded radar track) seems to be listed at " 1.4.10 " The Panel had access to the following evidence: ...."
Request - Can anyone kindly point me to anywhere in the SI, or otherwise explain where the information comes from that allows these excellent diagrams to be drawn and exhibited, or are they ABG ?
LFH
....
Ground track diagrams -
I can't find any reference to, or mention of the information sources used to determine the quite precise ground track diagrams exhibited in the SI.
Nothing seemingly relevant (such as a recorded radar track) seems to be listed at " 1.4.10 " The Panel had access to the following evidence: ...."
Request - Can anyone kindly point me to anywhere in the SI, or otherwise explain where the information comes from that allows these excellent diagrams to be drawn and exhibited, or are they ABG ?
LFH
....
Think it is a combination of radar track,txpdr,and aircraft GPS....
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Lordflasheart #173 - 2 Nov 23:40
Ground track diagrams -
I can't find any reference to, or mention of the information sources used to determine the quite precise ground track diagrams exhibited in the SI.
Nothing seemingly relevant (such as a recorded radar track) seems to be listed at " 1.4.10 " The Panel had access to the following evidence: ...."
Request - Can anyone kindly point me to anywhere in the SI, or otherwise explain where the information comes from that allows these excellent diagrams to be drawn and exhibited, or are they ABG ?
LFH
Ground track diagrams -
I can't find any reference to, or mention of the information sources used to determine the quite precise ground track diagrams exhibited in the SI.
Nothing seemingly relevant (such as a recorded radar track) seems to be listed at " 1.4.10 " The Panel had access to the following evidence: ...."
Request - Can anyone kindly point me to anywhere in the SI, or otherwise explain where the information comes from that allows these excellent diagrams to be drawn and exhibited, or are they ABG ?
LFH
I assume that the nearest area radar never saw the aircraft in its PEFATO, while any airfield radar had no data recording or was simply off. The report should have said that much.
The answer to your question is in para 1.4.187. “Downwind leg - lateral displacement. Interpretation of the ADR data and pilot's Global Positioning System (GPS) enabled a Graphical Data Analysis System (GDAS) replication of XX204's estimated ground track to be generated”.
1.4.4 tells us “XX204 was fitted with an Accident Data Recorder (ADR) … therefore … the Panel were able to establish the aircraft's flight profile”. 1.4.218 tells us “XX204's ADR data and flight characteristics were analysed by ATEC Test Pilots and Flight Test Engineers”.
Just by the way, may I guess that you have trouble wading through the report as given to us by the link at the beginning of the thread ? For what it is worth, I have speeded up my progress in and about the report by (a) copying the .PDF file to my own computer, thus avoiding the delays between my computer and the web, (b) using the FIND mechanism to visit (for instance) all 66 mentions of “ADR/adr” and just the 3 mentions of “GPS” and (c) generating an annotated word.doc index of section 1.4 to fit my .PDF version of the report.
Last edited by rlsbutler; 3rd Nov 2019 at 15:27.
Rumour has it that the Coroner may have agreed to this NOT being an Article 2 Inquest. In other circumstances this may have passed without comment, but he has form. The family of a Tornado airman who died in an accident almost 8 years ago awaits an Inquest, but he has shown no inclination.
This incident appears to bear some striking resemblance to that which occurred to Hawk T1A XX334 on 19(R) Sqn at 2TWU in September 1992.
https://aviation-safety.net/wikibase/wiki.php?id=55475
In this instance, the person that died was I believe, an experienced Hawk QFI, participating in a QWI course. He was in the rear cockpit, with the Captain in the front cockpit.
This incident still haunts me to this day and I wonder were the lessons learned adequately promulgated around the Hawk community of today?
I speak only as an armourer on the squadron that was 'back-seat qualified' and on shift at the time of the crash. I/we flew many times in the rear cockpit, sometimes to deploy to Coningsby or Leuchars for a small '2-ship' Det. and on occasion, just for fun in the weather ship or a target tug. The practice was actively encouraged by our aircrew and the guys and girls the squadron loved it. But let's be clear, we were passengers, not supernumerary crew.
To the best of my knowledge, EFATO was never practiced when ground crew were being carried in the rear cockpit. We were however always meticulously briefed, each trip, on the possibility and procedure for ejection. Always challenged to confirm that the Command Selector Valve in the rear cockpit was 'down and off' during taxi, even though the pilot would have checked it when we got to the aircraft.
Fair to say that I had a very good understanding of the ejection seat, but I'm not sure that I would have ever initiated ejecting without being instructed to do so; maybe if I knew that the pilot had been incapacitated by something like a birdstrike, but highly unlikely. If an engine failure had ever occurred on take-off (and I don't recall any during my six years on the Hawk), the only thing I would have done is sit tight, keep quiet and wait for instructions!
For us ground crew minions, we place our trust in our pilots and accept the risk.
I'm sure that Cpl Bayliss was like I, was just pinching himself at how lucky he was to be able to have such an experience. RIP mate....
https://aviation-safety.net/wikibase/wiki.php?id=55475
In this instance, the person that died was I believe, an experienced Hawk QFI, participating in a QWI course. He was in the rear cockpit, with the Captain in the front cockpit.
This incident still haunts me to this day and I wonder were the lessons learned adequately promulgated around the Hawk community of today?
I speak only as an armourer on the squadron that was 'back-seat qualified' and on shift at the time of the crash. I/we flew many times in the rear cockpit, sometimes to deploy to Coningsby or Leuchars for a small '2-ship' Det. and on occasion, just for fun in the weather ship or a target tug. The practice was actively encouraged by our aircrew and the guys and girls the squadron loved it. But let's be clear, we were passengers, not supernumerary crew.
To the best of my knowledge, EFATO was never practiced when ground crew were being carried in the rear cockpit. We were however always meticulously briefed, each trip, on the possibility and procedure for ejection. Always challenged to confirm that the Command Selector Valve in the rear cockpit was 'down and off' during taxi, even though the pilot would have checked it when we got to the aircraft.
Fair to say that I had a very good understanding of the ejection seat, but I'm not sure that I would have ever initiated ejecting without being instructed to do so; maybe if I knew that the pilot had been incapacitated by something like a birdstrike, but highly unlikely. If an engine failure had ever occurred on take-off (and I don't recall any during my six years on the Hawk), the only thing I would have done is sit tight, keep quiet and wait for instructions!
For us ground crew minions, we place our trust in our pilots and accept the risk.
I'm sure that Cpl Bayliss was like I, was just pinching himself at how lucky he was to be able to have such an experience. RIP mate....
Rolling 20 / Mortmeister
I know nothing of the 1992 accident, but the general point (recurrence) is well made and is one reason why this should be an Article 2 Inquest. Another reason, and perhaps better known, is that this XX204 accident shares (according to MoD) twelve common factors with that of Flt Lt Cunningham in 2011. The Coroner is required to ask why.
I know nothing of the 1992 accident, but the general point (recurrence) is well made and is one reason why this should be an Article 2 Inquest. Another reason, and perhaps better known, is that this XX204 accident shares (according to MoD) twelve common factors with that of Flt Lt Cunningham in 2011. The Coroner is required to ask why.
Reference tuc's comments on Sean Cunningham's avoidable death in 2011, could I remind member's of the excellent book Red5 presently available in Kindle form at the very reasonable price of £3.99 from you know where :-
More details and background here :-
https://sites.google.com/site/militaryairworthiness/
More details and background here :-
https://sites.google.com/site/militaryairworthiness/
Inquest to be resumed 14 May
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I am told that the inquest into the death of Corporal Jonathan Bayliss RAF will be resumed on 14th May, under the auspices of the new Senior Coroner for North West Wales.
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I am told that the inquest into the death of Corporal Jonathan Bayliss RAF will be resumed on 14th May, under the auspices of the new Senior Coroner for North West Wales.
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