Fuel Decision in Military Aviation
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TTN, no, before your time, it crashed! Crew survived. I think this is the one:
ASN Aircraft accident 14-JUN-1962 Handley Page Victor B.1A XH613
ASN Aircraft accident 14-JUN-1962 Handley Page Victor B.1A XH613
I don't own this space under my name. I should have leased it while I still could
Further to CMs F3 case, it had been the norm for Vulcans to reduce AUW to below 140k. As there was no fuel jettison system the only option was to burn it off.
After the Vulcan crash at Cottesmore the lost control due to a bomb bay fire while burning off fuel Hawker Siddley said the aircraft had always been clear to !and at any takeoff weight subject to heavy landing checks.
I suspect the brains trust had forgotty this in an attempt to avoid avoidable down time for heavy landing checks. Readiness everything and cost lives and and aircraft.
After the Vulcan crash at Cottesmore the lost control due to a bomb bay fire while burning off fuel Hawker Siddley said the aircraft had always been clear to !and at any takeoff weight subject to heavy landing checks.
I suspect the brains trust had forgotty this in an attempt to avoid avoidable down time for heavy landing checks. Readiness everything and cost lives and and aircraft.
Thanks P-N I remeber it now. One of the very few successful rear crew abandonments from a Victor.
I love the bit about the rear crew getting the landlord to lock the pilots out of the pub!
I love the bit about the rear crew getting the landlord to lock the pilots out of the pub!
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HOT - Curry?
Back in the days of Ex Crusader in the mid-late 70s (Biggest UK Peacetime call out of the reserves, IIRC) there were may off-shoot exercises, one of these being Exercise Curry Express. At Brüggen 14Sqn was tasked to fly to the last man and as such their Jaguars flew with EVERYTHING hanging off stuffed into corners and as many round as the guns would take. On return Everything, including the fletchers were stripped out of the aircraft by station base engineers, as if returning from a real war sortie. If I remember correctly 14 lasted 4 days and then ceased to exist.
Those that took part that year will remember that it was a very hot German summer with temps in the 30s C (+?). In the tower it was not unusual to hear a high pitched cry of Barrier!! from a departing 14 Jag, and the departure barrier in the standby position (halfway up) would be hurriedly lowered by the local controller. IIRC the standby height of the barrier was about 8' and the aircraft crossed the barrier at about 4'
Those that took part that year will remember that it was a very hot German summer with temps in the 30s C (+?). In the tower it was not unusual to hear a high pitched cry of Barrier!! from a departing 14 Jag, and the departure barrier in the standby position (halfway up) would be hurriedly lowered by the local controller. IIRC the standby height of the barrier was about 8' and the aircraft crossed the barrier at about 4'
About the only thing interesting or challenging about AT flying in the VC10 was the art of fuel calculation, so that the Air Movs people could have the best possible payload offered.
Nowadays a good mission planning system can plan the minimum fuel load required for even a very complex AAR trail mission to the last kilogram in a few seconds. Either statistical, still-air or forecast met data can be used and due allowance made for contingency fuel requirements. Play tunes on prudent extra fuel requirements and payload and a good AT/AAR solution can be found, essential for a multi-role tanker transport aircraft.
A pity that some air forces still have to rely on last century planning methods though.... They must waste thousands of kilograms burning fuel to carry unnecessary extra fuel due to excessively conservative fuel planning.
I once did a transit back from Goose to the UK with a very good tailwind in a VC10K2 with a high ZFW. The very experienced navigator computed the fuel and I rounded it up a little further for a little 'wotif' comfort.. But an old Victor captain travelling in the back advised me to 'fill it up' - because that's what they always did on Victors. The Nav and I both told him he was wrong; had we followed his 'advice' we'd probably have been over max normal landing weight back at Brize....
Nowadays a good mission planning system can plan the minimum fuel load required for even a very complex AAR trail mission to the last kilogram in a few seconds. Either statistical, still-air or forecast met data can be used and due allowance made for contingency fuel requirements. Play tunes on prudent extra fuel requirements and payload and a good AT/AAR solution can be found, essential for a multi-role tanker transport aircraft.
A pity that some air forces still have to rely on last century planning methods though.... They must waste thousands of kilograms burning fuel to carry unnecessary extra fuel due to excessively conservative fuel planning.
I once did a transit back from Goose to the UK with a very good tailwind in a VC10K2 with a high ZFW. The very experienced navigator computed the fuel and I rounded it up a little further for a little 'wotif' comfort.. But an old Victor captain travelling in the back advised me to 'fill it up' - because that's what they always did on Victors. The Nav and I both told him he was wrong; had we followed his 'advice' we'd probably have been over max normal landing weight back at Brize....
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Victor fuel
Victor engines lived in paired nacelles so if one engine was lost it tended to throw bits into the intake of the other so in slow time shut down the engine next to the failed one
Victor built as a bomber so lots of fuel tanks in case of holes
With two engines shut down the electrics were badly short and half the fuel pumps unpowered so half the fuel became unavailable
At Gaydon 1962 engine failure shut the other one down. burn off fuel in the overhead , 60,000 lbs fuel half available 30,000 left. Some time later 45,000 lbs fuel hald available so 27,000 left. Some time later 30,000 lbs fuel half available///// quiet innit?
I joined Victors in 1966, they were still wondering how it happened
Victor built as a bomber so lots of fuel tanks in case of holes
With two engines shut down the electrics were badly short and half the fuel pumps unpowered so half the fuel became unavailable
At Gaydon 1962 engine failure shut the other one down. burn off fuel in the overhead , 60,000 lbs fuel half available 30,000 left. Some time later 45,000 lbs fuel hald available so 27,000 left. Some time later 30,000 lbs fuel half available///// quiet innit?
I joined Victors in 1966, they were still wondering how it happened
I don't own this space under my name. I should have leased it while I still could
Tinribs, ah, thats the one. And how iutr happened was the brains trust on the ground was asking the wrong question and cooking up with the wrong answer rather than leaving the crew too do the calculations. Then four some reason the crew based their endurance on the calculations on the ground.
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"On the subject of fuel. If there was more than sufficient why was it said we had "gujons of petrol"? was this just a harrier thing?"
Didn't the Harriers have a very limited supply of water required for injecting into the Pegasus engine for cooling during a vertical landing? I have heard that the cooling water supply might only last 90 seconds when performing a vertical hover/landing at high GW.
Didn't the Harriers have a very limited supply of water required for injecting into the Pegasus engine for cooling during a vertical landing? I have heard that the cooling water supply might only last 90 seconds when performing a vertical hover/landing at high GW.
I've never really understood why, according to that article, AAR was planned beyond what is described as the 'go no-go' point.
Another learning point - the plan should make sure that the receivers are airborne before launching the tanker.
But good teamwork to salvage what, to be honest, reads like a bit of a cluster.....
Another learning point - the plan should make sure that the receivers are airborne before launching the tanker.
But good teamwork to salvage what, to be honest, reads like a bit of a cluster.....
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Finding nowadays that the fuel calculation is simpler than the crew composition and crew duty requirements to accommodate a jet that could fly 24 hours or more.
Ref #50. The Marine Corps KC130 crew were in the BX, Mess, Etc with only the Air Eng at the aircraft when drama happened. He managed to get hold of crew and had the engines running before the rest of the crew arrived to Scramble just in time to assist. The approach back to Lajes was on the fumes over the sea at VERY low altitude to the NW runway.
A potentially similar event occured to the RAF in Nov 1986. We had deployed 2 VC10K3s and 2 VC10K2s to Roosevelt Roads in Puerto Rico to recover 10 Buccs from Ex Caribbean Cutlass. The VC10K2s had to route via Lajes due to insufficient fuel to go direct to RR. The first K2 landed without a problem, but the second, which arrived 30 mins later, had to make several approaches to get in due to the bad weather that had appeared unforecast.
3 days later we launched for the recovery from RR to Lajes as waves of a VC10K2, a VC10K3 and five Buccs. Due to Wx problems there were no Jetplans or Weather info (phone lines flooded), but decision was made to launch, RV at height out of the weather and get weather forecasts en-route. There was a complete clusterf**k in the predawn darkness which caused us, in the lead tanker, to launch, only to find the rest of the wave was delayed by at least 30 mins. The formation eventually joined up 200 miles NE of RR, but still with no weather forecasts for Lajes or Santa Maria.
After the first AAR Bracket it was discovered that the Formation Fuel was very close to the minimum required to continue. Planned Tailwind was actually (unusually for the North Atlantic) a Headwind.
After the second AAR Bracket, still with no weather forecasts and still with the headwinds, the formation was now on minimum fuel to continue. Bearing mind the weather problems at Lajes outbound the only way to alleviate the situation was to reduce the formation fuel burn, which could only be achieved by one tanker leaving the formation. So after transferring all available fuel to the Buccs in an unscheduled bracket we diverted to the "tropical paradise" of Bermuda. The rest continued to Lajes where Wx was fine. The inevitable criticism of the decision which had "obviously been made in the bar the night before" was only stemmed when the Gold 11 story appeared in Air Clues a couple of months later!!
There but for the Grace of God etc.
Incidently I did get a photo of BEagle dancing with a BA hostie by the hotel pool, but since it was West of 10W it obviously did not happen!
A potentially similar event occured to the RAF in Nov 1986. We had deployed 2 VC10K3s and 2 VC10K2s to Roosevelt Roads in Puerto Rico to recover 10 Buccs from Ex Caribbean Cutlass. The VC10K2s had to route via Lajes due to insufficient fuel to go direct to RR. The first K2 landed without a problem, but the second, which arrived 30 mins later, had to make several approaches to get in due to the bad weather that had appeared unforecast.
3 days later we launched for the recovery from RR to Lajes as waves of a VC10K2, a VC10K3 and five Buccs. Due to Wx problems there were no Jetplans or Weather info (phone lines flooded), but decision was made to launch, RV at height out of the weather and get weather forecasts en-route. There was a complete clusterf**k in the predawn darkness which caused us, in the lead tanker, to launch, only to find the rest of the wave was delayed by at least 30 mins. The formation eventually joined up 200 miles NE of RR, but still with no weather forecasts for Lajes or Santa Maria.
After the first AAR Bracket it was discovered that the Formation Fuel was very close to the minimum required to continue. Planned Tailwind was actually (unusually for the North Atlantic) a Headwind.
After the second AAR Bracket, still with no weather forecasts and still with the headwinds, the formation was now on minimum fuel to continue. Bearing mind the weather problems at Lajes outbound the only way to alleviate the situation was to reduce the formation fuel burn, which could only be achieved by one tanker leaving the formation. So after transferring all available fuel to the Buccs in an unscheduled bracket we diverted to the "tropical paradise" of Bermuda. The rest continued to Lajes where Wx was fine. The inevitable criticism of the decision which had "obviously been made in the bar the night before" was only stemmed when the Gold 11 story appeared in Air Clues a couple of months later!!
There but for the Grace of God etc.
Incidently I did get a photo of BEagle dancing with a BA hostie by the hotel pool, but since it was West of 10W it obviously did not happen!
I'm de-lurking briefly to say thanks to LW20 for starting a thread on an aspect of military aviation that is not 'warry' - but just as interesting!
Tengah Type, I remember the occasion well - for obvious reasons...
One of Lord Peter of the Bogs' more spectacularly poor trail plans!
If you recall, our other problem was that our K2 hadn't been given all the fuel we'd hoped for and also had to taxy over from the other side of the field, so we were down on fuel prior to launch as well. I say 'we', but I was only along as a spare captain cum trolley tart.
Passing the extra fuel to one of the other tankers, then diverting ourselves to Bermuda was the best plan; however, we did wonder whether the poo might hit the fan and accusations made about the reason for diverting by those who didn't know the whole picture. The sweeper Herk was so disappointed when we told him that we didn't need him, so he didn't have to divert to Bermuda....
Things didn't get rather more 'interesting' once the dancing was over after we didn't repair to the Bermudiana for an alternative form of 'entertainment'...
Of course not.... West of 10°W, so it couldn't have happened. Nor did anything ever happen in Atlanta, as I'm sure you'd confirm.
Late departure the following day as it was Armistice day and the airport opened later in the morning - which begat another ching!
Happy times!!
One of Lord Peter of the Bogs' more spectacularly poor trail plans!
If you recall, our other problem was that our K2 hadn't been given all the fuel we'd hoped for and also had to taxy over from the other side of the field, so we were down on fuel prior to launch as well. I say 'we', but I was only along as a spare captain cum trolley tart.
Passing the extra fuel to one of the other tankers, then diverting ourselves to Bermuda was the best plan; however, we did wonder whether the poo might hit the fan and accusations made about the reason for diverting by those who didn't know the whole picture. The sweeper Herk was so disappointed when we told him that we didn't need him, so he didn't have to divert to Bermuda....
Things didn't get rather more 'interesting' once the dancing was over after we didn't repair to the Bermudiana for an alternative form of 'entertainment'...
Of course not.... West of 10°W, so it couldn't have happened. Nor did anything ever happen in Atlanta, as I'm sure you'd confirm.Late departure the following day as it was Armistice day and the airport opened later in the morning - which begat another ching!
Happy times!!
Last edited by BEagle; 29th Mar 2016 at 06:13.
BEagle
As I said in my post it was West of 10W so it did not happen and RFK was not singing Irish songs. Anyway I missed it all as I was in my hotel room reading the Gideon bible.
See you on the 14th perhaps?.
As I said in my post it was West of 10W so it did not happen and RFK was not singing Irish songs. Anyway I missed it all as I was in my hotel room reading the Gideon bible.
See you on the 14th perhaps?.
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riff_raff, the venerable Harrier indeed did hold up to 495lbs of demineralised water. Operated or armed via an in-cockpit switch, the water was directly injected at high pressure onto the Pegasus turbine blades, cooling the JPT by around 25degC. That drop in temperature allowed more fuel to be added to reach the [now slightly higher] DECS JPT limit, whilst also increasing overall engine mass flow - i.e. increasing thrust. If used in one go it lasted 90 sec which was (normally) plenty of time to get the old girl on the deck or a pad in high OAT and/or high AUW recovery conditions, though it did concentrate the mind if you were "wet committed" and needed the water to land. Bit like the Countdown show clock running. This was routine for the Pegasus 105 engine (-406). For the more powerful 107 (-408) we hardly used the water in the UK but carried it anyway as ballast to maintain CofG margin.
Last edited by MSOCS; 28th Mar 2016 at 22:57.
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MSOCS, thanks for the info. The Pegasus engine was definitely an impressive piece of design work at the time with its four lift nozzles. I believe the water was injected ahead of the 1st stage turbine nozzle to keep turbine inlet gas temps within safe limits. But as you noted, the latent cooling from the water injection allowed the fuel/air ratio in the combustor to run closer to stoichiometric.
I was involved with some of the early conceptual design work for the JSF lift fan. I wish people would appreciate the technical challenge of designing this huge 30,000 horsepower counter-rotating fan, gear drive and clutch system. The F-35B's shaft driven fan is actually much more efficient at producing vertical lift than the Harrier's use of compressor airflow.
I was involved with some of the early conceptual design work for the JSF lift fan. I wish people would appreciate the technical challenge of designing this huge 30,000 horsepower counter-rotating fan, gear drive and clutch system. The F-35B's shaft driven fan is actually much more efficient at producing vertical lift than the Harrier's use of compressor airflow.
Tengah Type, I have an early start the following day, so am not sure about TBs on the 14th.
I do hope that the tranquillity of your bible-reading evening wasn't disturbed by any sounds from nearby rooms....
Out of interest, a trail plan I've recently been assessing required a tanker to fly across Europe, RV with 3 Typhoons on their way home, then cast them off before offering 45 min opportunity training to any 'on call'
receivers in an AARA before landing.
Put the route in and the answer was that, without any receivers, the route required 36675 kg with 85% stat met and normal contingency fuel. Add receivers and the figure became 62382 kg with 85% stat met and normal contingency. A prudent tanker commander would elect to take more fuel to allow for wotifs, but other factors have to be considered - with average met of the day (50% stat met), the figure became 61064 kg. 'Fill it up' wouldn't be possible due to RW perf. limits; if the tanker was too heavy then the planned transit altitude might be too high and any advantage wasted.
Personally, I would have taken 66000 kg - a reasonably prudent surplus and enough for a little opportunity training. If the Typhoons had been late off and put pedal to the metal to make the RV time instead of asking for the tanker to delay at the RVIP (as a bunch of F3s once did to me....), then bin the AARA and there would still be enough to meet the trail task when contingency, planned extra and no AARA time was added together - about 8500 kg or over an hour's extra fuel for each of the receivers.
I do hope that the tranquillity of your bible-reading evening wasn't disturbed by any sounds from nearby rooms....
Out of interest, a trail plan I've recently been assessing required a tanker to fly across Europe, RV with 3 Typhoons on their way home, then cast them off before offering 45 min opportunity training to any 'on call'
receivers in an AARA before landing.Put the route in and the answer was that, without any receivers, the route required 36675 kg with 85% stat met and normal contingency fuel. Add receivers and the figure became 62382 kg with 85% stat met and normal contingency. A prudent tanker commander would elect to take more fuel to allow for wotifs, but other factors have to be considered - with average met of the day (50% stat met), the figure became 61064 kg. 'Fill it up' wouldn't be possible due to RW perf. limits; if the tanker was too heavy then the planned transit altitude might be too high and any advantage wasted.
Personally, I would have taken 66000 kg - a reasonably prudent surplus and enough for a little opportunity training. If the Typhoons had been late off and put pedal to the metal to make the RV time instead of asking for the tanker to delay at the RVIP (as a bunch of F3s once did to me....), then bin the AARA and there would still be enough to meet the trail task when contingency, planned extra and no AARA time was added together - about 8500 kg or over an hour's extra fuel for each of the receivers.
